US-12618964-B2 - State detection

US12618964B2US 12618964 B2US12618964 B2US 12618964B2US-12618964-B2

Abstract

Embodiments relate to using an active reflected wave detector to classify the state of a person in an environment and optionally respond accordingly. In one embodiment there is provided a computer implemented method of determining a state of a person comprising: receiving an output of an active reflected wave detector; classifying a state of the person as being in a safe supported state based on the output using measurements of reflections associated with the person, wherein said classifying is based at least on: a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector; and a plurality of velocity magnitude measurements of the person corresponding to different times, each of said velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector.

Inventors

Ohad AMIR
Jonathan Mark SCHNAPP
Ilan HEVDELI
Benyamin FINKELSTEIN
Boaz Menis

Assignees

ESSENCE SMARTCARE LTD.

Dates

Publication Date: 20260505
Application Date: 20201229
Priority Date: 20191231

Claims (20)

1 . A computer implemented method of determining a state of a person in an environment, the method comprising: receiving an output of an active reflected wave detector; based on the output of the active reflected wave detector, classifying a state of the person as being in any one of: a first standing state, wherein the first standing state comprises standing without oscillating about a position; or a second standing state, wherein the second standing state comprises standing with oscillating about a position; wherein said classifying uses measurements of reflections associated with the person conveyed in the output of the active reflected wave detector, and said classifying is based at least on: a plurality of velocity magnitude measurements of the person corresponding to different times, each of said velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector; and at least one of: (i) a spatial distribution of the measurements of the reflections associated with the person conveyed in the output of the active reflected wave detector; or (ii) a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector.
2 . The computer implemented method of claim 1 , the method comprising classifying the state of the person as being in any one of the first standing state or the second standing state based on: determining the person is not in a fall position based on the height metric; and determining one or more of the velocity magnitudes of the person present in the environment is below a velocity threshold.
3 . The computer implemented method of claim 1 , wherein the height metric comprises one or more of: an average vertical height of the reflections associated with the person that are conveyed in the output of the active reflected wave detector; a maximum height of multiple reflections from a body of said person or a portion thereof that are conveyed in the output of the active reflected wave detector; and a height of a weighted centre of the reflections associated with the person that are conveyed in the output of the active reflected wave detector.
4 . The computer implemented method of claim 1 , further comprising accumulating the velocity magnitude measurements to determine a total distance travelled by a centre of mass of said person over a first time period comprising said different times, and said classifying is further based on the total distance.
5 . The computer implemented method of claim 1 , further comprising determining a total displacement of a centre of mass of said person across said environment over a second time period, and said classifying is further based on the total displacement.
6 . The computer implemented method of claim 1 , wherein the active reflected wave detector is a radar sensor.
7 . The computer implemented method of claim 1 , wherein the first standing state comprises standing in a still state, and the second standing state comprises standing in a still state.
8 . A non-transitory computer-readable storage medium comprising instructions which, when executed by a processor of a device cause the processor to perform the method of claim 1 , wherein the first standing state comprises standing in a still state, and the second standing state comprises standing in a still state.
9 . The computer-implemented method of claim 1 , wherein classifying the state of the person as being in the first standing state comprises classifying the person as standing with support of an object, and classifying the state of the person as being in the second standing state comprises classifying the person as standing without support of an object.
10 . A non-transitory computer-readable storage medium comprising instructions which, when executed by a processor of a device cause the processor to perform a method of determining a state of a person in an environment, the method comprising: receiving an output of an active reflected wave detector; based on the output of the active reflected wave detector, classifying a state of the person as being in any one of: a first standing state, wherein the first standing state comprises standing without oscillating about a position; or a second standing state, wherein the second standing state comprises standing with oscillating about a position; wherein said classifying uses measurements of reflections associated with the person conveyed in the output of the active reflected wave detector, and said classifying is based at least on: a plurality of velocity magnitude measurements of the person corresponding to different times, each of said velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector; and at least one of: (i) a spatial distribution of the measurements of the reflections associated with the person conveyed in the output of the active reflected wave detector; or (ii) a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector.
11 . The non-transitory computer-readable storage medium of claim 10 , wherein the method further comprises accumulating the velocity magnitude measurements to determine a total distance travelled by a centre of mass of said person over a first time period comprising said different times, and said classifying is further based on the total distance.
12 . The non-transitory computer-readable storage medium of claim 11 , wherein the method further comprises determining a total displacement of a centre of mass of said person across said environment over a second time period, and said classifying is further based on the total displacement.
13 . The non-transitory computer-readable storage medium of claim 10 , wherein classifying the state of the person as being in the first standing state comprises classifying the person as standing with support of an object, and classifying the state of the person as being in the second standing state comprises classifying the person as standing without support of an object.
14 . A device for determining a state of a person in an environment, the device comprising a processor configured to: receive an output of an active reflected wave detector; based on the output of the active reflected wave detector, classify a state of the person as being in either: a first standing state, wherein the first standing state comprises standing without oscillating about a position; or a second standing state, wherein the second standing state comprises standing with oscillating about a position; wherein said classification uses measurements of reflections associated with the person conveyed in the output of the active reflected wave detector, and said classification is based at least on: a plurality of velocity magnitude measurements of the person corresponding to different times, each of said plurality of velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector; and at least one of: (i) a spatial distribution of the measurements of the reflections associated with the person conveyed in the output of the active reflected wave detector; or (ii) a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector.
15 . The device of claim 14 , wherein the processor is further configured to accumulate the velocity magnitude measurements to determine a total distance travelled by a centre of mass of said person over a first time period comprising said different times, and said classifying is further based on the total distance.
16 . The device of claim 15 , wherein the processor is further configured to determine a total displacement of a centre of mass of said person across said environment over a second time period, and said classifying is further based on the total displacement.
17 . The device of claim 14 , wherein the processor is configured to classify the state of the person as being in one of the first standing state or the second standing state based on determining that the height metric is above a height threshold.
18 . The device of claim 14 , wherein the first standing state comprises standing in a still state, and the second standing state comprises standing in a still state.
19 . The device of claim 14 , wherein classifying the state of the person as being in the first standing state comprises classifying the person as standing with support of an object, and classifying the state of the person as being in the second standing state comprises classifying the person as standing without support of an object.
20 . The device of claim 14 , wherein the active reflected wave detector is a radar sensor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a filing under 35 U.S.C. 371 as the National Stage of International Application No. PCT/IL2020/051345, filed Dec. 29, 2020, entitled “STATE DETECTION,” which claims priority to United Kingdom Application No. 1919449.7 filed with the Intellectual Property Office of the United Kingdom on Dec. 31, 2019, both of which are incorporated herein by reference in their entirety for all purposes. TECHNICAL FIELD The present invention relates generally to a device and method for determining a state of a person in an environment. BACKGROUND There is a need to use a monitoring system to automatically detect a status and/or presence of a person in a designated space, for example in an interior of a building. For example, an elderly person may end up in a hazardous situation in which they are unable to call for help, or unable to do so quickly. One such situation may be if they have fallen. Some known systems have been developed in which the person wears a pendant which has an accelerometer in it to detect a fall based on kinematics. The pendant upon detecting a fall can transmit an alert signal. However the person may not want to wear, or may be in any case not wearing, the pendant. Other reflected-wave based systems such as radar (whether radio wave, microwave or millimeter wave), lidar or sonar, are known to monitor a person in a designated space. SUMMARY The inventors have identified that there is a need to accurately identify the state of a person in an environment. For example, incorrectly identifying a person as being in a fall state can lead to significant power and network resources being consumed in the generation and transmission of a fall detection alert to a remote device, and may result in an unnecessary response from a monitoring station. In embodiments described herein an active reflected wave detector is used to accurately classify the state of a person in the environment and optionally respond accordingly. According to one aspect of the present disclosure there is provided a computer implemented method of determining a state of a person in an environment, the method comprising: receiving an output of an active reflected wave detector; classifying a state of the person as being in a safe supported state based on the output of the active reflected wave detector, wherein said classifying uses measurements of reflections associated with the person conveyed in the output of the active reflected wave detector, and said classifying is based at least on: a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector; and a plurality of velocity magnitude measurements of the person corresponding to different times, each of said velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector. According to another aspect of the present disclosure there is provided a device for determining a state of a person in an environment, the device comprising a processor configured to: receive an output of an active reflected wave detector; classify a state of the person as being in a safe supported state based on the output of the active reflected wave detector, wherein said classification uses measurements of reflections associated with the person conveyed in the output of the active reflected wave detector, and said classification is based at least on: a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector; and a plurality of velocity magnitude measurements of the person corresponding to different times, each of said plurality of velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector. According to another aspect of the present disclosure there is provided a computer implemented method of determining a state of a person in an environment, the method comprising: receiving an output of an active reflected wave detector; classifying the state of the person as being in a crawling state based on the output of the active reflected wave detector, wherein said classifying uses measurements of reflections associated with the person conveyed in the output of the active reflected wave detector, and said classifying is based at least on: a plurality of velocity magnitude measurements of the person corresponding to different times, each of said plurality of velocity magnitude measurements determined using the reflections associated with the person conveyed in the output of the active reflected wave detector; and a height metric associated with at least one reflection from the person conveyed in the output of the active reflected wave detector. According to another aspect of the present disclosure there is provided a device for determining a st