Description:FIELD OF INVENTION
[001]The field of invention generally relates to measuring core body temperature. More specifically, it relates to a system and method for measuring core body temperature of a subject.

BACKGROUND
[002]Core body temperature measurement serves as a vital sign that provides valuable information about an individual's overall health status. This can be done through probes or wireless techniques. Hospital probes used for accurate core temperature measurements are uncomfortable, prone to ambient temperature errors, and carry risks of infection and complications. Peripheral measurements are delayed and may not reflect immediate spikes or dips in core body temperature. Infrared (IR) and distance-based light sensors have errors due to factors like skin color, user expertise, distance, ambient light, and temperature.
[003]Currently, existing systems do not succeed in utilizing blood flow measurements or other metrics to determine core temperature. Some devices, like IR sensors and multiparameter wearables/patches, have a standard offset for peripheral temperature, focusing on trends rather than precise core temperature. Most wearables lack clinical-grade accuracy within +- 0.5 degrees Celsius.
[004]Other existing systems have tried to address this problem. However, their scope was limited to placing a sensor on the skin for temperature measurement. The existing temperature probes primarily capture skin temperature, which is significantly influenced by changes in the surrounding environment. Moreover, there are challenges related to incomplete probe connections or susceptibility to sweat, which diminishes their effectiveness, particularly for continuous temperature monitoring.
[005]Thus, in light of the above discussion, it is implied that there is need for a system and method for more accurate estimation and determination of core body temperature of the subject, which is less invasive, more accurate and does not suffer from the problems discussed above.

OBJECT OF INVENTION
[006]The principal object of this invention is to provide a system and method to measure core body temperature of a subject with high accuracy.
[007]A further object of the invention is to provide a system and method for measuring core body temperature of the subject by measuring perfusion indices and cardiac behavior, which offer higher accuracy.
[008]Another object of the invention is to provide a less invasive system and method for measuring core body temperature of the subject.
[009]Another object of the invention is to provide a multiparametric approach to improve quality and accuracy of estimating core body temperature of the subject.
[0010]Another object of the invention is to provide a capacitance sensor to ensure proper contact and alert if contact of the system with the subject skin is disrupted, thereby avoiding poor contact of the system and ambient fluctuation errors.
[0011]Another object of the invention is to acquire temperature data from both ambient surroundings and multiple or single points on the body to estimate the core body temperature of the subject.
[0012]Another object of the invention is to provide a predictive algorithm that improves the accuracy of temperature measurement and represents a trend close to the core body temperature.
[0013]Another object of the invention is to provide a calibration protocol involving single or multiple points and considering physical markers such as Body Mass Index (BMI), skin color, and age.
[0014]Another object of the invention is to calculate the offset between peripheral and core temperature to create a non-invasive, discrete, or continuous representation of temperature.
[0015]Another object of the invention is to provide at least one or more cardiac sensors configured to measure cardiac flow for continued adjustment of temperature readings for higher accuracy.

BRIEF DESCRIPTION OF FIGURES
[0016]This invention is illustrated in the accompanying drawings, throughout which, like reference letters indicate corresponding parts in the various figures.
[0017]The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0018]Figure 1 depicts a system for measuring core body temperature of a subject, in accordance with an embodiment of the present disclosure;
[0019]Figure 2 depicts a block diagram depicting components for measuring core body temperature of the subject, in accordance with an embodiment of the present disclosure;
[0020]Figure 3 depicts a wearable for measuring core body temperature of the subject, in accordance with an embodiment of the present disclosure; and
[0021]Figure 4 illustrates a method for measuring core body temperature of a subject, in accordance with an embodiment of the present disclosure.

STATEMENT OF INVENTION
[0022]The present invention discloses a system and method for measuring core body temperature of a subject. The system comprises a temperature estimation unit that comprises a thermistor configured to acquire skin temperature of the subject from at least one contact point on the subject skin, at least one or more heating elements configured to create a no heat flux environment by controlling the surface temperature of the system in contact with skin, a capacitance sensor configured to ensure proper contact and alert if contact of the system with the subject skin is disrupted, at least one or more cardiac sensors configured to measure cardiac flow for continued adjustment of temperature readings for higher accuracy.
[0023]The system further comprises a processing unit configured to acquire temperature data from the thermistor, the at least one or more heating elements, the capacitance sensor, and the at least one or more cardiac sensors in the temperature estimation unit and the processing unit further configured to dynamically adjust the subject temperature reading based on the acquired temperature data from the at least one or more cardiac sensors.
[0010]

DETAILED DESCRIPTION
[0024]The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and/or detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0025]The present invention discloses a system and a method for measuring core body temperature. The primary method through which the mammalian body maintains its temperature is via blood flow. When blood flows into a specific area of the body, the temperature in that region usually increases, and conversely, when it flows out, the temperature drops. The method of the proposed invention comprises conducting an initial calibration of the body temperature, followed by continuous measurement of blood movement using various metrics, including perfusion index, to quickly and accurately detect any changes in body temperature.
[0026]In this system, a temperature sensing unit is placed on the subject's body, alongside cardiac flow sensors to capture cardiac flow inputs. The invention utilizes the current gold standards for temperature collection to establish a precise baseline for each individual subject. To estimate the relative variance between the core and other measurement points, temperature measurements are taken from different areas of the patient's body, ranging from smaller to larger regions. This calibration exploits the consistent relative difference between the core and skin points specific to each patient, resulting in a more robust data collection system tailored to individuals.
[0027]Figure 1 depicts a system for measuring core body temperature of a subject, in accordance with an embodiment of the present disclosure;
[0028]In an embodiment, the system comprises a subject 100, an ambient sensor 103, a temperature estimation unit 104, a processing unit 106, a display unit 108 and the like. In an embodiment, the system may be worn on the wrist like a watch or can be placed as a patch on the chest or band on the forehead.
[0029]In an embodiment, the subject 100 may be any individual like a patient, a participant in a study, or any person for whom core body temperature is being measured using the described system. The core body temperature is measured using at least one single point and multipoint calibration protocol. When the single point protocol is used, continuous monitoring of the core body temperature of the subject 100 occurs on the single point on the skin, and when the multi point protocol is used, the initial calibration is performed with multi-point temperature measurements using the temperature estimation unit 104. The system itself is used for calibration or a separate probe placed in areas such as the mouth, armpit, chest, or rectum is used to input values.
[0030]In an embodiment, the ambient sensor 103 is configured to acquire ambient temperature data by exposing it to air. Thereby, calculating the deviation of the skin temperature.
[0031]In an embodiment, the temperature estimation unit 104 is configured to estimate the core body temperature of the subject 100. The temperature estimation unit 104 comprises a thermistor 202, at least one or more heating elements 204, a capacitance sensor 206, a movement sensor 208, at least one or more cardiac sensors 210and the other sensors. The core body temperature of the subject 100 is estimated, by considering subject 100 variances based on skin color, body fat, perfusion, and other related factors.
[0032]Upon estimating the core temperature data by the temperature estimation unit 104, the data is transferred to the processing unit 106 for further processing. The temperature data from the temperature estimation unit 104 is transferred to the processing unit 106. Thereafter, the processing unit 106 dynamically adjusts the subject 100 temperature reading based on the acquired temperature data from the at least one or more cardiac sensors 210.
[0033]Further, the reading of the core temperature is transferred on to the display unit 108. In an embodiment, the display unit 108 is configured to receive and display high accuracy estimation of the core body temperature. The display unit 108 may be wearable device, mobile phones, PDA, smartphones, smart band, smart watch, laptop, computer and the like.
[0034]Figure 2 depicts a block diagram depicting components for measuring and determining core body temperature of the subject 100, in accordance with an embodiment of the present disclosure;
[0035]Firstly, the temperature estimation unit 104 estimates the core body temperature of the subject 100. The temperature estimation unit 104 comprises a thermistor 202, at least one or more heating elements 204, a capacitance sensor 206, a movement sensor 208, at least one or more cardiac sensors 210 and the other sensors.
[0036]In an embodiment, the thermistor 202 is configured to acquire skin temperature of the subject 100 from at least one contact point on the subject 100 skin. acquire skin temperature of the subject 100 from at least one contact point on the subject 100 skin.
[0037]In an embodiment, the at least one or more heating elements 204 are configured to create a no heat flux environment by controlling the surface temperature of the system in contact with skin.
[0038]In an embodiment, the capacitance sensor 206 is configured to ensure proper contact and alert if contact of the system with the subject 100 skin is disrupted.
[0039]In an embodiment, the movement sensor 208 is configured to detect movement and ensure stable contact with the skin.
[0040]In an embodiment, the at least one or more cardiac sensors 210 are configured to measure cardiac flow comprises at least one of peripheral capillary oxygen saturation (SpO2) sensor, Heart Rate (HR) sensor, Respiratory Rate (RR) sensor, a photoplethysmography (PPG) optical-based sensor, an auscultation sensor ring, electrodes, skin impedance sensor, and perfusion index sensor, wherein the one or more cardiac sensors 210 to measure blood flow improves the accuracy of the core temperature. The at least one or more cardiac sensors 210 acquire one or more cardiac/ blood flow parameters such as SpO2, HR, RR, PPG, Perfusion index and the like.
[0041]In an embodiment, the perfusion index is a metric that measures the strength of blood flow in the body's tissues. In addition to its use in assessing tissue perfusion, it can also be used as an indicator of core body temperature. This is because blood flow is a major factor in regulating body temperature, and changes in blood flow to a particular area can result in changes in the temperature of that area. By continuously monitoring the perfusion index in a particular area of the body, such as the finger or earlobe, and combining this with other physiological metrics like heart rate and respiratory rate, it is possible to estimate changes in core body temperature. For example, if the perfusion index in the finger decreases, it may indicate that blood flow to the finger has reduced, which could be due to vasoconstriction as a response to a decrease in core body temperature. By tracking these changes over time, it is possible to estimate changes in core body temperature and use this information for diagnostic or therapeutic purposes.
[0042]The incorporation of cardiac input allows for dynamic adjustments of temperature readings, thereby enhancing the accuracy of measurements taken from the skin. Additionally, by considering variations in the ambient temperature and calculating the deviation of the skin temperature, data acquisition becomes easier while simultaneously improving the precision and reliability of skin-based temperature sensing.
[0043]In an embodiment, the processing unit 106 is configured to acquire temperature data from the thermistor 202, the at least one or more heating elements 204, the capacitance sensor 206, and the at least one or more cardiac sensors 210 in the temperature estimation unit 104 and the processing unit 106 further configured to dynamically adjust the subject 100 temperature reading based on the acquired temperature data from the at least one or more cardiac sensors 210.
[0044]The temperature data collected by the temperature estimation unit 104 can be pre-processed using various methods, including feature extraction, pattern recognition, data fusion, normalization, statistical estimation, weighting, validation, filtering, noise reduction, smoothing, filling, model fitting, binning, windowing, clipping, mathematical operations, interpolation, extrapolation, clustering, visualization, and other suitable processing techniques.
[0045]In an embodiment, the processing unit 106 comprises a processor. The processor may comprise one or more microprocessors, circuits, and other hardware configured for processing. The processor is configured to execute instructions stored in the memory module as well as communicate with the display unit 108 via a communication module. In an embodiment, the memory module of the processing unit 106 comprises one or more volatile and non-volatile memory components which are capable of storing data and instructions to be executed.
[0046]In an embodiment, the communication module of the display device may include wired and wireless communication, including but not limited to, GPS, GSM, LAN, Wi-fi compatibility, Bluetooth low energy as well as NFC. The wireless communication may further comprise one or more of Bluetooth (registered trademark), ZigBee (registered trademark), a short-range wireless communication such as UWB, a medium-range wireless communication such as WiFi (registered trademark) or a long-range wireless communication such as 3G/4G or WiMAX (registered trademark), according to the usage environment.
[0047]The system has the capability to determine other physiological metrics by utilizing the perfusion parameter functions. This can aid in determining a metric associated with the user's condition, which can help in characterizing and improving the state of the user's condition.
[0048]Figure 3 depicts a wearable for measuring core body temperature of the subject, in accordance with an embodiment of the present disclosure;
[0049]The wearable for measuring core body temperature of the subject comprises the heating elements (T1 and T2), the thermistor (T0), the capacitance sensor (C), the movement sensor (A), and the one or more cardiac flow sensors such as peripheral capillary oxygen saturation (SpO2) sensor, Heart Rate (HR) sensor, Respiratory Rate (RR) sensor, and perfusion index sensor. The purpose of the heating elements (T1 and T2) is to establish a no heat flux environment, which ensures that the skin temperature remains unaffected by the ambient temperature. T0 represents the thermistor or the sensing unit in direct contact with the skin, which is responsible for measuring the temperature. C serves as the capacitance sensor, detecting whether proper contact is being maintained and alerting the user if contact is lost. A function as the movement sensor, ensuring that the sensing unit remains stable on the skin and monitoring gross patient movements. Additionally, the SpO2, HR, RR, and perfusion index sensors are employed to continually adjust readings based on blood flow and deliver accurate temperature measurements.
[0050]Figure 4 illustrates a method 400 for measuring the core body temperature of a subject 102.The method begins with configuring a temperature estimation unit 104 that comprises a thermistor 202, at least one or more heating elements 204, a capacitance sensor 206, at least one or more cardiac sensor 210, as depicted at step 402. Subsequently, the method 400 discloses acquiring skin temperature of the subject 102 from at least one contact point on the subject 102 skin, as depicted at step 404. Subsequently, the method 400 discloses creating a no heat flux environment by controlling the surface temperature of the system 100 in contact with skin by at least one or more heating elements 204, as depicted at step 406. Subsequently, the method 400 discloses ensuring proper contact and alerting, by a capacitance sensor 206, if contact of the system 100 with the subject 102 skin is disrupted, as depicted at step 408. Subsequently, measuring cardiac flow for continued adjustment of temperature readings for higher accuracy by at least one or more cardiac sensors 210, as depicted at step 410. Thereafter, the method 400 discloses the method 400 discloses acquiring temperature data from the thermistor 202, the at least one or more heating elements 204, the capacitance sensor 206, and the at least one or more cardiac sensors 210 in the temperature estimation unit 104 and the processing unit 106 further configured to dynamically adjust the subject 102 temperature reading based on the acquired temperature data from the at least one or more cardiac sensors 210 by a processing unit 106, as depicted at step 412.
[0051]The advantages of the current invention include the high accurate, less invasive system and method to measure core body temperature of a subject with high accuracy.
[0052]An additional advantage is that the current invention approach can yield core body temperature estimates that are more precise than those obtained using an exposed sensor attached to the skin.
[0053]An additional advantage is that the current invention provides a multiparametric approach to improve quality and accuracy of estimating core body temperature of the subject.
[0054]An additional advantage is that the current invention relies on measuring perfusion indices, and cardiac behavior, for which measurement devices have much higher accuracy.
[0055]An additional advantage is that the current invention avoids poor contact of the system and ambient fluctuation errors.
[0056]Applications of the current invention include medical diagnostics, sports performance monitoring, environmental and occupational health, home health monitoring and the like.
[0057]The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described here. , Claims:We Claim:

1.A system (100) for measuring core body temperature of a subject (102), the system (100) comprising:
a temperature estimation unit (104) that comprises:
a thermistor (202) configured to acquire skin temperature of the subject (102) from at least one contact point on the subject (102) skin;
at least one or more heating elements (204) configured to create a no heat flux environment by controlling the surface temperature of the system (100) in contact with skin;
a capacitance sensor (206) configured to ensure proper contact and alert if contact of the system (100) with the subject (102) skin is disrupted; and
at least one or more cardiac sensors (210) configured to measure cardiac flow for continued adjustment of temperature readings for higher accuracy; and
a processing unit (106) configured to acquire temperature data from the thermistor (202), the at least one or more heating elements (204), the capacitance sensor (206), and the at least one or more cardiac sensors (210) in the temperature estimation unit (104) and the processing unit (106) further configured to dynamically adjust the subject (102) temperature reading based on the acquired temperature data from the at least one or more cardiac sensors (210).

2.The system (100) as claimed in claim 1, wherein the thermistor (202) is placed at one or more contact points of the subject (102) skin in order to obtain an initial baseline characterization.

3.The system (100) as claimed in claim 1, wherein an ambient sensor (103) is configured to acquire ambient temperature data, wherein the ambient sensor (103) is exposed to air.

4.The system (100) as claimed in claim 1, wherein the processing unit (106) is configured to acquire the ambient temperature data from the ambient sensor (103) and determine the variation in the measured core temperature.

5.The system (100) as claimed in claim 1, wherein a movement sensor is configured to detect movement and ensure stable contact with the skin.

6.The system (100) as claimed in claim 1, wherein the at least one or more cardiac sensors (210) to measure cardiac flow comprises at least one of peripheral capillary oxygen saturation (SpO2) sensor, Heart Rate (HR) sensor, Respiratory Rate (RR) sensor, a photoplethysmography (PPG) optical-based sensor, an auscultation sensor ring, electrodes, skin impedance sensor, and perfusion index sensor, wherein the one or more cardiac sensors (210) to measure blood flow improves the accuracy of the core temperature.

7.The system (100) as claimed in claim 1, wherein the system is worn on the wrist like a watch or can be placed as a patch on the chest or band on the forehead.

8.The system (100) as claimed in claim, wherein the core body temperature of the subject (102) is measured using at least one of single point and multipoint calibration protocol, wherein when the single point protocol is used, continuous monitoring of the core body temperature of the subject occurs on the single point on the skin, and when the multi point protocol is used, the initial calibration is performed with multi-point temperature measurements using the temperature estimation unit, wherein the system (100) itself is used for calibration or a separate probe placed in areas such as the mouth, armpit, chest, or rectum is used to input values.

9.The system (100) as claimed in claim 1, wherein a display unit (108) is configured to receive and display high accuracy estimation of the core body temperature.

10.The system (100) as claimed in claim 1, wherein the core body temperature of the subject (102) is estimated, considering subject (102) variances based on skin color, body fat, perfusion, and other factors.

11.A method (400) for measuring the core body temperature of a subject (102), the method (400) comprising:
configuring a temperature estimation unit (104) that comprises:
acquiring, by a thermistor (202), skin temperature of the subject (102) from at least one contact point on the subject (102) skin;
creating, by at least one or more heating elements (204), a no heat flux environment by controlling the surface temperature of the system (100) in contact with skin;
ensuring proper contact and alerting, by a capacitance sensor (206), if contact of the system (100) with the subject (102) skin is disrupted; and
measuring, by at least one or more cardiac sensors (210), cardiac flow for continued adjustment of temperature readings for higher accuracy; and
acquiring, by a processing unit (106), temperature data from the thermistor (202), the at least one or more heating elements (204), the capacitance sensor (206), and the at least one or more cardiac sensors (210) in the temperature estimation unit (104) and the processing unit (106) further configured to dynamically adjust the subject (102) temperature reading based on the acquired temperature data from the at least one or more cardiac sensors (210).

12.The method (400) as claimed in claim 11, comprising placing the thermistor (202) at one or more contact points of the subject (102) skin in order to obtain an initial baseline characterization.

13.The method (400) as claimed in claim 11, configuring an ambient sensor (103) to acquire ambient temperature data, wherein the ambient sensor (103) is exposed to air.

14.The method (400) as claimed in claim 11, configuring the processing unit (106) to acquire the ambient temperature data from the ambient sensor (103) and determine the variation in the measured core temperature.

15.The method (400) as claimed in claim 11, configuring a movement sensor to detect movement and ensure stable contact with the skin.

16.The method (400) as claimed in claim 11, configuring the at least one or more cardiac sensors (210) to measure cardiac flow comprises at least one of peripheral capillary oxygen saturation (SpO2) sensor, Heart Rate (HR) sensor, Respiratory Rate (RR) sensor, a photoplethysmography (PPG) optical-based sensor, an auscultation sensor ring, electrodes, skin impedance sensor, and perfusion index sensor, wherein the at least one or more cardiac sensors (210) to measure blood flow improves the accuracy of the core temperature.

17.The method (400) as claimed in claim 11, comprising wearing the system on the wrist like a watch or can be placed as a patch on the chest or band on the forehead.

18.The method (400) as claimed in claim 11, comprising measuring the core body temperature of the subject (102) using at least one of single point and multipoint calibration protocol, wherein when the single point protocol is used, continuous monitoring of the core body temperature of the subject occurs on the single point on the skin, and when the multi point protocol is used, the initial calibration is performed with multi-point temperature measurements using the temperature estimation unit, wherein the system (100) itself is used for calibration or a separate probe placed in areas such as the mouth, armpit, chest, or rectum is used to input values.

19.The method (400) as claimed in claim 11, configuring a display unit (108) to receive and display high accuracy estimation of the core body temperature.

20.The method (400) as claimed in claim 11, comprising estimating the core body temperature of the subject (102), considering subject (102) variances based on skin color, body fat, perfusion, and other factors.