Systems and methods for monitoring and providing therapeutic support for a user

Systems and methods for monitoring pressure exerted on an individual at one or more points by a support structure and adjusting the support structure in response to the monitored pressure are disclosed. The method for monitoring pressure may include the step of periodically receiving with at least three radio frequency readers, localized contact pressure data from a radio frequency addressable sensor placed on an individual. The method may further include, when an adjustment is required, calculating a radial distance defining a radius of the radio frequency addressable sensor to the at least three radio frequency readers, and calculating an intersection location or overlap of the radii such that the location of the radio frequency addressable sensor is determined. The method may also include, when the location of the radio frequency addressable sensor is determined, adjusting cells within a zone or subzone corresponding to the location.

FIELD OF THE INVENTION

The present invention is related to systems and methods for monitoring pressure exerted on an individual at one or more points by a support structure and adjusting the support structure, in response to the monitored pressure.

BACKGROUND

The prevention and treatment of bedsores (and similar pressure injuries) is a serious issue facing hospitals and other healthcare facilities. Bedsores (also known as decubitus ulcers or pressure sores) result from prolonged pressure on an area. For example, a bedsore is a tissue injury that develops when soft tissue is compressed between a bony prominence and an external surface for a prolonged period of time. Bedsores are most likely to form on the back of the head, the sacrum, heels, ankles, buttocks, or shoulders. Bedsores are painful and can be life-threatening to patients, particularly the elderly and disabled. Excessive pressure on recent surgical incisions can lead to wound healing complications with similar etiology. The National Decubitus Foundation estimated that as many as 16% of the population of U.S. hospitals, alone, suffered from some form of pressure wound such as a bedsore.

Bedsores are most common for patients confined to a bed, chair or wheelchair. These furniture support systems often include padding made from cotton, feathers, foam, or the like. Some techniques for preventing bedsores focus on the design of the furniture and padding. To ease pressure, furniture has been introduced that include a fixed quantity of air or liquid in one or more chambers to provide therapeutic benefits, including minimizing the severity of pressure points on a user's body. In addition, some of these support systems include manual or programmable adjustable cushion sections. However, these systems cannot be adjusted based on feedback about the current condition of a patient and therefore, a patient may still develop bedsores using therapeutic furniture. Once a bedsore develops it is important to mitigate continued excessive pressure to the region to facilitate the healing process.

Another typical method for preventing bedsores involves frequent repositioning of a patient. However, this method of prevention is highly time consuming for medical and care facilities, particularly facilities having a large number of disabled or immobile patients. What is therefore needed is a system that can automatically adjust a support structure (or external padding for furniture) based on pressure monitored on one or more areas of a patient.

DETAILED DESCRIPTION

The following detailed description of systems and methods for monitoring and providing therapeutic support for a user refers to the accompanying drawings that illustrate exemplary embodiments. Unless otherwise noted, all embodiments and examples should be considered prophetic examples. Other embodiments are possible. Modifications can be made to the embodiments described herein without departing from the spirit and scope of the present invention. Therefore, the following detailed description is not meant to be limiting. Further, it would be apparent to one of skill in the art that the systems and methods described below can be implemented in many different embodiments of hardware, software, and/or firmware. Any actual hardware, software, and/or firmware described are not meant to be limiting.

Presented herein are embodiments of systems and methods for monitoring pressure on a patient and adjusting a support structure accordingly. In one embodiment, a pressure monitor can continuously (or semi-continuously) measure contact pressures between a portion of a user's body and a section of a support surface of a support system, such as a hospital bed. For example, the pressure monitor can measure contact pressure between a support surface and the user's head, arms, legs, feet, arms, torso, or any other suitable location on the user.

In embodiments, a pressure monitor can be configured to transmit measured pressure data to a networkable device (e.g., a laptop computer, PDA, cell phone, a processor located in the bed, or other patient monitor) using RF communications. The networkable device can then send a signal to actuators located within the bed to adjust the pressure of one or more sections in the support surface of the bed. The networkable device can additionally communicate the user's status and condition to a healthcare provider station (e.g., staffed by nurses, doctors, and other hospital personnel) or directly to a healthcare providers' wireless networkable device (e.g. cell phone, pager, or personal digital assistant (PDA)) through a communication network such as a local area network (LAN), wide area network (WAN), or the like. This communication allows the healthcare provider to remotely monitor a user, such as a hospital patient and take action when certain conditions are indicated. The networkable device, or associated computing system, can additionally record and display temporal trends, minima, and maxima in the pressure data and optionally log the data to the patient's electronic health records. The networkable device, or associated computing system, can also compare the pressure data to the patient's diastolic blood pressure or other measurement, and calculate relevant clinical gradients in real time.

FIGS. 1Aand B illustrate an exemplary operating environment for a system for monitoring pressure for an individual confined to a support structure for a period of time, such as a bed or a chair, according to an embodiment of the present invention. As shown inFIG. 1A, the system includes a support system110. In the example ofFIG. 1A, the support system is depicted as a bed. However, as discussed in detail below, the support system may be a mattress pad, a chair such as wheelchair or a similar form of support. An individual, e.g., patient190, comes into direct or indirect contact with the support system. As shown inFIG. 1A, the individual is lying on structure110. However, in other embodiments, the individual may be sitting or reclining in a different position.

Prior to placement on the support structure, one or more RF addressable pressure sensors100are placed on the individual. These pressure sensors may be placed at locations highly susceptible to pressure injuries such as the sacrum, back of the head, elbows, shoulders, ankles, etc. In an embodiment, these sensors are placed on the skin of the patient in a location most likely to have direct or indirect contact with the support structure or upon which the support structure is likely to exert pressure.FIG. 1Bis the rear view of a patient depicting exemplary placement of a plurality of RF addressable pressure sensors, according to embodiments of the present invention. RF addressable pressure sensors100are described in further detail below.

The system further includes an RFID reader150and a controller160. Although depicted as separate components, RFID reader150and controller160could be implemented in a single structure. RFID reader150is configured to communicate with the one or more RF addressable pressure sensors100and obtain data therefrom. RFID reader150is placed proximate to the individual. AlthoughFIG. 1Adepicts the reader150attached to the foot of the bed, the RFID reader may be placed at any location to permit detection and access to the RF addressable sensors. For example, RFID reader150may be placed on the support structure, under the support structure, above the support structure, or next to the support structure (e.g., on a mobile station).

RFID reader150is coupled to a controller160. In an embodiment, controller160is configured to receive data from reader150and to determine whether adjustments should be made to support structure to reduce pressure in one or more areas. In an alternative embodiment, reader150includes the logic to determine whether adjustments should be made to support structure. Controller160is further configured to cause adjustments to be made to the support structure.

In addition, RFID reader150and/or controller160may be connected to an external monitoring station. The communication infrastructure is described in further detail below.

Support Systems

FIG. 2is a perspective view of a support system200incorporating a system for monitoring and providing therapeutic support for a user, in accordance with an embodiment of the present invention. Support system200can be one of many forms, including but not limited to, a bed including a mattress and bed frame, such as a hospital bed configured for use during or after medical procedures, a conventional bed used for sleeping, a mattress for a bed, a mattress cover configured to be placed on top of a mattress, a chair such as a wheelchair, couch, or any other suitable support system having a support surface.

In some embodiments, support system200comprises conventional components of a hospital bed, for example mattress215, head end280on one side of the mattress, including headboard285, foot end290on the opposite side of mattress215, bed frame130disposed underneath and supporting mattress215, and side rails120for constraining a user within support system200. Support system200can further include wheels140to facilitate moving the system. Alternatively, the support system can be in the form of a padded layer to be placed on top of a mattress, chair, couch, or other surface.

In some embodiments, mattress215can include a support surface205which includes areas corresponding to a conventionally sized user's body. For example, head portion250can be configured to receive the user's head, torso portion260can be configured to receive the user's torso, and leg portion270can be configured to receive the user's legs and feet. Mattress215can further include a plurality of adjustable sections210. In some embodiments, each of adjustable sections210are in the shape of a square and are arranged to form a square grid, in other embodiments, one or more of adjustable sections210can be in the form of a shape other than a square. For example, a non-square rectangle, an oval, a sphere, a cylinder, or any other suitable geometric shape. In some embodiments, one or more sections can be shaped to contour the shape of the user's body. For example, mattress215can include a single adjustable section or a plurality of adjacent adjustable sections formed to provide a recess contour for the user's head.

In some embodiments, adjustable sections210of mattress215include a confined gas, liquid or other suitable flowable material. The support characteristics, such as inflation level can be adjusted with the aid of an air or liquid supply means, such as one or more pumps or a centralized facility air supply. In some embodiments, a single pump provides air to each of the sections. In other embodiments, multiple pumps provide air to multiple sections.

FIG. 3is a schematic view of air hose assembly300of the support system ofFIG. 2. In some embodiments, adjustable sections210are operatively connected to air pump assembly310to allow for inflation and deflation of adjustable sections210. For example, air hose assembly300can be attached to central air line340, which is then delivered through branch air lines320via line connections330. Branch air lines320are also operatively connected to adjustable sections210to provide for inflation and deflation. Line connections330may include individual solenoid valves or other means of controlling flow into or out of each chamber.

FIG. 4is a schematic view of a support surface405in accordance with an embodiment. Like support surface205ofFIG. 2, support surface405comprises portions corresponding to a conventionally sized user's body. For example, head portion450can be configured to receive the user's head, torso portion460can be configured to receive the user's torso, and leg portion470can be configured to receive the user's legs and feet. Adjustable sections410can be smaller in size compared to adjustable sections210of support surface205shown inFIG. 2. Adjustable sections210can be of any suitable size and shape.

FIG. 5is a schematic view of a support surface505in accordance with an embodiment. Like support surface205ofFIG. 2, support surface505comprises portions corresponding to a conventionally sized user's body. For example, head portion550can be configured to receive the user's head, torso portion560can be configured to receive the user's torso, and leg portion570can be configured to receive the user's legs and feet. Adjustable sections510can be arranged to generally follow the outline of the user's body in various conventional positions, as shown for Example inFIG. 2. In some embodiments, support surface505can further comprise an outer section507that surrounds the adjustable sections. Outer section507can comprise conventional bedding materials, such as foam or other padding, can alternatively comprise additional adjustable sections, non-adjustable inflated sections, or any suitable combination thereof.

FIG. 6is a schematic view of a support surface605in accordance with an embodiment. Like support surface205ofFIG. 2, support surface605comprises portions corresponding to a conventionally sized user's body. For example, head portion650can be configured to receive the user's head, torso portion660can be configured to receive the user's torso, and leg portion670can be configured to receive the user's leg and feet. Adjustable sections610can be arranged to generally follow the outline of the user's body in various conventional positions, as shown, for example, inFIG. 2. In some embodiments, support surface605can further comprise an outer section607that surrounds the adjustable sections. Outer section607can comprise conventional bedding materials, such as foam or other padding, can alternatively comprise additional adjustable sections, non-adjustable inflated sections, or any suitable combination thereof. Adjustable sections610can be rectangular in shape and smaller in size compared to adjustable sections210shown inFIG. 2and adjustable sections410shown inFIG. 4. Adjustable sections610can be of any suitable size and shape.

RF Addressable Pressure Monitor

FIG. 7is a schematic view of an RF addressable pressure monitor700in accordance with an embodiment presented herein. In some embodiments, RF addressable pressure monitor700is configured to be placed on a user and comprises a pressure sensor710operatively connected to an RFID device715disposed on a substrate730. In some embodiments, pressure sensor710is a microelectromechanical system (MEMS) sensor on the order of 1 mm. The relatively small size of a MEMS pressure sensor allows easy placement on the user. Such MEMS sensors use a change in resistance, change in capacitance, change in voltage, or a piezoelectric effect to convert changes in pressure on a sensing membrane to a voltage, current, or frequency change in the output signal.

Pressure sensor710is coupled to a wire740coupled to a radiofrequency (RF) device715on substrate730, which can be in the form of a surface patch or bandage. Substrate730can include an adhesive material on one surface for affixing to the skin of the patient. Substrate730can further include multiple layers. In some embodiments, RF device715and RF antenna760can be integrated within layers of substrate730.

In some embodiments, pressure sensor710could be an air or fluid filled contained volume coupled to an appropriate sensor through a tube communicating with the sensing membrane. The sensor could therefore be separate from the bandage packaging.

In some embodiments, RF device715comprises a RF antenna760and a battery750coupled to RFID chip720to provide power and to transmit data. RF device715powers pressure sensor710, and interprets or relays the data from pressure sensor710to an interrogating reader. The RF device can be passive, pass-active (battery assisted), or fully active (battery dependent) depending upon the frequency of desired reads, the estimated distance of the interrogating device from the RF device, and the power consumption needs of the RF device. In alternative embodiments, the pressure sensor is integrated with Bluetooth, ZIGBEE or other radios compatible with wireless devices such as cell phones.

Substrate730(e.g., a layer of an adhesive bandage) is used to maintain RF device715and battery750on the surface of the user's skin or clothing. In some embodiments, sterile gauze can be placed between the electronic components and the surface of the skin.

In operation, a pressure change between pressure sensor710and the support surface is registered at pressure sensor710. In the embodiment shown, the pressure data is then communicated to RF device715coupled to pressure sensor710. In the embodiment shown, pressure sensor710and RF device715are powered by battery750. Battery750can be substantially rigid or can be flexible. As would be appreciated by persons of skill in the art, RF device715and/or pressure sensor710can be powered by other techniques. Adhesive bandage material can be used to house and maintain RF device715, battery750, and pressure sensor710. Additional external sensors can further be included in pressure monitor700, e.g., in the adhesive bandage material or on substrate730. Sterile gauze can be present in between adhesive bandage or substrate730and the surface of the user's skin or clothing.

FIG. 8is a top view of a bandage810incorporating a pressure monitor800and substrate830in accordance with an embodiment presented herein. Similar to the pressure monitor shown, for example, inFIG. 7, pressure monitor800can comprise an RF device815and RF antenna860. In the embodiment illustrated inFIG. 8, the RF device is placed on top of substrate830. InFIG. 8the bandage is an oval shape, of course the bandage could be any other suitable shape. Bandage810can be used with any of the pressure monitors described above.

FIG. 9is a top view of a bandage910incorporating a pressure monitor900and substrate930in accordance with an embodiment presented herein. Similar to the pressure monitor shown, for example, inFIG. 7, pressure monitor900can comprise an RF device915, RF antenna960, and battery950.

FIG. 10is an RF device1000according to an embodiment. RF device1000is coupled to one or more external sensors1010a-1010n. RF device1000includes RF core1020, an analog to digital converter (ADC)1030, and one or more antennas1040. These components are mounted or formed on a substrate. Additionally, the RF core1020and/or ADC1030can be included in an integrated circuit. RF device1000can also include one or more sensor elements1050a-1050n. Sensor elements1050a-1050ncan be included in the integrated circuit, on the substrate, external to substrate, or in any combination of the above. Any compatible sensor element can be used as sensor element.

External sensors1010a-1010ninclude the sensors (e.g., MEMS sensor) described above for measuring compartment pressure. These external pressure sensors can be coupled to a pressure probe through a wire connector or an inelastic fluid filled tube. In an alternate embodiment, a fiber optic connection can be used.

Various types of sensor elements can be implemented as sensors1050a-1050nor external sensors1010a-1010n. For example, integrated or external sensor can include a temperature sensor element that generate information indicating ambient temperature; a pH sensor element; or other biological or chemical sensors. The system can include other types of sensor elements or combinations thereof, as would be apparent to persons skilled in the relevant art(s). Testing has shown that some RFID reader chips are not well suited to read complex RFID sensors due to timing and/or power issues. The readers are essentially meant to read ID numbers and have a very short interrogation/response cycle time. Furthermore when the technology is passive (as is the case for most RFID) substantial power fluctuations occur on the RFID chip and this affects sensor accuracy.

RFID core1020includes a communications module coupled to antenna1040, an RFID tag logic module, a power module and memory. In an embodiment, the memory stores an identifier for the RFID tag associated with the pressure sensor. The tag identifier, for example, may be used to associate the RF addressable sensor with an individual. In this example, a provider could maintain a database mapping tag identifiers to individuals.

A modified RFID chip can be used to facilitate these readers to read the pressure monitors comprising a complex MEMS sensor. Such a modified chip includes a serial peripheral interface (SPI) port and allows pre-processed sensor data to be stored in memory directly linked to the ID interrogation process of the RFID tag. This type of RFID tag therefore serves as a low cost “pass-through” radio. This design and method allows any sensor to be connected to common RFID technology and be read directly with current RFID enabled cell phones. The technology can be configured for ISO 15693 tags for example and is directly compatible with multiprotocol 13.56 MHz RFID reader chips for cell phones such as the PN 544 C2 reader chip made by NXP.

Different circuit designs and options are possible for the pass through method.FIG. 11depicts an exemplary system1100having a modified RFID chip, and antenna1190according to an embodiment.FIG. 11illustrates how complex sensors can be handled using a passive modified RFID radio, where the processed sensor data is passed through the RFID core as part of the standard interrogation—transmission of RFID data. The system1100includes a plurality of external sensors. In embodiments, the plurality of external sensors includes a complex calibrated external MEMS sensor1110and an ultra-precise external thermistor to allow medical grade combined pressure and temperature sensor measurements.

Each of the plurality of external sensors is coupled to a sensor interface1120. Sensor interface1120includes an analog to digital converter (ADC) and multiplexer1130, an external microprocessor (MCU) and firmware1140, and memory1150. Using an external microprocessor and firmware allows compression of complex sensor data and extremely fast passage of information via the RFID chip, well within the limits of current standard RFID reader chips. Sensor interface1120further includes an external power source (e.g. battery, energy harvesting, solar, chemical, motion, etc.) that also can include a reference voltage calibration circuit. In an embodiment, sensor interface1120is included in a separate chip.

Sensor interface1120is coupled to modified RFID chip1160. The command set for the external MCU1140is passed through the RFID chip1160. The memory on the RFID chip is cleared either when full or bumped with each new interrogation or sensor data download or by external command from the RFID interrogator (e.g., a cell phone, or other wireless networkable device).

The RFID chip1160and sensor interface1120ofFIG. 11can be integrated into a single hybrid chip, whereby the packaged sensor data is placed in memory and where the main processor would be powered by the external power source and the communication part built to handle the constraints imposed by current RFID interrogators. Alternatively, the components of sensor interface1120can be included in a separate integrated circuit chip.

Various designs are possible for the fully integrated chip. The system ofFIG. 11illustrates the combination of an external temperature sensor1170, external MEMS sensor1110, and other sensor(s)1180. For temperature on chip a single calibration point digital sensor can be used. Such sensor technology is described in U.S. Pat. No. 7,461,972 that is included by reference in its entirety.

Network

FIG. 12is a block diagram of an illustrative network for monitoring one or more pressure sensors integrated with RF devices and adjusting a support structure to accommodate for changes in pressure, in accordance with an embodiment of the present invention. The network includes one or more RF addressable sensors1200, one or more RFID/sensor readers1250and a controller1260. Exemplary RF addressable sensors are described above. The network may optionally include a communications network1270coupled to the controller1260and a remote monitoring station1280.

Communications network1270is a publicly accessible communications network. Communications network1270may be a wired network, wireless network, or a combination therefore. In another embodiment, communications network1270is a private network or a hybrid network including public and private portions. Persons skilled in the relevant art(s) will recognize that various network architectures could be used for communication network1270.

Wireless RFID/sensor reader1250includes logic to read sensor data and RFID tag data transmitted by RF addressable sensor1200. In an embodiment, wireless RFID/sensor reader1250also includes logic to process the received sensor data. Wireless RFID/sensor reader1250can be any wireless device capable of communicating via an air interface protocol with RF addressable sensor1200. In some embodiments, wireless RFID/sensor reader1250could be a wireless phone, a personal digital assistant (PDA), a computer having wireless communications capabilities, or other type of mobile, handheld, and/or computing device (e.g., an iPAD).

According to an embodiment, signals are exchanged between the wireless RFID/sensor reader1250and RF addressable sensor1200according to one or more protocols. In an embodiment, reader1250and the RF addressable sensor1200communicate via a single protocol for both RFID tag communications and sensor communications. In an alternate embodiment, reader1250and RF addressable sensor1200communicate via a first protocol for RFID tag communications and via a second protocol for sensor communications. Examples of protocols used for RFID tag communications include binary tree traversal, HF ISO 15693 and EPC global Gen 2. An embodiment is also applicable to any other types of communication protocols between tags and readers otherwise known or yet to be developed.

RFID/sensor reader1250is coupled to a controller1260. RFID/sensor reader1250communicates data obtained from the one or more RF addressable sensors1200to controller1260. Controller1260includes a pressure monitoring module1264and a support structure adjustment module1266.

Pressure monitoring module1264is configured to determine whether a pressure adjustment needs to be made to the support structure and isolates one or more cells to adjust. In an alternative embodiment, pressure monitoring module1264may be included as a component of RFID/sensor reader1250or distributed between the RFID/sensor reader and the controller1260. Pressure monitoring module1264communicates adjustment information to support structure adjustment module1266.

Support structure adjustment module1266is configured to adjust one or more cells in the support structure. In an embodiment, support structure adjustment module1266includes logic to determine the amount of adjustment to make to a specific cell. In an alternate embodiment, pressure monitoring module1264determines the amount of adjustment to make to a specific cell.

In an embodiment, controller1260and/or RFID/sensor reader1264communicates data to an external monitoring station. Controller1260and/or RFID/sensor reader1250may communicate all data obtained to external monitoring station1280. In addition or alternatively, controller1260and/or RFID/sensor reader1250may communicate only when certain conditions are detected. For example, controller1260and/or RFID/sensor reader1250may alert the external monitoring station1280when pressure in a certain area remains elevated and/or is not reduced after a series of adjustments.

External monitoring station1280receives sensor data over network1270, and processes the data. In an embodiment, the system associates tag identification data for an RF addressable sensor with an individual. External monitoring station1280may store data for each RF addressable sensors associated with an individual. The external monitoring station1280may analyze the pressure data associated with the individual and make an independent assessment of whether adjustments should be made to the support structure. External monitoring station1280may further be configured to communicate a request to adjust the structure to reduce pressure measurements for one or more tags associated with an individual. Records for individuals may be stored in a database1282coupled to external monitoring station1280.

In an embodiment, a healthcare provider determines if medical intervention is necessary based on alerts from RFID/sensor reader1264, controller1266, and/or external monitoring station1280. External monitoring station1280can display historical data or trends for one or more individuals.

Methods

FIG. 13is a flowchart1300of a method for monitoring pressure and adjusting a support structure to compensate for measured pressure, according to embodiments of the present invention. Flowchart1300is described with reference to the embodiment ofFIG. 12. However, flowchart1300is not limited to that embodiment.

In step1310, pressure monitoring module1264obtains pressure data from one or more RF addressable sensors1200placed on an individual. The pressure monitoring module1264may also obtain a tag identification number associated with the RF addressable sensor1200providing sensor data. In an embodiment, RFID/sensor reader1250polls the one or more RF addressable sensors1200. In an alternate embodiment, the one or more RF addressable sensors1200are configured to periodically send data to RFID/sensor reader1250. RFID/sensor reader1250then communicates the received data to pressure monitoring module1264. In embodiments RFID/sensor reader1250may process the sensor data, e.g., to calibrate or smooth the received data, prior to communicating the data to pressure monitoring module1264.

In step1320, a determination is made whether the pressure data indicates an adjustment is required. In an embodiment, this determination is made on a per RF addressable sensor basis. For example, pressure monitoring module1364may determine for an RF addressable sensor whether the pressure data exceeds a threshold. In addition, or alternatively, the determination may be based on a historical trend for the RF addressable sensor. For example, if the pressure data has been consistently increasing over a predetermined period of time, an adjustment may be indicated for the RF addressable sensor. The networkable device, or associated computing system, can also compare the pressure data to the patient's diastolic blood pressure or other measurement, and calculate relevant clinical gradients in real time. As would be appreciated by persons of skill in the art, other techniques for determining whether an adjustment is required may be used with the present invention. If an adjustment is required, operation proceeds to step1330. If no adjustment is required, operation returns to step1310.

In step1330, one or more cells of the support structure to be adjusted are identified and adjusted. One method for identifying the cell or cells to adjust is discussed inFIG. 14. As would be appreciated by persons of skill in the art, other techniques may be used in the present invention, e.g. triangulation of the sensors position by multiple RFID interrogators.

In step1340, pressure monitoring module1264obtains pressure data from the RF addressable sensors identified for adjustment. In an embodiment, pressure data may be obtained from all RF addressable sensors, as in step1310.

In step1350, a determination is made whether the pressure measurements in the RF addressable sensors identified for adjustment has improved. If pressure measurements indicate that the pressure data still indicates adjustment is necessary, pressure monitoring module may repeat step1340and1350over a pre-defined period of time after an initial adjustment is made. If improvement is not realized over that period of time, pressure monitoring module1264may repeat step1330to alter the adjustments. Additionally, if no improvement is achieved, the pressure monitoring module1264may alert external monitoring station1280of a potential bedsore/pressure sore risk.

If pressure measurements indicate an improvement, the adjustments made in step1330may be maintained for a specific period of time. After that time has expired, the system may return the cell or cells to their status prior to the adjustment.

FIG. 14illustrates a flowchart1400for a method for determining an adjustment for one or more cells in a support structure, in accordance with embodiments of the present invention.FIG. 14is described with reference to the embodiments ofFIG. 12. However, the method is not limited to that embodiment.

In step1410, the support structure is divided into one or more zones or clusters.FIG. 15Adepicts an exemplary support structure. As shown inFIG. 15A, the support structure is divided into a plurality of zones1520. The zones may be of equal size and shape as shown inFIG. 15A. Alternatively, the zones may be defined based on the likely position of an individual on the support structure, as depicted inFIG. 15B. As would be appreciated by persons of skill in the art, other arrangements for zones could be used with the present invention.

In step1420, one or more zones may be further divided into a plurality of sub-zones.FIG. 15Adepicts a zone1520having a plurality of sub-zones. In embodiments, a sub-zone may be furthered divided into clusters. Step1420is optional.

In step1430, a first zone for adjustment is identified. In an embodiment, the pressure monitoring module1264prioritizes zones based on likelihood of a pressure injury occurring in the zone. For example, the zone associated with an individual's sacrum may be prioritized first.

In step1440, cells in the identified zone are adjusted. For example, the cells may be adjusted as described above inFIG. 3.

In step1445, pressure data is obtained from RF addressable sensors identified for adjustment.

In step1450, a determination is made whether an improvement in pressure is reflected in the obtained data. If an improvement is indicated, operation proceeds to step1460. If no improvement is indicated by the data, operation proceeds to step1452.

Note that steps1440and1450may be repeated over a pre-determined period of time before an action is taken to give time for pressure changes to be reflected.

In step1452, a determination is made whether all zones in the support structure have been processed. If all zones have been processed, an alert may be sent to external monitoring station1280and processing of flowchart1400ends. If additional zones remain to be processed, operation proceeds to step1454.

In step1454, the next zone is identified. In embodiments, pressure monitoring module1264includes data specifying an order to process zones.

Operation then returns to step1440.

In step1460(if improvement is indicated in step1450), a sub-zone within the zone is identified. As with the zone, the pressure monitoring module1264may include data specifying an order to process sub-zones within a zone. Step1460is optional.

In step1462, cells in the sub-zone are adjusted. For example, the cells may be adjusted as described above inFIG. 3.

In step1464, pressure data is obtained from RF addressable sensor identified for adjustment.

In step1466, a determination is made whether an improvement in pressure is reflected in the obtained data. If an improvement is indicated, operation proceeds to step1470. If no improvement is indicated by the data, operation proceeds to step1490.

Note that steps1464and1466may be repeated over a pre-determined period of time before an action is taken to give time for pressure changes to be reflected.

In step1470, a first cell within the sub-zone (or zone) is identified. As with the zone, the pressure monitoring module1264may include data specifying an order to process cells within a zone or sub-zone.

In step1472, the cell is adjusted. For example, the cell may be adjusted as described inFIG. 3.

In step1474, pressure data is obtained from the RF addressable sensor identified for adjustment.

In step1476, a determination is made whether an improvement in pressure is reflected in the obtained data. If an improvement is indicated, operation proceeds to step1478. If no improvement is indicated by the data, operation proceeds to step1480.

Note that steps1474and1476may be repeated over a pre-determined period of time before an action is taken to give time for pressure changes to be reflected.

In step1478, a determination is made whether additional cells should be processed. If additional cells should be processed, operation proceeds to step1480. If no additional cells are to be processed, operation ends.

In step1480, a determination is made whether all cells in zone or sub-zone have been processed. If all cells have been processed, an alert may be sent to external monitoring station1280and processing of flowchart1400ends. If additional cells remain to be processed, operation proceeds to step1482.

In step1482, the next cell for adjustment is determined and operation returns to step1472.

In step1490, a determination is made whether all sub-zones in the support structure have been processed. If all sub-zones have been processed, an alert may be sent to external monitoring station1280and processing of flowchart1400ends. If additional sub-zones remain to be processed, operation proceeds to step1494.

In step1494, the next sub-zone is identified. In embodiments, pressure monitoring module1264includes data specifying an order to process zones.

Operation then returns to step1462.

Computer Architecture

FIG. 16illustrates a block diagram of a data processing unit1603that can be used to implement portions of the RFID reader/sensor or controller illustrated inFIG. 12. It is noted that the entities shown inFIG. 12may be implemented using any number of data processing units1603, and the configuration actually used is implementation specific.

Data processing unit1603may represent a computer, a hand-held computer, a lap top computer, a personal digital assistant, a mobile phone, and/or any other type of data processing device. The type of data processing device used to implement the entities shown inFIG. 12is implementation specific.

Data processing unit1603includes a communications medium1610(such as a bus, for example) to which other modules are attached.

Data processing unit1603also includes one or more processors1620and a main memory1630. Main memory1630may be RAM, ROM, or any other memory type, or combinations thereof.

Data processing unit1603may also include secondary storage devices1640such as but not limited to hard drives1642or computer program product interfaces1644. Computer program product interfaces1644are devices that access objects (such as information and/or software) stored in computer program products1650. Examples of computer program product interfaces1644include, but are not limited to, floppy drives, CD drives, DVD drives, ZIP drives, JAZ drives, optical storage devices, universal serial bus (USB), etc. Examples of computer program products1650include, but are not limited to, floppy disks, CDs, DVDs, ZIP and JAZ disks, memory sticks, memory cards, or any other medium on which objects may be stored.

The computer program products1650include a computer useable medium1652on which objects may be stored, such as but not limited to optical mediums, magnetic mediums, etc.

Control logic or software may be stored in main memory1630, second storage device(s)1640, and/or computer program products1650.

More generally, the term “computer program product” refers to any device in which control logic (software) is stored, so in this context a computer program product could be any memory device having control logic stored therein. The invention is directed to computer program products having stored therein software that enables a computer/processor to perform functions of the invention as described herein.

The data processing unit1603may also include an interface1660which may receive objects (such as data, applications, software, images, etc.) from external entities1680via any communications media including wired and wireless communications media. In such cases, objects1670are transported between external entities1680and interface1660via signals1665,1675. In other words, signals1665,1675include or represent control logic for enabling a processor or computer to perform the functions of the invention. According to embodiments of the invention, such signals1665,1675are also considered to be computer program products, and the invention is directed to such computer program products.

As discussed above with reference to at leastFIGS. 1A, 1B, and 12-14, an in particular with reference to step1330of the method shown inFIG. 12, one or more cells of the support structure to be adjusted may be identified and adjusted. One method for identifying the cells to adjust includes geolocation of the sensors. In some embodiments, geolocation of a particular sensor may be advantageous in that the number of zones and subzones that may need to be adjusted to provide treatment may be minimized due to increased accuracy of geolocation. This may be achieved, for example, by methods involving triangulation of the sensor's position using multiple RFID interrogators. In one embodiment, the sensor may be an RF addressable sensor100/1200, or the like, which may measure the patient contact pressure with a bed. In another embodiment the RFID interrogators may be RFID/sensor readers150/1250, or the like. Disclosed embodiments of RF addressable sensors and RFID sensors/readers may be interchanged as would be appreciated by those of ordinary skill in the art.

In some embodiments, using a process such as triangulation may decrease the time it would take to adjust zones and subsequent subzones whose pressures may need to be altered. For example certain zones or subzones may be unlikely to be in the immediate vicinity of a pressure sensor affixed to a patient in a region that requires protection from pressure. Those zones and subzones could then be quickly identified and omitted from adjustment. With only iterative adjustments of broader zones and then subzones, there is a potential for a patient to experience an undesirable pressure level prior to the proper zone being identified. Minimizing the time to adjust zones and subzones to mitigate undesirable pressure will lead to improved patient care with less risk of bed sores, and improved management of existing bed sores.

As discussed with reference toFIGS. 1A and 1B, in some embodiments, the system includes an RFID reader150and a controller160. Although depicted as separate components, RFID reader150and controller160could be implemented in a single structure. RFID reader150is configured to communicate with the one or more RF addressable pressure sensors100and obtain data therefrom. RFID reader150is placed proximate to the individual. AlthoughFIG. 1Adepicts the reader150attached to the foot of the bed, the RFID reader may be placed at any location to permit detection and access to the RF addressable sensors. For example, RFID reader150may be placed on the support structure, under the support structure, above the support structure, or next to the support structure (e.g., on a mobile station).

FIG. 17illustrates a flowchart1700for a method for determining an adjustment for one or more cells in a support structure, in accordance with embodiments of the present invention.FIG. 17is described with reference to the embodiments ofFIGS. 1 and 12, and may include aspects of other disclosed methods. However, the method is not limited to those embodiments.

In step1710, pressure monitoring module obtains pressure data from one or more RF addressable sensors100placed on an individual. The pressure monitoring module may also obtain a tag identification number associated with the RF addressable sensor100providing sensor data. In an embodiment, RFID/sensor reader150polls the one or more RF addressable sensors100. In an alternate embodiment, the one or more RF addressable sensors100are configured to periodically send data to RFID/sensor reader150. RFID/sensor reader150then communicates the received data to pressure monitoring module. In embodiments RFID/sensor reader150may process the sensor data, e.g., to calibrate or smooth the received data, prior to communicating the data to pressure monitoring module.

In step1720, a determination is made whether the pressure data indicates an adjustment is required. In an embodiment, this determination is made on a per RF addressable sensor basis. For example, pressure monitoring module may determine for an RF addressable sensor whether the pressure data exceeds a threshold. In addition, or alternatively, the determination may be based on a historical trend for the RF addressable sensor. For example, if the pressure data has been consistently increasing over a predetermined period of time, an adjustment may be indicated for the RF addressable sensor. The networkable device, or associated computing system, can also compare the pressure data to the patient's diastolic blood pressure or other measurement, and calculate relevant clinical gradients in real time. As would be appreciated by persons of skill in the art, other techniques for determining whether an adjustment is required may be used with the present invention. If an adjustment is required, operation proceeds to step1730. If no adjustment is required, operation returns to step1710.

In step1730, if an adjustment is required, pressure monitoring module triangulates a position of required adjustment and adjusts one or more cells of support structure corresponding to that position.

Once adjusted, in step1740pressure monitoring module obtains pressure data from one or more RF addressable sensors100.

Pressure monitoring module determines in step1750whether the pressure measurements have improved. If there is no improvement, the system may adjust cells proximate the adjusted cell, or further adjust the adjusted cell. Steps1730-1750may be repeated as required.

In some embodiments, multiple RFID readers150may be placed about a patient support structure. For example, in one embodiment, multiple RFID readers150may be placed beneath a mattress, at the 4 corners of a support pad.

FIG. 18illustrates a flowchart1800for a method for determining an adjustment for one or more cells in a support structure, in accordance with embodiments of the present invention.FIG. 18is described with reference to the embodiments ofFIGS. 1 and 12, and may include aspects of other disclosed methods. However, the method is not limited to those embodiments.

In step1802, as in similar disclosed methods, pressure monitoring module obtains pressure data from one or more RF addressable sensors100placed on an individual. In some embodiments, the system or method may utilize a synchronized clock time between processors associated with each RFID reader150, (e.g., each active antenna/RF Interrogator). In one embodiment, all antennae may be energized as in step1806, and configured to receive a response from RF addressable sensor100. When a response is received, the system may assess a time delay between the transmission and arrival of the response as in step1808. When a time delay is assessed, the system may process relative distance between RF addressable sensor100and each RFID reader150as in step1810. The system may then calculate a radius of RF addressable sensor100to each RFID reader150as in step1812and the system may then calculate an intersection location or overlap using at least 3 RFID readers, such that the location of RF addressable sensor100is determined. Once a location is determined, controller160may adjust only the zone or subzone within which the triangulated location lies, at step1814. The system may detect whether or not there is a change in detected pressure from RF addressable sensor100, and if there is no change in pressure, the controller may adjust an adjacent subzone until response in pressure is obtained as in steps1814-1817. In some embodiments, additional adjacent subzones may be adjusted until a response in pressure is obtained. Steps1806-1817may be repeated as necessary.

In some embodiments, the system may simultaneously energize all antennae on RFID readers150(e.g., in parallel) and each one may be configured to receive a response from the transmitter/RF addressable sensor100. In one embodiment, the system may be able to assess time delay between arrival of the responses.

In some embodiments, the system may energize each antenna discretely (e.g., serially) and calculate a delay in response of each transmitter/RF addressable sensor100. The system may serially energize and calculate delays through a plurality of antennae/RFID readers150and store a response time for each. After all distances between antenna/RFID readers150and transmitter/RF addressable sensor100are determined, the system may proceed as described above with calculation of location and adjustment of pressure. In this regard, one processor may control all interrogators/RFID readers150without the need to synchronize clocks.

Because the distances between each antenna/RFID readers150and transmitter/RF addressable sensor100are small, a relatively high time resolution may be required, as the relative difference in arrival times may be very small (as compared to GPS triangulation systems and methods where the transmitters are satellites). Thus, in some embodiments, signal intensity may be used as a proxy for distance, rather than delay in arrival time. Because the signals involved may be low energy signals, their intensity decay over a particular distance through a particular medium would be significant, and is predictive of distance with reasonable accuracy (e.g., higher intensity received indicates the RF addressable sensor is closer, where as a lower intensity received indicates the RF addressable sensor is further away). In some embodiments, the system may calculate a decay rate function of the transmitted signals on a particular medium (for example, a typical mattress, or other common support surface) along with particular sizes and shapes, and use this data to triangulate the location based on signal intensity at each antenna/RFID reader150.

In some embodiments, RFID reader150may receive and analyze information regarding an initial incoming wave front of one or more alternating current RF waves transmitted by the RF addressable sensor100. By way of example, a 13.56 MHz RF wave and a 433 MHz RF wave may be generated simultaneously such that their first rising peak is in phase, that is, rising together. Because the wavelength of the 13.56 MHz wave is approximately 22.11 meters and the wavelength of the 433 MHz wave is approximately 0.69 meters, an interference pattern is created. As the distance from the transmitter of the RF addressable sensor100increases, the difference in arrival time of the 2 wave peaks will increase proportionally to the distance between the RF addressable sensor100and RFID reader150. By examining the interference pattern between the waveforms, known as interferometry, the distance between the transmitter and receiver can be accurately calculated.

In an embodiment, the system may measure the fluctuation in signal intensity compared to a pure sine wave of the fundamental frequency, which represents the interference pattern of the two waves. In another embodiment, the system may look for the arrival time of the wave peak, or through of each of the 2 fundamental frequencies being broadcast. This interference pattern will form a repeating sequence over time and space, and if measured at longer distances (e.g., hundreds of meters) would lead to multiple potential solutions for the location of the transmitter. However, because the typical support structure may be smaller than the approximately 22.11 meter wavelength of the 13.56 MHz wave, there will be only one solution within the confines of the support surface. The two frequencies used in this example are for illustrative purposes only, and as such other frequencies may be used in the systems and methods described herein. The system may therefore utilize wave front interferometry techniques in order to further resolve position determination of the RF addressable sensor100.

In some embodiments, addressable sensors and readers may be used, such that a single sensor may utilize dual frequency transmitting antennas and utilize the interference pattern (e.g., difference in arrival time of discrete peaks/troughs) received at the reader in order to determine the position of the sensor. In some embodiments, the sensors may be RF addressable sensors configured to transmit dual frequencies. Utilization of these discrete frequencies as two carrier waves enables the system to obtain very high resolution of location

As discussed above, in an embodiment, the memory may store an identifier for the RFID tag associated with the pressure sensor. The tag identifier, for example, may be used to associate the RF addressable sensor with an individual, or a body position for an individual (e.g., left leg, right leg, right forearm, etc.). In some embodiments, these identifiers could be used by the system to further refine position determination, for example, by initially searching in a given set of zones based on identifier. For example, the system may use an identifier such as “left leg” to initially focus on zones and subzones where it is likely that a “left leg” identified tag may be positioned. In this regard, it may be possible to optimize processing time during the aforementioned triangulation operation and position determinations. In this example, a provider could maintain a database mapping tag identifiers to individuals and or locations. Multiple tags may be utilized such that each tag has a unique identifier and is associated with a different area that requires pressure adjustment. Using the aforementioned geolocation/triangulation techniques, each RF addressable sensor may be located to the zone or subzone level to minimize the time required to address problematic pressure readings.

CONCLUSION