US-20260123838-A1 - WEARABLE DEVICE FOR NONINVASIVE BODY TEMPERATURE MEASUREMENT

US20260123838A1US 20260123838 A1US20260123838 A1US 20260123838A1US-20260123838-A1

Abstract

A wearable device configured to secure to skin of a user and noninvasively measure body temperature of the user can include first and second pairs of temperature sensors configured to generate one or more signals responsive to detected thermal energy, a thermally conductive element positioned at least partially between the second pair of temperature sensors, and one or more hardware processors configured to receive the one or more signals generated by each of said first and second pairs of temperature sensors and determine one or more body temperature values of the user based on at least comparisons between different ones of the first and second pairs of temperature sensors. In some implementations, the wearable device includes thermally conductive probes for transmitting thermal energy toward ones of the first and second pairs of temperature sensors and a substrate positioned between the probes and the skin.

Inventors

Ammar Al-Ali
Stephen Scruggs
Joel Amposta
Valery G. Telfort

Assignees

MASIMO CORPORATION

Dates

Publication Date: 20260507
Application Date: 20251215

Claims (19)

1 .- 18 . (canceled)
19 . A wearable device configured to secure to skin of a user, the wearable device comprising: a first pair of temperature sensors, said first pair of temperature sensors comprising a first temperature sensor and a second temperature sensor, each of said first and second temperature sensors configured to generate one or more signals responsive to detected thermal energy, said first temperature sensor operably positioned to be closer to the user's skin than the second temperature sensor when the wearable device is secured to the user's skin; a second pair of temperature sensors spaced from said first pair of temperature sensors, said second pair of temperature sensors comprising a third temperature sensor and a fourth temperature sensor, each of said third and fourth temperature sensors configured to generate one or more signals responsive to detected thermal energy, said third temperature sensor operably positioned to be closer to the user's skin than the fourth temperature sensor when the wearable device is secured to the user's skin; and a thermally conductive element positioned at least partially between the third and fourth temperature sensors.
20 . The wearable device of claim 19 , wherein the first pair of temperature sensors are thermally insulated from one another by an air gap.
21 . The wearable device of claim 20 , wherein: the wearable device further comprises a first circuit board and a second circuit board, the first and second circuit boards spaced from one another, the first circuit board positioned closer to the skin of the user than the second circuit board when the wearable device is secured to the user's skin; said first temperature sensor is mounted to the first circuit board and the second temperature sensor is mounted to the second circuit board; said third temperature sensor is mounted to the first circuit board and spaced from the first temperature sensor; said fourth temperature sensor is mounted to the second circuit board and spaced from the second temperature sensor; a distance between the first temperature sensor and the second circuit board at least partially defines said air gap; and said thermally conductive element is positioned between the third temperature sensor and a portion of the second circuit board that is adjacent to the fourth temperature sensor.
22 . The wearable device of claim 21 , wherein: said first circuit board comprises a first surface and a second surface; said second circuit board comprises a first surface and a second surface; said first surface of the first circuit board faces toward the second surface of the second circuit board; said first and third temperature sensors are mounted on the first surface of the first circuit board; said second and fourth temperature sensors are mounted on the first surface of the second circuit board; and said thermally conductive element is positioned between the third temperature sensor and a portion of the second surface of the second circuit board that is adjacent to the fourth temperature sensor.
23 . The wearable device of claim 22 , wherein said second circuit board comprises at least one opening positioned between the fourth temperature sensor and a portion of said thermally conductive element, said at least one opening configured to allow thermal energy to pass from the thermally conductive element through the second circuit board and to the fourth temperature sensor.
24 . The wearable device of claim 23 , wherein said first and second temperature sensors are substantially aligned with one another and wherein said third and fourth temperature sensors are substantially aligned with one another.
25 . The wearable device of claim 23 , wherein said thermally conductive element comprises a metal strip.
26 . The wearable device of claim 25 , wherein said metal strip comprises copper.
27 . The wearable device of claim 26 , wherein the first and second circuit boards are arranged to be substantially parallel to one another.
28 . The wearable device of claim 19 , wherein the wearable device comprises a first portion configured to be secured to the user's skin and a second portion configured to removably secure to the first portion, and wherein one or more hardware processors, the thermally conductive element, the first pair of temperature sensors, and the second pair of temperature sensors are positioned within the second portion of the wearable device.
29 . The wearable device of claim 28 , wherein the first portion comprises a frame and a substrate coupled to the frame, the substrate configured to secure to the user's skin, and wherein the second portion comprises a housing.
30 . The wearable device of claim 29 , wherein the housing comprises a first shell and a second shell, and wherein the first and second shells are permanently secured together.
31 . The wearable device of claim 19 , wherein none of the first temperature sensor, second temperature sensor, third temperature sensor, and fourth temperature sensor contact the user's skin when the wearable device is secured to the user.
32 . A wearable device configured to secure to skin of a user, the wearable device comprising: a first pair of temperature sensors, said first pair of temperature sensors comprising a first temperature sensor and a second temperature sensor, said first temperature sensor operably positioned to be closer to the user's skin than the second temperature sensor when the wearable device is secured to the user's skin; and a second pair of temperature sensors spaced from said first pair of temperature sensors, said second pair of temperature sensors comprising a third temperature sensor and a fourth temperature sensor, said third temperature sensor operably positioned to be closer to the user's skin than the fourth temperature sensor when the wearable device is secured to the user's skin.
33 . The wearable device of claim 32 , further comprising a thermally conductive element positioned at least partially between the third and fourth temperature sensors.
34 . The wearable device of claim 33 , wherein: the first pair of temperature sensors are thermally insulated from one another by an air gap; the wearable device further comprises a first circuit board and a second circuit board, the first and second circuit boards spaced from one another, the first circuit board positioned closer to the skin of the user than the second circuit board when the wearable device is secured to the user's skin; said first temperature sensor is mounted to the first circuit board and the second temperature sensor is mounted to the second circuit board; said third temperature sensor is mounted to the first circuit board and spaced from the first temperature sensor; said fourth temperature sensor is mounted to the second circuit board and spaced from the second temperature sensor; a distance between the first temperature sensor and the second circuit board at least partially defines said air gap; and said thermally conductive element is positioned between the third temperature sensor and a portion of the second circuit board that is adjacent to the fourth temperature sensor.
35 . The wearable device of claim 34 , wherein: said first circuit board comprises a first surface and a second surface; said second circuit board comprises a first surface and a second surface; said first surface of the first circuit board faces toward the second surface of the second circuit board; said first and third temperature sensors are mounted on the first surface of the first circuit board; said second and fourth temperature sensors are mounted on the first surface of the second circuit board; and said thermally conductive element is positioned between the third temperature sensor and a portion of the second surface of the second circuit board that is adjacent to the fourth temperature sensor.
36 . The wearable device of claim 35 , wherein said second circuit board comprises at least one opening positioned between the fourth temperature sensor and a portion of said thermally conductive element, said at least one opening configured to allow thermal energy to pass from the thermally conductive element through the second circuit board and to the fourth temperature sensor.

Description

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS The present application is a continuation of U.S. application Ser. No. 17/933,604, filed Sep. 20, 2022, titled “Wearable Device for Noninvasive Body Temperature Measurement”, which claims priority to U.S. Provisional Application No. 63/261,500, filed Sep. 22, 2021, titled “Wearable Device for Noninvasive Body Temperature Measurement”, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present disclosure relates to devices, methods, and/or systems for monitoring a subject's physiological information. More specifically, the present disclosure describes, among other things, a wearable device for measuring a subject's body temperature. BACKGROUND Core body temperature is an important vital sign used by clinicians to monitor and/or manage the condition of a subject (for example, a patient). Core body temperature is the internal temperature of a subject. Internal body temperatures are typically maintained within a specific range in order for the body to carry out essential functions. Variations in core body temperature can be indicative of a deteriorating condition of a subject and can negatively impact the body's ability to maintain critical life-sustaining functions. SUMMARY Despite the importance of core body temperature as a vital sign, many commonly employed devices, methods, and/or systems for estimating (via noninvasive or minimally invasive means) core body temperature based on skin surface or peripheral measurements lack accuracy. Skin surface temperature, typically measured using single point measurement devices or heat flux measurement devices, can vary dramatically from core body temperature in some cases depending on physiology of the subject such as properties of the subject's skin (for example, thickness, impedance), condition of the subject's skin when measurements are taken (for example, moisture/sweat), environment of the subject, perfusion, and/or other conditions. Temperature measurements obtained with a thermometer at a subject's periphery (such as at the subject's armpit, rectum, or under a subject's tongue) also do not represent a true measurement of internal body temperature, but rather, simply an approximation. The present disclosure provides improved devices, methods, and systems for noninvasively determining a subject's internal body temperature based upon temperature measurements obtained from the subject's skin. Various implementations of the disclosed wearable devices include multiple temperature sensors operably positioned in different locations with respect to one another and with respect to the wearer's skin when in use. Such configurations can allow temperature to be determined at each of these different locations and compared with one another. In some implementations, thermal paths (which may be referred to as “thermal flow paths” or “heat flow paths” or “thermal energy paths”) between pairs of temperature sensors are defined by air and/or a thermally conductive element, which can provide additional information where thermal properties (for example, thermal conductivity values) are known. Temperature values at various ones of the temperature sensors and differences between such values can be utilized to provide more accurate estimates of internal body temperature of a subject. Some implementations of the wearable devices disclosed herein include two pairs of temperature sensors aligned with one another, where one of each pair is positioned farther from the subject's skin (when the wearable device is in use) and the other one of each pair is positioned closer to the subject's skin. Some implementations include an air gap (which can act as a thermal insulator) between one of such pairs and a thermally conductive element (for example, a metallic material) between the other one of such pairs. Temperature values determined based on each of the temperature sensors (and/or each of the pairs of temperature sensors) can be compared and/or otherwise utilized to approximate internal body temperature value(s) of the subject. In various implementations, one or more thermally conductive probes can be utilized to transmit energy from a substrate of the wearable device (which can adhere to the subject's skin) toward aligned temperature sensor(s). Some implementations of the disclosed wearable devices (or portions of such devices) can be disposable, which can reduce the risk of cross-contamination between multiple subjects. Some implementations of the disclosed wearable devices (or portions of such devices) can be waterproof, thereby allowing the subject to carry out ordinary activities (for example, showering) without disrupting operation of the wearable device. Some implementations of the disclosed wearable devices include two separable components (which may also be referred to as “separate portions” or “first and second portions”). In such implementations, a first one of the components can be configured to sec