Patent Application
20250073104
This Application describes technologies that can be used with inventions, and other technologies, described in a Technical Appendix, hereby incorporated by reference as if fully set forth herein.
Patients and other users who have restricted mobility, or who otherwise have difficulty obtaining comfortable seating, might sometimes be subject to adverse medical conditions, such as pressure sores and/or decubitus ulcers. These conditions, left undetected or untreated, can involve serious adverse consequences, such as loss of muscle mass, serious infection, and even death.
Accordingly, it would be advantageous to provide a device that can be responsive to such patients, is relatively accommodating to user needs or preferences, and is relatively inexpensive in comparison with known devices.
The technologies described herein can also be useful for patients and other users, whether they have restricted mobility or are otherwise fully mobile. When users remain seated, or are otherwise restrained, for an extended period of time (such as being confined to a hospital bed or to a wheelchair), those users might be subject to “seating fatigue”. This can lead to camped muscles, pain, sores, or other discomfort, even for completely healthy persons. For example, persons who participate in extended automobile or airline travel might find it necessary to leave their seats and stretch periodically. But this can be difficult in a moving vehicle or if the user is otherwise temporarily constrained.
Accordingly, it would be advantageous to provide a device that can be responsive to those patients and other users, such as to allow for more extended seating without discomfort and without the user's desire for breaks.
This Application describes devices, and methods for using them, that are disposed to promote healthy blood flow within the body, such as the buttock and leg region when the patient is sitting, or the back region when the patient is lying down or leaning on a support. This can include a pressure controlling cushion and/or support that can automatically balance or offset the user's weight, whether the user continuously and improperly applies their weight to a fixed location, or whether the user applies their weight to an at-risk location, or otherwise as described herein. Pressure can be distributed or redistributed, by inflation/deflation of individual bladders, to dynamically balance or rebalance pressure underneath the user. Thus, if the user applies their weight to a fixed location or an at-risk location, the cushion/support can prevent that weight from impeding the user's blood flow, cramping the user's musculature, or otherwise damaging the user.
The cushion and/or support can also massage the user's musculature to promote blood flow and to reduce seating fatigue. The cushion can select an amount of pressure which is more or less than an amount used for support of the user (thus, a pressure difference). The cushion can select individual bladders to which to apply the pressure difference, thus causing the user to perceive that the pressure difference is effectively massaging the user's musculature. This can have a positive effect on the user's musculature, similar to when the user fidgets or shifts in their seat or gets up and stretches.
The cushion and/or support can reduce pressure load on the user's load bearing points, such as when the user is in a sitting and/or lying down position. This can assist individuals in attaining comfortable seating, in avoiding pressure sores or associated medical conditions, in improving circulation, and in otherwise improving the user's seating comfort. The cushion and/or support can be disposed to aid individuals in the recovery process of healing from a decubitus ulcer, or the process of healing from related medical conditions sometimes resulting from relative immobility. The cushion and/or support can also be disposed to aid otherwise mobile individuals who must remain seated or otherwise relatively motionless for an extended period of time. This can have a positive effect of reducing pain, cramping, or stiffness, when the user maintains substantially the same position for an extended time.
The cushion and/or support can detect changes in amount of pressure applied to each bladder. Thus, when the user fidgets or shifts in their seat, the cushion can detect that movement and measure how often and how extensive is that movement. In one embodiment, the cushion and/or support (or a controller coupled thereto) can predict user movement and adjust the amount of pressure in response to predicted movement. Thus, when the user moves, the cushion and/or support can adjust the pressure associated with one or more bladders to support the user in their new position. If the user does not move for an extended period of time, the cushion and/or support can adjust the pressure to massage the user's musculature, to prevent pressure sores or other adverse medical conditions. If the user gets up from, or sits/lies down on, the cushion and/or support, it can detect this condition and turn on/off in response thereto.
In one embodiment, the device can be disposed to inflate/deflate regions, such as using inflatable/deflatable bladders, supporting the patient, so as to provide (A) therapeutic massaging of affected regions and regions that are subject to possible pressure sores or related medical conditions, (B) comfortable support to muscles and other regions subject to possible pressure sores or subject to pressure from internal bony structures, (C) detection of patient movement, or lack thereof, possibly leading to patient injury, such as from pressure sores or from falling or sliding off the support, (D) detection of inadequate blood flow or other initial signs of pressure sores, possibly leading to patient injury, such as from unhealthy blood flow, muscular pinching, or otherwise as described herein.
In one embodiment, the device can be disposed to receive, maintain, and process, information from the patient with respect to the user's (patient's) sitting (or lying down) behavior. This can have the effect that the devices can be disposed to determine a model of user behavior and one or more optimal methods of treatment suited to the patient. For example, the device can be disposed to determine one or more methods for therapeutic massaging of the patient's body, including determining which methods are best suited to the patient when the patient is relatively active or relatively immobile.
In one embodiment, the device can be disposed to receive information from the patient with respect to pain or related medical conditions. For example, the device can be disposed to respond to the patient's indication of pain with one or more changes in static pressure, or in dynamic pressure adjustments, so as to improve patient comfort and/or to reduce the likelihood of pressure sores or other debilitating medical conditions. For another example, the patient's degree of comfort or discomfort can be inferred by the device in response to a measure of movement levels (or lack thereof) by the patient. For another example, the device can be disposed to respond to the patient's indication of pain with one or more determinations of a severity of the patient's medical condition. For another example, the device can be disposed to receive information from medical personnel, and act on that information, with respect to the patient's medical condition.
In one embodiment, the device can be disposed to alert the patient and/or caregivers that the patient (A) is, or is about to, fall or slide off a support, such as when the patient loses their balance or grip and slides off a seat, (B) is failing to move sufficiently so as to avoid pressure sores or pain, such as when the patient is unable to move about while on a support, such as when the patient has insufficient muscle tone or muscle control, or (C) is otherwise unable to avoid pressure sores or pain and needs assistance, such as from a caregiver. For example, the alert can include an audible or visual alarm, or can include an electronic signal to an external device that is disposed to alert the patient or a caregiver.
In one embodiment, the device can be disposed to automatically turn on in response to the patient sitting down or lying down on the device. Similarly, the device can be disposed to automatically turn off in response to the patient getting up from the device and no longer placing any pressure thereon. This can have the effect that the device can be left in a substantially off state while the patient is not using it, thus using a relatively less amount of power and not degrading the useful life of device components while not in use. This can also have the effect that the device can notify one or more caretakers when the patient lifts themselves up from the cushion, or otherwise gets up from the device.
In one embodiment, the device can be disposed to encourage the patient to lift themselves completely up from the device, thus reducing pressure on the device to zero (or nearly zero); this is sometimes referred to as an “offload exercise”. For example, the device can be disposed to alert the patient and one or more caretakers if the patient has not performed an offload exercise in a selected amount of time. In such cases, the device can include a speaker capable of notifying the patient, preferably in a pleasant manner, to improve their medical condition, such as through better compliance with offload exercises and/or other medical advice.
In one embodiment, the device can be disposed to respond to a user interface in addition to or in lieu of its automatic response to user fidgeting or movement (or lack thereof). For example, the device can be disposed to respond to a user interface on a set of buttons, a touch panel, one or more voice commands, or otherwise as described herein. Thus, the user can configure the device using the user interface to suit the user's individual preferences. The user interface can be wirelessly coupled to the device from a remote control physically separate but still reachable by the user. Moreover, the user interface can be disposed to calibrate and adjust the device so as to account for differences in user size, weight, and firmness preference. The device can also be disposed to determine a map of pressure on the cushion when the user is in a relatively neutral position; this map can be used to calibrate the cushion for the user, and to calibrate control with respect to pressure on specific locations, either generally or specific to the particular user.
In one embodiment, the pressure on each bladder supporting a patient (such as one supporting a region underneath the patient) can be measured concurrently with inflation/deflation of those bladders, notwithstanding that inflation/deflation and pressure affect each other and produce substantially inaccurate concurrent measurements. A software controller can be disposed to inflate/deflate those bladders and to concurrently measure pressure, such as by predicting an actual pressure in response to a measured pressure while inflation/deflation is being performed. Moreover, the device can distinguish a pressure measured for each bladder due to a weight of the patient from a pressure measured for each bladder due to internal gas pressure. The software controller can be disposed to determine the separable amounts of pressure, such as in response to a Kalman filter applied to a set of (possibly unreliable) measurements. This can have the effect that no separate measurement of the patient's location or weight, such as using strain gauges, is involved.
In one embodiment, the device includes deflation apparatus, such as shown with respect to
In one embodiment, the pneumatic solenoid valves and pump mountings can be disposed to mitigate sounds experienced by the user that might be produced by either the positive displacement pump (such as described with respect to
In one embodiment, the pressure cushion system can include a quick-disconnect interface between the cushion component and the pneumatic subsystem. In one embodiment, the quick disconnect interface can include a set of quick-disconnect couplings, such as a set of pneumatic snap-on quick disconnects (such as shown with respect to
In one embodiment, the pressure cushion system can include a user interface, such as a set of touch controls or a program app executable on a smartphone or other mobile device or a console or other wired controller, disposed to provide the user with the ability to control operation of the system. For example, the user interface can provide a display of a pressure map, showing where the user is exerting pressure (or undue pressure, if requested) on the cushion component. For another example, the user interface can provide an alert to the user or to one or more caretakers if the user is about to slide off the cushion component. For another example, the user interface can provide an alert to the user or to one or more caretakers if the user has remained substantially immobile or otherwise is at risk for a medical problem.
In one embodiment, the user interface can be coupled to the pressure cushion system using a wireless connection, such as using a wireless capability of a smartphone or another mobile device. Similarly, the pressure cushion system can couple at least a portion of the cushion component (such as the air bladders, pumping or venting elements, or solenoids coupled thereto) to at least a control portion of the electrical subsystem using a wireless connection.
In one embodiment, the electrical subsystem can be disposed to halt an inflate/deflate operation in response to an error determination, for example, so as to prevent or mitigate overinflation or underinflation. In such cases, pressure data from the bladders may be coupled to the electrical subsystem so as to determine whether one or more bladders are not maintaining pressure within a set of selected limits.
In one embodiment, an additional pressure transducer may be coupled to one or more selected pump or vent lines, so as to allow for fault tolerance. For example, when pressure is added or removed from selected bladders, the value on the additional pressure transducer can be disposed to be compared with a dedicated transducer for the respective bladder. If the difference between the transducers is greater than a selected threshold, the additional pressure transducer can be checked against another selected one of the dedicated transducers; the malfunctioning transducer can be determined; and appropriate action can be taken. A relief valve can also be coupled to one or more selected pump or vent lines, or to one or more selected bladders, so that if overinflation occurs (or is threatened to occur), pressure can be vented to ameliorate the problem.
In one embodiment, a pressure cushion system includes (A) a cushion component, such as shown and described at least with respect to
In one embodiment, the cushion component includes
In one embodiment, the cushion component can be coupled to (or can include) a set of electromechanical elements disposed to be controlled by the control system component, such as one or more of: a set of pumps and vents coupled to the air bladders, suitable for inflating/deflating the air bladders; a set of solenoids disposed to operate the pumps and/or open/close the vents in response to one or more control signals from the control system component; and otherwise as described herein. In such cases, the electromechanical elements can be disposed within the cushion component using rubber mounting, or other forms of mounting suitable to muffle sound and/or reduce an amount of noise experienced by the user when the pressure cushion system is operating.
In one embodiment, the control system component includes
In one embodiment, the pneumatic subsystem can include one or more controlling solenoids for each air bladder, so as to couple a compressor/pump to that air bladder and a vent/exit from that air bladder. The compressor/pump and vent/exit associated with each air bladder can be suitable to inflate/deflate the air bladder under control of the electrical subsystem, such as by a microcontroller operating under suitable software control.
In one embodiment, the pneumatic subsystem can include a set of solenoids, each coupled to one (or more) of the air bladders and disposed to open/close an input (such as from a pump) or an output (such as to a vent/exit) coupled to its associated air bladder. In such cases, each such solenoid can be coupled to a pressure transducer disposed to measure pressure in the air bladders. The pressure transducers can include a set of piezoresistive strain gauges each disposed to be pneumatically coupled to an associated one (or more) air bladder; a differential voltage associated with each one (or more) of the strain gauges can provide information from which pressure in the associated air bladder can be determined.
In one embodiment, the pneumatic subsystem can be disposed to simulate zero pressure with respect to each one (or more) of the air bladders, so as to determine an offset voltage generated by its associated strain gauge. For example, to simulate zero pressure at a bladder, the pneumatic subsystem can be disposed to open a vent/exit from that bladder, or from multiple such bladders at once. The offset voltages might be associated with an ambient environment, imperfect fabrication, or other influences. In such cases, the electrical subsystem, or other controller element, can be disposed to record and maintain the offset voltages and compensate therefor during operation.
In one embodiment, airflow to the cushion component can be controlled using a normally closed solenoid associated with each one (or more) bladder and disposed to receive a voltage to open a value to inflate/deflate that bladder (or multiple such bladders). To open each such solenoid the electrical subsystem can be disposed to receive information from the pneumatic subsystem, so as to detect when the voltage has successfully opened the valve. For example, relevant information can include one or more of: a change in solenoid current in response to actuation; a measurement of current applied to a pump associated with the solenoid; a measurement of pressure at the bladder, such as pressure leading on the valve controlled by the solenoid; or otherwise as described herein. The electrical subsystem can determine an approximate minimum amount of power to apply to the solenoid for the valve, in response to information it receives from the pneumatic subsystem, and can adjust an amount of power it applies when attempting to open the valve.
In one embodiment, a vent/exit from the pneumatic system can be routed into a portion of the cushion component, such as a set of air passages or air cells in the foam element, so as to provide active cooling in areas where the patient is sitting. This can have the effect that the patient's sitting or lying on the cushion component does not unduly heat the cushion component, as active management of the air bladders can provide cooling to those areas being heated by the patient's natural body heat or pressure on the cushion component.
In one embodiment, the electrical subsystem includes a relatively small, relatively low power processor having program and data memory and operating under control of software therein. For example, the program and data memory might be volatile or nonvolatile, combined or separate, internal or external, logically local or logically remote, or otherwise as described herein. When the program memory includes at least a portion that is volatile, the processor can be disposed to receive at least a portion of its program code from elsewhere upon startup. For example, the processor can be coupled to major electrical subsystems, and the program code it executes can be disposed to coordinate one or more electrical subsystems so as to provide efficient and/or safe control of pressures within the air bladders.
In one embodiment, the electrical subsystem can be disposed to receive information from the pneumatic subsystem, such as using electrical signals (such as voltages, other suitable electrical/electronic techniques, or as otherwise described herein). For example, the electrical subsystem can receive information with respect to pressure applied to regions of the cushion component, such as to individual bladders.
In one embodiment, the electrical subsystem can be disposed to measure pressure applied to each one (or more) of the air bladders in response to pressure measured with respect to the pumps and/or vents associated with each associated air bladder. The electrical subsystem can be disposed to obtain an accurate measure of external pressure, notwithstanding that the pressure measured with respect to the pumps and/or vents can be substantially inaccurate. In such cases, the electrical subsystem can include a processor operating under software control. The software can use an artificial intelligence or machine learning technique to determine parameters by which it can provide a substantially accurate measurement in response to relatively inaccurate measurements received from the pumps and/or vents.
In one embodiment, the electrical subsystem can also be disposed to measure a portion of the pressure measured at each associated air bladder in response to the user's sitting or lying thereon, versus a portion of the pressure applied to each associated air bladder in response to the backpressure from the bladder surface. In such cases, the electrical subsystem software can use a Kalman filter, or another suitable technique, applied to a set of individually unreliable information, to obtain a relatively reliable collective evaluation of what portion of the measured pressure is in response to each source.
In one embodiment, the electrical subsystem can also be disposed to apply electrical signals to elements of the pneumatic subsystem to control the latter. For example, the electrical subsystem can be disposed to inflate/deflate each one (or more) air bladders in response to one or more of: user movement; changes in an ambient environment, such as air pressure or humidity; changes in movement of the pressure cushion system, such as when used in a wheelchair being moved over a rough surface, or otherwise as described herein.
In one embodiment, a pressure cushion system (such as shown and described with respect to
In one embodiment, the cushion component can include a sheet (
In one embodiment, the control component can include a pneumatic subsystem (
In one embodiment, the electrical system and main circuit (
The cushion component is arranged for a user to sit upon or lean back upon (when positioned on a chair or other seating or resting surface) or to lie down upon (when positioned on a bed or other lying surface). For example, the cushion component can include (A) a fabric like sheet layer that works to provide form and house the various other aspects of the cushion component, (B) a bladder layer, arranged and coupled to devices so as to sense and respond to pressure from the weight or movement of the user, as described herein, and (C) a foam and or padding layer, arranged to provide a cushion between the user and the bladder layer. The cushion component can also include (D) a command element, arranged to receive input commands from the user, or a caregiver, so as to optimize the user's comfort and minimize any adverse medical conditions that might occur due to the user's relative immobility. The cushion component further can also include (E) a rigidizer or a form of thin rigid structure, typically a piece of wood, that acts as a support for the user to sit on.
In one embodiment, the bladder layer (
In one embodiment, the bladder layer (
In one embodiment, the bladder layer is connected to the control component of the unit (
The air hoses can be welded to the bladders and all of them run through a slit in the back right of the cushion element through the sheet (
In one embodiment, the control component can be disposed to sense the position of the user, possibly over a period of time, and to control the stiffness of individual portions of the cushion component in response thereto, as described herein. For example, the control component can include a computing device, arranged and coupled to elements of the cushion component so as to (A) receive sensory data from the cushion component, and operating under control of software elements arranged to (B) process that sensory data, (C) determine one or more medical conditions associated with the user, (D) determine one or more treatments appropriate to those medical conditions, and (E) control one or more elements of the cushion component to apply those treatments.
In one embodiment, the control component consists of a physical shell containing five (or another number) independently controlled pressurized zones corresponding to associated air bladders (
As further described herein, the control component can dispose individual bladders to support the user, in response to where the user sits, lies, or moves. The cushion can support portions of the user's body when the user sits or lies on the cushion, whether or not the user moves about or is stationary. When the user moves about, whether due to normal movement, due to fidgeting, or due to discomfort or pain, the cushion can detect the user's new position and adjust the amount of inflation/deflation of each bladder to support the user's new position. When there are multiple bladders, as described herein, the control component can adjust the amount of inflation/deflation of each bladder to support the user's body, particularly those hard portions of the user's body such as bony structures that might press upon the user's musculature and lead to pressure sores or other medical conditions.
As further described herein, the control component can adjust the amount of pressure provided by each individual bladder to provide a distinct amount of support to each portion of the user's body. Thus, when the user's weight, particularly those hard portions of the user's body such as bony structures, exerts pressure on the cushion, the pressure provided by each individual bladder can respond by exerting pressure to support the user's body. When the user moves, the pressure provided by each individual bladder can adjust to support the user, such as by dynamically balancing or rebalancing pressure underneath the user.
As further described herein, the control component can also adjust the amount of pressure provided by each individual bladder to massage the user's musculature to promote blood flow and to reduce seating fatigue. Thus, the control component can adjust the amount of pressure provided by each individual bladder to provide a difference in the amount of support to individual bladders, which can be felt by the user as a change in pressure at different places in their musculature. The difference in the amount of support can be a positive/negative pressure difference, which can be moved about to affect different portions of the user's musculature. The pressure difference can be cycled through a sequence of bladders periodically, can be moved about the set of bladders randomly or pseudo-randomly, or otherwise as described herein.
As further described herein, the control component can detect changes in amount of pressure applied to each bladder due to weight applied by the user. The control component can determine one or more patterns of activity associated with the user's movement, such as when the user gets up from or sits/lies back down upon the cushion and/or support, when the user deliberately moves to a new position or when the user is fidgeting, or when the user fails to move for a substantially period of time without having left their seating/resting area.
In one embodiment, the control component can (A) detect a sequence of weights applied by the user's body to one or more of the bladders, (B) determine a pattern of activity being performed by the user in response to that sequence of weights, and can (C) perform one or more actions in response to the detected pattern.
In one embodiment, the valves (
Similar to inflation, the control loop can also manage bag deflation. This can be accomplished using a dedicated relief valve (
In one embodiment of the deflation apparatus (
In one embodiment, the circuit board can receive data on the current state of pressure in the bladders using board mounted pressure transducers (
In one embodiment, to mitigate sounds experienced by the user from electromechanical devices in the control component, both the positive displacement pump (
In one embodiment, the control element can include a primary microcontroller (and any co-processors) operating under control of software disposed to maintain the pressure within the bladders at intended levels. For example, a set of pressure transducers can be disposed to monitor the current pressure in each bladder; if the pressure of a bladder falls outside a selected range (such as exceeding a predefined or an automatically-tuned threshold), the control system can correct this with one or more possible procedures. A duration of each such procedures can be determined by a timer, by watching for pressures to reach a selected threshold, and/or by using the Prediction subsystem outlined in the Machine Learning subsection to halt the procedure at a time for reaching a desired operating pressure.
For example, the control system can open the airway from one or multiple bladders to the pump and apply power to the pump. This state can be maintained for a time, and then the pump may be shut off, and the airway to the bladder/bladders may be closed.
For example, the control system can open the airway from one or multiple bladders to the vent and apply power to the vent. This state can be maintained for a time, and then the vent may be shut off, and the airway to the bladder/bladders may be closed.
For example, the control system can open the airway between multiple bladders by energizing the solenoids attached to both. This will cause the pressures between the bladders to equalize. This state can be maintained for a time, and then the solenoids may be de-energized to cancel the procedure.
In one embodiment, pressure transducers responsible for measuring the pressure of the air bladders might fail to be located directly in the air bladders themselves, or even sufficiently close to those air bladders to provide substantially accurate measurements. For example, the bladders might be located relatively far away from the transducers, with thin, flow-restricting tubing connecting the two pneumatic regions. This can have the effect that when the bladders are inflated/deflated, the distance between where pressure is measured and where pressure is desired to be known, as well as movement of air through these tubes, can cause a substantially difference between measured pressure and actual pressure. Moreover, closing the pneumatic valves used to fill the region while the air is still moving will cause an effect, wherein the momentum of the air will temporarily cause a region of increased pressure downstream and reduced pressure upstream; this can have the effect that the measurement of pressure downstream can differ significantly from measurement of pressure upstream.
As pressure transducers located within the cushion subsystem are not located in the pneumatic area that the control subsystem is trying to control, using the reported pressures without adjustment by the control subsystem can result in incorrect pressure-adjustment behavior. If the control subsystem only causes pumping/venting of a bladder until the measured pressure reaches a selected target, the actual pressure can stabilize at a different value from (above or below) that target, instead of precisely at that target. If it were possible to precisely model behavior of air flow in the cushion component by precisely controlling geometry of air flow of the unit cushion component, it might be possible to use a fixed equation to negate this effect; however, any change in the geometry of the pneumatic pathways to or from the air bladders would likely cause any such fixed equation to be subject to substantially change.
In one embodiment, the control subsystem can use a predictor system to identify a relationship between measured pressure and actual pressure. For example, the predictor system can use an artificial intelligence or machine learning technique to approximate a set of fluid-dynamics equations describing a relationship between measured pressure and actual pressure, such as described herein. This can compensate for differences between pneumatic systems in distinct production units.
In one embodiment, the predictor system can determine a selected function of measurement inputs and a set of weights, so as to provide a predicted measurement. In such cases, the dynamic nature of the selected function can have the effect that particular units selected for the inputs and outputs should not make any substantially difference, so long as those units used do not change during operation, as the predictor system should be able to adapt to whatever units are used.
In one embodiment, input measurements for the predictor can include, but are not limited to, measured pressure at the time of the prediction request, measured pressure prior to the start of the current pump or vent operation, and how much time has elapsed between the start of the pump or vent operation and the time at which the prediction request is made. Other and further input measurements could be used in addition to or in lieu of these selected inputs.
In one embodiment, selected weights can include values selected in response to physical behavior of the unit. For example, weights can be selected in response to iterative backpropagation of measurements, such as described herein. In one embodiment, two separate sets of weights are maintained for each air bladder, one for inflation and one for deflation.
As described herein, an output from the predictor represents the predicted pressure that the bladder will settle to after the current pump or vent operation is terminated. While the predictor is primarily described with respect to pounds per square inch (PSI) measurements provided by the pressure transducers, there is no particular requirement for any such limitation. Any consistent units may be used.
In one embodiment, the particular backpropagation technique for determining the weights can be similar to that described by the following pseudocode. This procedure can be performed substantially every time a pump or vent operation is terminated.
As described herein, this procedure can have the effect of backpropagating the final prediction error back to a correction on each weight, where the correction is proportional to the effect each associated weight had in the final prediction. This can enable a relatively fast convergence rate, requiring only about several hundred cycles to stabilize to reasonable predictions. While this predictor is primarily described with respect to backpropagation, other and further training algorithms may be used in addition or in lieu thereof when they are able to converge to a stable prediction.
In one embodiment, the input measurement values used for prediction start with: the pressure of the bladder at the start of the pump or vent operation (denoted herein as A), the pressure of the bladder at the time of the proposed pump or vent halt (denoted herein as B), and the inverse of the time spent in the operation in seconds (denoted herein as C). For example, a prediction function can include a quadratic function of these parameters, thus:
f(a,b,c,w0,w1, . . . w9)=w0+aw1+bw2+cw3+aaw4+bbw5+ccw6+abw7+acw8+bcw9
For example, the prediction function f( . . . ) is thus responsive to changes in the variable a (in the terms aw1, aaw4, abw7, and acw8), and similarly to changes in the variables b and/or c (in other terms). While the prediction function f( . . . ) is primarily described herein with respect to this one quadratic function, there is no particular requirement for any such limitation. For example, a different quadratic function, a cubic or quartic or another polynomial function, or a function having other or further types of terms or computation could be used. The inventors have found that the particular function f( . . . ) has a preferred degree of prediction power and the number of required samples involved for convergence.
As described herein, in this particular implementation (others may be used), the variable b represents the pressure (provided to the control system from the transducer) that loosely corresponds to the pressure in the bladder at the time. This value can be generally imperfect, as the transducer might be physically located at a substantially different point in the pneumatic system than the pressure the system generally prefers to be measuring. The system generally prefers to be measuring the actual value of the pressure inside the bladder; therefore, it would be advantageous to have a method of refining the value given by the variable b into the actual value of the pressure. The output of f( . . . ) represents this prediction (in the same units as the variable b), and can be used frequently during the operation of the device.
In one embodiment, the weights that this process generates can also be used to monitor the overall performance or health of a pressure cushion system. If parameters of the electrical or mechanical components of the pressure cushion system change over a time duration, this can have the effect of inducing a change in the weights over that time duration. If the weights are observed to change too much (such as, more than a selected threshold) over that time duration, the prediction subsystem can determine that the pressure cushion system has physically degraded too much; the user, one or more caretakers, or the manufacturer, can be alerted.
In one embodiment, when the pressure applied to the transducers is determine to be too low (such as, lower than a selected threshold), or the pump is determined to not affect the pressure when given a chance to for a small period of time, the prediction subsystem can determine that the system is either defective, or can determine that the box assembly has become separated from the cushion assembly. In either such case, the user or one or more caretakers can be alerted.
One class of information that we can get from the control system is regarding the external force applied to the bags of the cushion. With this information many sub-features can be realized. This will first describe some different ways this information could be collected, and afterward we will describe the different ways for the information to be used.
In one embodiment, the system can infer external pressure (force on a user) from a measurement of volume and a measurement of internal pressure (pneumatic pressure). The system can use a valve (such as a solenoid valve) to allow air within a selected volume under test to equalize with another air body (such as a selected air volume) that has a known volume. The system can measure an equilibrium pressure reached by equalizing air pressures. In response to the internal pressure, the volume, and the equilibrium pressure, the system can determine the external pressure.
In one embodiment, the system can keep track of an amount of an expected air mass moved over time. In response to the expected air mass moved and the internal pressure, the system can estimate the external pressure. For example, the system can track the contained air mass by one or more data merging approaches disposed to find agreement in multiple data points received from individual sources that are believed to be unreliable (such as one or more sensors). These data merging approaches may be either statically defined, or they may be dynamic and able to adjust to different observed system behavior. These data merging approaches may also employ a simulated version of the pneumatic system to aid in finding agreement between the unreliable data-points.
Without a direct way to measure the external force applied to the bladders in the cushion, it is possible to build a guess for this value (on a per-bladder basis) which can be refined over time as various sensor readings are collected and combined.
One numerical method that may be used to merge these input hints into a coherent guess is known as a Kalman Filter (alternatively, an Extended Kalman Filter, or one or more other techniques for combining multiple measurements that are only partially certain or trusted into a single trusted measurement) may be used to provide a live prediction of the state of the system in response to one or more such input hints. This state may include pressures, air flows, temperatures, forces, masses, and/or other metrics. Values associated with this state do not necessarily need to be able to be directly measured. For example, this state may be initialized to an expected initial state and allowed to correct itself over time in response to sensor data. The Kalman filter can establish, for each potential input data stream (such as one or more such data streams described herein), a predicted value for that data stream. The Kalman filter can also establish, for each potential input data stream, a relationship between any error seen in the sensor data (thus, one or more differences between perceived and predicted values) and how that error should be propagated to update the predicted value.
While this Application primarily describes merging multiple uncertain information inputs using a Kalman Filter, there is no particular requirement for any such limitation. In alternative embodiments, other and further numerical processes may be used in additional to or in lieu of a Kalman Filter. For example, one such alternative can include Bayesian updates.
Selected uncertain information inputs can include one or more of the following observations. When the predicted value is expected to have a known value (or a value in a known range), the predicted value may be set to this value or range, or alternatively, moved closer thereto; when the predicted value is expected to have a known derivative (or a derivative in a known range) the predicted value may be shifted to match the derivative having the expected value or in the expected range.
One or more known scenarios the pressure cushion system might encounter (for example, when the user sits down on the cushion subsystem, this can cause all or most of the bladder pressures to increase rapidly). One or more known scenarios can also provide hints as to the current state of the external pressure of the cushion. While this Application describes some selected known scenarios, there is no particular requirement for any such limitation; other and further such scenarios, and/or combinations thereof, are also possible. Moreover, information from more than one such scenario can be combined when so identified.
The cushion (or a processor coupled thereto) can be disposed to receive pressure and/or volume information and to determine one or more useful responses thereto.
While this Application primarily describes determining a measure of external pressure (force on the user) in response to the internal pressure (pneumatic pressure on the bladder) using a Kalman Filter or Extended Kalman Filter, there is no particular requirement for any such limitation. In alternative embodiments, other and further numerical processes may be used in additional to or in lieu of a Kalman Filter or Extended Kalman Filter. For example, one such alternative can include Bayesian updates, artificial neural networks or other artificial intelligence techniques, or other techniques described herein.
The cushion can also be disposed to determine information about the user in response to pressure and/or volume information. For example, the cushion can be disposed to:
The cushion can also be disposed to determine information about the bladders or foam, and/or how the user is sitting/laying thereon, in response to pressure and/or volume information. For example, the cushion can be disposed to determine and present (such as in a visual “heatmap”) a set of pressure information at selected locations on the cushion. This can be used to show the user, medical personnel, and/or one or more caregivers, how the user is sitting/laying on the cushion and whether the user's disposition on the cushion is more or less likely to lead to pressure sores, injury, or other untoward conditions.
Through the use of state estimation, a flow meter, or an accumulator with known volume and a known orifice diameter which fills whenever a bladder is adjusted and allows estimation of flow rate and bag volume, along with various other techniques of measuring volume, the surface pressure between the user and the top of the cushion may be estimated, as otherwise described herein. With this data there are numerous ways that we may provide value to the consumer including but not limited to:
Through the adjustment of air bladders beneath the foam, the shape and properties of the foam which support a user is able to be varied in a way that allows the foam to react to a user's body as though it were custom molded. When the bladders compress the foam from the bottom, they increase the upward pressure, which can effectively lift the foam and increase the force that the user feels from the foam in that region. This method of custom molding enables adjustment to create different user profiles which enable the cushion to change how it supports the user in different scenarios. This method of custom molding also enables dynamic adjustment, so as to change the molding in response to user activity or other circumstances relating to the user's medical conditions, comfort, likelihood of slippage or falling, or other events.
Other and further known scenarios involve the pressure cushion system having an interaction between an observed externally applied pressure (such as from a weight on the pressure cushion system), with an internally applied pressure (such as from an internally-generated pressure by the air bladders within the cushion component). While this Application describes some selected known scenarios, there is no particular requirement for any such limitation; other and further such scenarios, and/or combinations thereof, are also possible. Moreover, information from more than one such scenario can be combined when so identified.
A value of the mean externally applied pressure can be measured, and this information can be used to predict the weight of the user. The pressure cushion system can communicate the user's predicted weight to the user and/or one or more caretakers. When tracked over a time duration, the pressure cushion system can be disposed to provide a calibrated time-graph of the user's weight.
There are a number of alternative uses for the cushion and/or support. For example, the cushion and/or support can be disposed for use by medical patients who are relatively immobile, either because their musculature is weakened, because they are restrained by medical devices, or because medical personnel would like them not to move selected parts of their bodies (whether because those selected parts are healing, because movement would disrupt or interfere with medical devices or with user healing, or because movement would cause undue pain to the user). For another example, the cushion and/or support can be disposed for use by persons who are confined for relatively long periods of time, such as drivers engaged in automobile travel, pilots or other personnel (such as medical or military personnel) who are engaged in activity that demands their full attention and for which they cannot move about. For another example, the cushion and/or support can be disposed for use by persons who are required by their activity to position themselves in an awkward or strained manner.
Users may read any of the below measurements via the user's mobile control unit. Users may also set desired thresholds for this information and be alerted using one of the methods described below if any measurements exceed the provided thresholds. The position of the unit can be estimated with a variety of methods, including GPS, Cellular positioning, adjacency to various wifi devices, and adjacency to various Bluetooth devices. The temperature of the user, the atmosphere, and/or moisture within the cushion component of the unit may all be measured directly with various sensors.
The pressure cushion system can be disposed so as to allow the user, and/or one or more caretakers, to use an external device as a control input, or as a notification source or information readout. Such external devices can include, but are not limited to, Mobile Phones (Android™-based, iPhone™-based, or others), Tablets/Phablets, Laptops, Desktops, simple remote controllers (IR based, RF based, or others), audio-only interactive devices (Amazon Alexa™, Google Home™, or others). These devices can provide one or more user interface points and can allow the user and/or one or more caretakers a degree of control/output with respect to the pressure cushion system. The pressure cushion system can be disposed to allow one or more such devices to be connected using a wired connection, Bluetooth™, Wi-Fi, cellular, other forms of RF control, sonically, or by IR tranceiving solutions.
Although this Application primarily describes one set of apparatuses, methods, and preferred techniques, in the context of the invention, there is no particular requirement for any such limitation. Other apparatuses, methods, and techniques, and related matters, would also be workable, and are within the scope and spirit of this description. After reading this Application, those skilled in the art would be able to incorporate such other techniques with the techniques shown herein.
This Application describes a preferred embodiment with preferred process steps and, where applicable, preferred data structures. After reading this Application, those skilled in the art would recognize that, where any calculation or computation is appropriate, embodiments of the description can be implemented using general purpose computing devices or switching processors, special purpose computing devices or switching processors, other circuits adapted to particular process steps and data structures described herein, or combinations or conjunctions thereof, and that implementation of the process steps and data structures described herein would not require undue experimentation or further invention.
The claims are incorporated by reference as if fully set forth herein.
The cushion component can be wrapped in a number of cover interfaces in order to contain the various other aspects found within this portion of the device. The cover aspect (
The cover can further be designed to consist of a knit polyester fabric with a rubberized non-porous material backing on the top and side layer. The rubberized knit polyester fabric is sewn to a perforated non-slip expanded pvc fabric bottom layer. The lower back right of the cushion cover is left unsewn between the pvc and polyester fabric to allow the hoses to pass through. An additional piece of fabric is sewn onto the outside of the knit polyester fabric to indicate the orientation of the cushion.
Typically the cover there will be an allowance for space if the user needs to insert a form of rigidizer; which can range from a piece of wood, to a plastic layer, to any other rigid and thin structure as shown in (
In addition to the various forms of cushion component covers, if the user requires it, a separate waterproof cover may be placed over the entire cushion component and or unit assembly. Such waterproof covers may be made out of polyester terry fabric, vinyl, polyurethane, silicon spray, or any other various waterproofing material layer.
A foam layer is the top layer of the inner aspects of the cushion component (
In one embodiment, the control element can operate under control of software disposed to detect and avoid states in which safety of the user is at risk. For example, if measurements returned from the transducer subsystem are ever significantly lower than the calibrated 0 psi value, or ever significantly higher than the expected max pressure experienced by the unit, the control element can determine that the associated transducer might be faulty. In such cases, faulty transducers can be ignored, and the unit may be disposed to fail softly to a safe state, such as by venting the corresponding bladder.
The control unit is supplied with an off-the-shelf AC/DC power supply (15V 3A in the case of our implementation) that is connected in order to recharge the battery. When this power is connected, the charge chip connects the system bus to the 15V input in addition to using this input to charge the battery.
The wireless communications module provides an interface that allows the microcontroller to communicate with both the internet (via a Wi-Fi connection) and the control device (via a Bluetooth connection). It is important to note that other communication methods, particularly a cellular connection, could also be used to achieve the same or possibly expanded functionality. Additionally, a simplified version of the device could be built with no wireless connectivity or less wireless connectivity. The wireless communications module serves almost entirely as a communications relay, receiving communications over bluetooth and WiFi and performing a relatively minimal amount of translation to turn them into commands that are sent to the main microcontroller over an SPI connection (other types of link between the wireless communications module and microcontroller could serve the exact same purpose). It should be noted that the wireless communications module itself contains a microcontroller, which could be used as an alternative to the microcontroller described below. Due to limitations of the interfaces available on the microcontroller in the wireless communications module, it was deemed more cost-effective to use a second microcontroller with more interfacing capability, described below, to perform the majority of the system control. Despite this, the wireless module microcontroller can be used to offload tasks from the main microcontroller. In particular, the wireless module microcontroller can be used to generate audio signals.
The microcontroller is a small microprocessor with internal code and data memory that is used for control of all of the other subsystems on the printed circuit assembly. Its most significant task is to provide control over the inflation level of the individual bladders inside the cushion. This is achieved via software containing the machine learning algorithm detailed later. Additionally, the microcontroller is connected to all of the major subsystems on the printed circuit assembly. The software running on the microcontroller provides control over power sequencing, fault detection and response and data logging. The microcontroller is connected to additional, external non-volatile memory that is used to store data logs and system firmware updates that have been received over the wireless links but not yet programmed into the storage internal to the microcontroller or wireless communication module. This non-volatile memory may also store code or data (especially audio samples) that are too large to fit into the aforementioned internal memories. In the case of our implementation, this memory is implemented as NOR flash connected over the SPI interface, but other types of memory could be used to implement similar functionality.
The analog front end provides signal conditioning to transform the signals from the pressure transducers into a form that can be accurately measured by the analog to digital converter built into the microcontroller. The signal output by the pressure transducers is a differential signal (desired quantity is encoded as the difference between two voltages) with a maximum amplitude of a small fraction of a volt, while the microcontroller is designed to measure single ended (desired quantity is encoded as the difference between a single voltage and system ground) signal with a few volts of amplitude. A high-level schematic of the Analog Front End is shown in
The instrumentation amplifier used in the Analog Front End is a low-performance variety to enable lower overall cost of the system. With the selection of this component a significant offset in the measured differential voltage of the transducer output is introduced by nonidealities in the amplifier, in particular the input offset voltage Vos, which affects the amplifier output as shown in Eq. 2
The input offset voltage is affected by numerous parameters that vary over time, such as temperature, voltage at the amplifier inputs (this effect is also known as the common-mode rejection ratio or CMRR of the amplifier), and amplifier power supply voltage. The net effect of this is to create a time-varying offset on all pressure readings produced by the analog front end, which degrades system performance. In order to reduce this effect, Vref can also be selected by the multiplexers to be applied to both inputs of the instrumentation amplifier (Vp=Vn=Vref). According to Eq. 2, the output of the instrumentation amplifier is now Vos*Gain+Vref. When the microcontroller samples both Vout and Vref with this multiplexer selection (Input 7 in the case of the figure), it can thus assume that any difference between the two is caused by amplifier offset, and can thus trivially compute the offset of the amplifier. The microcontroller software then computes this difference and subtracts it out from any measurements taken in the future, cancelling out the error. Because the offset is time-varying, it is periodically re-measured. Finally, note that Vref is specifically selected to be very close to the common-mode voltage ((Vp+Vn)/2) output by an ideal pressure transducer reading 0 psi. This reduces the detrimental effect of the common mode rejection ratio, which would otherwise cause an unmeasured change in the offset Vos when the amplifier switched from measuring Vref to measuring the pressure transducer output with a different common-mode voltage. It is important to note that while our implementation used the same Vref as a self-calibration signal and as an output level reference for the instrumentation amplifier, this was solely done to simplify the circuit, and another voltage level could be used for the instrumentation amplifier output reference level without needing to be subject to the previously mentioned constraint to reduce the effects of CMRR. This could slightly increase the allowable gain of the amplifier before hitting voltage limitations and thereby slightly decrease the amount of noise in the measurements. In our case, the reference voltage Vref was generated using a voltage divider that divides the supply voltage to the pressure transducers by two followed by an op-amp configured as a unity-gain buffer (item 3 in the
The valve/pump drivers are used to control the valves and pump in the control unit. An overview is shown in (
Alternatively, pump current may be measured to see if it changes when the valve is commanded open (which would suggest a change in the head pressure of the pump corresponding to a successful valve actuation), or the pressure in the bladder may be measured to ensure that it starts rising. If the valve is not detected to open even with an increased duty cycle, the unit will alert the user of the error and may halt the pump/vent operation to prevent over/underinflation.
The duty cycle of the pump PWM is determined based on the measured current; if the current exceeds a set value the PWM output is set low for the rest of the cycle. This is used to soft-start the motor and avoid current transients that would otherwise necessitate the use of larger and more expensive power electronics. In steady-state the pump driver PWM duty cycle is 100%. The pump current limit also protects the motor driver from short-circuits, if the current limit is engaged for too long the microcontroller software shuts down the pump driver PWM entirely to prevent overheating and alerts the user of an error. When the solenoid current exceeds a setpoint (set well above the normal operating current), the solenoid driver is shut down to protect it from short circuits and the unit alerts the user of an error.
The battery charger is in charge of charging the Lithium-Ion battery (other types may also be applicable) that powers the product while it is unplugged. It consists of a DC-DC buck converter (other topologies may be applicable depending on the input power source) that converts the input from the DC power supply to the correct voltage to charge the battery according to a standard lithium ion charge cycle. A constant current is supplied until the battery reaches a specified voltage, then a constant voltage is applied until the charge terminates when the current supplied to the battery is below a charge termination threshold or the charge cycle has been in progress for longer than the maximum charge cycle length. The charge chip is capable of reducing the current into the battery when the current needed to run the system increases in order to avoid exceeding the rated output of the supplied AC/DC power supply, which must supply the combined charge and operation current. While the unit is plugged in, the battery charger connects the system bus (which powers the remainder of the system) to the DC input voltage. When the charger is not connected, the system bus rail is connected to the battery. All of the downstream circuitry must be designed to handle the abrupt change in input voltage that occurs when the charger is plugged in or unplugged. Finally, the battery charger circuit provides information to the microcontroller that is used to monitor the DC input voltage, battery voltage, input current, and battery current along with other parameters. These parameters are used to track the state of charge and state of health of the battery. Additionally, the microcontroller is able to send new charging voltage and current setpoints to the charge chip. When USB-C power delivery based charging is implemented in the future, this will enable the system to adapt its power demand to power source capabilities.
The electrical system of the control unit consists of a battery, a printed circuit assembly, a power switch, a pump (described in the section above), and solenoid valves (also described above). Additionally, a DC power supply is shipped with the unit. Of these components, only the printed circuit assembly is specifically designed for the application, although future design improvements may include development of customized versions of the aforementioned components. A block diagram of the control unit electronics is provided in (
The printed circuit assembly (
The system contains, at a minimum, one pressure transducer per inflatable bladder that is used to measure bladder pressure and feed the control loop. In our system, these are piezoresistive MEMS pressure transducers. They are manufactured as a bridge circuit made from strain sensitive resistors and output a differential voltage that is fed into the analog front end described below before finally being measured by the microcontroller. Lastly, a digital temperature sensor is optionally placed near the pressure transducers to allow software to compensate for error in the pressure readings caused by temperature variations. In order to aid in this, the pressure transducers may be placed in a thermal “island” on the printed circuit assembly that is isolated from the rest of the board by routed out slots in order to make all of the pressure transducers operate as close to the same temperature as possible.
It is worth noting that other types of pressure transducers could be used with no effect on functionality. Additionally, fewer pressure transducers could be used along with valves to select the pressure being sampled, or a singular pressure transducer could be placed on the pump/valve line to reuse the existing valves for this task. This would result in an acoustically noisier, more power hungry system with a much slower pressure response, and thus was not selected for our design.
The control unit printed circuit assembly contains a power management subsystem to allow the unit to achieve the following key functions in addition to the power related functions mentioned previously: turning the unit on and off, gating power to unneeded parts of the unit to extend battery life, and converting power to the appropriate voltage for other subsystems. In future units, this may also interface with a USB type C connection to provide USB Power Delivery functionality and allow battery charging over USB. A high-level diagram of the Power Management Subsystem is shown in (
In normal operation, the control unit printed circuit assembly is never truly “off” after the battery is first installed at the factory. When the user presses the power button to turn off the unit, the main microcontroller safely shuts down all of the subsystems which can be power gated and then removes their power, then turns off the power light. The system is also powered off when the battery voltage goes below a preset threshold. Only the battery charge controller (which may be put into a low-power mode) and the main microcontroller (which is also put into a low-power mode) continue to receive power in the fully power-gated system. In this state even a battery with only 10% charge remaining can last for thousands of hours. In this “off” mode, the microcontroller may be woken up (and the system powered on) by the power switch. Additionally, the microcontroller may be woken up periodically and power to subsystems temporarily reapplied to enable the unit to be powered on by a change in bladder pressures, time based alarm, bluetooth, WiFi, or other external stimulus. Whenever the microcontroller software resumes normal operation the power light is turned back on.
The unit has several power switches that can be controlled by the microcontroller software to minimize power consumption. These are as follows. It is worth noting that no power gating is required to create a functional device, it is used to improve battery life and may also be used as a method to shut down power to components that the software has determined to be faulty in order to reduce the risk of harm to the user.
The system has a total of 5 major power rails that are not generated internally to the component they feed. They are as follows:
Magnets are installed into the base of the control box (
The pressure cushion system can also be disposed to log one or more parameters so as to aid in manufacturer diagnostics and technical support. The logged parameters may be transmitted to the manufacturer either by having the system directly connected to the Internet or by storing them in volatile or nonvolatile memory to be transmitted to the internet using an external control device (such as described herein). Parameters that may be monitored include, but are not limited to: battery voltage, battery cycle count, time the pump has been in operation, number of solenoid or pump cycles, solenoid drive current waveforms, solenoid duty cycles, temperature of various components, specifically including; the pressure transducers or the battery, firmware and App versions, any detected software exceptions, auto-calibration results and leak rates, control system coefficients (as described with respect to the section on Machine Learning), serial number, connected Wi-Fi and Bluetooth device network names and addresses, and system pressures. These parameters may also be processed remotely by related IT infrastructure and used to inform the user and/or one or more caretakers with respect to system performance.
The printed circuit assembly may contain a Class-D (switching) integrated audio amplifier in order to allow it to produce pleasing tones and spoken words to inform the user of system status or provide reminders to the user. In the case of this specific implementation, the audio may be generated by the wireless microcontroller instead of the main microcontroller in order to more effectively use the peripherals on each microcontroller and distribute CPU load. The playback of the audio samples is commanded using the same communication link used to send translated commands and data between the wireless module and main microcontroller. Alternative types of audio amplifiers may also be used, as well as different sources of audio, with little to no functional impact.
Communicating with Users
In certain states it may be necessary to inform the user of the cushion of a state or change of state in the cushion. This communication may occur with either the individual sitting on the cushion or with one of the individuals who are responsible for the wellbeing of the individual who is sitting on the cushion. Communication may be used in, although is not limited to, the following ways: an audible notification, either from the control box or from a mobile control unit, shifting pressure between the bladders, submitting a push notification to the user's mobile control unit, a light on the control box.
Due to variances in the pressure transducers and the electronic components used to read from them, it may be necessary to automatically calibrate the control system to compensate for these variances. The calibration procedure may take one of many forms, but here is one such form.
First, the offset of each transducer may be determined by completely venting the zone and attached pneumatics that map to the transducer. After waiting for a time to allow the pressure to equalize, the value of the transducer may be recorded and used as a baseline offset. The baseline can now be subtracted from the raw value returned by the transducer in operation to gain a more accurate measurement.
Second, to calibrate against transducer-to-transducer variation, each transducer's operating range may be compared against one ground-truth transducer. This will not improve the absolute accuracy of any given transducer, but will ensure that all transducers on the unit have similar scaling. This calibration scenario may be realized by activating multiple solenoids simultaneously and allowing their pneumatic regions to equalize, while using the pump and/or vent to direct the pressure up and down. The pressure relationships between the calibrating transducer and the one ground-trute transducer will be recorded, and can be consulted whenever the transducer in question is read from.
There are a number of alternative uses for the cushion and/or support. For example, the cushion and/or support can be disposed for use by medical patients who are relatively immobile, either because their musculature is weakened, because they are restrained by medical devices, or because medical personnel would like them not to move selected parts of their bodies (whether because those selected parts are healing, because movement would disrupt or interfere with medical devices or with user healing, or because movement would cause undue pain to the user). For another example, the cushion and/or support can be disposed for use by persons who are confined for relatively long periods of time, such as drivers engaged in automobile travel, pilots or other personnel (such as medical or military personnel) who are engaged in activity that demands their full attention and for which they cannot move about. For another example, the cushion and/or support can be disposed for use by persons who are required by their activity to position themselves in an awkward or strained manner.
Users may read any of the below measurements via the user's mobile control unit. Users may also set desired thresholds for this information, and be alerted using one of the methods described below if any measurements exceed the provided thresholds:
The position of the unit can be estimated with a variety of methods, including GPS, Cellular positioning, adjacency to various wifi devices, and adjacency to various bluetooth devices. The temperature of the user, the atmosphere, and/or moisture within the cushion component of the unit may all be measured directly with various sensors.
| Number | Date | Country | Kind |
|---|---|---|---|
| 63222955 | Jul 2021 | US | national |
| 17866491 | Jul 2022 | US | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/037404 | 7/16/2022 | WO |
