Sensing unit, detection module and detection terminal

Abstract

The embodiment of the invention provides a sensing unit, a detection module and a detection terminal. The sensing unit includes: a current-to-voltage conversion circuit that receives a current analog signal through an input terminal, converts the current analog signal into a voltage analog signal, and outputs the voltage analog signal through an output terminal; the analog-to-digital conversion circuit is used for receiving a common-mode signal of the voltage analog signal through a first input end and a second input end and converting the common-mode signal into a digital signal; and the first filter circuit is connected between the output end and the second input end of the current-voltage conversion circuit. Therefore, on the basis of ensuring the filtering purpose, the design cost can be reduced, and the suppression capability on high-frequency-band noise or high-frequency common-mode interference generated by high-frequency signals in other electrochemical reactions is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, and in particular to a sensing unit, a detection module, and a detection terminal. Background Technology

[0002] A physiological data monitoring terminal is a device used to monitor and record key physiological parameters of an individual in real time. These devices are designed to help users better understand their health and provide important diagnostic and treatment information for healthcare professionals. Physiological data monitoring terminals come in a wide variety of types, including but not limited to heart rate monitors, blood pressure monitors, electrocardiographs, thermometers, sleep analyzers, and continuous glucose monitoring (CGM) systems.

[0003] For example, in diabetes management, continuous glucose monitoring (CGM) plays a crucial role in blood glucose monitoring by detecting the glucose concentration in subcutaneous interstitial fluid. Typically, the effective signal generated by the CGM device, as the detection terminal, to monitor blood glucose responses is in a lower frequency band. However, in actual monitoring, other reactions within the body can also cause electrochemical reactions with the sensors within the CGM device, generating interference signals that may be in higher frequency bands. Because the acquisition circuit typically has a wide bandwidth and significant high-frequency noise, the human body and the external environment may also exert significant out-of-band noise (such as power frequency interference, electromagnetic field coupling, etc.) on the signal chain path of the CGM device, thus causing deviations in blood glucose measurements.

[0004] To suppress various noises in the detection module of the detection terminal, related technologies typically add a low-pass filter to the signal chain path of the detection terminal to compress the link bandwidth to an acceptable range. However, the internal structure of the low-pass filter in related technologies is relatively complex, resulting in high design costs. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a sensing unit, a detection module, and a detection terminal to solve or alleviate the problem that the internal structure of related technologies is relatively complex, resulting in high design costs.

[0006] According to a first aspect of the present invention, a sensing unit is provided, comprising: a current-to-voltage conversion circuit, which receives an analog current signal through an input terminal, converts the analog current signal into an analog voltage signal, and outputs an analog voltage signal through an output terminal; an analog-to-digital conversion circuit, which receives a common-mode signal of the analog voltage signal through a first input terminal and a second input terminal, and converts the common-mode signal into a digital signal; and a first filtering circuit connected between the output terminal and the second input terminal of the current-to-voltage conversion circuit.

[0007] In some embodiments of the present invention, the analog-to-digital conversion circuit includes a first operational amplifier, a first input terminal being the non-inverting input terminal of the first operational amplifier, and a second input terminal being the inverting input terminal of the first operational amplifier.

[0008] In some embodiments of the present invention, the first filter circuit includes a first capacitor, one end of which is connected to the output terminal of the current-to-voltage conversion circuit, and the other end of which is connected to the inverting input terminal of the first operational amplifier.

[0009] In some embodiments of the present invention, the non-inverting input of the first operational amplifier is connected to the output of the current-to-voltage conversion circuit to receive a first differential signal, wherein the inverting input of the first operational amplifier receives a second differential signal from the output of the current-to-voltage conversion circuit through a first capacitor, and the first differential signal and the second differential signal form a common-mode signal.

[0010] In some embodiments of the present invention, the current-to-voltage conversion circuit includes a second operational amplifier, the non-inverting input of the second operational amplifier receiving a reference voltage, the inverting input of the second operational amplifier receiving a current analog signal, and outputting a voltage analog signal corresponding to the current analog signal according to the reference voltage; the sensing unit further includes a second filtering circuit, which is connected between the inverting input of the second operational amplifier and the output of the current-to-voltage conversion circuit.

[0011] In some embodiments of the present invention, the second filter circuit includes a second resistor and a second capacitor, which are connected in parallel between the inverting input terminal of the second operational amplifier and the output terminal of the current-to-voltage conversion circuit.

[0012] In some embodiments of the present invention, the current-to-voltage conversion circuit further includes a reference voltage source for providing a reference voltage, the reference voltage source being connected between the bias low voltage and the non-inverting input of the second operational amplifier.

[0013] In some embodiments of the present invention, the current-to-voltage conversion circuit further includes a sensing electrode for sensing an analog current signal, the sensing electrode being connected to the inverting input of a second operational amplifier.

[0014] According to a second aspect of the present invention, a detection module is provided, comprising: a sensing unit according to any of the above embodiments; and a controller for receiving digital signals and performing detection based on the digital signals to obtain physiological detection data.

[0015] According to a third aspect of the present invention, a detection terminal is provided, comprising: a detection module according to the above embodiments; and a data communication module for acquiring physiological detection data from the detection module and uploading the physiological detection data to a physiological data management device.

[0016] According to the embodiments of the present invention, the sensing unit, detection module, and detection terminal can convert the received analog current signal into an analog voltage signal for processing through a current-to-voltage conversion circuit, an analog-to-digital conversion circuit, and a first filtering circuit. The first filtering circuit between the output terminal of the current-to-voltage conversion circuit and the second input terminal of the analog-to-digital conversion circuit filters high-frequency interference signals. Compared with setting multiple resistors and capacitors to filter high-frequency interference signals, this method can reduce design costs while ensuring the filtering purpose. Furthermore, the first filtering circuit of the present invention significantly improves the ability to suppress high-frequency common-mode interference generated by high-frequency noise or high-frequency signals in other electrochemical reactions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the circuit structure of a common low-pass filter used in detection terminals;

[0019] Figure 2 This is a schematic diagram of the circuit structure of another common low-pass filter used in detection terminals;

[0020] Figure 3 This is a schematic diagram of the circuit structure of another common low-pass filter used in detection terminals;

[0021] Figure 4 This is a schematic diagram of the structure of a sensing unit according to an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the circuit structure of a sensing unit according to an embodiment of the present invention;

[0023] Figure 6 This is a structural block diagram of a detection module according to an embodiment of the present invention;

[0024] Figure 7 This is a structural block diagram of a detection terminal according to an embodiment of the present invention. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0026] For example, Figure 1 This is a schematic diagram of the circuit structure of a common low-pass filter used in detection terminals.

[0027] like Figure 1 As shown, the low-pass filter includes an IV conversion circuit (current-to-voltage conversion circuit) and an ADC conversion circuit (analog-to-digital conversion circuit). The IV conversion circuit has a first-stage filtering structure, and the ADC conversion circuit has a second-stage filtering structure. The cascaded two-stage filtering structure forms a second-order low-pass filter. The IV conversion circuit includes a sensing electrode, a reference voltage source, an operational amplifier, a resistor R1, and a capacitor C1. The grounded reference voltage source is connected to the non-inverting input of the operational amplifier to provide a reference voltage to the operational amplifier. The sensing electrode is connected to the inverting input of the operational amplifier to input a current signal to the operational amplifier. R1 and C1 are connected to the inverting input and output of the operational amplifier for first-stage filtering. The ADC conversion circuit includes resistors R3 and R4, capacitors C3 and C4, and an operational amplifier. Resistor R3 is connected to the non-inverting input of the operational amplifier and the grounded capacitor C3, and resistor R4 is connected to the inverting input of the operational amplifier and the grounded capacitor C4 for second-stage filtering.

[0028] Figure 1 The transfer function of a common low-pass filter shown is:

[0029]

[0030] Wherein, VINp is the output signal and Is is the input signal, which originates from the analog current of the sensing electrode. According to the transfer function, the low-pass filter is a second-order low-pass filter. In the case of common-mode interference signal, both the non-inverting and inverting input terminals of the operational amplifier in the second stage of the low-pass filter have input signals, and it operates in differential input mode, which can suppress common-mode interference.

[0031] For example, Vc1 is the common-mode interference of the VINp path, Vc2 is the common-mode interference of the VINn path, and the common-mode interference signal entering the ADC is as shown in formula (2).

[0032]

[0033] Vc1 and Vc2 have basically the same frequency and phase, but their amplitudes may be different. When R3 = R4 and C3 = C4, if the amplitude of Vc1 is the same as that of Vc2, then the common-mode interference signal Vadc_cm is 0, indicating that the common-mode interference has been completely canceled. If the amplitude of Vc1 is different from that of Vc2, then according to the characteristic that the frequency and phase of Vc1 and Vc2 are basically the same, it can be known that the common-mode interference signal Vadc_cm is not completely 0, and the common-mode interference has not been completely canceled. Furthermore, the mismatch between the two sets of components R3 and R4, and C3 and C4, will also worsen the common-mode rejection capability, resulting in poor common-mode interference rejection capability. In addition, the circuit structure of this low-pass filter is relatively complex and requires a large design cost.

[0034] Figure 2 This is a schematic diagram of the circuit structure of another common low-pass filter used in detection terminals. (Example:) Figure 2 As shown, the low-pass filter includes an IV conversion circuit and an ADC conversion circuit. The IV conversion circuit has a first-stage filtering structure, and the ADC conversion circuit has a second-stage filtering structure. The cascaded two-stage filtering structure forms a second-order low-pass filter. The IV conversion circuit includes a sensing electrode, a reference voltage source, an operational amplifier, a resistor R1, and a capacitor C1. The grounded reference voltage source is connected to the non-inverting input of the operational amplifier to provide a reference voltage to the operational amplifier. The sensing electrode is connected to the inverting input of the operational amplifier to input a current signal to the operational amplifier. R1 and C1 are connected to the inverting input and output of the operational amplifier for first-stage filtering. The ADC conversion circuit includes a resistor R3, a capacitor C3, and an operational amplifier. The resistor R3 is connected to the non-inverting input of the operational amplifier and the grounded capacitor C3 for second-stage filtering.

[0035] Figure 2 The transfer function of a common low-pass filter shown is:

[0036]

[0037] Where VINp is the output signal and Is is the input signal, which originates from the analog current of the sensing electrode. According to the transfer function, the low-pass filter is a second-order low-pass filter. Since the inverting input terminal of the operational amplifier in the second stage of the low-pass filter does not receive an effective signal, the low-pass filter does not operate in differential input mode and cannot suppress common-mode interference.

[0038] Figure 3 This is a schematic diagram of the circuit structure of another common low-pass filter used in detection terminals. (Example:) Figure 3 As shown, the low-pass filter includes an IV conversion circuit and an ADC conversion circuit. The IV conversion circuit has a first-stage filtering structure, and the ADC conversion circuit has a second-stage filtering structure. The two-stage filtering structures cascaded together form a second-order low-pass filter.

[0039] The IV conversion circuit includes a sensing electrode, a reference voltage source, an operational amplifier, a resistor R1, and a capacitor C1. The grounded reference voltage source is connected to the non-inverting input of the operational amplifier to provide a reference voltage to the operational amplifier. The sensing electrode is connected to the inverting input of the operational amplifier to input a current signal to the operational amplifier. R1 and C1 are connected to the inverting input and output of the operational amplifier for first-stage filtering.

[0040] The ADC conversion circuit includes resistors R5 and R6, capacitor C5, a first operational amplifier, and a second operational amplifier. The non-inverting input of the operational amplifier in the IV conversion circuit is connected to the non-inverting input of the first operational amplifier in the ADC conversion circuit. Resistors R5 and R6 and capacitor C5 are connected to the inverting input of the first operational amplifier. Resistors R5 and capacitor C5 are also connected to the output of the first operational amplifier for secondary filtering. The output of the first operational amplifier is connected to the non-inverting input of the second operational amplifier, and the inverting input of the second operational amplifier is grounded through a reference voltage source.

[0041] Figure 3 The transfer function of a common low-pass filter shown is:

[0042]

[0043] Where VINp is the output signal and Is is the input signal, which originates from the analog current of the sensing electrode. According to the transfer function, the low-pass filter is a second-order low-pass filter. Since the inverting input terminal of the second operational amplifier in the second stage of the low-pass filter does not have an effective signal, the low-pass filter does not work in differential input mode and cannot suppress common-mode interference.

[0044] Based on this, the present invention provides a sensing unit that, through a current-to-voltage conversion circuit, an analog-to-digital conversion circuit, and a first filtering circuit, can convert the received analog current signal into an analog voltage signal for processing. The first filtering circuit between the output terminal of the current-to-voltage conversion circuit and the second input terminal of the analog-to-digital conversion circuit filters high-frequency interference signals. Compared with setting multiple resistors and capacitors to filter high-frequency interference signals, this method can reduce design costs while ensuring the filtering purpose. Furthermore, the first filtering circuit of the present invention significantly improves the ability to suppress high-frequency common-mode interference generated by high-frequency noise or high-frequency signals in other electrochemical reactions.

[0045] The specific implementation of the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0046] Figure 4 This is a schematic diagram of the structure of a sensing unit according to an embodiment of the present invention. Figure 4 As shown, the sensing unit 400 includes: a current-to-voltage conversion circuit 401, which receives an analog current signal through its input terminal, converts the analog current signal into an analog voltage signal, and outputs the analog voltage signal through its output terminal; an analog-to-digital conversion circuit 402, which receives a common-mode signal of the analog voltage signal through its first and second input terminals, and converts the common-mode signal into a digital signal; and a first filter circuit 403, which is connected between the output terminal and the second input terminal of the current-to-voltage conversion circuit.

[0047] Specifically, the sensing unit 400 refers to the low-pass filter in the detection terminal. For example, this detection terminal is a CGM device that reflects blood glucose levels by detecting the glucose concentration in subcutaneous interstitial fluid, playing a crucial role in blood glucose monitoring. The low-pass filter can filter out higher-frequency interference signals and out-of-band noise signals (such as power frequency interference, electromagnetic field coupling, etc.) to ensure the accuracy of blood glucose monitoring.

[0048] The current-to-voltage conversion circuit 401 can be configured as an operational amplifier connected in parallel with a feedback resistor, or an operational amplifier connected in parallel with a feedback resistor and a feedback capacitor, to achieve the function of converting a current analog signal into a voltage analog signal. The current analog signal can be an effective signal generated during the monitoring of blood glucose response, and the frequency band of this current analog signal is in a low-frequency range.

[0049] The first filter circuit 403 can be configured as a capacitor connected in series with the equivalent resistance in the analog-to-digital converter circuit 402, so as to filter out the high-frequency interference signal through the RC filter circuit and the analog-to-digital converter circuit 402, and retain only the required low-frequency blood glucose monitoring signal. Compared with setting multiple resistors and capacitors to filter high-frequency interference signals, it can reduce the design cost while ensuring the filtering purpose.

[0050] When the current-to-voltage conversion circuit 401 converts the analog current signal into an analog voltage signal and outputs it to the first input terminal of the analog-to-digital conversion circuit 402, and outputs it to the second input terminal of the analog-to-digital conversion circuit 402 through the first filter circuit 403, the analog-to-digital conversion circuit 402 performs analog-to-digital conversion on the common-mode signal of the analog voltage signal to convert the analog common-mode signal into a digital signal, which is then sent to the corresponding controller to realize blood glucose detection. The current-to-voltage conversion circuit 401 constitutes the first-stage filter of the sensing unit 400, and the analog-to-digital conversion circuit 402 and the first filter circuit 403 constitute the second-stage filter of the sensing unit 400.

[0051] It is understood that, since the output terminal of the current-to-voltage conversion circuit 401 is connected in series with the second input terminal of the analog-to-digital conversion circuit 402, the first filter circuit 403 can filter out as many high-frequency signals as possible. Furthermore, this invention sufficiently suppresses the common-mode signal generated by the high-frequency signal entering the analog-to-digital conversion circuit 402. For example, the common-mode signal entering the analog-to-digital conversion circuit 402 can be expressed as V adc_cm ,

[0052]

[0053] Where R is the equivalent resistance of the second input terminal of the analog-to-digital converter circuit 402, and C is the capacitor set in the first filter circuit 403. It can be seen that for common-mode interference of high-frequency signals, its high-frequency gain is close to 0, and for common-mode interference of low-frequency signals, its low-frequency gain is close to 1. In this way, it plays a comprehensive role in suppressing high-frequency common-mode interference.

[0054] According to the sensing unit of the present invention, the received analog current signal can be converted into an analog voltage signal for processing through a current-to-voltage conversion circuit, an analog-to-digital conversion circuit, and a first filtering circuit. The first filtering circuit between the output terminal of the current-to-voltage conversion circuit and the second input terminal of the analog-to-digital conversion circuit filters high-frequency interference signals. Compared with setting multiple resistors and capacitors to filter high-frequency interference signals, the design cost can be reduced while ensuring the filtering purpose. Moreover, the first filtering circuit of the present invention significantly improves the ability to suppress high-frequency common-mode interference generated by high-frequency noise or high-frequency signals in other electrochemical reactions.

[0055] It should be noted that the first filter circuit 403 of the present invention can also be configured as a capacitor and a resistor connected in parallel / in series, and then connected in series with the equivalent resistance in the analog-to-digital conversion circuit 402, so as to filter out the high-frequency interference signal and retain only the required low-frequency blood glucose monitoring signal. The specific circuit design can be adjusted accordingly according to actual needs.

[0056] In some embodiments, the analog-to-digital converter circuit 402 includes a first operational amplifier, a first input terminal being the non-inverting input terminal of the first operational amplifier, and a second input terminal being the inverting input terminal of the first operational amplifier.

[0057] For example, Figure 5 This is a schematic diagram of the circuit structure of a sensing unit according to an embodiment of the present invention. Figure 5 As shown, the analog-to-digital conversion circuit (and ADC conversion circuit) 402 includes a first operational amplifier (the first operational amplifier is located inside the ADC module). The first input terminal of the analog-to-digital conversion circuit 402 is the non-inverting input terminal VINp of the first operational amplifier, and the second input terminal is the inverting input terminal VINn of the first operational amplifier. The operational amplifier is used in conjunction with the first filter circuit to comprehensively suppress the common-mode signal of the high-frequency signal.

[0058] In some embodiments, the first filter circuit 403 includes a first capacitor, one end of which is connected to the output of the current-to-voltage conversion circuit, and the other end of which is connected to the inverting input of the first operational amplifier.

[0059] Continue to refer to Figure 5 The first capacitor C1 is connected between the output terminal of the current-to-voltage conversion circuit 401 and the inverting input terminal VINn of the first operational amplifier in the analog-to-digital conversion circuit 402. One end of the equivalent resistance R1 of the inverting input terminal VINn of the analog-to-digital conversion circuit 402 is grounded, and the other end is connected to the inverting input terminal VINn. The interference signal is filtered through the equivalent resistance R1 and the first capacitor C1.

[0060] Furthermore, in some embodiments, the non-inverting input of the first operational amplifier is connected to the output of the current-to-voltage conversion circuit 401 to receive a first differential signal, wherein the inverting input of the first operational amplifier receives a second differential signal from the output of the current-to-voltage conversion circuit 401 through a first capacitor, and the first differential signal and the second differential signal form a common-mode signal.

[0061] Continue to refer to Figure 5 The non-inverting input terminal VINp of the first operational amplifier is connected to the output terminal of the current-to-voltage conversion circuit 401 to receive the first differential signal Vc1. The inverting input terminal VINn of the first operational amplifier receives the second differential signal Vc2 from the output terminal of the current-to-voltage conversion circuit 401 through the first capacitor C1, so as to form a common-mode signal based on the first differential signals Vc1 and Vc2.

[0062] For example, the common-mode signal entering the analog-to-digital converter circuit 402 can be represented as V adc_cm The V adc_cm It can be calculated using the following formula.

[0063] V adc_cm =Vc1-Vc2 Formula (6)

[0064] in, Substituting it into formula (4), we can see that...

[0065]

[0066] It is understood that for common-mode interference of high-frequency signals, the high-frequency gain is close to 0, and for common-mode interference of low-frequency signals, the low-frequency gain is close to 1. Compared with the common-mode signal in formula (2), the common-mode signal of the present invention does not need to consider whether the amplitudes of Vc1 and Vc2 are the same. It only needs to determine the gain according to the frequency of the signal to improve the high-frequency common-mode rejection capability. Moreover, the present invention avoids the problem of common-mode rejection capability deterioration due to the mismatch of the two sets of components R3 and R4, C3 and C4. Thus, by designing a simple first filter circuit and cooperating with the first operational amplifier, the common-mode interference rejection capability can be improved at low cost.

[0067] In some embodiments, the current-to-voltage conversion circuit 401 includes a second operational amplifier, the non-inverting input of which receives a reference voltage, the inverting input of which receives a current analog signal, and outputs a voltage analog signal corresponding to the current analog signal according to the reference voltage; the sensing unit 400 also includes a second filtering circuit, which is connected between the inverting input of the second operational amplifier and the output of the current-to-voltage conversion circuit.

[0068] Specifically, in some embodiments, the current-to-voltage conversion circuit 401 further includes a reference voltage source for providing a reference voltage, the reference voltage source being connected between the bias low voltage and the non-inverting input of the second operational amplifier. Furthermore, in some embodiments, the current-to-voltage conversion circuit 401 further includes a sensing electrode for sensing an analog current signal, the sensing electrode being connected to the inverting input of the second operational amplifier.

[0069] For example, continue to refer to Figure 5The current-to-voltage conversion circuit 401 includes a second operational amplifier. The non-inverting input of this operational amplifier receives a reference voltage provided by a reference voltage source, Vref, connected between a low bias voltage (such as GND) and the non-inverting input of the second operational amplifier. The inverting input of the second operational amplifier receives a current analog signal transmitted by a sensing electrode connected to the inverting input of the second operational amplifier. This provides a current analog signal to the current-to-voltage conversion circuit 401 through the sensing electrode and a reference voltage to the current-to-voltage conversion circuit 401 through the reference voltage source. This allows the inverting input of the second operational amplifier to output a voltage analog signal corresponding to the current analog signal to the analog-to-digital conversion circuit 402 based on the reference voltage. In this way, the analog-to-digital conversion circuit and the first filtering circuit can perform common-mode rejection on the common-mode signal of the voltage analog signal.

[0070] In some embodiments, the second filter circuit includes a second resistor and a second capacitor, which are connected in parallel between the inverting input of the second operational amplifier and the output of the current-to-voltage conversion circuit.

[0071] Continue to refer to Figure 5 The second resistor R2 and the second capacitor C2 are connected in parallel between the inverting input terminal of the second operational amplifier and the output terminal of the current-to-voltage conversion circuit 201. The second filter circuit is used to perform initial filtering on the noise signal of the input sensing unit 400, and the first filter circuit performs secondary filtering on the noise signal of the input sensing unit 400.

[0072] For example, Is is the current originating from the sensing electrode, which enters the analog-to-digital converter circuit 402 through the current-to-voltage conversion circuit 201 to achieve signal acquisition. The transfer function from Is to VINp at the non-inverting input of the first operational amplifier is:

[0073]

[0074] The ADC signal of the analog-to-digital converter circuit 202 is

[0075] V adc =VINp-VINn formula (9)

[0076] VINp to V adc The transfer function is

[0077]

[0078] Combining the above formulas, we can obtain Is to V adc The transfer function is

[0079]

[0080] Therefore, this invention realizes a second-order low-pass filter, and the circuit structure of this invention is simpler, the design cost is lower, and it can effectively filter noise signals.

[0081] It should be noted that when the inverting input of the second operational amplifier receives the current analog signal and converts it into the corresponding voltage analog signal according to the reference voltage, the operation requires the cooperation of the second operational amplifier, the reference voltage source, and the resistor. This resistor can be the second resistor in the second filter circuit.

[0082] Figure 6 This is a structural block diagram of a detection module according to an embodiment of the present invention.

[0083] like Figure 6 As shown, the detection module 600 includes a sensing unit 400 according to any of the above embodiments; and a controller 601 for receiving digital signals and performing detection based on the digital signals to obtain physiological detection data. The digital signals are converted by an analog-to-digital converter 402 in the sensing unit 400, and the physiological detection data refers to the user's blood glucose detection data.

[0084] According to the detection module of the present invention, the received analog current signal can be converted into an analog voltage signal for processing through a current-to-voltage conversion circuit, an analog-to-digital conversion circuit, and a first filtering circuit. The first filtering circuit between the output terminal of the current-to-voltage conversion circuit and the second input terminal of the analog-to-digital conversion circuit filters high-frequency interference signals. Compared with setting multiple resistors and capacitors to filter high-frequency interference signals, the design cost can be reduced while ensuring the filtering purpose. Moreover, the first filtering circuit of the present invention significantly improves the ability to suppress high-frequency common-mode interference generated by high-frequency noise or high-frequency signals in other electrochemical reactions.

[0085] Furthermore, the functional implementation of each module in the detection module of this embodiment can be referred to the description of the corresponding part in the foregoing method embodiment, and will not be repeated here.

[0086] Figure 7 This is a structural block diagram of a detection terminal according to an embodiment of the present invention.

[0087] like Figure 7 As shown, the detection terminal 700 includes a detection module 600 according to the above embodiment; and a data communication module 701, used to acquire physiological detection data from the detection module 600 and upload the physiological detection data to a physiological data management device. The physiological data management device can be a remote management device or a local management device, used to display blood glucose detection data to users or doctors.

[0088] According to the detection terminal of the present invention, the received analog current signal can be converted into an analog voltage signal for processing through a current-to-voltage conversion circuit, an analog-to-digital conversion circuit, and a first filtering circuit. The first filtering circuit between the output terminal of the current-to-voltage conversion circuit and the second input terminal of the analog-to-digital conversion circuit filters high-frequency interference signals. Compared with setting multiple resistors and capacitors to filter high-frequency interference signals, the design cost can be reduced while ensuring the filtering purpose. Moreover, the first filtering circuit of the present invention significantly improves the ability to suppress high-frequency common-mode interference generated by high-frequency noise or high-frequency signals in other electrochemical reactions.

[0089] Specific embodiments of the subject matter have now been described. Other embodiments are within the scope of the appended claims. In some cases, the actions described in the claims can be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing can be advantageous.

[0090] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0091] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0092] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0093] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A sensing unit, characterized in that, include: A current-to-voltage conversion circuit receives an analog current signal at its input terminal, converts the analog current signal into an analog voltage signal, and outputs the analog voltage signal at its output terminal. The analog-to-digital converter circuit receives the common-mode signal of the analog voltage signal through a first input terminal and a second input terminal, and converts the common-mode signal into a digital signal. The first filter circuit is connected between the output terminal of the current-to-voltage conversion circuit and the second input terminal.

2. The sensing unit according to claim 1, characterized in that, The analog-to-digital converter circuit includes a first operational amplifier, the first input terminal being the non-inverting input terminal of the first operational amplifier, and the second input terminal being the inverting input terminal of the first operational amplifier.

3. The sensing unit according to claim 2, characterized in that, The first filter circuit includes a first capacitor, one end of which is connected to the output terminal of the current-to-voltage conversion circuit, and the other end of which is connected to the inverting input terminal of the first operational amplifier.

4. The sensing unit according to claim 2, characterized in that, The non-inverting input of the first operational amplifier is connected to the output of the current-to-voltage conversion circuit to receive a first differential signal. The inverting input of the first operational amplifier receives a second differential signal from the output of the current-to-voltage conversion circuit through the first capacitor. The first differential signal and the second differential signal form the common-mode signal.

5. The sensing unit according to claim 1, characterized in that, The current-to-voltage conversion circuit includes a second operational amplifier. The non-inverting input of the second operational amplifier receives a reference voltage, and the inverting input of the second operational amplifier receives the analog current signal. The circuit also outputs an analog voltage signal corresponding to the analog current signal based on the reference voltage. The sensing unit further includes a second filtering circuit, which is connected between the inverting input of the second operational amplifier and the output of the current-to-voltage conversion circuit.

6. The sensing unit according to claim 5, characterized in that, The second filter circuit includes a second resistor and a second capacitor, which are connected in parallel between the inverting input of the second operational amplifier and the output of the current-to-voltage conversion circuit.

7. The sensing unit according to claim 5, characterized in that, The current-to-voltage conversion circuit further includes a reference voltage source for providing the reference voltage, the reference voltage source being connected between the bias low voltage and the non-inverting input of the second operational amplifier.

8. The sensing unit according to claim 5, characterized in that, The current-to-voltage conversion circuit further includes a sensing electrode for sensing the analog current signal, the sensing electrode being connected to the inverting input of the second operational amplifier.

9. A detection module, characterized in that, include: The sensing unit according to any one of claims 1-8; A controller is used to receive digital signals and perform detection based on the digital signals to obtain physiological detection data.

10. A detection terminal, characterized in that, include: The detection module according to claim 9; The data communication module is used to acquire physiological detection data from the detection module and upload the physiological detection data to the physiological data management device.

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