Patent Application
20230338231
The present disclosure is related to systems for providing manual or automated chest compressions to a patient and, in particular, to systems that provide chest compressions at scheduled depths according to an initial compression protocol and/or at patient-specific depths, which can be determined based on sensed motion and force information for chest compressions provided to the patient.
For cardiac arrest patients, cardiopulmonary resuscitation (CPR) may include a variety of therapeutic interventions including chest compressions, defibrillation, and ventilation. Chest compressions during CPR may maintain blood circulation so that oxygen can be delivered to the body until the heart resumes an effective rhythm. The chest compressions may be performed by automated mechanical devices, such as, for example, the ZOLL® AutoPulse® mechanical chest compression device.
Alternatively, or additionally, chest compressions may be performed manually. During manual chest compressions, a rescuer, such as an acute care provider or lay person, places his or her hands on the patient's chest and pushes on the chest to perform the chest compression. Various devices are available for providing mechanical assistance for manual chest compressions. For example, an acute care provider may use a hand-held device, such as, for example, the ZOLL® ResQPump® active compression decompression device, positioned on the patient's chest to enhance movement of the patient's chest during chest compression and decompression.
Computer devices and systems are available for providing feedback to rescuers (e.g., acute care providers and lay persons) about chest compressions performed for a patient. Some devices provide feedback relating to characteristics of the chest compressions, such as measured values for compression depth or rate for chest compressions provided to a patient, in real-time, during the chest compressions. Such feedback may allow the acute care provider to modify and, thereby, improve the efficacy of the chest compressions. Feedback can also include instructions or notifications directing the rescuer to modify an aspect of provided chest compressions, such as a verbal or visual instruction to “Press Harder” or “Release the Chest between Chest Compressions.” Feedback may also be provided to assist acute care providers at a rescue scene to more effectively combine and coordinate the chest compressions with other resuscitative therapies. In some situations, during the initial period of chest compressions, the patient may be vulnerable to injury due to the repeated impact of the chest compression forces.
According to an aspect of the disclosure, a system for administering patient-specific chest compressions to a patient includes an automated chest compressor configured to be applied to the chest of the patient to administer chest compressions to the patient; at least one force sensor configured to sense force information for force exerted on the patient by the chest compressor from the applied chest compressions; and at least one processor and memory communicatively coupled with the chest compressor and the at least one force sensor. The at least one processor and memory are configured to: control the chest compressor to administer the chest compressions over an initial compression period according to an initial compression protocol. The initial compression protocol includes a plurality of chest compressions of increasing scheduled depths with a first compression at an initial depth and a final compression at a final target depth greater in magnitude than the initial depth. The processor and memory are further configured to receive and process the sensed force information to estimate force applied to the chest during the chest compressions, and adjust a magnitude of the scheduled depths to patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol based on the estimated force applied to the chest during one or more preceding chest compressions of the plurality of chest compressions.
According to another aspect of the disclosure, a system for administering chest compressions to a patient includes an automated chest compressor configured to be applied to a chest of the patient to administer chest compressions to the patient. The chest compressor includes a compression surface configured to be positioned on the patient's chest, a driver configured to move the compression surface in a first direction to compress the patient's chest and in a second direction to release the patient's chest, and at least one displacement sensor configured to measure distance traveled by the patient's chest and/or the compression surface to estimate a depth and/or decompression height of the chest compression. The chest compressor further comprises at least one processor and memory communicatively coupled with the chest compressor and the at least one displacement sensor. The at least one processor and memory are configured to cause the chest compressor to: repeatedly cause the driver of the chest compressor to move the compression surface in the first direction until a signal received by the at least one processor from the at least one displacement sensor indicates that the compression surface has moved a sufficient distance to perform a chest compression of a temporary target depth, and, once the temporary target depth is reached, causing the driver to move the compression surface in the second direction to a temporary decompression height identified based on the signal from the at least one displacement sensor. The processor and memory are further configured to: following one or more of the compressions, adjust the target compression depth and/or target decompression height according to a predetermined initial compression protocol including a predetermined number of chest compressions; after completion of the predetermined number of chest compressions of the initial compression protocol, cause the driver of the chest compressor to repeatedly move the compression surface in the first direction until the signal received by the at least one processor from the at least one displacement sensor indicates that the compression surface has moved a sufficient distance to perform a chest compression of a predetermined final target depth; and cause the driver to move the compression surface in the second direction to a predetermined final decompression height identified based on the signal from the at least one displacement sensor.
According to another aspect of the disclosure, a system for assisting an acute care provider in performance of chest compressions to a patient includes: at least one chest compression sensor configured to sense displacement information in response to chest compressions administered by the acute care provider; a feedback device for providing guidance for the acute care provider in the performance of the chest compressions; and at least one processor and memory communicatively coupled with the at least one chest compression sensor and the feedback device. The at least one processor and memory can be configured to: receive and process the sensed displacement information from the at least one chest compression sensor during the performance of the chest compressions; estimate compression depth based on the processed displacement information; and cause the feedback device to provide guidance for the acute care provider for administration of the chest compressions of scheduled depths over an initial compression period according to an initial compression protocol. The initial compression protocol includes a plurality of chest compressions of increasing scheduled depths with a first compression at an initial depth and a final compression at a final target depth greater in magnitude than the initial depth.
According to another aspect of the disclosure, a system for assisting an acute care provider in performance of chest compressions to a patient includes: at least one motion sensor configured to be positioned on the patient's chest to sense displacement information for the chest in response to chest compressions administered by the acute care provider; at least one force sensor configured to sense force information from the applied chest compressions; a feedback device for providing guidance for the acute care provider in the performance of the chest compressions; and at least one processor and memory communicatively coupled with the at least one motion sensor, the at least one force sensor, and the feedback device. The at least one processor and memory are configured to: receive and process the sensed displacement information from the at least one motion sensor during the performance of the chest compressions to estimate compression depth for the chest compressions; receive and process the sensed force information produced from the at least one force sensor during the performance of the chest compressions to estimate force applied to the chest for the chest compressions; and cause the feedback device to provide guidance for the acute care provider for administration of the chest compressions of scheduled depths over an initial compression period according to an initial compression protocol. The initial compression protocol includes a plurality of chest compressions of increasing scheduled depths with a first compression at an initial depth and a final compression at a final target depth greater in magnitude than the initial depth. The processor and memory are further configured to periodically adjust a magnitude of the scheduled depths to patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol based on the estimated force applied to the chest during one or more preceding chest compressions of the plurality of chest compressions.
Examples of the present disclosure will now be described in the following numbered clauses:
Clause 1: A system for administering patient-specific chest compressions to a patient, the system comprising: an automated chest compressor configured to be applied to the chest of the patient to administer chest compressions to the patient; at least one force sensor configured to sense force information for force exerted on the patient by the chest compressor from the applied chest compressions; and at least one processor and memory communicatively coupled with the chest compressor and the at least one force sensor, wherein the at least one processor and memory are configured to: control the chest compressor to administer the chest compressions over an initial compression period according to an initial compression protocol, the initial compression protocol comprising a plurality of chest compressions of increasing scheduled depths with a first compression at an initial depth and a final compression at a final target depth greater in magnitude than the initial depth, receive and process the sensed force information to estimate force applied to the chest during the chest compressions, and adjust a magnitude of the scheduled depths to patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol based on the estimated force applied to the chest during one or more preceding chest compressions of the plurality of chest compressions.
Clause 2: The system of clause 1, wherein the initial compression protocol comprises at least a first portion of the plurality of chest compressions in which the scheduled depth of the chest compressions increases at a first rate.
Clause 3: The system of clause 2, wherein the initial compression protocol comprises at least a second portion of the plurality of chest compressions in which the scheduled depths of the chest compressions increase at a second rate, the second rate being different from the first rate.
Clause 4: The system of clause 3, wherein the second rate is greater than the first rate.
Clause 5: The system of any of clauses 1-4, wherein the adjustment of the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions occurs at regular intervals.
Clause 6: The system of any of clauses 1-5, wherein the initial compression protocol comprises a continuous linear increase in the scheduled depths over the initial compression period.
Clause 7: The system of any of clauses 1-5, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths of the one or more remaining chest compressions comprises a decrease of the scheduled depths for at least one of the one or more remaining chest compressions.
Clause 8: The system of any of clauses 1-7, wherein the adjustment of the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions is further based, at least in part, on a number of the preceding chest compressions already provided to the patient.
Clause 9: The system of any of clauses 1-8, wherein the at least one processor and memory are further configured to control the chest compressor to repeatedly administer chest compressions at the final target depth, once the adjusted patient-specific depths reaches the final target depth or following the plurality of chest compressions of the initial compression protocol.
Clause 10: The system of any of clauses 1-9, wherein the initial compression period comprises a period of time of about 30 seconds to about 5 minutes.
Clause 11: The system of any of clauses 1-9, wherein the initial compression period comprises a period of time of about 1 minute to about 2 minutes.
Clause 12: The system of any of clauses 1-11, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths is based on whether the estimated force falls outside of an expected range.
Clause 13: The system of clause 12, wherein determination of whether the estimated force falls outside of the expected range comprises determination of whether the estimated force exceeds a predetermined force threshold.
Clause 14: The system of any of clauses 1-13, wherein the at least one processor and memory are further configured to control the chest compressor to administer the chest compressions according to one or more additional patient-specific compression parameters over the initial compression period.
Clause 15: The system of clause 14, wherein the one or more patient-specific compression parameters comprise at least one of: compression force, compression hold time, release velocity, downstroke acceleration, downstroke velocity, lift displacement, lift force, upstroke acceleration, and upstroke velocity.
Clause 16: The system of any of clauses 1-15, further comprising at least one displacement sensor configured to sense displacement signals corresponding to displacement of the patient's chest during the applied chest compressions, wherein the at least one processor and memory are configured to receive and process the displacement signals to estimate displacement of the chest during the chest compressions.
Clause 17: The system of clause 16, wherein the adjustment of the magnitude of the scheduled depths to the patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions is based, at least in part, on the estimated displacement.
Clause 18: The system of clause 16, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions is based, at least in part, on estimated chest compliance over the one or more preceding chest compressions.
Clause 19: The system of clause 18, wherein the estimated chest compliance is based on the estimated force and the estimated displacement.
Clause 20: The system of any of clauses 1-19, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions comprises a non-linear increase in compression depths for the one or more remaining chest compressions based on an increase or decrease in an estimated chest compliance over the one or more preceding chest compressions.
Clause 21: The system of any of clauses 1-19, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions comprises a substantially linear increase in compression depths for the one or more remaining chest compressions.
Clause 22: The system of any of clauses 1-21, wherein the initial depth comprises a depth of about 0.1 inch to about 1.0 inch.
Clause 23: The system of any of clauses 1-22, wherein the target final depth comprises a depth of about 2.0 inches to about 2.4 inches.
Clause 24: The system of any of clauses 1-23, wherein the initial compression protocol comprises a first portion comprising chest compressions of the initial depth, a second portion comprising chest compressions of at least one intermediate depth between the initial depth and the final target depth, and a third portion comprising chest compressions at the final target depth.
Clause 25: The system of clause 24, wherein the at least one intermediate depth comprises a depth of about 0.5 inch to about 2.0 inches.
Clause 26: The system of any of clauses 1-25, wherein the chest compressor is configured to provide active compression/decompression treatment to the chest of the patient.
Clause 27: The system of any of clauses 1-25, wherein the chest compressor comprises a compression belt and a belt tensioner configured to tighten the compression belt around the chest of the patient in order to compress the chest of the patient.
Clause 28: The system of any of clauses 1-25, wherein the chest compressor is a piston-based system that comprises: a piston, a piston driver, support structures for supporting the piston and the piston driver, and a compression pad affixed to the piston.
Clause 29: A system for administering chest compressions to a patient, the system comprising: an automated chest compressor configured to be applied to a chest of the patient to administer chest compressions to the patient, the chest compressor comprising a compression surface configured to be positioned on the patient's chest, a driver configured to move the compression surface in a first direction to compress the patient's chest and in a second direction to release the patient's chest, and at least one displacement sensor configured to measure distance traveled by the patient's chest and/or the compression surface to estimate a depth and/or decompression height of the chest compression; and at least one processor and memory communicatively coupled with the chest compressor and the at least one displacement sensor, wherein the at least one processor and memory are configured to cause the chest compressor to: repeatedly cause the driver of the chest compressor to move the compression surface in the first direction until a signal received by the at least one processor from the at least one displacement sensor indicates that the compression surface has moved a sufficient distance to perform a chest compression of a temporary target depth, and once the temporary target depth is reached, causing the driver to move the compression surface in the second direction to a temporary decompression height identified based on the signal from the at least one displacement sensor, following one or more of the compressions, adjust the target compression depth and/or target decompression height according to a predetermined initial compression protocol comprising a predetermined number of chest compressions, and after completion of the predetermined number of chest compressions of the initial compression protocol, cause the driver of the chest compressor to repeatedly move the compression surface in the first direction until the signal received by the at least one processor from the at least one displacement sensor indicates that the compression surface has moved a sufficient distance to perform a chest compression of a predetermined final target depth and cause the driver to move the compression surface in the second direction to a predetermined final decompression height identified based on the signal from the at least one displacement sensor.
Clause 30: The system of clause 29, wherein the initial compression protocol comprises at least one portion in which the temporary target depth increases at a constant rate per compression.
Clause 31: The system of clause 30, wherein the initial compression protocol comprises at least a first portion in which the temporary target depth increases at a first rate per compression and at least a second portion in which the temporary target chest compression depth increases at a second rate per compression, the second rate being different from the first rate.
Clause 32: The system of clause 31, wherein the second rate is greater than the first rate.
Clause 33: The system of any of clauses 29-32, wherein the adjustment of the temporary target compression depth according to the initial compression protocol comprises a continuous linear increase in compression depth over the predetermined number of the chest compressions.
Clause 34: The system of any of clauses 29-32, wherein the adjustment in the temporary target compression depth according to the initial compression protocol comprises a decrease in compression depth over at least a portion of the predetermined number of the chest compressions.
Clause 35: The system of any of clauses 29-34, wherein the predetermined number of chest compressions lasts between about 30 seconds and about 5 minutes.
Clause 36: The system of any of clauses 29-34, wherein the predetermined number of chest compressions lasts between about 1 minute and about 2 minutes.
Clause 37: The system of any of clauses 29-36, wherein the at least one processor and memory are configured to control the chest compressor to administer the chest compressions according to one or more additional patient-specific compression parameters over the initial compression protocol.
Clause 38: The system of clause 37, wherein the one or more patient-specific compression parameters comprises at least one of: compression force, compression hold time, release velocity, downstroke acceleration, downstroke velocity, lift displacement, lift force, upstroke acceleration, and upstroke velocity.
Clause 39. The system of any of clauses 29-36, wherein the adjustment of the temporary target compression depth comprises a substantially linear increase in the temporary target compression depth over the predetermined number of chest compressions.
Clause 40: The system of any of clauses 29-39, wherein the temporary target compression depth for a first chest compression of the initial compression protocol is about 0.1 inch to about 1.0 inch.
Clause 41: The system of any of clauses 29-40, wherein the final target compression depth is about 2.0 inch to about 2.4 inch.
Clause 42: The system of any of clauses 29-36, wherein the adjustment of the temporary target compression depth according to the initial compression protocol comprises a first portion of one or more chest compressions of a first temporary target depth, a second portion of one or more chest compressions of at least one intermediate temporary target compression depth, and a third portion of one or more chest compressions of a third temporary target compression depth.
Clause 43: The system of clause 42, wherein the at least one intermediate compression depth comprises a depth of about 0.5 inch to about 2.0 inches.
Clause 44: The system of any of clauses 29-43, wherein the temporary target decompression height for at least one of the chest compressions is a vertical distance above a neutral position of the patient's chest, thereby providing active chest decompression.
Clause 45: The system of any of clauses 29-44, wherein the compression surface comprises a compression belt and the driver comprises a belt tensioner configured to tighten the compression belt around the chest of the patient in order to compress the chest of the patient.
Clause 46: The system of any of clauses 29-44, wherein the chest compressor is a piston-based system, in which the driver comprises a piston and a piston driver, and the compression surface comprises a compression pad affixed to the piston, the system further comprising support structures for supporting the piston and piston driver.
Clause 47: A system for assisting an acute care provider in performance of chest compressions to a patient, the system comprising: at least one chest compression sensor configured to sense displacement information in response to chest compressions administered by the acute care provider; a feedback device for providing guidance for the acute care provider in the performance of the chest compressions; and at least one processor and memory communicatively coupled with the at least one chest compression sensor and the feedback device, wherein the at least one processor and memory are configured to: receive and process the sensed displacement information from the at least one chest compression sensor during the performance of the chest compressions, estimate compression depth based on the processed displacement information, and cause the feedback device to provide guidance for the acute care provider for administration of the chest compressions of scheduled depths over an initial compression period according to an initial compression protocol, the initial compression protocol comprising a plurality of chest compressions of increasing scheduled depths with a first compression at an initial depth and a final compression at a final target depth greater in magnitude than the initial depth.
Clause 48: The system of clause 47, wherein the at least one chest compression sensor comprises at least one of: an accelerometer, a displacement sensor, a velocity sensor, and a force sensor.
Clause 49: The system of clause 47 or clause 48, wherein the guidance provided by the feedback device comprises at least one of: visual feedback, audible feedback, and haptic feedback.
Clause 50: The system of any of clauses 47-49, wherein the feedback device is configured to provide an indication of whether the estimated depth for a particular chest compression of the plurality of chest compressions falls outside of a range of the scheduled depth for the particular chest compression of the plurality of chest compressions.
Clause 51: The system of any of clauses 47-50, wherein the initial compression protocol comprises at least a first portion of the plurality of chest compressions in which the scheduled depth of the chest compressions increases at a first rate per compression.
Clause 52: The system of clause 51, wherein the initial compression protocol comprises at least a second portion of the plurality of chest compressions in which the scheduled depth of the chest compressions increases at a second rate, the second rate being different from the first rate.
Clause 53: The system of clause 52, wherein the second rate is greater than the first rate.
Clause 54: The system of any of clauses 47-53, wherein the initial compression protocol comprises a first portion comprising chest compressions of the initial depth, a second portion comprising chest compressions of at least one intermediate depth between the initial depth and the final target depth, and a third portion comprising chest compressions at the final target depth.
Clause 55: The system of clause 54, wherein the at least one intermediate depth comprises a depth of about 0.5 inch to about 2.0 inches.
Clause 56: The system of any of clauses 47-55, wherein the initial compression protocol comprises a continuous linear increase in the scheduled depths over the initial compression period.
Clause 57: The system of any of clauses 47-56, wherein the initial depth comprises a depth of about 0.1 inch to 1.0 inch.
Clause 58: The system of any of clauses 47-57, wherein the final target depth comprises a depth of about 2.0 inches to about 2.4 inches.
Clause 59: The system of any of clauses 47-58, wherein the initial compression period comprises a period of time of about 30 seconds to 5 minutes.
Clause 60: The system of any of clauses 47-58, wherein the initial compression period comprises a period of time of about 1 minute to about 2 minutes.
Clause 61: The system of any of clauses 47-60, wherein the at least one chest compression sensor comprises at least one motion sensor configured to sense the displacement information, the system further comprising at least one force sensor configured to sense force information from the applied chest compressions, wherein the at least one processor and memory are configured to receive and process the sensed force information produced from the at least one force sensor to estimate force applied to the chest.
Clause 62: The system of clause 61, wherein the at least one processor and memory are configured to adjust a magnitude of the scheduled depths to patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol based on the estimated force applied to the chest during one or more preceding chest compressions of the plurality of chest compressions so that guidance provided by the feedback device is for administration of chest compressions at the adjusted patient-specific depths for the one or more remaining chest compressions of the initial compression protocol.
Clause 63: The system of clause 62, wherein the adjustment of the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions occurs at regular intervals.
Clause 64: The system of clause 62, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths is based on whether the estimated force falls outside of an expected range.
Clause 65: The system of clause 64, wherein determination of whether the estimated force falls outside of the expected range comprises determination of whether the estimated force exceeds a predetermined force threshold.
Clause 66: The system of clause 62, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions is based, at least in part, on estimated chest compliance over the one or more preceding chest compressions.
Clause 67: The system of clause 66, wherein the estimated chest compliance is based on the estimated force and the estimated displacement.
Clause 68: The system of clause 62, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions comprises a non-linear increase in compression depths for the one or more remaining chest compressions based on an increase or decrease in an estimated chest compliance over the one or more preceding chest compressions.
Clause 69: The system of clause 62, wherein the adjustment in the magnitude of the scheduled depths to the patient-specific depths of the one or more remaining chest compressions comprises a decrease of the scheduled depths to the patient-specific depths for at least one of the one or more remaining chest compressions.
Clause 70: The system of clause 62, wherein the adjustment of the magnitude of the scheduled depths to the patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol is further based, at least in part, on a number of the preceding chest compressions already provided to the patient.
Clause 71: The system of clause 62, wherein the at least one processor and memory are configured to cause the feedback device to repeatedly provide guidance for the acute care provider for administration of the chest compressions at the final target depth, once the adjusted patient-specific depth reaches the final target depth, or following the plurality of chest compressions of the initial compression protocol.
Clause 72: The system of any of clauses 47-71, wherein the at least one processor and memory are configured to control the feedback device to provide guidance for the acute care provider for the administration of the chest compressions according to one or more additional compression parameters over the initial compression period.
Clause 73: The system of clause 72, wherein the one or more additional compression parameters comprise at least one of: compression hold time, release velocity, downstroke acceleration, downstroke velocity, lift displacement, lift force, upstroke acceleration, and upstroke velocity.
Clause 74: The system of any of clauses 71-73, wherein the feedback device comprises a visual display that displays a user interface for providing the guidance for the acute care provider for the administration of the chest compressions.
Clause 75: The system of clause 74, wherein the user interface comprises a visual indicator for actual compression depth and at least one dynamic target indicator showing the scheduled depth for a particular chest compression of the plurality of chest compressions.
Clause 76: The system of clause 75, wherein the at least one dynamic target indicator comprises a first indicator showing a minimal acceptable depth related to the scheduled depth and a second indicator showing a maximum acceptable depth related to the scheduled depth.
Clause 77: The system of clause 75 or clause 76, wherein the at least one processor and memory are configured to adjust a position of the at least one dynamic target indicator on the user interface according to the initial compression protocol to guide the acute care provider in administration of a next chest compression of the plurality of chest compressions.
Clause 78: The system of any of clauses 47-77, further comprising an active compression decompression device configured to be used by the acute care provider for administration of active compression/decompression treatment to the patient.
Clause 79: A system for assisting an acute care provider in performance of chest compressions to a patient, the system comprising: at least one motion sensor configured to be positioned on the patient's chest to sense displacement information for the chest in response to chest compressions administered by the acute care provider; at least one force sensor configured to sense force information from the applied chest compressions; a feedback device for providing guidance for the acute care provider in the performance of the chest compressions; and at least one processor and memory communicatively coupled with the at least one motion sensor, the at least one force sensor, and the feedback device, wherein the at least one processor and memory are configured to: receive and process the sensed displacement information from the at least one motion sensor during the performance of the chest compressions to estimate compression depth for the chest compressions, receive and process the sensed force information produced from the at least one force sensor during the performance of the chest compressions to estimate force applied to the chest for the chest compressions, cause the feedback device to provide guidance for the acute care provider for administration of the chest compressions of scheduled depths over an initial compression period according to an initial compression protocol, the initial compression protocol comprising a plurality of chest compressions of increasing scheduled depths with a first compression at an initial depth and a final compression at a final target depth greater in magnitude than the initial depth, and periodically adjust a magnitude of the scheduled depths to patient-specific depths for one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol based on the estimated force applied to the chest during one or more preceding chest compressions of the plurality of chest compressions.
Clause 80: The system of clause 79, wherein the at least one motion sensor comprises at least one of: an accelerometer, a displacement sensor, and a velocity sensor.
Clause 81: The system of clause 79 or clause 80, wherein the at least one force sensor comprises a strain gauge.
Clause 82: The system of any of clauses 79-81, wherein the guidance provided by the feedback device comprises at least one of: visual feedback, audible feedback, and haptic feedback.
Clause 83: The system of any of clauses 79-82, wherein the feedback device is configured to provide an indication of whether the estimated depth for a particular chest compression of the plurality of chest compressions falls outside of a range of the patient-specific depth for the particular chest compression of the plurality of chest compressions.
Clause 84: The system of any of clauses 79-83, wherein the initial compression protocol comprises at least a first portion of the plurality of chest compressions in which the scheduled depths of the chest compressions increases at a first rate per compression.
Clause 85: The system of clause 84, wherein the initial compression protocol comprises at least a second portion of the plurality of chest compressions in which the scheduled depths of the chest compressions increases at a second rate, the second rate being different from the first rate.
Clause 86: The system of clause 85, wherein the second rate is greater than the first rate.
Clause 87: The system of any of clauses 79-86, wherein the initial compression protocol comprises a first portion comprising chest compressions of the initial depth, a second portion comprising chest compressions of at least one intermediate depth between the initial depth and the final target depth, and a third portion comprising chest compressions of the final target depth.
Clause 88: The system of clause 87, wherein the at least one intermediate depth comprises a depth of about 0.5 inch to about 2.0 inches.
Clause 89: The system of any of clauses 79-88, wherein the initial compression protocol comprises a continuous linear increase in the scheduled depths over the initial compression period.
Clause 90: The system of any of clauses 79-89, wherein the initial depth comprises a depth of about 0.1 inch to 1.0 inch.
Clause 91: The system of any of clauses 79-89, wherein the final target depth comprises a depth of about 2.0 inches to about 2.4 inches.
Clause 92: The system of any of clauses 79-91, wherein the initial compression period comprises a period of time between about 30 seconds and about 5 minutes.
Clause 93: The system of clause 79, wherein the initial compression period comprises a period of time of about 1 minute to about 2 minutes.
Clause 94: The system of any of clauses 79-93, wherein the periodic adjustment of the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions occurs at regular intervals.
Clause 95: The system of any of clauses 79-93, wherein the periodic adjustment in the magnitude of the scheduled depths to the patient-specific depths is based on whether the estimated force falls outside of an expected range.
Clause 96: The system of clause 95, wherein determination of whether the estimated force falls outside of the expected range comprises determination of whether the estimated force exceeds a predetermined force threshold.
Clause 97: The system of any of clauses 79-96, wherein the periodic adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions is based, at least in part, on estimated chest compliance over the one or more preceding chest compressions.
Clause 98: The system of clause 97, wherein the estimated chest compliance is based on the estimated force and the estimated displacement.
Clause 99: The system of any of clauses 79-98, wherein the periodic adjustment in the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions comprises a non-linear increase in compression depths for the one or more remaining chest compressions based on an increase or decrease in an estimated chest compliance over the one or more preceding chest compressions.
Clause 100: The system of any of clauses 79-99, wherein the periodic adjustment in the magnitude of the scheduled depths to the patient-specific depths of the one or more remaining chest compressions comprises a decrease of the scheduled depths to the patient-specific depths for at least one of the one or more remaining chest compressions.
Clause 101: The system of any of clauses 79-100, wherein the periodic adjustment of the magnitude of the scheduled depths to the patient-specific depths for the one or more remaining chest compressions of the plurality of chest compressions of the initial compression protocol is further based, at least in part, on a number of the preceding chest compressions already provided to the patient.
Clause 102: The system of any of clauses 79-101, wherein the at least one processor and memory are configured to cause the feedback device to repeatedly provide guidance for the acute care provider for administration of the chest compressions at the final target depth, once the adjusted patient-specific depth reaches the final target depth, or following the plurality of compressions of the initial compression protocol.
Clause 103: The system of any of clauses 79-102, wherein the at least one processor and memory are configured to control the feedback device to provide guidance for the acute care provider for the administration of the chest compressions according to one or more additional compression parameters over the initial compression period.
Clause 104: The system of clause 103, wherein the one or more additional compression parameters comprise at least one of: compression hold time, release velocity, downstroke acceleration, downstroke velocity, lift displacement, lift force, upstroke acceleration, and upstroke velocity.
Clause 105: The system of any of clauses 79-104, wherein the feedback device comprises a visual display that displays a user interface for providing the guidance for the acute care provider for the administration of the chest compressions.
Clause 106: The system of clause 105, wherein the user interface comprises a visual indicator for actual compression depth and at least one dynamic target indicator showing the patient-specific depth for a particular chest compression of the plurality of chest compressions.
Clause 107: The system of clause 106, wherein the at least one dynamic target indicator comprises a first indicator showing a minimal acceptable depth related to the patient-specific depth and a second indicator showing a maximum acceptable depth related to the patient-specific depth.
Clause 108: The system of clause 106 or clause 107, wherein the at least one processor and memory are configured to adjust a position of the at least one dynamic target indicator on the user interface according to the initial compression protocol to guide the acute care provider in administration of a subsequent chest compression of the plurality of chest compressions.
Clause 109: The system of any of clauses 79-108, further comprising an active compression decompression device configured to be used by the acute care provider for administration of active compression/decompression treatment to the patient.
Various aspects of the disclosure are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. The figures are included to provide an illustration and a further understanding of various examples, and are incorporated in and constitute a part of this specification, but are not intended to limit the scope of the disclosure. The drawings, together with the remainder of the specification, serve to explain principles and operations of the described and claimed aspects and examples. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every figure. A quantity of each component in a particular figure is an example only and other quantities of each, or any, component could be used.
These and other features and characteristics of the present disclosure, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limit of the disclosure.
As used herein, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.
As used herein, the terms “right”, “left”, “top”, and derivatives thereof shall relate to aspects of the present disclosure as it is oriented in the drawing figures. However, it is to be understood that embodiments of the present disclosure can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Also, it is to be understood that embodiments of the present disclosure can assume various alternative variations and stage sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are provided as examples. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.
As used herein, including in the claims, “and” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, and C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C), or combinations with more than one feature (e.g., AA, AAB, ABBC, etc.). As used herein, including in the claims, unless otherwise stated, a statement that a function or operation is “based on” an item or condition means that the function or operation is based on the stated item or condition and may be based on one or more items and/or conditions in addition to the stated item or condition.
As used herein, the terms “communication” and “communicate” refer to the receipt or transfer of one or more signals, messages, commands, or other type of data. For one unit or component to be in communication with another unit or component means that the one unit or component is able to directly or indirectly receive data from and/or transmit data to the other unit or component. This can refer to a direct or indirect connection that can be wired and/or wireless in nature. Additionally, two units or components can be in communication with each other even though the data transmitted can be modified, processed, routed, and the like, between the first and second unit or component. For example, a first unit can be in communication with a second unit even though the first unit passively receives data, and does not actively transmit data to the second unit. As another example, a first unit can be in communication with a second unit if an intermediary unit processes data from one unit and transmits processed data to the second unit. It will be appreciated that numerous other arrangements are possible.
Systems and methods for assisting rescuers, such as acute care providers or lay persons, to treat patients during medical emergencies, particularly cardiac arrest, are disclosed herein. Medical emergencies require a rapid response to increase the likelihood of achieving a positive outcome for the patient and to provide the best chance for patient survival. For victims of cardiac arrest, cardiopulmonary resuscitation (CPR) is an indicated form of treatment, which includes chest compressions for increasing circulation of blood to core and peripheral tissues. However, by their nature of providing substantial force to the thorax, chest compressions may cause accidental injuries to the patient. While fairly uncommon, these accidental injuries may be life-threatening. Common injuries related to chest compressions may include fractures of the ribs and/or sternum. Elderly patients and those with compromised skeletal systems may be especially susceptible to such injuries. Moreover, such injuries often reduce the effectiveness of the chest compressions as the injuries may affect how well or how much the patient's chest is able to return to its starting or initial position after a chest compression down stroke.
Accordingly, systems and methods are disclosed herein for providing an initial compression protocol (also referred to as a ramp up protocol) for an initial compression or ramp up period during CPR. During the initial compression protocol, the chest compressions are applied with gradually increasing scheduled depths until a final target depth is reached. For an adult patient, the final target depth can be about 2.0 inches to about 2.4 inches, as recommended by the 2015 American Heart Association Guidelines for chest compressions; however, it can be appreciated that other final target depths may be indicated or otherwise preferred. For example, the final target depth may be relatively greater for a larger person, or less for a smaller person. Once the final target depth is reached, chest compressions can be applied to the patient at the final target depth for an extended predetermined or indeterminate period of time, such as throughout the remainder of the time in which CPR is administered. For example, chest compressions at the final target depth may continue to be applied until other types of treatment, such as a defibrillation shock, can be applied to the patient.
In some examples, the initial compression protocol may be adjusted (e.g., in real time) to provide chest compressions at patient-specific depths for one or more remaining chest compressions of the initial compression protocol. As used herein, a “patient-specific depth” can refer to an adjusted target depth customized to the particular patient, determined based on measured parameters from preceding chest compressions having been provided to the patient, measured physiological parameters for the patient, and/or anatomical features of the patient. Adjusting target compression depths to the “patient-specific depth” during the initial compression or ramp up period allows a patient's chest to acclimate to chest compressions at its own “patient-specific” pace. For example, a patient's chest may require extra time to stretch out and physically adapt to receiving chest compressions, meaning that a magnitude of target depths and/or a rate of increase for target depths, for the initial compression protocol, may initially be less than that of the final target depth and may gradually increase so as to reach the final target depth once the patient's body has acclimated to the force caused by the chest compressions. Another patient's chest may be especially flexible and resilient, meaning that target compression depth can be increased, so that the final target depth can be achieved more quickly, without as much risk of injury. In general, the measured parameter(s) used for adjusting the initial compression protocol comprises measurements showing how the patient's chest is affected by the chest compressions. These measured parameter(s) provide information about whether increasing the chest compression depth would be more likely to cause damage or injury. For example, the target depths of the initial compression protocol may be adjusted based on input from force sensors configured to measure a force exerted on the patient's chest during chest compressions. Generally, force may be expected to decrease as chest compressions are performed, as the patient's chest is stretched and deformed by the compressions, becoming more accustomed to withstanding the repeated compression force.
As described in further detail herein, a medical device, such as a patient monitor, defibrillator, ventilator, or automated external defibrillator, may comprise and/or control a chest compression feedback device that guides an acute care provider in providing chest compressions according to selected chest compression parameters. The medical device can cause the feedback device to provide guidance according to an initial compression protocol and/or for chest compressions at patient-specific depths. Similarly, the medical device may also be in communication with and/or control an automated chest compressor to provide automated chest compressions to a patient according to the initial compression protocol and/or at the adjusted patient-specific depths. For example, if a force measurement (e.g., sensed measurements for force applied to the patient's chest during chest compressions) is above a predetermined threshold, there typically may be an increased chance of causing injury to the patient. In response to the force measurement exceeding the threshold, the medical device may control the feedback device or automated mechanical chest compressor to adjust a depth of future (e.g., remaining) chest compressions of the compression protocol from the scheduled target depth to a shallower (e.g., lower magnitude) patient-specific depth.
In many cases, the depth of the compressions would continue to increase throughout the initial compression protocol; however, the rate of increase may be reduced compared to the scheduled or predetermined target depths to account for the force measurements. Reducing a rate of increase of the target depth of the chest compressions may be expected to reduce the measured force values, thereby decreasing a likelihood of causing injuries to the patient during chest compressions.
Reducing the risk of injury during an initial compression period by employing a period of ramp up compressions is believed to be beneficial in the long term, for example, because the patient's chest is generally able to retain elasticity (i.e., ability to return to its original position). Retaining elasticity of the chest can improve effectiveness of future chest compressions, by allowing the heart to fill with a greater blood volume, compared to when the chest does not return to its original position following each compression. Retaining elasticity may also improve a velocity at which blood is expelled from the heart during compressions. Additionally, by preserving the natural elasticity, specifically of sternal cartilage, recoil velocity on compression upstroke may be better preserved, which may enhance negative intrathoracic pressure and, thereby, enhance diastolic filling of the heart. In addition to preserving natural elasticity, the initial compression period may also increase the range of vertical motion of the sternum, while preventing or minimizing nosocomial chest compression-related injury, thereby increasing the range of upward motion during active compression decompression (ACD) and enhancing diastolic filling and blood flow during chest compressions. There may be additional advantages to employing a ramp up period of chest compressions. For example, it may be beneficial to soften the myocardium and/or surrounding tissues to facilitate or otherwise enhance circulation. The ramp up period may also effectively serve to massage or increase muscular flexibility, which enables muscle and/or connective tissue to expand in a manner that more readily accepts blood during venous return and to compress in a manner that more readily expels blood during arterial contraction. Because the ramp up period reduces the risk of injury by preventing rib fractures, the ramp up period may further serve to protect the lungs from injury. For instance, broken ribs can lead to pneumothorax (i.e., collapsed lung) or lung contusion, and such injuries to the lungs could decrease the effectiveness of ventilation during CPR. Another potential injury that could be avoided is cardiac tamponade (i.e., fluid buildup around the heart). Cardiac tamponade may impair hemodynamics of circulation. Other organs, such as the spleen or liver, can also be lacerated with abrupt chest compression forces. Avoiding these injuries is of further benefit for the patient. Reducing injury can also make the recovery easier for patients that achieve sustained return of spontaneous circulation.
The systems and methods for providing the initial compression protocol and/or chest compressions at the patient-specific compression depths disclosed herein can be adapted for use with a variety of different types of chest compressions and/or chest compression devices, as are known in the art. Table 1 lists examples of different types of chest compressions and delivery systems that may be adapted for providing chest compressions according to an initial compression protocol and/or compressions at patient-specific depths. These various types of chest compressions are discussed in detail in connection with
Standard chest compressions refers to classic chest compressions by a caregiver's hands, for example, two-hand CPR (e.g., compressions according to Advanced Cardiac Life Support (ACLS) guidelines) or other techniques provided to pediatric patients such as two-finger CPR, where two fingers are used to compress the chest, or thumbs CPR, where an infant is held and compressed between the thumb positioned on the anterior side and the index fingers positioned on the posterior side. When the caregiver is manually providing compressions with his/her hands, the compression parameters are controlled by and subject to variability due to physical actions of the acute care provider or lay person. ACD chest compressions (e.g., delivered manually using an ACD device) refer to compressions delivered using devices that, though mechanical in nature, depend on the physical activity of the acute care provider to control the chest compressions. Automated chest compressions refer to chest compressions delivered by electromechanical devices (e.g., electromechanical belt-based system, electromechanical piston-based system, or electromechanical piston-based ACD system) that are controlled by computerized control systems, where compression parameters are predetermined by the programming and/or design of the device. The programming of the electromechanical devices often enables the parameters to be modified in real time. Beneficially, the electromechanical devices may not be subject to variability in compression depth or rate in the same way as standard chest compressions, which can be affected by a level of experience or fatigue of the individual performing the chest compressions.
With reference to
Force measurements can be analyzed to estimate compression rate or depth (in conjunction with a measurement of displacement or compliance). For example, when using force to estimate depth, the compliance or stiffness of the chest will affect how the chest deforms. Accordingly, when the compliance of the chest is known or can be estimated with reasonable accuracy, the depth can also be estimated from a force measurement. Also, force measurements can be used as input for a chest compression system (e.g., used for manual compressions and/or automated compressions) to adjust a target depth of remaining chest compressions of an initial compression protocol. Information and signals detected and output by the sensors 112, 114 may be represented using any of a variety of different technologies and techniques. For example, information or signals detected or output by the sensor(s) may be represented by voltages, currents, electromagnetic waves, magnetic fields, or any combination thereof, which may be processed in a manner that is useable to estimate physical measurements, such as force, displacement, compliance, etc.
The system 110 further comprises feedback device(s) in communication with the controller 150 for providing guidance for the acute care provider 10 in the performance of manual chest compressions. As used herein, “feedback” can refer to prompts, notifications, displays of chest compression information, and/or instructions, including haptic feedback, audible feedback, and/or visual feedback, which may be used to assist in guiding the acute care provider 10 in performance of the chest compressions according to certain criteria or parameters. Chest compression parameters can include, for example, compression force, compression rate (in compressions per minute), measured compression depth, and/or a decompression velocity (e.g., a release velocity). Chest compression parameters that can be measured or derived from information detected by the chest compression sensor(s) can also comprise compression hold time, downstroke acceleration, downstroke velocity, lift displacement, lift force, upstroke acceleration, and upstroke velocity.
Information and signals from the chest compression sensor(s) may be evaluated or analyzed to generate the feedback for the acute care provider 10. For example, the information from the chest compression sensor(s) may be used to determine, calculate, and/or estimate present values for the chest compression evaluation criteria or parameters. In that case, the feedback may provide an indication of the present values for such chest compression parameters. The feedback can also comprise information about target values for chest compression parameters and/or recommended changes to measured chest compression parameters or values relative to the target values. For example, the feedback may comprise indications to increase or decrease compression depth depending on whether the measured compression depth falls within a desired target range for compression depth, indications to compress at a faster or slower rate depending on whether the measured compression rate falls within a desired target range for compression rate, and/or indications to quickly and completely release the chest of the patient after each compression depending on whether the measured release velocity falls within a desired target range for release velocity. In general, feedback may be corrective feedback (i.e., feedback configured to cause an acute care provider 10 to change an aspect of the resuscitative care) and/or may be reported measurements (i.e., feedback that indicates a value or status of an aspect of the resuscitative care without a suggested change).
As shown in
In some examples, the feedback device is positioned in the housing 118. For example, a haptic feedback device, such as a vibrator 120, may be positioned in the housing 118 and configured to cause the housing 118 to vibrate to provide feedback to the acute care provider 10. For example, the vibrator 120 may vibrate with a first haptic pattern to instruct the acute care provider 10 to begin a chest compression, and with a second haptic pattern when a target depth has been reached, indicating that the acute care provider 10 should release the compression. Alternatively or additionally, the system 110 may comprise separate feedback devices, such as a medical device 122 connected by wires 124 or wirelessly to the hand-held sensor device 116 and/or controller 150. In some examples, the controller 150 can be a computer processor of the medical device 122. The medical device 122 may comprise components for providing haptic, audible, and/or visual feedback to the acute care provider 10. For example, the medical device 122 may comprise a display 128 configured to display visual indicators and icons that provide information to the acute care provider 10 about how chest compressions should be performed. Examples of interfaces provided on displays of a medical device 122 are shown in
The medical device 122 may be, for example, a patient monitor, a defibrillator, a mechanical chest compression device (e.g., an automated chest compression device, a belt-based chest compression device, a piston-based chest compression device, an active compression-decompression device, or combinations thereof), a ventilator, an intravenous cooling device, and/or combinations thereof. The ventilator may be a mechanical ventilator. The mechanical ventilator may be a portable, battery powered ventilator. The intravenous cooling device may deliver cooling therapy and/or may sense a patient's temperature. The medical device 122 may provide, for example, electrical therapy (e.g., defibrillation, cardiac pacing, synchronized cardioversion, diaphragmatic stimulation, and/or phrenic nerve stimulation), ventilation therapy, therapeutic cooling, temperature management therapy, invasive hemodynamic support therapy (e.g., extracorporeal membrane oxygenation (ECMO)), and/or combinations thereof. The medical device 122 may also be a wearable device (not shown), such as a smartwatch, worn by the acute care provider 10 for providing alarms, notifications, and feedback about the chest compressions.
In addition to the chest compression sensors (e.g., the depth sensor 112 and the force sensor 114), the system 110 may comprise additional sensors incorporated with and/or coupled (e.g., mechanically, electrically, and/or communicatively coupled) to the medical device 122. The additional sensors can be patient physiological sensors 126. The patient physiological sensors 126 may comprise, for example, cardiac sensing electrodes, ventilation sensor(s), and/or sensors capable of providing signals indicative of vital sign(s) of the patient 12, such as electrocardiogram (ECG), blood pressure (e.g., invasive blood pressure (IBP), non-invasive blood pressure (NIBP)), heart rate, pulse oxygen level, respiration rate, heart sounds, lung sounds, respiration sounds, end tidal CO2, saturation of muscle oxygen (SMO2), arterial oxygen saturation (SpO2), cerebral blood flow, electroencephalogram (EEG) signals, brain oxygen level, tissue pH, tissue oxygenation, or tissue fluid levels. The physiological sensors 126 may also comprise sensors capable of providing signals indicative of parameters determined via ultrasound, video-laryngoscopy, airway or esophageal pressure sensors, near-infrared reflectance spectroscopy, pneumography, cardiography, ocular impedance, spirometry, tonometry, plethysmography, eye tracking, drug delivery parameters, fluid delivery parameters, transthoracic impedance, blood sampling, venous pressure monitoring (e.g., CVP), temperature, and/or non-invasive hemoglobin parameters. In some examples, the physiological sensors 126 may comprise electrodes or drug delivery devices that provide therapy to the patient 12.
As shown in
The processor 152 and memory 154 can also be configured to receive and process sensed force information from the force sensor 114 to estimate force applied to the chest 14 of the patient 12 during the chest compressions. As described in detail in connection with
These protocols 202a, 202b, 202c, 202d, 202e represent desired or scheduled target depths that the acute care provider 10 should aim to achieve for chest compressions during an initial compression period. In particular, the acute care provider 10 aims to increase compression depth from an initial compression depth 204 for a first compression of the protocol 202a, 202b, 202c, 202d, 202e to a final target compression depth 206 at the competition of the protocol. For example, the initial depth can be a depth of about 0.1 inch to 1.0 inch. The final target depth can be the America Heart Association (AHA) guideline depths, which are currently about 2.0 inches to about 2.4 includes (or 5-6 cm) for adults; approximately ⅓ the diameter of the chest of the child, which can be about 2.0 inches (5 centimeters) for a child; and about 1.5 inches (4 centimeters) for infants. However, the final target depth or final target range may vary from these guidelines.
As detailed above, the goal of using the initial compression protocol 202a, 202b, 202c, 202d, 202e is to slowly or gradually increase the displacement (depth) of the patient's chest 14 over time. A benefit of using an initial compression protocol 202a, 202b, 202c, 202d, 202e comprising a ramp up procedure is to provide a “break-in” period for the patient's chest 14. That is, the chest 14 is able to acclimate to the chest compressions, which may reduce or eliminate injuries caused by chest compressions (e.g., broken ribs or sternum) and help the chest 14 to retain its elasticity and structural integrity, which may help chest compressions maintain effectiveness, or to become even more effective than if the break-in period were not implemented, throughout the duration of the resuscitation. As noted herein, the initial compression protocol 202a, 202b, 202c, 202d, 202e may be applicable in providing feedback for a caregiver administering manual chest compressions, or the initial compression protocol 202a may be applicable as input for an automated chest compressor to administer compressions according to the initial compression protocol.
As discussed previously, the 2015 AHA guidelines indicate that chest compressions should be delivered at approximately 100-120 times per minute and that a depth of 2.0 to 2.4 inches should be achieved. In accordance with these guidelines, by way of example, the initial treatment protocol 202a may achieve a final target depth of 2.0 inches in an initial compression period of 60 seconds. In order to achieve this result, each chest compression should be increased by 0.02 inches per compression (i.e., 2 inches divided by 100 compressions per minute). In alternative examples, the chest compression rate could be any rate between 100 and 120 compressions per minute, and the final depth could be any depth between 0.5 inches and 5.0 inches (e.g., between 2.0 inches and 2.4 inches). The initial compression period may be, for example, from 20 seconds to 2 minutes (or longer) in duration. Target depth ranges may change over time, depending on modified guidelines and/or customized chest compression protocols that are specifically tailored for each patient.
Similarly, the Timemax represents a maximum amount of time or maximum number of compressions for which the initial compression protocol 202a, 202b, 202c, 202d, 202e or ramp up protocol should be performed before switching to chest compressions performed at the final target depth 206 or final target depth range, for example, in the case of feedback for manual compressions. Limiting the maximum time or number of compressions for the initial compression protocol 202a, 202b, 202c, 202d, 202e ensures that chest compressions of sufficient depth to ensure sufficient blood flow begin to be provided to the patient within a medically beneficial amount of time. As detailed above, no two patients will have identical physiologies, thus the Timemax may be set to 30 seconds (50 compressions), 35 seconds (58 compressions), 40 seconds (66 compressions), 45 seconds (75 compressions), 50 seconds (83 compressions), 55 seconds (92 compressions), 60 seconds (100 compressions), 90 seconds (150 compressions), 120 seconds (200 compressions), or 180 seconds (250 compressions), or more.
With specific reference to
As shown in
In one example, the processor 152 and memory 154 of the system 110 may be configured to adjust a duration of the segments 210, 212, 214, 216 based on a quality of chest compressions provided by the acute care provider 10. For example, the system 110 may monitor whether the acute care provider 10 successfully performs chest compressions of the scheduled target depths by comparing measured parameters for each chest compression to the scheduled target depth for the chest compression. The processor 152 and memory 154 may be configured to only continue to the next step or segment 212, 214, 216 when the acute care provider 10 successfully performs a predetermined number of chest compressions at the scheduled target depth for the current step or segment 210, 212, 214. However, the maximum time boundary Timemax can still apply. Accordingly, the processor 152 and memory 154 can be configured to begin providing instructions to perform chest compressions at the final target depth 206 after the maximum time Timemax, even if the acute care provider 10 has not finished all the steps or segments 210, 212, 214, 216 of the protocol 202b in the allotted time.
With reference to
Similarly, for certain examples, an initial compression protocol 202d may employ a substantially logarithmic profile, including an initial relatively fast rate of increase in the target depth of chest compressions, followed by a slower rate of increase in the target depth of compressions. A logarithmic profile may be beneficial because increasing the target compression depth may be more physiologically beneficial early on during the ramp up period to move blood through the circulatory system during initial chest compressions. Or, in certain examples, an initial compression protocol 202e may comprise a combination of profiles. For example, after reaching an intermediate target compression depth (e.g., about 1.0 inch), it may be preferable to slightly ease the overall force of compressions so as to reduce the risk of breaking the ribcage. Once the ribcage is suitably conditioned, then it may be preferable to increase the target compression depth at a relatively faster rate.
While these illustrated examples are described with respect to manual chest compressions performed by the acute care provider 10, any of these initial compression protocols 202a, 202b, 202c, 202d, 202e shown in
As discussed previously, feedback from the system 110 can be provided on a display 128 of a medical device 122. Examples of user interfaces 310 comprising visual indicators and icons shown on the display 128 for providing feedback about chest compressions and, in particular, for guiding the acute care provide 10 in performing chest compressions according to an initial compression protocol, are shown in
With specific reference to
The CPR dashboard 312 further comprises a dynamic indicator, such as a window 324, showing a target depth for a chest compression to be performed by the acute care provider 10. In
While not illustrated in
As discussed previously, the graduated numerical values 322 and/or window 324 are dynamic indicators, meaning that a position and/or appearance of the scale 318 and/or window 324 can be automatically adjusted on the display 128 following each chest compression or each group of chest compressions to indicate to the acute care provider 10 that a future compression(s) should be performed at different scheduled depths. Changes in numerical values 322 and position of the window 324 are shown by comparing the dashboard in
In some examples, the medical device 122 can also be configured to provide visual or audible feedback instructing the acute care provider 10 about certain aspects of providing chest compressions. For example, the medical device 122 may provide a reminder to “release” in situations where the acute care provider 10 is performing improper release. In particular, an ill-trained, naïve or fatigued acute care provider 10 may lean forward on the chest 14 of a patient 12 and not sufficiently release pressure on the sternum of the patient 12 at the top of each decompression stroke, which may reduce the effectiveness of the chest compressions. The reminder could by a visual pop-up notification on the CPR dashboard 312 portion of the user interface 310. Similarly, the medical device 122 may provide spoken and/or tonal audible feedback and/or haptic feedback reminding the acute care provider 10 to fully release the patient's chest 14.
As shown in
Another exemplary interface 310 for providing feedback about chest compressions and for guiding the acute care provide 10 in performing chest compressions according to an initial compression protocol is shown in
For example, in
Another exemplary interface 310 is shown in
With reference to
As previously discussed, chest compressions of an initial compression protocol can also be provided manually using an active compression-decompression (ACD) device that provides active compression and decompression of the chest. Exemplary ACD devices that can be used to provide chest compressions according to the initial compression protocols disclosed herein are described, for example, in U.S. Pat. No. 8,702,633 entitled “Guided active compression decompression cardiopulmonary resuscitation systems and methods” and U.S. Pat. No. 9,724,266 entitled “Enhanced guided active compression decompression cardiopulmonary resuscitation systems and methods,” as well as in U.S. Patent Application Publication No. 2019/0255340 entitled “Active compression decompression resuscitation integrated treatment system,” which are incorporated by reference in their entirety.
The system 410 for providing active compression-decompression according to an initial compression protocol 502a-502d (shown in
In some examples, the ramp up period may be applicable for active compression decompressions. Physically speaking, the mechanical behavior associated with compression and decompression may differ from one another. For example, chest compliance during compressions and chest elasticity during chest lift or decompression may involve different parts of the chest and may require softening independent of each other. During compressions, tissues such as the ribcage, muscles, and underlying organs may soften and/or shift position as they are pushed downward. However, when pulled upward, such tissues may or may not be mechanically involved in resisting lift or decompression. In various embodiments, the target decompression height may be set according to instantaneous compliance calculations of the chest, which may be estimated based on force and displacement measurements for each compression/decompression (or group of compressions/decompressions averaged together). For example, a threshold of minimum instantaneous compliance may be set where the caregiver is provided with a warning or prompt that the risk of injury is elevated if the instantaneous compliance falls below the threshold. During decompressions, the instantaneous compliance of the chest is likely to decrease, particularly as the end of the free range of motion of sternal cartilage and thoracic cage is reached. In such examples, in the context of the ramp up period, the target decompression height may be set to gradually increase until the instantaneous compliance falls below a predetermined threshold.
With reference to
The chest compression protocols 202a, 202b, 202c, 202d, 202e or patterns detailed in
As in previous protocol examples, in
As was the case for
With specific reference to
The acute care provider 10 is able to use the ACD device 412 to perform active decompressions on the patient 12. As shown in
With reference to
It will be appreciated, however, that the examples in
With reference to
The ACD device 412 of system 410 may be equipped to provide real-time feedback to the acute care provider 10 to guide the acute care provider 10 in performing active chest compressions/decompressions according to the initial compression protocols 502a, 502b, 502c, 502d. As in previous examples, the feedback can comprise haptic feedback, audible feedback, and/or visual feedback. In order to provide visual feedback, the ACD device 410 comprises a display 428 located on an upwardly facing surface of the handle 414 that shows a user interface 610 to the acute care provider 10. Examples of user interfaces 610 are shown in
The user interface 610 may be similar to the CPR dashboard 312 shown in
The user interface 610 further comprises the graduated numerical values 622 indicating an actual depth or decompression height for the chest compressions and decompressions. The numerical values 622 also include a neutral point, indicated by 0.0. The numerical values 622 can be dynamic, changing in value as the scheduled depth for a compression and/or scheduled decompression height for a chest decompression changes. For example, the range for the numerical values 622 in
As in previous examples, the interface 610 can comprise a visual indicator showing the scheduled target compression depth, such as a window 624. The interface 610 can also include a window 632 showing a scheduled target decompression height for a chest decompression to be performed. The interface 610 can be configured to adjust a position of the windows 624, 632 in accordance with the initial compression protocol following each compression or decompression. In some examples, the windows 624, 632 can include the first side 626, 634 showing the minimum acceptable compression depth or decompression height related to the scheduled target compression depth or target decompression height and a second side 628, 636 showing a maximum acceptable compression depth or decompression height related to the scheduled target compression depth and decompression height for each compression and decompression. As noted above in connection with
As in previous examples, as the acute care provider 10 provides a chest compression to the patient 12, the bars 620 illuminate or change in appearance indicating a current depth for the compression. The acute care provider 10 is instructed to continue to compress the chest 14 of the patient 12 until the target compression depth is obtained, as shown when the indicator bar 620 enclosed by the window 624 illuminates or changes in appearance. The acute care provider 10 then pulls up on the handles 414 of the ACD device 412 for active decompression. As the chest moves from the compressed position to the neutral point, the various indicator bars 620 turn off or change color. Once the neutral point is reached, the acute care provider 10 continues to lift up on the handles 414 to the target decompression height, such as a decompression height of 0.6 inch (in
While not illustrated, as in previous examples, the indicator bars 620 may also change in appearance to indicate when the compression has gone too deep or the chest is lifted above the target decompression height. For example, each indicator bar 620 may change from no color to green as the acute care provider 110 compresses the patient's chest 14. If the acute care provider exceeds the target depth, as shown by window 624, the color of the indicator bars 620 may change to orange or red. The indicator bars 620 may also flash to indicate that a compression has gone too deep.
As in previous examples, the ACD device 412 may further comprise a speaker 430 to provide verbal instructions encouraging the acute care provider 10 to adjust how chest compressions/decompressions are being performed. For example, the speaker 430 may emit reminders or notification, such as a reminder instructing the acute care provider 10 to “Increase Speed” or “Lift Faster” if decompressions are not occurring at a selected rate.
The chest compression systems 110, 410 described herein are configured to guide the acute care provider in performing chest compressions according to the initial compression protocol. As discussed previously, certain measured parameters can be used to adjust the initial compression protocol in real time so that, for some patients, the final target compression depth or final target decompression height can be achieved more quickly than provided by a predetermined initial compression protocol. For example, force measurements, such as force measurements from the force sensor 114 (shown in
For illustrative purposes,
With reference to
Typically, the initial compression protocol, which may comprise a procedure for ramping up the compression target depth over the protocol period, is applied to patients who have not yet received chest compressions. In that case, the initial target depth may be a depth measured from a natural position of the patient's chest 14, such as an initial position of the patient's chest 14 before chest compressions. Alternatively, in some cases, an initial compression protocol comprising a procedure for ramping up target compression depth may be applied in situations where the patient 12 has already been receiving chest compressions. For example, chest compressions or CPR may be applied by untrained individuals (e.g., laypersons) prior to the arrival of a medical professionals (EMT, Paramedics, acute care providers, doctors, nurses, and/or first responders) to a rescue scene. The untrained lay persons may have provided chest compressions that were too shallow and not in compliance with the AHA (American Heart Association) Guidelines. Accordingly, despite CPR having been applied, it may still be desirable to employ an initial compression protocol for ramping up the target compression depth. As discussed previously, the 2015 AHA guidelines for compression depth are between 2.0 and 2.4 (or 5-6 cm) inches for adults; approximately ⅓ the diameter of the chest of the child or about 2 inches (5 centimeters) for a child; and about 1.5 inches (4 centimeters) for infants. In this case, the initial target depth may be measured from a depth of the shallow chest compressions provided by the lay person. In this way, over the course of the initial compression protocol, the patient's chest 14 acclimates from relatively shallow chest compressions (provided by the lay person) to full depth chest compressions in compliance with the 2015 AHA guidelines, in a safe manner while reducing risk of injury to the patient 12.
Next, in step 704, the acute care provider 10 applies manual chest compressions to the patient 12. As chest compressions are being applied, in step 706, the processor 152, such as the processor of the medical device 122, obtains and processes force information from the force sensor 114. Similarly, at step 708, the processor 152 obtains and processes displacement information from the depth sensor 112 to determine a chest compression depth for chest compressions provided to the patient 12.
In step 710, the processor 152 determines if a final target compression depth has been achieved. This may be determined from a simple comparison between the measured compression depth determined in step 708 and the final target depth. If the final target compression depth has been achieved, in step 712, the processor 152 can cause the medical device 122 to provide an indication that the final target compression depth has been achieved. Also, the processor 152 can cause the medical device 122 to provide feedback instructing the acute care provider 10 to continue providing chest compressions at the achieved final target compression depth for a predetermined or indeterminate amount of time. For example, chest compressions at the final target depth can continue to be performed for the remaining period of the resuscitation (e.g., for periods during which compressions are to be applied) until chest compressions are no longer needed for the patient 12. This step is effectively the cross-over point for switching from the initial compression protocol which comprises a ramp up procedure to providing chest compressions at the final target depth.
If the final target compression depth has not yet been achieved, the processor 152 is then configured to continue to provide chest compression feedback according to the initial compression protocol. The processor 152 may also adjust a magnitude of the target compression depths to patient-specific depths for remaining chest compressions of the initial compression protocol based on the estimated force measurements determined at step 706.
Given that chest compliance may vary from person to person and the force associated with a given depth will also vary for different people, the manner in which the measured force or compliance of the patient changes during the ramp up period may be used to determine how the chest is softening or remodeling due to the applied compressions and/or whether the patient is at an increased risk of injury. Accordingly, changes in measured force and compliance can affect how target compression depths (and thus, feedback for manually provided CPR) are adjusted to be patient-specific.
In order to adjust the target depths to patient-specific target depths, at step 714, the processor 152 is configured to use the displacement and force sensor input to determine how the target depth should be modified so as to be customized to the patient. For example, the processor 152 may be configured to determine whether the measured force and/or the change in measured force (e.g., force gradient) for one or more preceding chest compressions exceeds a maximum threshold. Further, the processor 152 may be configured to determine whether the measured force or change in measured force (e.g., force gradient) exceeds a predetermined acceptable range of forces or force gradients that can be exerted on the patient's chest without causing injury. If the measured force or change in measured force exceeds a predetermined threshold, for example, then it may be desirable to decrease the amount of force applied to the patient's chest, or provide chest compressions in a more gentle fashion. For example, the feedback system may reduce the increase in target compression depth (e.g., reduce a slope of the protocol line for target chest compression depths) so that the ramp up in target compression depth is more gradual. When the maximum threshold for force or force gradient is exceeded, the target compression depth may increase only a smaller amount than would otherwise be the case, may remain constant for a period of time rather than increase in magnitude, or may even slightly decrease for a period of time so that even less force is applied to the patient.
In one example, the maximum threshold of force applied to the thorax could be set according to a predefined limit (e.g., between 20 kg and 60 kg, between 30 kg and 50 kg for compressions; between 5 kg and 20 kg, between 10 kg and 15 kg for decompressions). In other examples, the maximum threshold of force gradient or change in force for compressions and/or decompressions could be a percentage (e.g., 20%, 25%, 30%, 35%, 45%, or less than 50%) of the previous measured force value. Exceeding that maximum threshold of force and/or force gradient for compressions and/or decompressions may provide an indication that the acute care provider 10 is in danger of injuring the patient 12.
If the measured force and/or change in measured force (force gradient) exceeds the maximum threshold, the processor 152 can be configured to adjust the magnitude of the target depths to patient-specific depths for remaining scheduled chest compressions of the initial compression protocol, as shown at step 716. For example, the processor 152 may reduce the magnitude and/or slope of a target compression depth to patient-specific depths (e.g., due to an indication that an excessive force or force gradient has been measured) for some or all remaining chest compressions of the protocol or a limited number of remaining chest compressions by a selected amount (e.g., reduce a magnitude of the scheduled target depth by 5%, 10%, 15% or another amount). In some examples, changes to the scheduled target compression depths for remaining chest compressions of the protocol can be linear or non-linear. In that case, the adjustment could include increasing or decreasing the scheduled target depth by a predetermined amount for each remaining chest compression, so that a relatively continuous linear or non-linear relationship between the chest compressions is maintained. In other examples, the adjustment could include increasing or decreasing the magnitude of the compression depth for only a few chest compressions and then returning to the predetermined scheduled target depths for other remaining chest compressions of the initial compression protocol.
As discussed previously, the processor 152 can be configured to automatically update the user display or dashboard to include the adjusted patient-specific target compression depths. Once the display 128 and user interface 310 are updated, the acute care provider 10 can proceed to provide chest compressions in accordance with the adjusted or patient-specific target depths.
In some examples, adjustments of the magnitude of the scheduled target depths to the patient-specific depths for the remaining chest compressions of the initial compression protocol is based on an estimated or measured chest compliance for the patient. Chest compliance can be estimated based on estimated force and estimated displacement for one or more preceding chest compressions.
The processor 152 can also be configured to increase the scheduled target depths for the remaining chest compressions of the initial compression protocol, so that the final target depth is achieved more quickly. The determination of when to increase compression depth more quickly than scheduled can also be based on force measurements. For example, in step 718, if the measured force and/or force gradient does not exceed respective maximum thresholds, then the processor 152 is configured to determine if the measured force and/or force gradient is below a respective minimum threshold. Similar to the measure of the maximum threshold, the minimum threshold for force could be a predefined limit (e.g., a force of less than 10 kg, less than 5 kg, or a force between 1 kg and 5 kg). In an alternative example, the minimum threshold of force gradient or change in force could be a percentage (e.g., 20%, 25%, 30%, 35%, 45%, or greater than 50%) of the previous measured force value. A substantial decrease in measured force for compressions of the same depth may indicate that the patient's chest is stretching or acclimating to the compressions, indicating that deeper compressions could be performed without causing injury to the patient.
If the measured force and/or force gradient is not below the minimum threshold, then the processor 152 may be configured to provide guidance to the acute care provider 10 instructing the acute care provider 10 to continue performing chest compressions at scheduled target depths according to the initial compression protocol, as shown at step 722. However, if the measured force and/or force gradient is below the threshold, at step 720, the processor 152 may be configured to adjust scheduled target depths to patient-specific depths for remaining chest compressions so that the final target compression depth is achieved faster. That is, the patient's chest may have quickly acclimated to the force of compressions, meaning that it may be preferable to move on from the ramp up period of compressions in order to move blood more effectively through the circulatory system.
As a further example, in order to determine how the patient-specific target depth may vary and, in particular, whether the chest has been sufficiently softened during the ramp up period, the processor 152 may be configured to track how the peak force changes for the patient over time or per compression. Initially, during the start of compressions, the patient's thorax may be relatively stiff, meaning that the peak compression force may be at its highest point during the course of the resuscitation. Over time, as more compressions are applied, the patient's chest may be softened and the measured peak compression force may decrease to a point where it reaches a mechanical steady state. Once this mechanical steady state has been reached, it may be determined that the patient's thorax has been adequately broken-in, such that the caregiver can then move on from the ramp up period to the final target depth of compressions. Accordingly, when the slope of the maximal (peak) compression force reaches a value that is less than a predetermined threshold (e.g., less than 10 pounds/minute), the processor 152 may be configured to provide a signal to indicate to the caregiver that sufficient break-in of the patient's chest has been achieved and that the caregiver may proceed to the final target depth. Similarly, the slope of the instantaneous compliance may also be used to determine whether the patient's chest has been sufficiently broken-in.
At step 724, the processor 152 is configured to provide feedback instructing the acute care provider 10 to provide chest compressions according to the adjusted protocol including the patient-specific target compression depths. As discussed previously, the feedback can be haptic, audible, or visual. For example, the feedback may comprise adjusting the appearance of the CPR dashboard 312, shown in
While not shown in
As shown in
With reference to
A variety of different types of automated chest compressors 812 may be used with the systems 810. Automated chest compressors 812 generally comprise a compression surface, such as a belt 814 or pad 816, configured to be positioned on the patient's chest 14. The automated chest compressor 812 further comprises a driver configured to move the compression surface in a first direction to compress the patient's chest 14 and in a second direction to release the patient's chest 14. As described in further detail herein, the driver can be, for example, a motor 818, such as a belt-tensioner, for rotating a spindle (shown in
In some examples, the system 810 further comprises sensors for monitoring the performance of the chest compressions and/or a condition of the patient 14. For example, the system 810 can comprise a displacement or depth sensor 820 configured to directly measure distance traveled by the patient's chest 14 and/or the compression surface (e.g., the belt 814 or pad 816) to estimate a depth and/or decompression height for the chest compression. In some examples, the displacement or depth sensor 820 can be configured to measure a distance traveled by the piston 862 (shown in
The system 810 further comprises a force sensor 822 configured to sense force information for chest compressions. For example, the force sensor 822 can be a strain gauge, pressure sensor, or similar suitable electronic sensing device positioned on the patient's chest 14 configured to detect forces applied to the chest by the compression surface (e.g., the belt 814 or pad 816).
The system 810 can further comprise patient physiological sensors 828 for monitoring a condition of the patient 12 as chest compressions are being performed. As discussed previously, physiological sensors 828 can comprise, for example, cardiac sensing electrodes, ventilation sensor(s), and/or sensors capable of providing signals indicative of vital sign(s) of the patient 12, such as electrocardiogram (ECG), blood pressure (e.g., invasive blood pressure (IBP), non-invasive blood pressure (NIBP)), heart rate, pulse oxygen level, respiration rate, heart sounds, lung sounds, respiration sounds, end tidal CO2, saturation of muscle oxygen (SMO2), arterial oxygen saturation (SpO2), cerebral blood flow, electroencephalogram (EEG) signals, brain oxygen level, tissue pH, tissue oxygenation, or tissue fluid levels
Automated chest compressors 812 are configured to provide automated chest compressions to the patient 14 according to certain settings (e.g., chest compression parameters) including, for example, compression depth, decompression height, compression rate, compression force, compression hold time, release velocity, downstroke acceleration, downstroke velocity, lift displacement, lift force, upstroke acceleration, and upstroke velocity. Automated chest compressors 812 generally utilize pre-programmed values for various chest compression parameters. For example, device manufacturers may determine suitable pre-programmed values for parameters, which can be stored in on-board memory of the chest compressor 812. In some examples, automated chest compressors 812 comprise user interfaces that allow users to select or adjust these pre-programmed values. In that case, the chest compressor 812 can include a feedback unit 824 comprising, for example, a display screen 826 showing an acute care provider (not shown in
In some case, these parameters may not be adjustable by the acute care provider once chest compressions commence, to avoid causing a distraction during treatment of the patient 14. If the settings or parameters cannot be adjusted during treatment, the feedback unit 824 or display screen 826 may be turned off to avoid causing confusion and/or anxiety for the acute care provider. In particular, providing feedback for non-adjustable parameters may undesirably lead the acute care provider to interfere with the delivery of the chest compressions in an unnecessary attempt to change these parameters.
The systems 810 further comprise controllers 850 for controlling operation of the automated chest compressor 812 and, in some cases, for providing feedback to the acute care provider. For example, the feedback unit 824 can comprise a controller 850, comprising a computer processor 852 and memory 854, configured to control operation of the chest compressor 812. In some examples, the processor 852 and memory 854 are configured to cause the driver (e.g., the motor 818 for driving the spindle or piston) of the chest compressor 812 to move the compression surface (e.g., the belt 814 or pad 816) in the first direction, such as a vertically downward direction, until a signal received from the displacement sensor 820 indicates that the compression surface has moved a sufficient distance to perform a chest compression according to the device settings or compression parameters. Once the compression depth is reached, the processor 852 and memory 854 can be configured to cause the driver, such as the motor 818, to move the compression surface in the second direction, such as a vertically upwards direction, to a target decompression height identified based on the signal from the at least one displacement sensor 820. For standard chest compressions, there is effectively no decompression height. For active chest compressions/decompressions, the decompression height can be a selected distance above the neutral or initial position for the chest compression.
In some examples, the automated chest compression systems 810 are configured to provide chest compressions according to an initial compression protocol, such as one of the initial compression protocols shown in
The processor 852 and memory 854 can also be configured to adjust the initial compression protocol during performance of the chest compressions to provide chest compressions at patient-specific depths and/or patient-specific decompression heights. For example, during performance of compressions by the automated chest compressor 812, the processor 852 and memory 854 can be configured to receive and process sensed force information from the force sensor 822 to estimate force applied to the chest 14 during the chest compressions. The processor 852 and memory 854 are further configured to adjust a magnitude of the scheduled depths for chest compressions to patient-specific depths for the remaining chest compressions of the initial compression protocol. The adjustment is based, at least in part, on the estimated force applied to the patient's chest during preceding chest compressions of the plurality of chest compressions. For example, as discussed previously, the processor 852 and memory 854 may be configured to compare force measurements for previous chest compressions to threshold minimum or maximum force values to determine whether to adjust the scheduled compression depth to patient-specific compression depths. The processor 852 and memory 854 may also be configured to adjust the scheduled compression depths based on a percentage change in measured force between preceding chest compressions. When the automated chest compressor 812 is used to provide active compression/decompression for the patient 12, the processor 852 and memory 854 can be configured to adjust the scheduled decompression height to a patient-specific decompression height for remaining decompressions based on force measurements, in a similar manner.
Having described components of automated compression systems 810 generally, specific features of different chest compression devices will now be described in detail. With specific reference to
As shown in
In some examples, the displacement sensor 820 is mounted to the compression belt 814, as shown in
With reference to
The piston-based chest compressor 812 comprises a piston 862, a piston driver 864 coupled to the motor 818 (shown in
The piston-based chest compressor 812 further comprises the controller 850, which can be in the same housing 870 as the motor 818, or in a separate device, such as the feedback unit 824. The controller 850 comprises electronic circuitry, such as the processor 852 and the memory 854 (shown in
In some examples, the system 810 further comprises an adhesive pad 872 releasably adhered to the skin of the patient 12 for insulating the chest 14 from the compression forces of the piston 862 and, particularly, for distributing the forces over a greater area of the chest 14. The adhesive pad 872 can comprise a liner and an adhesive face. The liner can be configured to be removed or peeled away from the adhesive face by the acute care provider (not shown in
During operation of the compressor 812, the compression pad 816 contacts the adhesive pad 872 during performance of the chest compressions. Following completion of the chest compression, the acute care provider 10 may remove the adhesive pad 872, for example, by applying a solvent to the adhesive pad 872 and/or peeling the adhesive pad 872 away from the patient's chest 14. In some examples, one or more of the sensors, such as the displacement sensor 820 and/or force sensor 822, for detecting information about the chest compressions may be mounted to or embedded in the adhesive pad 872. The patient physiological sensors 828 may also be positioned in the adhesive pad 872. The sensors 820, 822, 828 may be coupled to controller 850 via a wired and/or wireless connection, such as a wire 874 extending from the adhesive pad 872 to the feedback unit 824. In some examples, the physiological sensor 828 may be a component of a defibrillation electrode assembly and/or used in conjunction and/or coordination with a defibrillation electrode assembly for providing defibrillation treatment to the patient.
As previously discussed, the manual or automated chest compression systems can be configured to adjust scheduled values for compression depth and/or rate of the chest compression protocol based on force measurements detected by the force sensors 822. Graphs showing initial chest compression protocols 902a, 902b, 902c, 902d, 902e modified based on the force measurements are shown in
With continued reference to
Accordingly, at the point in time represented by line 910, the processor 852 and memory 854 can be configured to cause the automated chest compressor 812 to adjust the scheduled compression depths for the remaining compressions of the compression protocol from scheduled depths (shown by dashed line 916) to patient-specific depths (shown by line 918) for remaining chest compressions. As shown by the force graph 906, the force measurements begin to increase in response to adjusting the scheduled depths to the patient-specific depths. Adjusting the initial compression protocol 902a to include the patient-specific depths (line 918) causes the initial compression protocol 902a to reach the final target depth (shown by line 920) in a shorter amount of time than provided by the predetermined scheduled depths before the benefit of the force measurements (shown by lines 914 and 916). Beneficially, the shorter initial compression protocol or ramp up period is achieved with minimal risk of injury to the patient 12, as indicated by the force measurements in the force graph 906, while also retaining the structural integrity of the patient's chest 14, which will allow for efficient chest compressions throughout the performance of the chest compressions.
Lastly, after the final target compression depth 920 is reached, at a time shown by the vertical line 912, the force continues to decrease. This decrease in force is expected, as the patient's chest 14 further acclimates to chest compressions applied at the final target compression depth 920. However, as the final target compression depth has already been achieved, the automated chest compressor 812 would not adjust the depth of chest compressions at this point.
As shown in
As discussed previously, the adjustment from the scheduled depths to the patient-specific depths is based on measured forces shown in the force graph 928 and, in particular, the changes in measured forces at periods of time indicated by vertical lines 938, 940, 942. The vertical line 938 represents a point in time in which the measured forces begin a slight downward trend, as shown in the force graph 928. At a point in time represented by the vertical line 940, the measured force continues to decrease. This decrease or drop-off in the measured force indicates that the chest compressions could still be achieving a deeper compression depth. Accordingly, the processor 852 and memory 854 can be configured to adjust the scheduled target depths for the remaining chest compressions to patient-specific target depths for remaining compressions. Applying chest compressions at the increased patient-specific target depths allows the chest compressor 812 to achieve the final target compression depth, shown by line segment 944, much faster than would have been possible following the predetermined initial compression protocol, shown by segment line 932.
With reference to
Adjusting the target compression depth as shown in
In other examples, a more dynamic algorithm may be employed to periodically adjust a slope of the line representing the target compression depths for the initial compression protocol (referred to herein as the “ramp up slope”) so that a drastic jump in the target chest compression depth does not occur at the time Timemax. For example, the processor 852 and memory 854 may be configured to employ a dynamic estimation of the ramp up slope and time to a final target compression depth 980 to provide a smooth transition to the final target depth 980 after the ramp up period. The dynamic estimation of the ramp up slope (shown in
As show in
Methods for Implementing Initial Compression Protocols with Automated Chest Compressors
With reference to
Conversely, if the final target compression depth is not yet achieved, at step 1014, the processor 852 and memory 854 are configured to compare the measured force and/or a change in the measured force (e.g., the force gradient) for preceding chest compressions to a respective maximum threshold force and/or force gradient. The maximum threshold force and/or force gradient can be a maximum amount of force or maximum gradient that can be safely applied to the patient's chest 14 without causing injury to the patient 12. If the measured force and/or force gradient exceeds the maximum threshold force, force gradient, or combination thereof, the processor 852 and memory 854 are configured to decrease the magnitude of scheduled compression depths to patient-specific depths for the remaining compressions of the initial compression protocol 902a, 902b, 902c, 902d. For example, the processor 852 and memory 854 may decrease a rate (e.g., slope of the line representing the initial compression protocol) at which the target depth gradually increases for remaining compressions of the initial compression protocol 902a, 902b, 902c, 902d, as shown at step 1016.
If the measured compression force and/or force gradient for the preceding chest compression does not exceed the respective maximum threshold force and/or force gradient, at step 1018, the processor 852 and memory 854 then compare the measured force and/or force gradient to a respective minimum threshold force and/or force gradient. As discussed previously, applying chest compressions below the minimum threshold force and/or force gradient may be undesirable, since compression depth could be increased to achieve the final compression depth more quickly, without causing injury to the patient 12. If the measured force and/or force gradient is less than the respective minimum threshold force and/or force gradient, the processor 852 and memory 854 are configured to increase the scheduled compression depth to deeper patient-specific compression depths for the remaining chest compressions of the initial compression protocol 902a, 902b, 902c, 902d, 902e. For example, at step 1020, the processor 852 and memory 854 may be configured to increase a rate/slope at which the patient-specific compression depth gradually increases for the remaining chest compression of the initial compression protocol 902a, 902b, 902c, 902d, 902e. Conversely, if the measured force and/or force gradient for the preceding chest compressions is not less than the respective minimum threshold force and/or force gradient, the processor 852 and memory 854 may not adjust scheduled depths for the chest compressions of the initial compression protocol 902a, 902b, 902c, 902d, 902e and, instead, at step 1022, cause the automated chest compressor 812 to continue applying chest compressions according to the chest compression protocol 902a, 902b, 902c, 902d, 902e.
As shown in
While not shown in
As will be appreciated by those skilled in the art, the processes and methods for implementing initial compression protocols and for determining patient-specific compression depths described herein can be implemented in digital electronic circuitry, or in computer hardware, firmware, and/or software. Further, features of the apparatuses described herein, including ACD devices, automated chest compressors, feedback units, medical devices, and chest compression feedback devices, can be implemented in a computer program product tangibly embodied in an information carrier, e.g., in a machine-readable storage device for execution by a programmable processor; and method steps can be performed by a programmable processor executing a program of instructions to perform functions of the described implementations by operating on input data and generating output. The described features can also be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device.
Some of the configurations described herein are described as a process depicted as a flow diagram or block diagram. Although each flow diagram or block diagram may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may have additional stages or functions not included in the figures. Furthermore, examples of the methods may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or microcode, the program code or code segments to perform the tasks may be stored in a non-transitory processor-readable medium such as a storage medium. Processors may perform the described tasks.
In the figures, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the configurations. This description provides example configurations only, and does not limit the scope, applicability, or configurations of the claims. Rather, the preceding description of the configurations will provide those skilled in the art with an enabling description for implementing described techniques. Various changes may be made in the function and arrangement of elements without departing from the scope of the disclosure.
The computer memory described herein can refer to internal computer memory, such as dynamic computer memory, as well as to computer storage devices and systems, as are known in the art. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. Common forms of physical and/or tangible processor-readable may further comprise a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read instructions and/or code.
The controllers and processors disclosed herein may be part of a computer system that includes a back-end component, such as a data server, or that includes a middleware component, such as an application server or an Internet server, or that includes a front-end component, such as a client computer having a graphical user interface or an Internet browser, or any combination of them. The components of the systems described herein can be connected by any form or medium of digital data communication such as a communication network. Examples of communication networks include a local area network (“LAN”), a wide area network (“WAN”), peer-to-peer networks (having ad-hoc or static members), grid computing infrastructures, and the Internet. The computer system can include clients and servers. A client and server are generally remote from each other and typically interact through a network, such as the described one. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.
Having described several example configurations, various modifications, alternative constructions, and equivalents may be used without departing from the disclosure. For example, the above elements may be components of a larger system, wherein other rules may take precedence over or otherwise modify the application of aspects of the present disclosure. Also, a number of operations may be undertaken before, during, or after the above elements are considered. Also, technology evolves and, thus, many of the elements are examples and do not bound the scope of the disclosure or claims. Accordingly, the above description does not bound the scope of the claims.
The following experimental examples are presented to demonstrate the general principles of embodiments of the present disclosure. The present disclosure should not be considered as limited to the specific examples presented. These experimental examples show how a series of initial chest compressions impact different patients. Differences in force and depth measurements for initial chest compressions show differences in how patients' chests acclimate to the chest compressions. These experimental measurements demonstrate the need for providing an initial compression or ramp up period for chest compressions, as provided by the methods and systems disclosed herein.
The graphs in
Conversely,
This application is the United States national phase of International Application No. PCT/US2021/039110 filed Jun. 25, 2021, and claims priority to U.S. Provisional Patent Application No. 63/045,402 filed Jun. 29, 2020, the disclosures each of which are hereby incorporated by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/039110 | 6/25/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63045402 | Jun 2020 | US |
