Patent Application
20150257972
The present disclosure relates generally to patient support surfaces and more particularly to methods and apparatus for providing emergency cardiopulmonary resuscitation (CPR) functions on a patient support surface.
Various apparatuses are known in the art for supporting patients. For example, some hospital and other beds include a mattress with a frame that is configured to raise and lower. Some such support apparatuses have a frame that can articulate and includes a back section, a seat section, and a leg section, each of which may be pivotable relative to one or more of the other sections. Often, the hospital beds employ linear actuators, which include motors, to lift and articulate the bed frame to various positions.
When the beds are connected to alternative current (AC) power and are functioning properly, software is used to control the position of the motors and thus the position of the bed. In an event where the clinician needs to initiate CPR or another emergency procedure on a patient in the bed, they will typically press a CPR button or pull a CPR lever and the bed software responds by controlling the motors to a position where the bed is flat and level. In cases where CPR is required but power to the bed is not available or there is an electrical problem with the bed, many beds have a provision for an emergency feature, which mechanically lowers the head of the bed. Most often, this is accomplished by pulling a cable, which releases a clutch on the linear actuator, causing the head motor to fall under gravity until the head of the bed is in a flat position. The limitation to this approach is that the head section is allowed to free fall onto the frame causing a potential for injury to the caregiver pulling the release handle and the patient in the bed due to the pinch points under the head section of the frame. Common feedback from nurses is that they are scared to pull the handle because the head section of the bed comes crashing down so loudly and abruptly.
In addition to increasing the risk of patient and caregiver injury, this back-up CPR method is more costly and requires more space to implement than the same actuator without the release clutch. A linear actuator equipped with a release clutch is approximately 40% more expensive than the same actuator without a release clutch. Additionally, routing the release cable and making room for the physically larger footprint of the actuator with the release clutch poses problems for low bed designs where space for additional components is very limited.
Some designs have attempted to solve the problem of having the head section fall rapidly by adding a gas spring in parallel with the head actuator. The limitations of this system are the additional cost of the gas spring and the space taken by the gas spring. Another limitation to the use of a gas spring is finding a constant that allows the head section to fall with very heavy and very light patients without heavy patients falling too quickly and light patient taking too long to descend to the flat position.
Accordingly, there is a need for improved apparatus and methods for providing CPR functionality on a hospital bed.
This disclosure includes embodiments of patient support apparatuses, control units, and methods.
In accordance with an exemplary embodiment, a patient support surface is provided with an emergency CPR feature that does not require a mechanical clutch to lower the head section of the bed when there is a lack of AC power or an electrical problem with the bed.
By wiring the linear actuator that controls the head section of the bed directly to the battery, CPR can still be achieved when the bed is without AC power or there is an internal failure of the bed electronics or software. Setting a “false bottom” in the software to prevent the batteries from ever completely depleting will ensure that battery power is available in the emergency situations described above. Using the power from the batteries to drive the motor will ensure that the head section is always lowered in a controlled rate of descent and that the head section is not allowed to slam down when the emergency CPR feature is activated.
The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be integral with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially,” “approximately,” and “about” are defined as largely but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art.
The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method that “comprises,” “has,” “includes” or “contains” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps.
Further, a device or structure that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described.
While exemplary embodiments of the present disclosure have been shown and described in detail below, it will be clear to the person skilled in the art that changes and modifications may be made without departing from the scope of the disclosure. As such, that which is set forth in the following description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims, along with the full range of equivalents to which such claims are entitled.
The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. The figures are drawn to scale (unless otherwise noted), meaning the sizes of the depicted elements are accurate relative to each other for at least the embodiment depicted in the figures.
a and 4b (collectively referred to herein as “FIG. 4”) illustrate an exemplary schematic for implementing an emergency CPR feature, wherein
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Combined, these two relay circuits 360 and 362 constitute two pieces of circuitry on a main controller board of the microcontroller 374 that operate together to disconnect the microcontroller 374 from the head motor(s) 211 while, at about the same time (subject to the approximately 2 ms delay of relay circuit 360), also ensuring that the motor(s) 211 get power. The result is, as long as the battery 380 is not damaged, the first portion 210 of the patient support platform 215 will lower, thereby lowering the head of the patient when the mechanical CPR lever 300 is pulled.
Because this system relies on one or more batteries 380 to drive down the head motor 211, it is important that the system always have a reserve of battery power to lower the head section 210 of the bed 50. In certain embodiments, reserve power is maintained by disconnecting battery power from the frame when the available power in the battery 380 drops below a set threshold. In this specific embodiment, reserve battery power is maintained by software action. Controller hardware associated with the frame measures the battery voltage and provides this value to the software. When the voltage drops below a threshold value, the software opens a relay (i.e., a third relay) that disconnects the battery 280 from the rest of the circuit, thereby preventing further usage of the battery except for emergency CPR usage. In an exemplary embodiment, the threshold value is 50% battery capacity. In this way, the microcontroller 374 operates using power from an AC source 376, or using power from both the AC source 376 and the battery 380, unless the battery capacity falls below a threshold value in which case power cannot be drawn from the battery 380 for normal operation of the bed 50, but power may be drawn solely from the AC power source 376 for this purpose. On the other hand, the battery 380 is still available to power the motor 211 when the emergency CPR handle or lever 300 is activated.
A backup CPR system in accordance with the above described embodiments allows CPR to be initiated in the event of power loss or electrical failure without allowing the head section to rapidly descend placing the patient and caregiver at risk for injury or adding significant cost and components to the design. Furthermore, the disclosed embodiments of the backup CPR system reduce the number of components and the complexity of the design so that other features may be implemented or so that lower bed heights may be achieved, thereby benefiting caregivers and patients who use the product.
The various illustrative embodiments of the present devices, apparatus, and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims. For example, embodiments other than the one shown may include some or all of the features of the depicted embodiment.
The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.
It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. It will further be understood that reference to ‘an’ item refers to one or more of those items, unless otherwise specified. The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate.
Where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and addressing the same or different problems. It will be understood that the above description of embodiments is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention.
This is a Continuation-in-Part application in the United States of International Patent Application No. PCT/US2013/067295, filed on Oct. 29, 2013, pursuant to 35 USC §365(c), which in turn claims benefit of priority to U.S. Provisional Application No. 61/719,796, filed on Oct. 29, 2012, the entire disclosures of which are expressly incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61719796 | Oct 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2013/067295 | Oct 2013 | US |
| Child | 14698143 | US |
