Calibrated systems, devices and methods for preventing, detecting, and treating pressure-induced ischemia, pressure ulcers, and other conditions
A system for monitoring medical conditions including pressure ulcers, pressure-induced ischemia and related medical conditions comprises at least one sensor adapted to detect one or more patient characteristic including at least position, orientation, temperature, acceleration, moisture, resistance, stress, heart rate, respiration rate, and blood oxygenation, a host for processing the data received from the sensors together with historical patient data to develop an assessment of patient condition and suggested course of treatment, including either suspending or adjusting turn schedule based on various types of patient movement. The sensor can include bi-axial or tri-axial accelerometers, as well as resistive, inductive, capacitive, magnetic and other sensing devices, depending on whether the sensor is located on the patient or the support surface, and for what purpose.
1. A method for automatically adjusting a turn protocol for a person, the method comprising:
providing the turn protocol for the person supported at least temporarily by a support surface, wherein the turn protocol defines a pressurization measure representing a pressurization of a particular body region,
receiving, at a processor, sensor signals from one or more sensors,
identifying, by the processor, based on the received sensor signals, when the person is in a pressurization position corresponding with the particular body region,
monitoring, by the processor, the pressurization measure over time based on the identifying step, including (a) increasing the pressurization measure for a first pressurization period spent on the support surface and in the pressurization position and (b) decreasing the pressurization measure at a first depressurization rate for a first depressurization period spent on the support surface but out of the pressurization position,
detecting, based on the received sensor signals, one or more body movements selected from the group of body movements consisting of a bed exit event, a standing event, and an ambulation event, and
in response to the detection of the one or more body movements:
selecting a constant predetermined depressurization rate higher than the first depressurization rate, and
decreasing the pressurization measure at the constant predetermined depressurization rate during a duration of a second depressurization period spent out of the pressurization position.
2. The method of claim 1 comprising selecting the constant predetermined depressurization rate based on person-specific data.
3. The method of claim 2 , wherein the step of selecting the constant predetermined depressurization rate based on the person-specific data comprises selecting the constant predetermined depressurization rate based on a determined frequency or duration of the one or more body movements.
4. The method of claim 1 wherein selecting the constant predetermined depressurization rate is based on predetermined parameters for care.
5. The method of claim 1 , wherein the step of receiving the sensor signals from the one or more sensors comprises receiving the sensor signals from the one or more sensors provided in a sensor device affixed to the person or carried by an article worn by the person.
6. The method of claim 1 , wherein the step of receiving the sensor signals from the one or more sensors comprises receiving acceleration data from one or more accelerometers.
7. The method of claim 1 , wherein:
detecting the one or more body movements comprises detecting the bed exit event, and
the second depressurization period spent out of the pressurization position comprises a period related to the bed exit event during which the person is out of bed.
8. The method of claim 1 , wherein:
detecting the one or more body movements comprises detecting the standing event, and
the second depressurization period spent out of the pressurization position comprises a period during which the person is standing.
9. The method of claim 1 , wherein:
detecting the one or more body movements comprises detecting the ambulation event, and
the second depressurization period spent out of the pressurization position comprises a period during which the person is ambulating.
10. A method for automatically adjusting a turn protocol for a person, the method comprising:
providing the turn protocol for the person supported at least temporarily by a support surface, wherein the turn protocol defines (a) a pressurization measure representing a pressurization of a particular body region, and (b) a depressurization rate for decreasing the pressurization measure,
receiving, at a processor, sensor signals from one or more sensors,
identifying, by the processor, based on the received sensor signals, when the person is in a pressurization position corresponding with the particular body region,
monitoring, by the processor, the pressurization measure over time based on the identifying step, including (a) increasing the pressurization measure for periods spent in the pressurization position and (b) decreasing the pressurization measure, based on the depressurization rate defined by the turn protocol, for periods spent out of the pressurization position,
determining person-specific historical body movement information, including at least one of:
determining a historical bed exit frequency for the person based on a series of bed exit events detected based on the received sensor signals,
determining a historical standing duration for the person based on a series of standing events detected based on the received sensor signals, or
determining a historical ambulation distance or speed for the person based on a series of ambulation events detected based on the received sensor signals, and
adjusting the depressurization rate based on the person-specific historical body movement information, and decreasing the pressurization measure using the adjusted depressurization rate.
11. The method of claim 10 , wherein the step of receiving the sensor signals from the one or more sensors comprises receiving the sensor signals from the one or more sensors provided in a sensor device affixed to the person or carried by an article worn by the person.
12. The method of claim 10 , wherein the step of receiving the sensor signals from the one or more sensors comprises receiving acceleration data from one or more accelerometers.
13. The method of claim 10 , wherein:
determining the person-specific historical body movement information includes determining the historical bed exit frequency for the person based on the series of detected bed exit events, and
adjusting the depressurization rate based on the person-specific historical body movement information comprises adjusting the depressurization rate as a function of the determined historical bed exit frequency.
14. The method of claim 10 , wherein:
determining the person-specific historical body movement information includes determining the historical standing duration for the person based on the series of detected standing events, and
adjusting the depressurization rate based on the person-specific historical body movement information comprises adjusting the depressurization rate as a function of the determined historical standing duration for the person.
15. The method of claim 10 , wherein:
determining the person-specific historical body movement information includes determining the historical ambulation distance or speed for the person based on the series of detected ambulation events, and
adjusting the depressurization rate based on the person-specific historical body movement information comprises adjusting the depressurization rate as a function of the historical ambulation distance or speed for the person.
16. A system for automated monitoring of a person, comprising:
a wearable sensor device body configured to be secured to the person or to an article worn by the person;
at least one sensor provided in the wearable sensor device body and configured to generate sensor signals regarding an orientation of the person; and
a processor configured to:
receive sensor signals from the at least one sensor,
identify based on the received sensor signals, when the person is in a pressurization position corresponding with a particular body region,
manage a pressurization timer for the pressurization position, including (a) increasing the pressurization timer for a first pressurization period spent on the support surface and in the pressurization position and (b) gradually decreasing the pressurization timer at a first depressurization rate for a first depressurization period spent on the support surface but out of the pressurization position,
detect, based on the received sensor signals, a bed exit event, a standing event, or an ambulation event, and
in response to detecting the bed exit event, the standing event, or the ambulation event:
select a second depressurization rate higher than the first depressurization rate, and
gradually decrease the pressurization timer at the second depressurization rate during a duration of a second depressurization period spent out of the pressurization position, such that the pressurization timer is gradually decreased over time by an amount defined by the duration of the second depressurization period.
17. The system of claim 16 , wherein the processor is provided in the wearable sensor device body.
18. The system of claim 16 , wherein the processor is remote from the wearable sensor device body and configured to receive the sensor signals from the at least one sensor via wireless communications.
19. The system of claim 16 , wherein the second depressurization period comprises a period during which the person is out of bed.
20. The system of claim 16 , wherein the second depressurization period comprises a period during which the person is standing.
21. The system of claim 16 , wherein the second depressurization period comprises a period during which the person is ambulating.