System and method for core body temperature measurement with variable heat flux

Abstract

The present disclosure relates to systems and methods for core body temperature measurement with variable heat flux. Aspects of the present disclosure provide methods, systems, devices, and devices that allow, alone or in combination, the determination of a core body temperature (CBT) of a subject.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 582,678, filed on September 14, 2023, the contents of which are hereby incorporated by reference in their entirety. Technical Field

[0003] The present disclosure relates generally to temperature measurement, and more particularly to core body temperature measurement with variable heat flux. Background Art

[0004] Electronic devices are often used as sensors that respond to physical stimuli. Human body temperature, especially core body temperature, is a medical parameter that can be measured and recorded, especially for those who are in poor health or in care facilities.

[0005] Core body temperature can be defined as the mass-weighted average temperature of the body's contents. In many clinical situations, it may be desirable to maintain core body temperature within the normothermic range. For example, maintaining core body temperature has been shown to reduce the incidence of many adverse consequences of anesthesia and surgery, including surgical site infection and bleeding; therefore, it is beneficial to monitor the core temperature of the patient's body before, during, and after surgery. For the safety and comfort of the patient and for the convenience of the clinician, non-invasive temperature measurement may be desirable. Therefore, many temperature sensors are designed as devices that are placed on the skin. However, measuring the core body temperature on the patient's skin introduces many possible errors. Summary of the invention

[0006] A simplified summary of one or more aspects is presented below to provide a basic understanding of such aspects. This summary is not an extensive overview of all intended aspects, and is neither intended to identify key or important elements of all aspects, nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that is presented later.

[0007] A method for determining the core body temperature of a subject according to one aspect of the present disclosure may include: measuring a first temperature of a first portion of a device in contact with the subject's skin at a first time, obtaining an observed first temperature, wherein the first portion is adjacent to the skin; measuring a first heat flux through the device in a direction perpendicular to the skin at a first time, obtaining an observed first heat flux; causing a temperature of a second portion of the device to reach a defined temperature, wherein the second portion is opposite to the first portion; measuring a second temperature of the first portion at a second time, obtaining an observed second temperature; measuring a second heat flux through the device in a direction perpendicular to the skin at a second time, obtaining an observed second heat flux; and using the observed first temperature, the observed first heat flux, the observed second temperature, and the observed second heat flux to determine the core body temperature of the subject. For purposes of illustration, in the present disclosure, "subject" refers to a mammal, such as a human or another type of mammal. Non-human mammals include dogs, cats, horses, chimpanzees and other non-human primates, livestock (such as cattle, pigs, sheep, etc.), and wild animals (land and marine).

[0008] A method for determining the core body temperature of a subject according to one aspect of the present disclosure may include: causing the temperature of a first portion of a device to reach a first defined temperature, wherein the device is in contact with the skin of the subject; measuring a first temperature of a second portion of the device opposite to the first portion at a first time to obtain an observed first temperature, wherein the second portion is adjacent to the skin at a first area; measuring a second temperature of a third portion of the device surrounding the second portion at a first time to obtain an observed second temperature, wherein the third portion of the device is adjacent to the skin at a second area; measuring a first heat flux through the device in a direction perpendicular to the skin at a first time to obtain an observed first heat flux; causing the temperature of the first portion to reach a second defined temperature; measuring a third temperature of the second portion at a second time to obtain an observed third temperature; measuring a fourth temperature of the third portion at a second time to obtain an observed fourth temperature; measuring a second heat flux through the device in a direction perpendicular to the skin at a second time to obtain an observed second heat flux; and determining the core body temperature of the subject using the observed first temperature, the observed second temperature, the observed first heat flux, the observed third temperature, the observed fourth temperature, and the observed second heat flux.

[0009] A method for determining the core body temperature of a subject according to one aspect of the present disclosure may include: causing the temperature of a first portion of a device to reach a first defined temperature near a static point of the device, wherein the device is in contact with the skin of the subject; measuring a first temperature of a second portion of the device opposite to the first portion at a first time to obtain an observed first temperature, wherein the second portion is adjacent to the skin at a first area; measuring a second temperature of a third portion of the device surrounding the second portion at a first time to obtain an observed second temperature, wherein the third portion of the device is adjacent to the skin at a second area; measuring a first heat flux through the device in a direction perpendicular to the skin at a first time to obtain an observed first heat flux; causing the temperature of the first portion to reach a second defined temperature near the static point; measuring a third temperature of the second portion at a second time to obtain an observed third temperature; measuring a fourth temperature of the third portion at a second time to obtain an observed fourth temperature; measuring a second heat flux through the device in a direction perpendicular to the skin at a second time to obtain an observed second heat flux; and determining the core body temperature of the subject using the observed first temperature, the observed second temperature, the observed first heat flux, the observed third temperature, the observed fourth temperature, and the observed second heat flux.

[0010] To achieve the foregoing and related ends, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A cross-sectional view of a sensor for measuring temperature according to one or more aspects of the present disclosure is illustrated.

[0012] Figure 2A An example of a sensor device for measuring temperature according to one or more aspects of the present disclosure is illustrated.

[0013] Figure 2B An example of a temperature sensing system according to one or more aspects of the present disclosure is illustrated.

[0014] Figure 3 An equivalent schematic circuit for temperature measurement according to one or more aspects of the present disclosure is illustrated.

[0015] Figure 4 A cross-sectional view of an apparatus according to one or more aspects of the present disclosure is illustrated.

[0016] Figure 5An equivalent schematic circuit for temperature measurement according to one or more aspects of the present disclosure is illustrated.

[0017] Figure 6 A flow chart illustrating an example method according to one or more aspects of the present disclosure is shown.

[0018] Figure 7 A cross-sectional view of an apparatus according to one or more aspects of the present disclosure is illustrated.

[0019] Figure 8 An equivalent schematic circuit for temperature measurement according to one or more aspects of the present disclosure is illustrated.

[0020] Fig. 9 A flow chart illustrating an example method according to one or more aspects of the present disclosure is shown.

[0021] Fig.10 A flow chart illustrating an example method according to one or more aspects of the present disclosure is shown.

[0022] Fig.11A A flow chart illustrating a portion of an example method according to one or more aspects of the present disclosure.

[0023] Fig. 11B The present invention illustrates one or more aspects of the present disclosure. Fig.11A Flowchart of another portion of the example method mentioned in .

[0024] Fig. 12A A flow chart illustrating a portion of an example method according to one or more aspects of the present disclosure.

[0025] Fig. 12B The present invention illustrates one or more aspects of the present disclosure. Fig. 12A Flowchart of another portion of the example method mentioned in . DETAILED DESCRIPTION

[0026] The detailed description set forth below in conjunction with the accompanying drawings is intended to describe various configurations and is not intended to represent only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagrams to avoid obscuring such concepts.

[0027] Overview

[0028] The present disclosure relates to measuring core body temperature (CBT) by using a heater device and / or a cooler device on a material of known electrical resistance (thermal resistor) placed on the skin. A device according to one aspect of the present disclosure measures the temperature and heat flux at the bottom of the device (skin side) while controlling the temperature or heat flux at the top of the device (ambient side) to estimate CBT. In one aspect of the present disclosure, the device can determine CBT by design and measurement techniques.

[0029] The present disclosure describes methods, devices, apparatuses, and systems that are non-invasive (e.g., can be worn on the surface of the skin) and that individually or collectively allow for measurement of CBT with clinical-grade accuracy. In addition, the present disclosure describes methods, devices, apparatuses, and systems that can monitor CBT periodically and / or continuously as needed, either individually or in combination.

[0030] In one aspect of the disclosure, a device may measure skin temperature and heat flux (represented herein by "φ") to determine CBT. In one aspect of the disclosure, the use of a heat input device (such as a heater device, a heat exchanger device, a thermoelectric generator, and / or a Peltier cell) may be used in a switching mode to reduce power consumption, which may be an improvement over other heat flux methods.

[0031] In one aspect of the present disclosure, a variable heat flux (VHF) method is disclosed. A VHF as described herein can use a single device whose heat flux through the body is controlled by a heater device / cooler device at the top of the device. A device according to one aspect of the present disclosure can operate in VHF mode or in a "dual heat flux mode", where different measurements and operating parameters can be used.

[0032] Heat flux measurements of a human body may have errors introduced because heat does not flow through the body in a vertical direction. Such errors may be referred to herein as "lateral heat flux errors."

[0033] To combat lateral heat flux errors, in one aspect of the present disclosure, lateral heat flux may be suppressed and / or eliminated by a metal housing and / or guard ring. The guard ring may operate at a quiescent point where the lateral heat flux is minimum and / or zero.

[0034] Devices according to aspects of the present disclosure regulate heat flux through the device and the body. In one aspect, a device according to the present disclosure regulates the top temperature of the device and measures the change in response of a temperature sensor (thermistor, etc.) during and / or after application of thermal energy.

[0035] Device Overview

[0036] Figure 1A cross-sectional view of a sensor for measuring temperature according to one or more aspects of the present disclosure is illustrated.

[0037] Device 100 shows a sensor device 102 coupled to a stimulus 104. In one aspect of the disclosure, sensor device 102 is a temperature sensor and stimulus 104 is a human body. Sensor device 102 is coupled to stimulus 104 at interface 106, which in one aspect of the disclosure is the outer surface of the skin. However, the desired temperature measurement is at surface 108, for example, core body temperature.

[0038] In one aspect of the present disclosure, the dimensions of the sensor device 102 are as follows: Figure 1 106. As shown, for example, sensor device 102 is the entire width / length / diameter of device 100. However, the heat flow or heat flux of stimulus 104 may not be completely perpendicular to interface 106. For example, and not by way of limitation, heat flux 110 is shown at an angle that is not perpendicular to interface 106. Similarly, heat flux 112 and heat flux 114 are shown as not perpendicular to interface 106. Flux line 116 shows that the heat flux of stimulus 104 may be curved when the desired measurement is at surface 108, thereby introducing errors into the temperature measurement at interface 106.

[0039] As with other stimuli described herein, stimulus 104 may have several layers or parameters that may be used to determine the thermal resistance of stimulus 104. When measured at interface 106, these various layers and / or parameters may be used to determine the temperature or other characteristics at surface 108.

[0040] For example, and not by way of limitation, stimulus 104 may include an epidermis layer, a papillary dermis layer, a reticular dermis layer, a fat layer, a muscle layer, and a bone layer, each having different layer thicknesses, specific heat capacities, thermal conductivity, density, blood perfusion rates, and metabolic heat generation to allow the temperature or other characteristics at surface 108 to be determined from measurements obtained at interface 106. These layers and their associated parameters may vary based on the placement and / or location of device 100 on the body, as these parameters may be different for an arm, a leg, a chest, different body types, etc., such that a more accurate determination of the parameters at surface 108 may be made at interface 106.

[0041] Figure 2AA sensor for measuring temperature according to one or more aspects of the present disclosure is illustrated. Device 200 shows a sensor device 202 coupled to a stimulus 204. In one aspect of the present disclosure, the sensor device 202 is a temperature sensor, and the stimulus 204 is a human body or a part thereof. In one aspect of the present disclosure, the device 200 includes a protective ring 206, which can be a metal ring, a thermally conductive ring, or other protective device included in the device 200. The sensor device 202 is coupled to the stimulus 204 at an interface 208, which in one aspect of the present disclosure is the outer surface of the skin. However, the desired temperature measurement is at the surface 210, for example, core body temperature.

[0042] In one aspect of the present disclosure, the dimensions of the sensor device 202 are as follows: Figure 2A As shown, for example, sensor device 202 is only a small portion, e.g., 10% of the width, of the entire width / length / diameter of device 200. However, sensor device 202 may be a larger or smaller percentage of device 200 without departing from the scope of the present disclosure.

[0043] exist Figure 2A In FIG. 2 , due to the protective ring 206, the heat flux of the stimulus 204 can be directed toward the device 200, rather than Figure 1 208, the guard ring 206 can reduce the error in the temperature measurement at the surface 210. For example, and not by way of limitation, heat flux 212 is shown at an angle that is not perpendicular to the interface 208 and is directed inwardly toward the guard ring 206. Similarly, heat flux 214 and heat flux 216 are shown as being not perpendicular to the interface 208 and are directed inwardly toward the guard ring 206. Flux line 218 shows that the heat flux for stimulus 204 can bend toward the guard ring 206, and because the sensor device 202 is close to and / or located at the center of the device 200, the heat flux at the sensor device 202 can more accurately represent the temperature at the surface 210 when measured at the interface 208.

[0044] Zero heat flux

[0045] Figure 2B An example of a temperature sensing system according to one or more aspects of the present disclosure is illustrated.

[0046] Many temperature sensors used to determine core body temperature use a technique known as "zero heat flux" (ZHF) temperature measurement. The ZHF sensing system 250 can use a device 252 having a pair of sensors 254, such as thermistors, separated by a thermal insulation layer 256. The temperature difference sensed by the sensors 254 can control the operation of a heater device 258 that stops or prevents heat flow through the skin surface area contacted by the lower surface 260 of the device 252.

[0047] Comparator 262 measures the difference in the sensed temperatures and provides the difference measurement to controller device 264. As long as the difference is not zero, heater device 258 operates. When the difference between the sensed temperatures reaches zero (or, in some cases, a tolerance value indicating that the difference is satisfactorily negligible), the zero heat flux condition is met and heater device 258 is operated as needed to maintain the condition. Sensor 254 at lower surface 260 senses a temperature that is close to (if not equal to) the temperature of the skin surface area, and the output of sensor 254 is amplified at amplifier 266 and provided at meter 268 as an output of system 250.

[0048] However, in various aspects of the present disclosure, methods similar to ZHF can be used Figure 1 and Figure 2A The sensor devices shown, and those described below, such as device 400 ( Figure 4 ) and device 700( Figure 7 That is, other devices described herein, such as device 400 and device 700, may replace device 252 to implement the techniques and / or other functions described herein. In one aspect of the present disclosure, a variable heat flux (VHF) method may be used.

[0049] Figure 3 An equivalent circuit schematic for temperature measurement according to one or more aspects of the present disclosure is shown. Schematic circuit 300 shows a resistor 302, which represents the resistance of the surrounding atmosphere or air, in series with a resistor 304, which is the resistance of a sensor (e.g., sensor device 102 or sensor device 202). It should be noted that the resistors described in the present disclosure represent thermal resistors.

[0050] Resistor 304 is connected in series with resistor 306, which is connected in parallel with resistor 308 and resistor 310. Resistor 306 is the resistance R of the stimulus. 身体 (or R b ), the stimulus is, for example, a human body, and the resistor 306 is connected to another resistor 308 (also represented by R 身体) are arranged in parallel, and resistor 308 represents the resistance of the stimulus at different points of the stimulus (e.g., the human body). Between these two resistors is resistor 310, which is composed of Figure 1 and Figure 2A The flux lines 116 and / or flux lines 218 depict a "lateral" resistance R 横向 (or R l ). Because the sensor can measure resistor 306 and resistor 308 which are very close, these resistors can be considered to be approximately equal, with the only difference being resistor 310.

[0051] The temperature measured at resistor 304 is T 皮肤 (Also known as T s )312, but the desired temperature measurement is at the T coupled to resistor 304. 核心 (Also known as T c ) 314. For nomenclature purposes only, resistor 304 is referred to as R 传感器 or R s In T s The heat flux 316 at m ; in T 核心 The heat flux 318 at 314 is φ v , and the heat flux 320 across the resistor 310 is φ l .

[0052] The resistors 304 and 310 are approximately constant with respect to changes in heat flux. To determine T c , the skin temperature and heat flux (or current through the various resistors shown in schematic circuit 300) can be measured at different times t1 and t2. In some cases, t1 occurs before t2. After performing such measurements, T can be determined according to the following expression c :

[0053] T c =T s，t1 +φ v，t1 R b (1)

[0054] T c =T s，t2 +φ v，t2 R b (2)

[0055]

[0056] In equation (1) and equation (2), T σ，τ represents the skin temperature measured at time τ, and Indicates that at time τ at T 核心The heat flux at . In equation (3), R is arranged in parallel s and R l The effective resistance of

[0057] Variable heat flux with housing

[0058] Figure 4 4 shows a cross-sectional view of an example of an apparatus according to one or more aspects of the present disclosure. Apparatus 400 may include a heater device 402, a first sensor 404, a sensor material 406, a housing 408, and a second sensor 410. Stimulus 412 is also shown and may be related to Figure 1 and Figure 2A The device 400 may be in contact with the skin of the subject.

[0059] Heater device 402 may be a heater device or a thermoelectric generator, or may be a device that can heat and cool (such as a Peltier cell). Heater device 402 may be referred to herein as a heat input device. First sensor device 404 may be used to determine the temperature closer to heater device 402 and to determine the heat flux through sensor material 406. Sensor material 406 may be a dielectric or other material that is less thermally conductive than housing 408. Housing 408 may be a metal housing or other thermally conductive material. Second sensor 410 may be used to determine the temperature at surface 414 of stimulus 412. Figure 1 and Figure 2A As in , the desired temperature measurement of stimulus 412 is at surface 416 , although access to stimulus 412 is typically limited to surface 414 .

[0060] In one aspect of the disclosure, a first measurement at time t1 and a second measurement at time t2 may be made by device 400. At time t1, heater device 402 may not be active, e.g., not providing heat to stimulus 412. At time t2, heater device 402 may be active, e.g., providing heat to stimulus 412. Measurements may be made by first sensor 404 and second sensor 410 at times t1 and t2.

[0061] Measurements made at times t1 and t2 may yield a temperature at surface 414, such as T s , which represents the skin temperature, which can be referred to as T s,t1 and T s,t2 In addition, the temperature difference between the first sensor 404 and the second sensor 410 can generate a heat flux through the device 400, such as φ m .

[0062] Figure 5illustratively illustrates an equivalent schematic circuit for temperature measurement according to one or more aspects of the present disclosure. Schematic circuit 500 illustrates an equivalent schematic circuit for temperature measurement according to one or more aspects of the present disclosure. Figure 4 An equivalent circuit diagram of the device 400 is described.

[0063] The schematic circuit 500 shows a top temperature 502, which represents the top temperature measured by the first sensor 404. Figure 4 400. In the schematic circuit 500, resistor 504 is the resistance of sensor material 406. Resistor 506 and resistor 508 are the resistance of the body (e.g., stimulus 412). Resistor 506 is in series with the parallel combination of resistor 504 and resistor 510 (lateral heat flux), and resistor 506 is arranged in parallel with resistor 508. Similarly, resistor 508 is the resistance of the human body at a different point, for example, the resistance outside the surface of the second sensor 410. Because the housing 408 surrounds the second sensor 410, resistor 508 is in parallel with resistor 504.

[0064] The temperature measured by the first sensor 404 at the top of the device 400 is T 顶部 502, and the temperature measured at the surface 414 is T s 512. Similarly, the expected temperature measurement is T 核心 (Tc)514. s The heat flux 516 at m ; in T 核心 The heat flux 518 at 514 is φ v , and the heat flux 520 across the resistor 510 is φ l The heater device 402 is shown as a voltage source 522. The temperature T 顶部 502 is determined by various factors, including the environment surrounding the device 400 (eg, the area covering the surface 414 ), and the presence or absence of heat supplied by the heater device 402 .

[0065] At a first time, denoted by t1, for nomenclature purposes only, the following measurements are performed: (T s,t1 ,φ m,t1 ). At the first time, the temperature T 顶部 502 has a sensor 404 ( Figure 4 ) The first value T measured 顶部,t1 (which can be represented by T top 1).

[0066] At a second time, denoted by t2, for nomenclature purposes only, the following measurements are performed: (T s,t2 ,φ m,t2 ). At the second time, the temperature T 顶部 502 has a sensor 404 ( Figure 4) The second value T measured 顶部,t2 (which can be represented by T top 2).

[0067] Here, the first time (t1) may occur before the second time (t2).

[0068] From these measurements at the first time (t1) and the second time (t2), the core body temperature T of the stimulus 412 can be determined as follows c And the total resistance R t :

[0069]

[0070] Wherein, as described herein, σ，τ represents the skin temperature measured at time τ, and φ μ，τ Indicates that at time τ at T s The heat flux measured at R is arranged in parallel s and R l The effective resistance of

[0071] Further references Figure 4 , variable heat flux measurements may be made using the device 400 of the present disclosure by controlling the heat generated by the heater device 402 and by measuring the skin temperature and heat flow caused by the stimulus 412 when the heater device 402 is off and when the heater device 402 is activated.

[0072] T with the desired accuracy (or error) c can be determined by generating a defined heat flux difference Δφ between the heat flux at the corresponding measuring times t2 and t1 目标 =φ t2 -φ t1 For example, this can be achieved by causing T 顶部，t2 The following relationship is satisfied to achieve such a defined heat flux difference:

[0073] T 顶部，t2 =T c -φ t2 (R t +R s ) (7)

[0074] In order to cause this type of T 顶部，t2 The heat supplied by the heater device 402 may be controlled (eg, via a PID control loop), and the T may be monitored via the sensor device 404. 顶部 , until T 顶部 At a specific time t, the above value T is reached 顶部，t2 This time defines t2.

[0075] It should be noted that since the subject's core body temperature is the quantity being detected, the target T of the subject being monitored (or, for example, stimulus 412) is 顶部,t2 is initially unknown. Therefore, T c and R t The prior value of can be used to provide the target T 顶部,t2 In one example, the prior value can be obtained by replacing T c and R t Configured as core body temperature T c (nom) and body resistance R t (nom) The nominal value of R s The specific value of R s The value of Rs may be calibrated during manufacture of the device 400 and remain constant thereafter. An exemplary value for Rs is approximately 0.1 K·m 2 / W. CBTT e (nom) and body resistance R t (nom) The examples are 37℃ and 0.1K·m 2 / W. After such a configuration, and assuming φ t1 = 0 (heater device 402 is in idle mode), precursor target value Can be determined for a desired accuracy (or error). Such precursors can be c and R t is used as the target T in the initial determination of 顶部，t2 . T c and R t Such initial values ​​can be used to convert the precursor Corrected to the appropriate T 顶部，t2 , to determine the subject's actual T according to equations (5) and (6) above c and R t .

[0076] Figure 6 400 ( FIG. 4A ) is a flowchart illustrating an example method 600 for determining the core body temperature of a subject according to one or more aspects of the present disclosure. The example method 600 may use the apparatus 400 ( Figure 4 ) to implement.

[0077] The example method 600 includes an initialization phase in which the core body temperature T c and body resistance R t Such estimates are used to determine the initial target temperature T described in this article. 顶部 (For example, T 顶部，t2The initialization phase may include block 602, wherein the apparatus 400 ( Figure 4 ) is initialized, wherein the heater device 402 is passive for a first measurement at a first time and is active for a second measurement at a second time. The first measurement produces (T s,t1 ,φ m,t1 ) and T 顶部，t1 , where t1 represents the first time. A second measurement is performed under the heat flux requirement described above, wherein the heat provided by the heater device 402 is controlled to reach the precursor T at a specific time. 顶部 Target temperature In some cases, the specific time defines the second time t2. In other cases, the second time may be a time after the specific time. The second measurement at t2 produces (T s,t1 ,φ m,t1 ).

[0078] At block 604, using the two measurements from block 602, the device may calculate some parameters, such as T according to equations (5) and (6). c and / or R t The core body temperature Tc obtained at block 604 is an initial estimate of the subject's actual core body temperature because The nominal value T has been used c (nom) and R t (nom) Such a device includes computing resources, such as a processor or processing circuit system and one or more memory devices. In some cases, the device may be device 400 or may include device 400. In other cases, the device may be functionally coupled with device 400.

[0079] At block 606, another first measurement may be taken with the heater device 402 "idle" (eg, not activated and / or providing no heat input), and the first sensor 404 and the second sensor 410 taking measurements. Such other first measurements produce another pair (T s,t1 ,φ m,t1 ).

[0080] At block 608, a decision may be made whether to activate the heater device 402. In response to the heater device 402 not being activated, route 610 is followed to return to block 606. In response to the heater device 402 being activated, flow continues to block 612 where another second measurement is made under the heat flux requirement described above.

[0081] Specifically, at block 612, another second measurement is taken at another second time, wherein the heater device 402 is in an active mode, e.g., providing heat to the device 400. As part of block 612, measurements are performed by the first sensor 404 and the second sensor 410. As described herein, the amount of heat provided by the heater device 402 is controlled to reach T at a particular time. 顶部 Temperature T 顶部，t2 Target temperature T 顶部，t2 The T obtained at block 604 may be used at least in part c and R t In some cases, the specific time defines another second time t2. In other cases, the other second time may be a time after the specific time. The second measurement at the other second time t2 produces (T s,t2 ,φ m,t2 ).

[0082] At block 614, using another first measurement from block 606 and another second measurement from block 612, the device may calculate some parameters, such as T according to equations (5) and (6). c and / or R t Temperature T c It may be provided as the core body temperature of the subject. The device includes a computing resource, such as a processor or processing circuit system and one or more memory devices. In some cases, the device that calculates the parameter at block 612 is the same device as the device that calculates the parameter at block 604.

[0083] Route 616 shows control returning to block 606. After returning to block 606, another core body temperature of the subject may be determined. By iteratively implementing blocks 606 to 614, the core body temperature of the subject may be monitored.

[0084] Although in Figure 6 4, but according to aspects described herein, the device 400 or a device functionally coupled thereto (eg, a controller device or a processor) may provide a calculated Tc or R t One or more of .

[0085] Variable heat flux with guard ring

[0086] Figure 7 700 may include a heat exchanger device 702, a first sensor 704, a sensor material 706, a protective ring 708, and a second sensor 710. A stimulus 712 is also shown and may be related to Figure 1 and Figure 2AThe device 700 may be in contact with the skin of the subject.

[0087] The heat exchanger device 702 can be, for example, a solid state heat pump device or a thermoelectric generator, and / or a device that can heat and cool, such as a Peltier cell. The heat exchanger device 702 can be referred to herein as a heat input device. The first sensor 704 can be used to determine the temperature closer to the heat exchanger device 702 and determine the heat flux through the sensor material 706. The sensor material 706 can be a dielectric or other material. The guard ring 708 can be a device that can measure the temperature T sedge that is, at the edge of the sensor area at the skin surface. In some cases, the protective ring 708 is cylindrically symmetric about the direction z and can thus contact the skin at the annular area. The second sensor 710 can be used to determine the temperature at the surface 714 of the stimulus 712. Figure 1 and Figure 2A Likewise, the desired temperature measurement of stimulus 712 is at surface 716 , although access to stimulus 712 is typically limited to surface 714 .

[0088] Figure 8 An equivalent schematic circuit for temperature measurement according to one or more aspects of the present disclosure is illustrated.

[0089] Schematic circuit 800 illustrates an example of Figure 7 An equivalent circuit diagram of the device 700 is described.

[0090] Schematic circuit 800 shows a top temperature 802 (T 顶部 ), which represents the value of Figure 7 The temperature at the top of the device 700 is shown.

[0091] Resistor 804 is the resistance of sensor material 706. Resistor 806 and resistor 808 are the resistance of the body (e.g., Figure 7 806 is connected in parallel with resistor 808. Similarly, resistor 808 is the resistance of the human body at a different point (e.g., outside the surface of second sensor 710). Because guard ring 708 surrounds second sensor 710, resistor 508 is connected in parallel with resistor 806.

[0092] The temperature measured by the first sensor 704 at the top of the device 700 is T 顶部 802, and the temperature measured at the surface 714 is T s 812. Similarly, the desired temperature measurement is at T 核心 (T c )814. In Ts The heat flux 816 at m ; in T 核心 The heat flux 818 at 814 is φ v , and the heat flux 820 across the resistor 510 is φ l The heat exchanger device 702 is shown as a voltage source 822 .

[0093] The protection ring 708 can be used to sfar 824, the guard ring 708 may be coupled to a resistor 826, which represents the resistance of the surrounding environment (R 空气 ). The temperature of the surrounding environment is at point 828 and is provided to the body (e.g., Figure 7 The heat of the stimulus 712 in is represented by a heater device shown as a voltage source 830.

[0094] At a first time, denoted by t1, for nomenclature purposes only, the following measurements are performed: (T s,t1 ,φ m,t1 , T sedge,t1 ).

[0095] At a second time, denoted by t2, for nomenclature purposes only, the following measurements are performed: (T s,t2 ,φ m,t2 , T sedge,t2 ).

[0096] In this article, the first time is before the second time.

[0097] From these measurements, the core body temperature T can be calculated according to the following expression c And the total resistance R b :

[0098]

[0099] Here, equation (8) is the same as equation (5). Although equation (9) has the same form as equation (6), the resistance determined via equation (6) corresponds to the resistance of the human body (e.g., stimulus 712). In other words, because sensor material 706 is a dielectric, And equation (9) corresponds to R b As described in this article, the total resistance of the body, R b A plurality of first resistors including corresponding layers of soft tissue and a second resistor of bone tissue.

[0100] Further references Figure 7, device 700 may be used to perform variable heat flux measurements by controlling the heat generated by heat exchanger device 702 and by measuring skin temperature and heat flow caused by stimulus 712 when heat exchanger device 702 is off and when heat exchanger device 702 is activated.

[0101] In addition, the static point T q It can be found at the intersection of two lines:

[0102] By the first endpoint (T 顶部,t1 , T s,t1 ) and (T 顶部,t2 , T s,t2 ) defined by line 1, where the first endpoint is obtained from appropriate measurements at a first time (t1) and a second time (t2).

[0103] By the second end point (T 顶部,t1 , T sedge,t1 ) and (T 顶部,t2 , T sedge,t2 ) defined by line 2, wherein the second endpoint is obtained from appropriate measurements at the first time (t1) and the second time (t2).

[0104] For purposes of illustration only, the static point represents heating or cooling the top of the device 700 - e.g., the distal end of the device 700 relative to the subject's skin, along a direction perpendicular to the skin - resulting in the skin temperature under the first sensor of the device 700 near the skin being the same temperature as the skin temperature farther from the sensor. Thus, the device 700 does not present a thermal resistance. That is, the heat flux through the skin with the device 700 in contact with the skin is the same as the heat flux without the device 700 in contact with the skin. Thus, the subject does not feel (or substantially does not feel) the heat injected into the subject's body.

[0105] For illustrative purposes only and without intending to be bound by theory and / or model, at a static point T q , the skin temperature under the sensor device 710 is the same as the skin temperature at a location spaced apart from the sensor device 710. Therefore, at the static point T 顶部，q , device 700 presents no thermal resistance. That is, the heat flux through the skin when device 700 is present is the same as the heat flux through the skin when device 700 is not present.

[0106] T with the desired accuracy (or error) c can be determined by inducing a defined heat flux difference (or a defined heat flux condition) Δφ between the heat fluxes at the corresponding measuring times t2 and t1 目标 =φ t2 -φ t1This type of heat flux difference can be achieved in at least two forms. In the first form, it can be achieved by making T 顶部，t2 The following relationship is satisfied to achieve the defined heat flux difference: T 顶部，t2 =T c -(φ m，t1 -Δφ 目标 )(R b +R s ). Such a first modality does not involve static points and may be referred to as a "spot-check mode" for nomenclature purposes only. It should be noted that the expected T of the subject being monitored (or, for example, stimulus 712) is 顶部，t2 Initially unknown, since the subject's core body temperature is the quantity being detected.

[0107] In the second form, the static point T can be obtained by moving from the first time t1 to the second time t2 around the static point T q Convert T 顶部 To achieve the defined heat flux difference, where T 顶部，t1 and T 顶部，t2 The following relations are satisfied:

[0108] T 顶部，t1 =T c (φ m，q +Δφ 目标 / 2)(R b +R s ) (10)

[0109] T 顶部，t2 =T c -(φ m，q -Δφ 目标 / 2)(R b +R s ) (11) As can be gathered from equations (10) and (11), T 顶部 By relative to the static point φ m，q The heat flux at the supply heat is realized, and at the second time t2 T 顶部 By relative to φ m，q This second mode can be referred to as "dithering mode" for nomenclature only. It should be noted that the desired T 顶部，t2 and the T of the subject being monitored (or, for example, stimulus 712) 顶部，t2 Initially unknown, since the subject's core body temperature is the quantity being detected.

[0110] In both spot check mode and dither mode, the precursor target can be determined according to the aspects described above. and / or precursor targets Specifically, T c and R t The prior value of can be used to provide the target T 顶部 As mentioned above, in one example, the prior value can be obtained by replacing T c and R t Configured as core body temperature T c (nom) and body resistance R t (nom) The nominal value of R s As mentioned above, R s The value of can be calibrated during manufacture of the device 700 and remain constant thereafter. In addition, in spot check mode, when determining the precursor When using φ m，t1 The observed value of .

[0111] Fig. 9 900 is a flowchart illustrating an example method for determining the core body temperature of a subject according to one or more aspects of the present disclosure. Example method 900 may use apparatus 700 ( Figure 7 ) to implement.

[0112] The example method 900 includes an initialization phase, in which a static point T 顶部，q Core body temperature T c , body resistance R t and T 顶部 Such estimates are used to determine one or more initial target temperatures T described herein. 顶部 (For example, T 顶部，t2 or T 顶部，t1 and T 顶部，t2 Both).

[0113] The initialization phase may include block 902, at which the apparatus 700 ( Figure 7 ) is initialized, including configuring the heat exchanger device 702 to a passive state for a first measurement and configuring the heat exchanger device 702 to an active state for a second measurement.

[0114] At block 904, a first measurement may be performed with the heat exchanger device 702 "idle," e.g., passive and / or providing no heat input. The first measurement includes a measurement of temperature and heat flux at a first time (e.g., represented by t1). The first measurement produces (T s,t1 ,φ m,t1 , T sedge,t1 ) and T 顶部，t1 The first sensor 704 and the second sensor 710 may measure temperature and / or heat flux.

[0115] Also at block 904, a second measurement may be performed with the heat exchanger device 702 in an activated state. Specifically, the second measurement is performed under the heat flux requirement described above, wherein control may be performed by the heat exchanger device 702 ( Figure 7 ) to reach the precursor T at a specific time 顶部 Target temperature In some cases, the particular time defines the second time (e.g., represented by t2). In other cases, the second time may be a time after the particular time. The second measurement at t2 produces (T s,t2 ,φ m,t2 , T sedge,t2 ). The second time may be after the first time. The first sensor 704 and the second sensor 710 may measure temperature and heat flux under heat flux requirements.

[0116] Furthermore, at block 904, using the two measurements at the first time and the second time, various parameters may be calculated, for example, at the static point T 顶部，q T c , R b and T 顶部 . T c and R b The values ​​of can be calculated according to equation (7) and equation (8) respectively. 顶部,t1 , T s,t1 )、(T 顶部,t2 , T s,t2 )、(T 顶部,t1 , T sedge,t1 ) and (T 顶部,t2 , T sedge,t2 ) after which the static point T 顶部，q It can be calculated according to the above definition of Line 1 and Line 2. In some cases, a device including computing resources can calculate various parameters.

[0117] At block 905 , the device 700 operates in an idle mode, for example, where the heat exchanger device 702 does not provide any heat input to the stimulus 712 .

[0118] Since the static point T is obtained at block 904 顶部，q , so the device 700 can operate at this static point. Therefore, at block 906, the first sensor 704 is at the static point T 顶部，q To this end, the heat exchanger device 702 can be actively controlled to achieve T 顶部，q (From block 904). The particular time is then defined as a first time (eg, represented by t1).

[0119] At block 908, a decision is made whether to activate the heat exchanger device 702. In response to the heat exchanger device 702 not being activated, route 910 is followed to return to block 905 where the device 700 remains idle. In response to the heat exchanger device 702 being activated, at block 912 the device 700 is placed in a sensing mode.

[0120] In the sensing mode, the device 700 measures temperature and heat flux according to one of a spot check mode or a dithering mode.

[0121] At block 914 , in one aspect of the sensing mode, a spot check mode as described herein may be implemented where one or a small number of measurements are performed by various sensors in the device 700 .

[0122] At block 916, the device 700 operates in a spot check mode, wherein a first measurement of temperature and heat flux is performed at another first time while the heat exchanger device 702 is in an idle mode. The first measurement produces (T s,t1 ,φ m,t1 , T sedge,t1 ).

[0123] Also at block 916, a second measurement is performed at another second time, wherein the heat exchanger device 702 operates according to the heat flux requirement. As described herein, under the heat flux requirement (or condition), the heat exchanger device 702 can be controlled to cause T 顶部 Reach the target temperature T at a specific time 顶部，t2 =T c -(φ m，t1 -Δφ 目标 )(R b +R s ). As mentioned above, R s The value of can be calibrated during the manufacture of the device 700 and remain constant thereafter. 顶部，t2 The T obtained at block 904 may be used at least in part c and R b In some cases, the specific time defines another second time t2. In other cases, the other second time t2 may be a time after the specific time. The second measurement at the other second time t2 generates (T s,t2 ,φ m,t2 , T sedge,t2 ).

[0124] Still at block 916, the apparatus 700 may calculate some parameters based on the first measurement and the second measurement, such as the current T c , current Rb and current static point T 顶部,q More specifically, the current T cThe values ​​of the current Rb can be calculated according to equations (7) and (8), respectively. 顶部,t1 , T s,t1 )、(T 顶部,t2 , T s,t2 )、(T 顶部,t1 , T sedge,t1 ) and (T 顶部,t2 , T sedge,t2 ), calculate the current static point T according to the definition of line 1 and line 2 above 顶部,q In some cases, another device that is functionally coupled to or integrated into device 700 may calculate such parameters. The other device includes computing resources to calculate the parameters. Flow of example method 900 returns to block 905 via route 918 .

[0125] At block 920 , in another aspect of the sensing mode, a “continuous dithering” mode is implemented where measurements are performed by the various sensors in the device 700 around a static point under heat flux requirements.

[0126] At block 922, the device 700 operates in the dithering mode described above, wherein a series of measurements are repeated at a defined rate, thereby implementing a continuous dithering mode. The series of measurements includes a first measurement performed at a first time (e.g., represented by t1) wherein the heat exchanger device 702 is operated at a distance away from the static point under the heat flux requirement. More specifically, as an example, at a particular time, the device 700 may cause the temperature T 顶部 To reach T defined by equation (9) 顶部,t1 To this end, the amount of heat supplied or extracted by the heat exchanger device 702 may be controlled (eg, via a PID control loop), and T may be monitored via the sensor device 704. 顶部 , until T 顶部 At a specific time, the above value T is reached 顶部,t1 In some cases, such a specific time defines a first time. In other cases, the first time may be a time after the specific time. The first measurement at the first time produces (T s,t1 ,φ m,t1 , T sedge,t1 ).

[0127] The series of measurements also includes a second measurement performed at a second time (e.g., represented by t2) where the heat exchanger device 702 operates on the other side of the static point under the heat flux requirement. That is, as an example, at another specific time, the device 700 may cause the temperature T 顶部 To reach T defined by equation (10) 顶部,t2To this end, the amount of heat supplied or extracted by the heat exchanger device 702 can be controlled and T can be monitored via the sensor device 704. 顶部 , until T 顶部 At another specific time, the above value T is reached 顶部,t2 In some cases, such a specific time defines the second time. In other cases, the second time may be a time after the specific time. The second measurement at the second time produces (T s,t2 ,φ m,t2 , T sedge,t2 ).

[0128] Also at block 922, the apparatus 700 may calculate some parameters, such as T based on the series of measurements. c , R b and static point T 顶部，q In some cases, another device that is functionally coupled to or integrated into device 700 may calculate such parameters. The other device includes computing resources that calculate the parameters. The flow of example method 900 returns to block 920 via route 924. After returning to block 920, T may be determined. c , R b and static point T 顶部，q By further returning to block 920 and further determining T c , R b and static point T 顶部，q The current value of the CBT of the subject can be monitored at a defined rate.

[0129] Although in Fig. 9 700 or a device functionally coupled thereto (eg, a controller device or a processor) may provide a calculated T c , R b or T 顶部，q One or more of .

[0130] Fig.10 1 is a flow chart illustrating an example method 1000 for determining the core body temperature of a subject according to one or more aspects of the present disclosure. The example method 1000 may be performed by, for example, an apparatus 400 ( Figure 4 ) and a controller device and / or another type of processor. The system may be referred to as a sensing system or a sensing device. An example of a controller device is controller device 264 ( FIG. 2 ).

[0131] At block 1002, the system can measure a first temperature of a first portion of a device 400, which is in contact with the skin of a subject, at a first time (e.g., t1). The device 400 included in the system can measure the first temperature via a second sensor 410. The first portion of the device 400 abuts the skin and surrounds the vicinity of the second sensor 410. Measuring the first temperature results in an observed first temperature.

[0132] At block 1004, the system can measure at a first time the direction perpendicular to the skin (see Figure 4 A first heat flux (in the direction z) indicated by the arrow in FIG. 4 passes through the device 400 to obtain an observed first heat flux.

[0133] At block 1006, the system may cause a temperature of a second portion of the apparatus 400 to reach a defined temperature, wherein the second portion of the apparatus 400 is opposite the first portion of the apparatus 400. The defined temperature corresponds to a defined heat flux condition associated with an expected error in the determined core body temperature. The defined temperature may be a temperature defined by equation (7) and may be determined according to aspects described herein.

[0134] As described herein, device 400 includes heater device 402. Device 400 can be functionally coupled to a controller device, or in some cases, to other processors included in the system. Causing a temperature of a second portion of device 400 can include applying heat to device 400 via heater device 402, and monitoring the temperature of the second portion of device 400 in response to applying heat to device 400. The controller device or other processor can cause heater device 402 to apply heat, and can also monitor the temperature of the second portion of device 400.

[0135] At block 1008 , the system may measure a second temperature of the first portion of the device 400 at a second time (eg, t2 ), resulting in an observed second temperature. The device 400 included in the system may measure the second temperature via a second sensor 410 .

[0136] At block 1010, the system can measure at a second time the direction perpendicular to the skin (see Figure 4 A second heat flux through the device 400 in a direction z) indicated by an arrow in the graph is obtained to obtain an observed second heat flux.

[0137] At block 1012, the system may determine the core body temperature of the subject using the observed first temperature, the observed first heat flux, the observed second temperature, and the observed second heat flux. A controller device (e.g., controller device 264 ( Figure 2B )) or other processor can determine the subject's CBT according to equation (5).

[0138] At block 1014, the system may determine the total resistance of the subject's body using the observed first temperature, the observed second temperature, the observed first heat flux, and the observed second heat flux. A controller device (e.g., controller device 264 ( Figure 2B )) Such total resistance can be determined according to equation (6).

[0139] Although in Fig.10 , but example method 1000 may also include a box in which the system can provide a core body temperature of a subject. Providing the core body temperature of the subject can include, for example, storing data indicative of the core body temperature in a register or other type of memory device, where the register is accessible by an external computing device. In addition, or in other cases, providing the core body temperature of the subject can include causing an output of the core body temperature at a device (a computing device, a display device, or another type of device; wearable or otherwise). Outputting the core body temperature can include presenting a visual marker, an auditory marker (e.g., an audible sound), and / or a tactile marker (e.g., a movement) indicating the core body temperature.

[0140] Fig.11A and Fig. 11B 1 and 2 illustrate a flow chart of an example method 1100 for determining the core body temperature of a subject according to one or more aspects of the present disclosure. The example method 1100 may be performed by, for example, apparatus 700 ( Figure 7 ) and a controller device and / or another type of processor. An example of a controller device is controller device 264 (FIG. 2).

[0141] At block 1102, the system may cause a temperature of a first portion of the device 700 to reach a first defined temperature, wherein the device 700 is in contact with the skin of a subject. The defined temperature may correspond to a current static point of the device 700. As described herein, for purposes of illustration only, the static point represents a temperature at which heating or cooling the top of the device 700—e.g., the distal end of the device 700 relative to the skin of the subject, along a direction perpendicular to the skin—results in a skin temperature near the skin under a first sensor of the device 700 being the same as the skin temperature far from the sensor. Thus, the device 700 does not present a thermal resistance.

[0142] As described herein, the device 700 includes a heat exchanger device 702. The heat exchanger device 702 can be functionally coupled to a controller device or other processor included in the system. Causing the temperature of the first portion of the device 700 to reach a first defined temperature can include applying heat to the device 700 via the heat exchanger device; and monitoring the temperature of the first portion of the device in response to applying heat to the device. The controller device can cause the heat exchanger device 702 to apply heat, and can also monitor the temperature of the first portion.

[0143] At block 1104, the system can measure a first temperature of a second portion of the device 700 opposite the first portion at a first time (e.g., t1). The second portion abuts the skin at a first area. The device 700 included in the system can measure the first temperature via the second sensor 710. Measuring the first temperature results in an observed first temperature.

[0144] At block 1106, the system can measure a second temperature of a third portion of the device 700 surrounding the first region at a first time. The third portion of the device abuts the skin at the second region, where in some cases, the second region is an annular region. The device 700 included in the system can measure such second temperature via the protective ring 708. Measuring such second temperature results in an observed second temperature.

[0145] At block 1108, the system can measure at a first time the direction perpendicular to the skin (eg, Figure 7 The heat flux is measured to obtain a first observed heat flux. The heat flux is measured according to aspects described herein.

[0146] At block 1110, the system may cause the temperature of the first portion of the device 400 to reach a second defined temperature. The second defined temperature may correspond to a defined heat flux condition associated with the determined error in the core body temperature. Causing the temperature of the first portion to reach the second defined temperature may include applying heat to the device via a heat exchanger device; and monitoring the temperature of the first portion of the device in response to applying heat to the device. A controller device or other processor included in the system may cause the heat exchanger device 702 to apply heat, and may also monitor the temperature of the first portion.

[0147] At block 1112, the system may measure a third temperature of a second portion of the device 700 at a second time (eg, t2). The device 700 included in the system may measure the first temperature via the second sensor 710. Measuring such a third temperature results in an observed third temperature.

[0148] At block 1114 , the system can measure a fourth temperature of the third portion of the device 700 at the second time, resulting in an observed fourth temperature. The device 700 included in the system can measure such fourth temperature via the guard ring 708 .

[0149] At block 1116, the system can measure a second heat flux through the device 700 in a direction perpendicular to the skin at a second time (eg, t2). Measuring the second heat flux yields an observed second heat flux. The heat flux is measured according to aspects described herein.

[0150] At block 1118 ( Fig. 11B), the system can use the observed first temperature, the observed second temperature, the observed first heat flux, the observed third temperature, the observed fourth temperature, and the observed second heat flux to determine the core body temperature of the subject. A controller device (e.g., controller device 264 ( Figure 2B )) or another processor can determine the subject's CBT based on equation (8).

[0151] At block 1120 ( Fig. 11B ), the system can use the observed first temperature, the observed third temperature, the observed first heat flux, and the observed second heat flux to determine the resistance of the subject's body. A controller device (e.g., controller device 264 ( Figure 2B )) or another processor can determine such resistance, such as R, according to equation (9). b As described herein, the resistance determined is the thermal resistance.

[0152] At block 1122 ( Fig. 11B ), the system can determine a static point of the device. Determining the static point of the device includes: determining a first line extending from a first endpoint defined by a first defined temperature and an observed first temperature to a second endpoint defined by a second defined temperature and an observed third temperature; determining a second line extending from a third endpoint defined by the first defined temperature and the observed second temperature to a fourth endpoint defined by the second defined temperature and an observed fourth temperature; and determining a specific temperature corresponding to an intersection of the first line and the second line, wherein the specific temperature defines the static point of the device.

[0153] At block 1124 ( Fig. 11B ), the system can provide the core body temperature of the subject. Providing the core body temperature of the subject can include, for example, storing data indicative of the core body temperature in a register or other type of memory device, where the register is accessible by the external computing device. In addition, or in other cases, providing the core body temperature of the subject can include causing an output of the core body temperature at the device. Outputting the core body temperature can include presenting a visual marker, an auditory marker (e.g., an audible sound), and / or a tactile marker (e.g., a movement) indicative of the core body temperature.

[0154] Fig. 12A and Fig. 12B 1 is a flow chart illustrating an example method 1200 for determining the core body temperature of a subject according to one or more aspects of the present disclosure. The example method 1200 may be performed by, for example, apparatus 700 ( Figure 7 ) and a controller device and / or another type of processor. An example of a controller device is controller device 264 (FIG. 2).

[0155] At block 1202, the system may cause a temperature of a first portion of device 700 to reach a first defined temperature near a quiescent point of device 700, where device 700 is in contact with the skin of a subject.

[0156] At block 1204, the system may measure a first temperature of a second portion of the device 700 opposite the first portion of the device 700 at a first time (e.g., t1). The second portion abuts the skin at a first area. The device 700 included in the system may measure the first temperature via the second sensor 710. Measuring the first temperature results in an observed first temperature.

[0157] At block 1206, the system can measure a second temperature of a third portion of the device 700 surrounding the first region at a first time. The third portion of the device abuts the skin at the second region, where in some cases, the second region is an annular region. The device 700 included in the system can measure such second temperature via the protective ring 708. Measuring such second temperature results in an observed second temperature.

[0158] At block 1208, the system can measure at a first time the direction perpendicular to the skin (eg, Figure 7 The heat flux is measured to obtain an observed first heat flux. The heat flux is measured according to aspects described herein.

[0159] At block 1210, the system may cause the temperature of the first portion of the device 700 to reach a second defined temperature about the quiescent point. The magnitude of the difference between the first defined temperature and the quiescent point is substantially the same as the magnitude of the difference between the second defined temperature and the quiescent point.

[0160] With respect to causing the temperature of the first portion of the device 700 to reach a specific temperature, as described herein, the device 700 includes a heat exchanger device 702. The heat exchanger device 702 can be functionally coupled to a controller device included in the system. Causing the temperature of the first portion to reach a first defined temperature may include applying heat to the device 700 via the heat exchanger device; and monitoring the temperature of the first portion of the device in response to applying heat to the device. The controller device may cause the heat exchanger device 702 to apply heat, and may also monitor the temperature of the first portion. In addition, causing the temperature of the first portion to reach a second defined temperature may include extracting heat from the device 700 via the heat exchanger device; and monitoring the temperature of the first portion of the device in response to extracting heat from the device. The controller device may cause the heat exchanger device 702 to extract heat, and may also monitor the temperature of the first portion.

[0161] At block 1212, the system may measure a third temperature of a second portion of the device 700 at a second time (eg, t2). The device 700 included in the system may measure the first temperature via the second sensor 710. Measuring such a third temperature results in an observed third temperature.

[0162] At block 1214, the system may measure a fourth temperature of the third portion of the device 700 at the second time, resulting in an observed fourth temperature. The device 700 included in the system may measure such fourth temperature via the guard ring 708. Measuring such fourth temperature results in the observed second temperature.

[0163] At block 1216, the system can measure a second heat flux through the device 700 in a direction perpendicular to the skin at a second time. Measuring the second heat flux results in an observed second heat flux. The heat flux is measured according to aspects described herein.

[0164] At block 1218 ( Fig. 12B ), the system can use the observed first temperature, the observed second temperature, the observed first heat flux, the observed third temperature, the observed fourth temperature, and the observed second heat flux to determine the core body temperature of the subject. A controller device (e.g., controller device 264 ( Figure 2B )) or another processor can determine the subject's CBT based on equation (8).

[0165] At block 1220 ( Fig. 12B ), the system can use the observed first temperature, the observed third temperature, the observed first heat flux, and the observed second heat flux to determine the resistance of the subject's body. A controller device (e.g., controller device 264 ( Figure 2B )) or another processor can determine such resistance, such as R, according to equation (9). b As described herein, the resistance determined is the thermal resistance.

[0166] At block 1222 ( Fig. 12B ), the system can determine a current static point of the device. Determining the current static point of the device includes: determining a first line extending from a first endpoint defined by a first defined temperature and an observed first temperature to a second endpoint defined by a second defined temperature and an observed third temperature; determining a second line extending from a third endpoint defined by the first defined temperature and the observed second temperature to a fourth endpoint defined by the second defined temperature and an observed fourth temperature; and determining a specific temperature corresponding to an intersection of the first line and the second line, wherein the specific temperature defines the static point of the device.

[0167] At block 1224 ( Fig. 12B), the system can provide the core body temperature of the subject, for example, via a controller device. Providing the core body temperature of the subject can include storing data indicative of the core body temperature in a register or other type of memory device, where the register is accessible by the external computing device. In addition, or in other cases, providing the core body temperature of the subject can include causing an output of the core body temperature at the device. Outputting the core body temperature can include presenting a visual marker, an auditory marker (e.g., an audible sound), and / or a tactile marker (e.g., a movement) indicative of the core body temperature.

[0168] The example method 1200 may be repeated at a specific rate to iteratively determine the subject's core body temperature, thereby monitoring the subject's core body temperature at a specific rate. To this end, the flow of the example method 1200 may be continued from block 1224 ( Fig. 12B )Continue to block 1202 ( Fig. 12B ), and can be used at block 1222 ( Fig. 12B ) continues from the current static point determined by the RT. In some configurations at a particular rate, core body temperature can be monitored almost continuously.

[0169] The term "processor" as used in this disclosure refers to any computational processing unit or device, including a processing circuit system that can operate on data and / or signaling. The computational processing unit or device may include, for example, a single-core processor; a single processor with software multi-threaded execution capability; a multi-core processor; a multi-core processor with software multi-threaded execution capability; a multi-core processor using hardware multi-threading technology; a parallel platform; and a parallel platform with distributed shared memory. In addition, the processor may include an integrated circuit, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic controller (PLC), a complex programmable logic device (CPLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, which is designed to perform the functions described herein. In some cases, the processor may utilize nanoscale architectures, such as transistors, switches, and gates based on molecules and quantum dots, to optimize space usage or enhance the performance of user equipment. The processor may also be implemented as a combination of computational processing units.

[0170] It should be noted that the various example methods disclosed herein are presented and described in the form of a series of blocks (e.g., each block represents an operation or combination of operations in the method). However, the example methods are not limited by the order of the blocks and related operations, because some blocks can occur in different orders and / or occur simultaneously with other blocks of those shown and described herein. In addition, according to one or more aspects of the present disclosure, all illustrated blocks and associated actions may not be required to implement the example methods. Two or more of the example methods (and any other methods disclosed herein) can be implemented in combination with each other.

[0171] Therefore, in the absence of a process or method claim actually stating the order in which its actions or steps are to be followed, or in the absence of other specific statements in the claims or description of the subject disclosure that the steps are limited to a particular order, no order is intended to be inferred in any way. This applies to any possible non-express basis for interpretation, including: logical issues regarding the arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; the number or type of aspects described in the description or drawings; etc.

[0172] Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise or clear from the context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. Furthermore, the articles "a" and "an", as used in this specification and the drawings, should be construed to mean "one or more" unless specified otherwise or clear from the context to direct to a singular form.

[0173] In addition, the terms "example" and "such as" are used herein to mean used as an example or illustration. Any aspect or design described herein as an "example" or mentioned in conjunction with the "such as" clause is not necessarily to be interpreted as being preferred or advantageous relative to other aspects or designs described herein. On the contrary, the use of the terms "example" or "such as" is intended to present concepts in a concrete manner. Unless the context clearly indicates otherwise, the terms "first", "second", "third", etc., as used in the claims and descriptions, are merely for clarity and do not necessarily represent or imply any temporal or spatial order.

[0174] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to the exemplary aspects and aspects presented throughout this disclosure will be readily apparent to those skilled in the art, and the concepts disclosed herein may be applied in other contexts and for different purposes. Therefore, the claims are not intended to be limited to the exemplary aspects presented throughout the disclosure, but to conform to the full scope consistent with the language claims. All structural and functional equivalents of the elements of the exemplary aspects described throughout this disclosure known or to be known by a person of ordinary skill in the art are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. Unless the element is explicitly stated using the phrase "member for...", or in the case of a method claim, the element is stated using the phrase "step for...", otherwise the claim element should not be interpreted according to the provisions of 35 U.S.C. § 112 (f) or similar laws within the applicable jurisdiction.

Claims

1. A method for determining the core body temperature of a subject, comprising: measuring, at a first time, a first temperature of a first portion of the device in contact with the subject's skin to obtain a first observed temperature, wherein the first portion is adjacent to the skin; measuring a first heat flux through the device in a direction perpendicular to the skin at the first time to obtain an observed first heat flux; causing a temperature of a second portion of the device to reach a defined temperature, wherein the second portion is opposite the first portion; measuring a second temperature of the first portion at a second time to obtain an observed second temperature; measuring a second heat flux through the device in a direction perpendicular to the skin at the second time to obtain an observed second heat flux; as well as The core body temperature of the subject is determined using the observed first temperature, the observed first heat flux, the observed second temperature, and the observed second heat flux.

2. The method of claim 1, further comprising determining a total resistance of the subject's body using the observed first temperature, the observed second temperature, the observed first heat flux, and the observed second heat flux.

3. The method of claim 1, wherein the defined temperature corresponds to a defined heat flux condition associated with an error in the determined core body temperature.

4. The method of claim 1, wherein the device comprises a heater device and is functionally coupled to a controller device, and wherein the causing comprises, applying heat to the device via the heater device; and The temperature of the second portion of the device is monitored in response to the applying the heat to the device.

5. A method for determining the core body temperature of a subject, comprising: causing a temperature of a first portion of a device to reach a first defined temperature, wherein the device is in contact with the skin of the subject; measuring a first temperature of a second portion of the device opposite the first portion at a first time to obtain an observed first temperature, wherein the second portion abuts the skin at a first area; measuring a second temperature of a third portion of the device surrounding the second portion at the first time to obtain an observed second temperature, wherein the third portion of the device abuts the skin at a second area; measuring a first heat flux through the device in a direction perpendicular to the skin at the first time to obtain an observed first heat flux; causing the temperature of the first portion to reach a second defined temperature; measuring a third temperature of the second portion at a second time to obtain an observed third temperature; measuring a fourth temperature of the third portion at the second time to obtain an observed fourth temperature; measuring a second heat flux through the device in a direction perpendicular to the skin at the second time to obtain an observed second heat flux; as well as The core body temperature of the subject is determined using the observed first temperature, the observed second temperature, the observed first heat flux, the observed third temperature, the observed fourth temperature, and the observed second heat flux. The method of claim 5 , wherein the first defined temperature corresponds to a quiescent point of the device.

7. The method of claim 6, wherein the second defined temperature corresponds to a defined heat flux condition associated with an error in the determined core body temperature. The method of claim 5 , wherein the second region comprises an annular region.

9. The method of claim 5, further comprising determining an electrical resistance of the subject's body using the observed first temperature, the observed third temperature, the observed first heat flux, and the observed second heat flux.

10. The method of claim 9, wherein the electrical resistance of the body comprises a plurality of first resistances of respective layers of soft tissue and a second resistance of bone tissue. The method of claim 5 , further comprising determining a static point of the device.

12. The method of claim 11, wherein said determining the static point of the device comprises: determining a first line extending from a first endpoint defined by the first defined temperature and the first observed temperature to a second endpoint defined by the second defined temperature and the third observed temperature; determining a second line extending from a third endpoint defined by the first defined temperature and the observed second temperature to a fourth endpoint defined by the second defined temperature and the observed fourth temperature; as well as A specific temperature corresponding to the intersection of the first line and the second line is determined; the specific temperature defines the quiescent point of the device.

13. The method of claim 5, wherein the device comprises a heat exchanger device and is functionally coupled to a controller device, and wherein causing the temperature of the first portion to reach the second defined temperature comprises: applying heat to the device via the heat exchanger device; as well as The temperature of the first portion of the device is monitored in response to the applying the heat to the device.

14. The method of claim 13, wherein the heat exchanger device is one of a solid state heat pump device, a thermoelectric generator, or a Peltier cell.

15. A method for determining the core body temperature of a subject, comprising: causing a temperature of a first portion of a device to reach a first defined temperature near a quiescent point of the device, wherein the device is in contact with the skin of the subject; measuring a first temperature of a second portion of the device opposite the first portion at a first time to obtain an observed first temperature, wherein the second portion abuts the skin at a first area; measuring a second temperature of a third portion of the device surrounding the second portion at the first time to obtain an observed second temperature, wherein the third portion of the device abuts the skin at a second area; measuring a first heat flux through the device in a direction perpendicular to the skin at the first time to obtain an observed first heat flux; causing the temperature of the first portion to reach a second defined temperature about the quiescent point; measuring a third temperature of the second portion at a second time to obtain an observed third temperature; measuring a fourth temperature of the third portion at the second time to obtain an observed fourth temperature; measuring a second heat flux through the device in a direction perpendicular to the skin at the second time to obtain an observed second heat flux; as well as The core body temperature of the subject is determined using the observed first temperature, the observed second temperature, the observed first heat flux, the observed third temperature, the observed fourth temperature, and the observed second heat flux.

16. The method of claim 15, further comprising determining a current quiescent point of the device.

17. The method according to claim 16, further comprising: causing a second temperature of the first portion to reach another first defined temperature about the current static point of the device; measuring another first temperature of the second portion at another first time to obtain another observed first temperature; measuring another second temperature of the third portion at the another first time to obtain another observed second temperature; measuring another first heat flux through the device in a direction perpendicular to the skin at the another first time to obtain another observed first heat flux; causing the second temperature of the first portion to reach another second defined temperature about the current static point; measuring another third temperature of the second portion at another second time to obtain another observed third temperature; measuring another fourth temperature of the third portion at the another second time to obtain another observed fourth temperature; measuring another second heat flux through the device along the direction perpendicular to the skin at the another second time to obtain another observed second heat flux; as well as The core body temperature of the subject is determined using the another observed first temperature, the another observed second temperature, the another observed first heat flux, the another observed third temperature, the another observed fourth temperature, and the another observed second heat flux.

18. The method of claim 4, wherein the device comprises a heat exchanger device and is functionally coupled to a controller device, and wherein causing the temperature of the first portion to reach the first defined temperature comprises: applying heat to the device via the heat exchanger device; as well as The temperature of the first portion of the device is monitored in response to the applying the heat to the device.

19. The method of claim 18, wherein causing the temperature of the first portion to reach the second defined temperature comprises: extracting heat from said device via said heat exchanger device; as well as The temperature of the first portion of the device is monitored in response to the extracting the heat from the device.

20. The method of claim 15, wherein the magnitude of the difference between the first defined temperature and the quiescent point is substantially the same as the magnitude of the difference between the second defined temperature and the quiescent point.

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