Non-contact infrared body temperature monitoring chip and adaptive noise suppression system

Abstract

The invention relates to the technical field of body temperature monitoring, in particular to a non-contact infrared body temperature monitoring chip and a self-adaptive noise suppression system, comprising the following modules: an infrared signal acquisition module for receiving an infrared signal radiated by a human body and converting the infrared signal into a weak electric signal, adopting a thermopile sensor array and having a response wavelength range of 8-14 [mu] m; the pre-amplification module is connected with the infrared signal acquisition module and used for primarily amplifying the weak electric signals, a low-noise operational amplifier is adopted, and the noise density is smaller than or equal to 1.5 nV / Hz; the noise feature analysis unit adopts a time-frequency conjoint analysis algorithm, extracts time-varying feature parameters of noise in real time through short-time Fourier transform (STFT), realizes fine separation of noise in different frequency bands in combination with a wavelet packet decomposition technology, can identify and suppress various complex noise such as 50Hz / 60Hz power frequency interference, switching power supply ripple noise, ambient light flicker noise and the like, and is high in practicability. And the system can still keep the measurement precision of + / -0.1 DEG C in an ICU environment with dense medical equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of body temperature monitoring, and in particular to a non-contact infrared body temperature monitoring chip and an adaptive noise suppression system. Background Art

[0002] Non-contact infrared body temperature monitoring technology has been widely used in medical health, public health and other fields due to its advantages such as speed, convenience and safety. However, in actual use, environmental noise (such as electromagnetic interference and ambient temperature fluctuations) can have a significant impact on the measurement accuracy of infrared body temperature monitoring chips. Existing body temperature monitoring chips often use fixed-parameter filtering algorithms to process signals and are unable to adaptively adjust to changes in actual environmental noise. This leads to large measurement errors in complex environments, seriously affecting the accuracy and reliability of monitoring results, and making it difficult to meet the needs of high-precision body temperature monitoring. To this end, a non-contact infrared body temperature monitoring chip and an adaptive noise suppression system are proposed. Summary of the Invention

[0003] In view of this, the present invention provides a non-contact infrared body temperature monitoring chip and an adaptive noise suppression system to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0004] The technical solution of the present invention is implemented as follows: a non-contact infrared body temperature monitoring chip and adaptive noise suppression system, including the following modules:

[0005] The infrared signal acquisition module is used to receive infrared signals radiated by the human body and convert them into weak electrical signals. It uses a thermopile sensor array with a response wavelength range of 8-14μm.

[0006] The preamplifier module is connected to the infrared signal acquisition module to perform preliminary amplification on the weak electrical signal, using a low-noise operational amplifier with a noise density of ≤1.5nV / √Hz;

[0007] An adaptive noise suppression module includes a noise feature analysis unit, an adaptive filter parameter adjustment unit, and an adaptive filter. The noise feature analysis unit is used to analyze environmental noise features. The adaptive filter parameter adjustment unit adjusts the adaptive filter parameters according to the noise features. The adaptive filter filters the amplified signal. The adaptive filter adopts an IIR / FIR hybrid structure and supports dynamic adjustment in the 100Hz-10MHz frequency band.

[0008] Analog-to-digital conversion module, used to convert the filtered analog signal into a digital signal, using a 24-bit Σ-Δ ADC with a sampling rate ≥ 10kHz;

[0009] A microprocessor module, used to receive digital signals and calculate body temperature, integrates a dedicated temperature calculation DSP core, and has a built-in human skin emissivity database;

[0010] The display and communication module is used to display body temperature values ​​and transmit data, supporting Bluetooth 5.0 / BLE and the medical device-specific protocol IEEE11073.

[0011] Further preferably, the infrared signal acquisition module is composed of a high-performance infrared detector for receiving infrared signals radiated by the human body and converting them into weak electrical signals. The infrared detector adopts a thermopile sensor to accurately capture the changes in infrared radiation energy emitted by the human body.

[0012] Further preferably, the preamplifier module preliminarily amplifies the weak electrical signal output by the infrared detector to increase the signal strength. The module adopts a low-noise operational amplifier to minimize the introduction of noise while amplifying the signal.

[0013] Further preferably, the adaptive noise suppression module includes a noise feature analysis unit, an adaptive filtering parameter adjustment unit and an adaptive filter. The noise feature analysis unit collects noise signals in the environment in real time, performs spectrum analysis on them, and extracts characteristic parameters such as frequency and intensity of the noise; the adaptive filtering parameter adjustment unit automatically adjusts the filtering parameters of the adaptive filter based on the parameters obtained by the noise feature analysis unit and a preset algorithm; the adaptive filter performs filtering processing on the pre-amplified signal according to the adjusted parameters, suppresses environmental noise, and retains useful body temperature signals.

[0014] Further preferably, the analog-to-digital conversion module converts the analog signal processed by the adaptive noise suppression module into a digital signal, and uses a high-precision analog-to-digital converter to ensure that the converted digital signal can accurately reflect the characteristics of the original analog signal.

[0015] Further preferably, the microprocessor module receives the digital signal output by the analog-to-digital conversion module, processes and analyzes the signal according to the built-in algorithm, calculates the corresponding body temperature value, and is responsible for controlling the operation of the adaptive noise suppression module and coordinating the operation between various modules.

[0016] Further preferably, the display and communication module is used to display the measured body temperature value in real time. The communication module supports wireless communication methods such as Bluetooth and Wi-Fi, and can transmit the measured data to terminal devices such as mobile phones and computers to realize remote monitoring and management of data.

[0017] The embodiment of the present invention adopts the above technical solution, which has the following advantages:

[0018] 1. The noise characteristic analysis unit of the present invention adopts a joint time-frequency analysis algorithm to extract the time-varying characteristic parameters of noise in real time through short-time Fourier transform (STFT). Combined with wavelet packet decomposition technology, it can achieve fine separation of noise in different frequency bands. It can identify and suppress various complex noises such as 50Hz / 60Hz power frequency interference, switching power supply ripple noise, and ambient light flicker noise, enabling the system to maintain a measurement accuracy of ±0.1°C even in the ICU environment with dense medical equipment.

[0019] 2. The adaptive filter group of the present invention integrates a visible light filtering channel, an electromagnetic noise suppression channel, and a temperature drift compensation channel. The parameters of each channel can be adjusted independently and integrated in real time. In a strong light environment (such as a shadowless lamp in an operating room), the visible light filtering channel can suppress 850nm / 940nm infrared interference, and the measurement error is reduced from ±0.5℃ to ±0.05℃. The dynamic calibration channel compensates for the measurement deviation caused by changes in the blackbody radiation coefficient (ε value) by real-time monitoring of the ambient temperature, so that the system maintains medical-grade accuracy within the ambient temperature range of -20℃ to 60℃.

[0020] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 It is a hardware structure block diagram of the present invention;

[0023] Figure 2 It is a system module diagram of the present invention. DETAILED DESCRIPTION

[0024] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0025] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] like Figure 1-2As shown, the embodiment of the present invention provides a non-contact infrared body temperature monitoring chip and an adaptive noise suppression system, including the following modules:

[0027] The infrared signal acquisition module is used to receive infrared signals radiated by the human body and convert them into weak electrical signals. It uses a thermopile sensor array with a response wavelength range of 8-14μm.

[0028] The preamplifier module is connected to the infrared signal acquisition module to perform preliminary amplification on the weak electrical signal, using a low-noise operational amplifier with a noise density of ≤1.5nV / √Hz;

[0029] An adaptive noise suppression module includes a noise feature analysis unit, an adaptive filter parameter adjustment unit, and an adaptive filter. The noise feature analysis unit is used to analyze environmental noise features. The adaptive filter parameter adjustment unit adjusts the adaptive filter parameters according to the noise features. The adaptive filter filters the amplified signal. The adaptive filter adopts an IIR / FIR hybrid structure and supports dynamic adjustment in the 100Hz-10MHz frequency band.

[0030] Analog-to-digital conversion module, used to convert the filtered analog signal into a digital signal, using a 24-bit Σ-Δ ADC with a sampling rate ≥ 10kHz;

[0031] A microprocessor module, used to receive digital signals and calculate body temperature, integrates a dedicated temperature calculation DSP core, and has a built-in human skin emissivity database;

[0032] The display and communication module is used to display body temperature values ​​and transmit data, supporting Bluetooth 5.0 / BLE and the medical device-specific protocol IEEE11073.

[0033] In one embodiment, the infrared signal acquisition module is composed of a high-performance infrared detector for receiving infrared signals radiated by the human body and converting them into weak electrical signals. The infrared detector uses a thermopile sensor to accurately capture changes in infrared radiation energy emitted by the human body.

[0034] In one embodiment, the preamplifier module preliminarily amplifies the weak electrical signal output by the infrared detector to increase the signal strength. The module uses a low-noise operational amplifier to minimize noise introduction while amplifying the signal.

[0035] In one embodiment, the adaptive noise suppression module includes a noise feature analysis unit, an adaptive filtering parameter adjustment unit, and an adaptive filter. The noise feature analysis unit collects noise signals in the environment in real time, performs spectrum analysis on them, and extracts characteristic parameters such as the frequency and intensity of the noise. The adaptive filtering parameter adjustment unit automatically adjusts the filtering parameters of the adaptive filter based on the parameters obtained by the noise feature analysis unit and a preset algorithm. The adaptive filter filters the pre-amplified signal based on the adjusted parameters to suppress environmental noise and retain useful body temperature signals.

[0036] In one embodiment, the analog-to-digital conversion module converts the analog signal processed by the adaptive noise suppression module into a digital signal, and uses a high-precision analog-to-digital converter to ensure that the converted digital signal can accurately reflect the characteristics of the original analog signal.

[0037] In one embodiment, the microprocessor module receives the digital signal output by the analog-to-digital conversion module, processes and analyzes the signal according to the built-in algorithm, calculates the corresponding body temperature value, and is responsible for controlling the operation of the adaptive noise suppression module and coordinating the operation between various modules.

[0038] In one embodiment, the display and communication module is used to display the measured body temperature value in real time. The communication module supports wireless communication methods such as Bluetooth and Wi-Fi, and can transmit the measured data to terminal devices such as mobile phones and computers to realize remote monitoring and management of the data.

[0039] Comparison of experimental data:

[0040]

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various modifications and substitutions within the technical scope disclosed in the present invention, and such modifications and substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A non-contact infrared body temperature monitoring chip and adaptive noise suppression system, characterized by: Includes the following modules: The infrared signal acquisition module is used to receive infrared signals radiated by the human body and convert them into weak electrical signals. It uses a thermopile sensor array with a response wavelength range of 8-14μm. The preamplifier module is connected to the infrared signal acquisition module to perform preliminary amplification on the weak electrical signal, using a low-noise operational amplifier with a noise density of ≤1.5nV / √Hz; An adaptive noise suppression module includes a noise feature analysis unit, an adaptive filter parameter adjustment unit, and an adaptive filter. The noise feature analysis unit is used to analyze environmental noise features. The adaptive filter parameter adjustment unit adjusts the adaptive filter parameters according to the noise features. The adaptive filter filters the amplified signal. The adaptive filter adopts an IIR / FIR hybrid structure and supports dynamic adjustment in the 100Hz-10MHz frequency band. Analog-to-digital conversion module, used to convert the filtered analog signal into a digital signal, using a 24-bit Σ-Δ ADC with a sampling rate ≥ 10kHz; A microprocessor module, used to receive digital signals and calculate body temperature, integrates a dedicated temperature calculation DSP core, and has a built-in human skin emissivity database; The display and communication module is used to display body temperature values ​​and transmit data, supporting Bluetooth 5.0 / BLE and the medical device-specific protocol IEEE11073.

2. The non-contact infrared body temperature monitoring chip and adaptive noise suppression system according to claim 1, characterized in that: The infrared signal acquisition module is composed of a high-performance infrared detector, which is used to receive infrared signals radiated by the human body and convert them into weak electrical signals. The infrared detector uses a thermopile sensor to accurately capture the changes in infrared radiation energy emitted by the human body.

3. The non-contact infrared body temperature monitoring chip and adaptive noise suppression system according to claim 1, characterized in that: The preamplifier module performs preliminary amplification on the weak electrical signal output by the infrared detector to increase the signal strength. The module uses a low-noise operational amplifier to minimize noise introduction while amplifying the signal.

4. The non-contact infrared body temperature monitoring chip and adaptive noise suppression system according to claim 1, characterized in that: The adaptive noise suppression module includes a noise feature analysis unit, an adaptive filtering parameter adjustment unit and an adaptive filter. The noise feature analysis unit collects noise signals in the environment in real time, performs spectrum analysis on the noise, and extracts characteristic parameters such as frequency and intensity of the noise. The adaptive filter parameter adjustment unit automatically adjusts the filter parameters of the adaptive filter based on the parameters obtained by the noise characteristic analysis unit in combination with a preset algorithm; The adaptive filter filters the pre-amplified signal according to the adjusted parameters, suppresses the environmental noise and retains the useful body temperature signal.

5. The non-contact infrared body temperature monitoring chip and adaptive noise suppression system according to claim 1, characterized in that: The analog-to-digital conversion module converts the analog signal processed by the adaptive noise suppression module into a digital signal, and uses a high-precision analog-to-digital converter to ensure that the converted digital signal can accurately reflect the characteristics of the original analog signal.

6. The non-contact infrared body temperature monitoring chip and adaptive noise suppression system according to claim 1, characterized in that: The microprocessor module receives the digital signal output by the analog-to-digital conversion module, processes and analyzes the signal according to the built-in algorithm, calculates the corresponding body temperature value, and is responsible for controlling the work of the adaptive noise suppression module and coordinating the operation between various modules.

7. The non-contact infrared body temperature monitoring chip and adaptive noise suppression system according to claim 1, characterized in that: The display and communication module is used to display the measured body temperature value in real time. The communication module supports wireless communication methods such as Bluetooth and Wi-Fi, and can transmit the measured data to terminal devices such as mobile phones and computers to realize remote monitoring and management of data.

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