Systems and methods for multivariate stroke detection

Patent metadata

Field	Value
Publication number	US-2021106238-A1
Application number	US-202017070832-A
Country	US
Kind code	A1
Filing date	Oct 14, 2020
Priority date	Oct 15, 2019
Publication date	Apr 15, 2021
Grant date	—

Abstract

A system for detecting an anomalous event in a person includes a body in contact with a skin surface of a person; a heat source for heating the skin surface to a target temperature; a skin temperature sensor for measuring a temperature of the skin surface in contact with the heat source; a blood volume sensor for measuring a blood volume of the skin surface; and a hardware processor communicatively coupled to the heat source, the blood volume sensor, the skin temperature sensor, and an environmental temperature sensor. The hardware processor is configured to receive a baseline blood volume signal, output a heating signal to the heat source to initiate a heating cycle, receive a second blood volume signal from the blood volume sensor, compare the second blood volume signal to the baseline blood volume signal, and determine whether an anomalous biologic event has occurred.

First claim

What is claimed is:

1 . A wearable system for detecting a stroke event in a person, the wearable system comprising:
a first wearable device configured to be in contact with a first skin surface of a person, said first wearable device configured to be secured to a left limb of the person, said first wearable device comprising:
a first heat source in communication with the first skin surface, wherein the first heat source is configured to heat the first skin surface to a first target temperature;
a first skin temperature sensor configured to measure a first temperature of the first skin surface; and
a first blood volume sensor configured to measure a first blood volume at a first tissue site proximate to the first skin surface;
a second wearable device configured to be in contact with a second skin surface of the person, said second wearable device configured to be secured to a right limb of the person, said second wearable device comprising:
a second heat source in communication with the second skin surface, wherein the second heat source is configured to heat the second skin surface to a second target temperature;
a second skin temperature sensor configured to measure a second temperature of the second skin surface; and
a second blood volume sensor configured to measure a second blood volume at a second tissue site proximate to the second skin surface; and
one or more hardware processors configured to:
receive a first baseline blood volume signal from the first blood volume sensor;
receive a second baseline blood volume signal from the second blood volume sensor;
output a first heating signal to the first heat source to initiate a first heating cycle at a first time, wherein the first heating cycle comprises heating the first skin surface to the first target temperature; receive a first post stimulation blood volume signal from the first blood volume sensor in response to the first skin surface reaching the first target temperature; output a second heating signal to the second heat source to initiate a second heating cycle at a second time, wherein the second heating cycle comprises heating the second skin surface to the second target temperature; receive a second post stimulation blood volume signal from the second blood volume sensor in response to the second skin surface reaching the second target temperature; and determine a stroke event based on the first baseline blood volume signal, the second baseline blood volume signal, the first post stimulation blood volume signal, and the second post stimulation blood volume signal.

2 . The wearable system of claim 1 , wherein the second post stimulation blood volume signal comprises a set of blood volume signals, such that the second blood volume of the second skin surface is measured repeatedly before, during, and after a heating cycle of the second heat source.

3 . The wearable system of claim 1 , wherein the determination of the stroke event is further based on stored reference data corresponding to healthy individual.

4 . The wearable system of claim 1 , wherein the one or more hardware processors are further configured to calculate a first baseline ratio of alternating current (AC) to direct current (DC) for the first baseline blood volume signal and a second baseline ratio of AC to DC for the second blood volume signal and to compare the first baseline ratio to the second baseline ratio.

5 . The wearable system of claim 1 , wherein the first wearable device further comprises an environmental temperature sensor configured to measure ambient temperature.

6 . The wearable system of claim 1 , further comprising a remote computing device communicative coupled to the first wearable device and the second wearable device.

7 . The wearable system of claim 6 , wherein the remote computing device comprises one of:
a laptop, cellular device, a workstation, a server, a desktop computer, a personal digital assistant, a second wearable system or device, or a netbook.

8 . The wearable system of claim 1 , further comprising one or more electrodermal activity sensors.

9 . The wearable system of claim 8 , wherein the one or more electrodermal activity sensors are spaced apart from at least one of the first heat source or the second heat source by about 0.25 inches to about 4 inches.

10 . The wearable system of claim 1 , further comprising one or more motion sensors configured to measure a motion of a body portion to which at least one of the first wearable device or the second wearable device is coupled.

11 . The wearable system of claim 1 , further comprising at least one tensionable band coupled to the body.

12 . The wearable system of claim 1 , wherein the first heat source is positioned concentrically about one or both of the first blood volume sensor and the first skin temperature sensor.

13 . The wearable system of claim 1 , wherein the second heat source is positioned concentrically about one or both of the second blood volume sensor and the second skin temperature sensor.

14 . The wearable system of claim 1 , wherein the first blood volume sensor comprises a photoplethysmography sensor or an impedance plethysmographic sensor.

15 . The wearable system of claim 1 , wherein the first skin temperature sensor comprises a thermocouple, a resistance temperature detector, a thermistor, or an infrared temperature sensor.

16 . The wearable system of claim 1 , wherein the first blood volume sensor is further configured to measure one or more of: heart rate, heart rate variability, or oxygen saturation.

17 . The wearable system of claim 1 , wherein the second blood volume sensor is further configured to measure one or more of: heart rate, heart rate variability, or oxygen saturation.

18 . The wearable system of claim 1 , wherein at least one of the first target temperature or the second target temperature is individualized to the user.

19 . A wearable system for detecting a stroke event in a person, the wearable system comprising:
a first wearable device configured to be in contact with a first skin surface of a person, said first wearable device configured to be secured to a left limb of the person, said first wearable device comprising: a first stimulus source in communication with the first skin surface, wherein the first stimulus source is configured to apply a first stimulus to the first skin surface; and a first sensor configured to measure a first response at a first tissue site proximate to the first skin surface; a second wearable device configured to be in contact with a second skin surface of the person, said second wearable device configured to be secured to a right limb of the person, said second wearable device comprising:
a second stimulus source in communication with the second skin surface, wherein the second stimulus source is configured to apply a second stimulus to the second skin surface; and
a second sensor configured to measure a second response at a second tissue site proximate to the second skin surface; and
one or more hardware processors configured to: output a first stimulus signal to the first stimulus source to initiate the application of the first stimulus at a first time; receive the first response after the application of the first stimulus; output a second stimulus signal to the second stimulus source to initiate the application of the second stimulus at a second time; receive the second response after the application of the second stimulus; and determine a stroke event based on the first response and

Assignees

• Imperative Care Inc

Inventors

• Strasser Michael
• Hossainy Syed
• Park Sangshik
• Carroll Kirsten

Classifications

• A61B5/349

  Detecting specific parameters of the electrocardiograph cycle · CPC title

• A61B5/0295 Primary

  using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography · CPC title

• A61B5/0535

  Impedance plethysmography (for measuring blood flow A61B5/0295) · CPC title

• A61B5/1101

  Detecting tremor · CPC title

• A61B5/14542

  for measuring blood gases (A61B5/14551 takes precedence) · CPC title