A System And Method For Monitoring A Person Via An Analog Multi-Zone Pressure Sensitive Pad

• US 20180125413A1
• Filed: 05/16/2016
• Published: 05/10/2018
• Est. Priority Date: 05/15/2015
• Status: Active Grant

• Current Assignee: J Brasch Company LLC
• Original Assignee: J Brasch Company LLC
• Inventors: Smith, JR., Gordon, Brasch, John Joseph, Leacock, James R, Li, Yuanjian
• Granted Patent: US 10,357,197 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/06 Arrangements of multiple sensors of different types
• CPC Class Codes: A61B 2562/066 in a matrix array
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/1115 Monitoring leaving of a patient support, e.g. a bed or a wheelchair
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: A61B 5/447 specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
• CPC Class Codes: A61B 5/4815 Sleep quality
• CPC Class Codes: A61B 5/6891 Furniture
• CPC Class Codes: A61B 5/6892 Mats
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61G 2203/34 for pressure
• CPC Class Codes: A61G 2203/44 for weight
• CPC Class Codes: A61G 7/0527 Weighing devices
• CPC Class Codes: A61G 7/057 Arrangements for preventing bed-sores or for supporting patients with burns, e.g. mattresses specially adapted therefor ventilation openings in mattresses A47C21/042; pneumatic or hydraulic mattresses A47C27/08
• CPC Class Codes: A61G 7/108 Weighing means
• CPC Class Codes: G08B 21/22 responsive to presence or absence of persons

Abstract

A pressure sensitive pad, generally planar in shape for placement underneath a mattress or cushion, capable of outputting a spectrum of signals depending on the pressure applied on the pad, comprising a plurality of sensitive zones, each zone being connected to a respective controller, configured to measure the pressure on each zone. The pressure sensitive pad comprising two electrically conductive layers; a variable conductive foam layer between the two conductive layers; and a non-conductive layer comprising a plurality of holes, disposed between a first of the two electrically conductive layers and the conductive foam layer. A system operable with the pad calibrates to detect absence and presence of a person for a range of mattress types and mattress weights and person weights; and determines a relative weight and position of the person while the person is on the mattress.

Claims

1. A pressure sensitive pad, generally planar in shape for placement underneath a mattress or cushion, capable of outputting a spectrum of signals depending on the pressure applied on the pad.

2. The pressure sensitive pad of claim 1 configured for substantially not deforming the mattress or cushion.

3. The pressure sensitive pad of claim 1, comprising at least one of:

a conductive film;

a conductive foam;

a conductive ink; and

a strain gauge.

4. The pressure sensitive pad of claim 1, comprising a plurality of sensitive zones, each zone being connected to a respective controller, configured to measure the pressure on each zone.

5. The pressure sensitive pad of claim 1, comprising:

two electrically conductive layers;

a variable conductive layer between the two conductive layers, configured such that a resistance of the variable conductive layer decreases when pressure is applied on the variable conductive layer and the variable conductive layer is compressed;

wherein the two electrically conductive layers are separated by the variable conductive layer, such that the electrical resistance between the two conducting layers decreases as pressure is applied to the pad, by way of increasing electrical conductivity between the two conducting layers as mechanical pressure increases on the pad and the variable conductive layer is compressed.

6. The pressure sensitive pad of claim 5, wherein the variable conductive layer is a conductive foam layer.

7. The pressure sensitive pad of claim 6, comprising a non-conductive layer comprising a plurality of holes, disposed between a first of the two electrically conductive layers and the conductive foam layer;

wherein pressure applied to the pad increases contact between the first conductive layer and the conductive foam, thereby easing electrical conductivity between the two electrically conductive layers.

8. The pressure sensitive pad of claim 5, comprising a controller connected to the two conducting layers and configured to input a signal that passes through the two electrically conductive layers to read an output signal resulting from the input signal passing through the electrically conductive layers;

and two sheath layers that contain and protect the electrically conductive layers.

17. A method for calibrating a variable pressure sensitive pad to detect a person'"'"'s weight with the pad of claim 1 placed beneath a mattress of an unknown weight and the person is on the mattress, the calibration comprising:

a) placing the pressure variable pressure sensitive pad undress a mattress;

b) measuring a high, a low, a last reading and an average reading from the pad;

c) if the difference is smaller than a threshold, gathering more data until threshold is passed;

d) if the difference is greater than the threshold;

i) determining a deactivated zone, wherein the deactivated zone is a range of values from the high to a value that is a function of the low and high;

ii) determining an activated zone, wherein the activated zone is a range of values from the low to a value that is a second function of the low and high; and

iii) determining a transition zone, wherein the transition zone is range between the highest value of the activated zone and the lowest of deactivated zone;

e) if the average value is in the transitioning region, then performing an iterative process of lowering the record high by a second amount that is a third function of the previous record highs and lows and increasing the record low by a third amount that is a fourth function of the previous record highs and lows, until the last reading is out of the transitioning region.

18. The method of claim 17, wherein the second amount and the third amount are equal to each other.

19. A method for determining a person'"'"'s relative weight using the pad of claim 1, on a mattress of unknown weight, while the pad is beneath the mattress of an unknown weight and the person is on the mattress, comprising measuring an output voltage of the pad and determining the relative weight of the person based on the output voltage.

20. A method for determining the movement of a person on a mattress, using the pad of claim 4 under the mattress, comprising comparing measurements of an output from each of the sensitive zones over time and determining whether an output from a first zone is higher than an adjacent zone over time.

9. A system for detecting weight of a person or weight changes over time or movements of a person on a mattress, comprising:

an analog pressure sensitive pad; and

a control unit configured for processing data received from the pad, and the control unit operable to;

(a) calibrate the system to detect absence and presence of a person for a range of mattress types and mattress weights and person weights; and

(b) determine a relative weight of the person while the person is on the mattress.

10. The system of claim 9, wherein the control is operable to:

(c) send processed data to a remote system;

(d) emit an alarm if an undesirable situation concerning the person'"'"'s presence/absence occurs; and

(e) stop the alarm if a certain input is received.

11. The system of claim 9, wherein the pressure sensitive pad is a variable pressure sensitive pad configured for placement under a mattress.

12. The system of claim 10, comprising a local output unit configured for emitting an alarm in response to an undesirable condition of the person occurring based on information from the pad.

13. The system of claim 10, further comprising a local input configured for receiving a termination signal, communicated to the controller, whereby the controller if configured to terminate an emitted alarm.

14. The system of claim 10, comprising a remote communication unit configured to transmit data processed by the control unit to a remote system.

15. The system of claim 14, wherein the data transmitted is alert data.

16. The system of claim 14, wherein the data is weight data.