Patent Application
20230255537
The present disclosure is directed generally to systems for simulating cardio-pulmonary resuscitation (CPR) contamination of electrocardiogram signals.
Patient physiological signal simulation is commonly used in the medical community (e.g. manufacturers, hospitals, research facilities) to reproduce real-life scenarios for creating new devices and algorithms, or as training tools for physicians and/or paramedics to acquire realistic experience in a controlled environment. In the realm of electrocardiogram (ECG) signals, Automatic External Defibrillator (AED) manufacturers obtain field data from their distributed AEDs, but the collected data is often corrupted or noisy. This noise and/or corruption may be caused by numerous factors, such as patients' physiological status, environment factors, pad imbalance, etc. In addition, acquiring such patient data may require a high degree of administrative work.
Currently, AED users, mainly paramedics and emergency medical personnel, often ignore voice prompts from the device because of either a conflict between the AED audio instruction and their current medical practices or confusion with the use of the device. Thus, AED users continue to perform CPR during an analyzing period. As a result, the ECG analysis algorithm may not accurately identify the ECG rhythm and consequently delays defibrillation therapy. This delay can significantly impact patient survival rate and recovery. Moreover, it is difficult to generate and collect sample data, and the collected data usually contain undesired artifacts, adding levels of sophistication and impeding the development of algorithms.
There have been efforts in developing more realistic biosignals during CPR, but such signals have been digitally simulated. Digital simulation typically ignores some of the stochastic nature of the signal and reduces the realism of the signal. Therefore, there is a need for simulation devices that can accurately and consistently replicate ECG and impedance signals undergoing physiological changes due to CPR.
The present disclosure is generally directed to CPR-artifact simulation systems, methods, and apparatus. These systems may serve as usability-testing tools for new algorithms by contaminating simulated ECG signals in a manner representative of how CPR changes a body's thoracic impedance. Currently, heart-rhythm simulation devices may generate a large variety of noise-free ECG waveforms. However, a robust algorithm requires corrupted signals that closely resemble real-life situations. The disclosed systems can generate both corrupted ECG signals and impedance signals, resembling all possible signals by the AED. Furthermore, by using only analog systems, this invention can produce realistic CPR corrupted ECG signals that physically correlate with the impedance signal being recorded on the system. Additionally, the disclosed analog systems provide greater versatility than corresponding digital systems. The analog systems may be implemented with other simulation systems, simulation devices, or manikins without the complexity of digital interfacing, as analog interfacing may be achieved through a simple adapter.
Generally, in one aspect, an electrical system, method, and apparatus for generating a CPR-corrupted ECG signal is provided. The electrical system may include an ECG signal generator electrically coupled to a first contact of an AED. The electrical system may further include a backend circuit. The backend circuit may include a potentiometer. The potentiometer may be electrically coupled to the ECG signal generator and a second contact of the AED. A user input is configured to adjust an impedance of the potentiometer.
According to an example, the backend circuit may further include a divider impedance circuit electrically coupled to the potentiometer. The divider impedance circuit may form a voltage divider circuit with the potentiometer. The backend circuit may further include a reference voltage circuit electrically coupled to the divider impedance circuit and the potentiometer.
According to an example, the divider impedance circuit may include one or more resistors.
According to an example, the reference voltage circuit may include a DC voltage source.
According to an example, the reference voltage circuit may further include a regulator circuit. The regulator circuit may be a Zener diode shunt regulator circuit.
According to an example, the backend circuit may further comprise a potentiometer adjustment circuit electrically coupled in parallel to the potentiometer. The potentiometer adjustment circuit may include one or more resistors.
Generally, in another aspect, an electromechanical system, method, and apparatus for generating a CPR-corrupted ECG signal is provided. The electromechanical system may include an ECG signal generator electrically coupled to a first contact of an AED. The electromechanical system may further include a backend circuit. The backend circuit may include a potentiometer. The potentiometer may be electrically coupled to the ECG signal generator and a second contact of the AED. The electromechanical system, method, or apparatus may further include a compression mechanism. The compression mechanism may be configured to receive a vertical force. The compression mechanism may also be configured to adjust an impedance of the potentiometer according to the vertical force.
According to an example, the backend circuit may further include a divider impedance circuit electrically coupled to the potentiometer. The divider impedance circuit may form a voltage divider circuit with the potentiometer. The backend circuit may further include a reference voltage circuit electrically coupled to the divider impedance circuit and the potentiometer.
According to an example, the compression mechanism may include a rack having a plurality of teeth and an initial position. The rack may be configured to translate to a second position according to the vertical force. The compression mechanism may further include a gear with a plurality of teeth engaged with the teeth of the rack such that the gear rotates according to the translation of the rack.
According to an example, the rack may be configured to translate from the second position to the initial position after the application of the vertical force.
According to an example, the potentiometer may be a rotary potentiometer having a shaft coupled to the gear such that the rotation of the gear adjusts the impendence of the potentiometer.
Generally, in another aspect, an electromechanical system, method, and apparatus for adjusting the impedance of a circuit is provided. The electromechanical system may include a potentiometer. The electromechanical system may include a compression mechanism. The compression mechanism may be configured to receive a vertical force. The compression mechanism may be further configured to adjust the impedance of the potentiometer according to the vertical force.
According to an example, the compression mechanism may include a rack having a plurality of teeth and an initial position. The rack may be configured to translate according to the vertical force. The compression mechanism may further include a gear with a plurality of teeth engaged with the teeth of the rack such that the gear rotates according to the translation of the rack.
It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.
These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.
In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments.
The present disclosure describes various embodiments for systems for simulating CPR corruption of ECG signals. More generally, Applicant has recognized and appreciated that it would be beneficial to provide systems to generate CPR-corrupted ECG signals using an electromechanical device to model CPR administered by a first responder. These systems may be used as a usability testing tool to validate new defibrillator algorithms, functionality, or systems by (1) recognizing the rate, depth, onset, and offset for CPR, (2) analyzing corrupted ECG rhythms during CPR, and (3) evaluating CPR quality. These systems may also be used to enhance functionality and quality of a manikin product for medical training and usability testing by providing a CPR-corrupted ECG signal and a thoracic impedance signal as feedback that correlates with how the CPR is being performed.
Referring to
The electrical system 100 may further include a backend circuit 400. The backend circuit 400 may include a potentiometer 130. Potentiometer 130 is shown in
A user input 250 is configured to adjust an impedance of the potentiometer 130. In an example explained in greater detail below, the user input 250 may be downward thrust as would be performed by a first responder during CPR. A device, such as a compression mechanism 190 described in greater detail below, may then adjust the impedance of the rotary potentiometer by actuating its shaft. The potentiometer 130 may have an impedance range from 0 to 30 ohms. In one example, and as shown in
According to an example, the backend circuit 400 may further include a divider impedance circuit 140 electrically coupled to the potentiometer 130. The divider impedance circuit 140 may include one or more resistors. The one or more resistors may in serial and/or parallel configuration. As shown in
The backend circuit 400 may further include a reference voltage circuit 160 electrically coupled to the divider impedance circuit 140 and the potentiometer 130. The reference voltage circuit 160 may include a DC voltage source. The reference voltage circuit may further include a regulator circuit 170. The regulator circuit may be a Zener diode shunt regulator circuit. In an example shown in
According to an example, the backend circuit may further comprise a potentiometer adjustment circuit 180 electrically coupled in parallel to the potentiometer 130. The potentiometer adjustment circuit 180 may include one or more resistors. In the example shown in
In a further example, the electrical system 100 may further include an overvoltage circuit to protect the backend circuit 400 during the application of electric shock in defibrillation. In an example, the overvoltage circuit may include a gas discharge tube (GDT) and/or a transient voltage suppressor (TVS). In the event of delivering an electric shock into the system, the GDT and/or TVS may be activated to shunt excess transient current back to the AED 120 to reduce excess current in the backend circuit 400. In an example, the ECG signal generator 110 may be designed to withstand normal defibrillation without damage to its internal components. In this way, the ECG signal generator 110 may be used to reduce the electrical load on the other electrical components of the circuit.
As described above,
Further, the change in the output voltage level of the system 100 may be calculated as equation 2 below:
Referring to
The electromechanical system 200 may further include a backend circuit 400. The backend circuit 400 may include a potentiometer 130. The potentiometer 130 may be electrically coupled to the ECG signal generator 110 and a second contact 124 of the AED 124.
The electromechanical system 200 may further include a compression mechanism 190. The compression mechanism 190 may be configured to receive a vertical force, such as a downward thrust as would be performed by a first responder during CPR. The compression mechanism 190 may also be configured to adjust an impedance of the potentiometer 130 according to the vertical force.
Referring to
According to an example, the potentiometer 130 may be a wire-wound, rotary potentiometer having a shaft 260 coupled to the gear 230 such that the rotation of the gear 230 adjusts the impendence of the potentiometer 230. The potentiometer 130 may have a rotational range of 300 degrees. In an example configuration, a 5 cm translation of the rack 210 may result in 1 ohm of impedance change due to rotation of the shaft 260 of the potentiometer 230. The amount of impedance change per distance of rack translation may be controlled by a variety of factors including, but not limited to, the diameter of the gear 230, the impedance range of the potentiometer 130, and/or the impedance of the potentiometer adjustment circuit 180.
To facilitate the rotation of the shaft 260 of the potentiometer 130, the potentiometer 130 may sit in a potentiometer holder, as shown in
The rack 210 may be further configured to translate from the second position to the initial position after the application of the vertical force. This reflex response may be configured to mimic decompression of the human thorax during CPR following a downward thrust. In other embodiments, the rack 210 may be configured to translate from the second position to a third position, wherein the third position differs from the initial position.
According to an example, the backend circuit 400 may further include a divider impedance circuit 140 electrically coupled to the potentiometer 130. The divider impedance circuit 140 may form a voltage divider circuit 150 with the potentiometer 130. The backend circuit 400 may further include a reference voltage circuit 160 electrically coupled to the divider impedance circuit 140 and the potentiometer 130.
Referring to
According to an example, the potentiometer 130 may be a wire-wound, rotary potentiometer having a shaft 260 coupled to the gear 230 such that the rotation of the gear 230 adjusts the impendence of the potentiometer 130. The potentiometer 130 may have a rotational angle of 300 degrees.
The electromechanical system 300 may be configured to be installed in a manikin. Rack 210 may be clipped onto a plastic arch of a rib-piece of the manikin. When a user performs CPR on the manikin, the rib-piece and plastic arch may be pushed down so as to also slide the rack 210 down the potentiometer holder. The potentiometer holder may be secured in the manikin using epoxy.
To protect the potentiometer 130 from over-rotation, the electromechanical system 300 does not utilize the full rotation of the rotary potentiometer. In one example, the compression system 190 allows for 280 degree rotation of the gear 210 and the shaft 260 of the potentiometer 130.
Referring to
The system 600 is connected in series with a defibrillator analyzer 650 in order to sum voltage and resistance variations into a signal from the defibrillator analyzer 650 seen by the AED 610. With a standard 2 inch CPR compression stroke on a CPR mannequin chest, the system 600 shown is designed to add 0.5 mV peak-to-peak to the signal from the defibrillator analyzer 650, with the added voltage dependent on the instantaneous depth of a CPR compression stroke. The system 600 shown is also designed to add 1 ohm peak-to-peak to the resistance presented by the defibrillator analyzer 650, with an analogous dependence on the CPR stroke. The voltage and resistance variations are designed to be correlated.
As described above, the means of conversion of mechanical motion of the CPR mannequin chest to an electrical variation is by way of a potentiometer 620. The instantaneous resistance value of the potentiometer 620, in parallel with another passive resistor 630 to lower the overall resistance value, serves as both the direct resistance variation of the system 600, and also as part of a voltage divider, which divides a reference voltage by a (relatively large) ratio to provide the system 600 voltage variation. As shown in
The system 600 also includes protection from a shock delivered by the AED 610 to the series connection of the defibrillator analyzer 650 and the system 600. The protection is in the form of shunt anti-parallel diodes 640, for bidirectional protection. The shunt diodes 640 are intended to divert a high current defibrillation pulse from the remainder of the system 600, while clamping the voltage seen by the remaining circuit to the peak forward voltage of the diodes 640 during the pulse. In normal operation (rather than during a shock event), the voltage and resistance across the shunt diodes 640 is very low, and so the shunt diodes 640 have negligible impact on the system 600.
Selection of specific appropriate diodes 640 may be left to a user, beyond guidance that the diodes 640 must be capable of handling the peak defibrillation current and overall defibrillation current pulse, and must be fast enough to conduct the defibrillation current pulse without excess instantaneous voltage during the pulse.
Referring to
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.
It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.
In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively.
While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/067879 | 6/29/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63049155 | Jul 2020 | US |
