Modulation and demodulation device of hemorrhoid artery detector
By designing a modulation and demodulation device for the hemorrhoidal artery detector, and employing an in-phase amplifier circuit and a multi-stage demodulation and filtering circuit, the problem of weak signals from deep arteries was solved, thus improving the detection accuracy of the ultrasonic hemorrhoid diagnostic and treatment instrument.
Patent Information
- Application Number
- CN202422474496.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-10-14
AI Technical Summary
Existing handheld ultrasonic hemorrhoid diagnostic devices have weak signal strength when detecting deep arteries, which reduces diagnostic accuracy. In particular, due to the slow blood flow velocity in venous plexuses and arteries, the echo signal strength is weak, and clutter signals are mixed into the target signal, affecting the detection and diagnostic results.
A modulation and demodulation device for a hemorrhoidal artery detector was designed, including a signal modulation and transmission unit, a signal amplification unit, and a signal receiving and demodulation unit. It employs an in-phase amplifier circuit, a low-pass filter operational amplifier, and a multi-stage demodulation filter circuit to gradually filter out noise signals, amplify key target signals, and improve signal resolution and accuracy.
Through multi-stage filtering circuits and amplification processing, the accuracy of the detection and diagnosis results of the handheld ultrasonic hemorrhoid diagnostic instrument has been significantly improved, especially in the detection of deep arterial locations.
Smart Images
Figure CN223489746U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to medical device circuit technology, specifically to a modulation and demodulation device for a hemorrhoidal artery detector. Background Technology
[0002] Ultrasound, due to its high penetration and non-destructive nature, is widely used in clinical medical research and diagnosis. Handheld ultrasonic hemorrhoid diagnostic devices utilize plane wave-based Doppler ultrasound technology to detect blood flow within blood vessels, enabling rapid identification of lesions and making them a powerful tool for diagnosing hemorrhoids. Current handheld ultrasonic hemorrhoid diagnostic devices use an MCU-modulated electrical signal to control the ultrasound probe to emit continuous ultrasound waves onto the target area on the inner surface of the anal canal and rectum. The received echo signals are denoised and pre-amplified, then orthogonally demodulated and filtered to remove high-frequency carrier signals, obtaining low-frequency blood flow-related signals. These signals are then converted from analog to digital signals via AD sampling, achieving the effect of ultrasound sampling and processing. However, because the blood flow velocity in the venous plexuses and arteries of the anal canal and rectum is generally slow, the intensity of the echo signals caused by blood flow is very weak. The ultrasound modulation and demodulation process requires signal amplification, resulting in a large amount of unnecessary noise mixed in with the target signal, reducing the accuracy of signal acquisition and processing, and thus affecting the accuracy of the diagnostic results. In particular, when the artery being detected is located deep within the body, the target signal is weaker, and the accuracy of the detection results is more significantly affected. Therefore, it is necessary to research a modulation and demodulation device specifically designed for hemorrhoidal artery detectors to address the aforementioned technical problems. Utility Model Content
[0003] To address the aforementioned technical problems, this utility model provides a modulation and demodulation device for a hemorrhoidal artery detector, which includes a signal modulation and transmission unit, a signal amplification unit, and a signal receiving and demodulation unit.
[0004] The signal modulation and transmission unit modulates the control electrical signal and transmits ultrasonic waves through the ultrasonic transducer; the ultrasonic transducer receives the echo signal and converts it into an electrical signal.
[0005] The signal amplification unit receives and amplifies the electrical signal converted by the ultrasonic transducer. The signal amplification unit includes a non-inverting amplifier circuit and a filtering circuit. The amplification circuit has at least one non-inverting amplifier connected to the ultrasonic transducer, and amplifies the electrical signal converted by the ultrasonic transducer to obtain an amplified analog electrical signal. The input terminal of the filtering circuit is connected to the output terminal of the non-inverting amplifier. The filtering circuit includes a low-pass operational amplifier, and the output terminal of the low-pass operational amplifier is connected to the signal receiving and demodulation unit.
[0006] The signal receiving and demodulation unit receives the amplified electrical signal from the signal amplification unit, performs quadrature demodulation processing, and transmits the information after quadrature demodulation processing to the processor for analysis and processing.
[0007] As a preferred technical solution of this utility model, the non-inverting amplifier circuit further includes a filter resistor or a filter capacitor disposed on the positive input line of the non-inverting amplifier. One end of the filter resistor or filter capacitor is connected to the positive input line of the non-inverting amplifier, and the other end of the filter resistor or filter capacitor is grounded. The negative input line of the non-inverting amplifier is grounded through a first gain resistor. The other end of the first gain resistor is connected to the output terminal of the non-inverting amplifier through a second gain resistor.
[0008] In a preferred embodiment of this invention, the positive input terminal of the low-pass filter operational amplifier is connected to the output terminal of the non-inverting amplifier via two sets of gain resistors connected in series; the two sets of gain resistors include a third gain resistor and a fourth gain resistor, and the output terminal of the third gain resistor is connected to the output terminal of the low-pass filter operational amplifier via a first capacitor; the negative input terminal of the low-pass filter operational amplifier is connected to the output terminal of the low-pass filter operational amplifier.
[0009] As a preferred technical solution of this utility model, the positive voltage input terminal and the negative voltage input terminal of the in-phase amplifier are respectively connected to the positive and negative terminals of the external power supply through two sets of voltage-stabilizing capacitors connected in parallel.
[0010] As a preferred technical solution of this utility model, the positive voltage input terminal of the in-phase amplifier is connected to one end of the two sets of voltage-stabilizing capacitors, and is connected to an external power supply through this end; the other end of the two sets of voltage-stabilizing capacitors is grounded.
[0011] As a preferred embodiment of this invention, the signal receiving and demodulation unit includes at least one demodulation filter circuit and a quadrature demodulator circuit; the output of the low-pass filter operational amplifier is connected to the input of the quadrature demodulator circuit, and the amplified analog electrical signal is quadraturely demodulated by the quadrature demodulator circuit to obtain a differential analog signal with the carrier signal removed; the demodulation filter circuit includes at least one set of operational amplifiers, the demodulation filter circuit receives the differential analog signal, and filters the differential analog signal respectively to remove higher harmonics, and outputs a filtered differential analog signal containing Doppler signals.
[0012] As a preferred technical solution of this utility model, the signal receiving and demodulation unit includes a two-stage demodulation and filtering circuit; the two-stage demodulation and filtering circuit consists of a first-stage demodulation and filtering circuit and a second-stage demodulation and filtering circuit, the first-stage demodulation and filtering circuit is connected to the output terminal of the quadrature demodulator circuit, the second-stage demodulation and filtering circuit is connected to the output terminal of the first-stage demodulation and filtering circuit, and further filters the filtered signal output by the first-stage demodulation and filtering circuit.
[0013] As a preferred embodiment of this utility model, the first-stage demodulation and filtering circuit includes two primary filtering modules, each of which contains an operational amplifier; the second-stage demodulation and filtering circuit includes two secondary filtering modules, each of which contains two operational amplifiers.
[0014] As a preferred technical solution of this utility model, the positive voltage input terminal and the negative voltage input terminal of the operational amplifier are respectively connected to the positive and negative terminals of the external power supply through voltage regulating resistors.
[0015] As a preferred technical solution of this utility model, the secondary filtering module includes a first operational amplifier and a second operational amplifier, and the positive input terminal of the first operational amplifier is connected to the output terminal of the second operational amplifier through a buffer resistor.
[0016] The technical solution provided in this utility model has the following advantages compared with existing related solutions:
[0017] This invention features a targeted design for the signal amplification unit and signal receiving demodulation unit circuits in the modulation and demodulation device of the hemorrhoidal artery detector. This design enables the device to more fully acquire relevant signals caused by blood flow in the blood vessels and gradually filter out various noise and interference signals in the ultrasonic echo signal. Simultaneously, it amplifies key target signals such as blood flow velocity and blood flow rate, thereby effectively improving the resolution and accuracy of the target signal. In particular, the two-stage demodulation filtering circuit gradually filters and adjusts the differential analog signal Q and differential analog signal I after quadrature demodulation, making the target signal output by the modulation and demodulation device more accurate, thus improving the accuracy of the detection and diagnosis results of the handheld ultrasonic hemorrhoid diagnostic instrument. Attached Figure Description
[0018] To further explain the modulation and demodulation device of the hemorrhoidal artery detector in this utility model, corresponding drawings are provided. It should be noted that the drawings described in this utility model are only individual examples selected from all the drawings and are not intended to limit the claims. All other corresponding spectra obtained through the drawings provided in this utility model should be considered to be within the scope of protection of this utility model.
[0019] Appendix Figure 1 The non-inverting amplifier circuit of the signal amplification unit provided by this utility model;
[0020] Appendix Figure 2 The filtering circuit of the signal amplification unit provided by this utility model;
[0021] Appendix Figure 3 The first-stage demodulation and filtering circuit of the signal receiving and demodulation unit provided by this utility model;
[0022] Appendix Figure 4 The present invention provides a second-stage demodulation and filtering circuit for a signal receiving and demodulation unit. Detailed Implementation
[0023] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.
[0024] In the following explanation and description of this utility model, the terms "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying relative importance. The following description provides multiple embodiments of this utility model, and different embodiments can be substituted or combined. Therefore, this application can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then this application should also be considered to include embodiments containing one or more other possible combinations of A, B, C, and D, even if such embodiments are not explicitly described in the following text.
[0025] The modulation and demodulation device for the hemorrhoidal artery detector provided by this utility model includes a signal modulation and transmission unit, a signal amplification unit, and a signal receiving and demodulation unit. The signal modulation and transmission unit mainly includes a processor and an ultrasonic transducer. The processor controls the ultrasonic transducer to continuously transmit ultrasonic waves of a certain frequency through a modulated electrical signal. The ultrasonic waves are reflected by the area to be detected and further received by the ultrasonic transducer, where they are converted into electrical signals and transmitted to subsequent units for processing. This utility model does not impose any special limitations on the specific selection of the processor; it can employ, but is not limited to, 16-bit ultra-low-power mixed-signal microcontrollers from the Texas Instruments MSP430F series, which are well-known to those skilled in the art. Similarly, this utility model does not impose any special limitations on the specific selection of the ultrasonic transducer; various transducers well-known to those skilled in the art can be used, as long as they can transmit ultrasonic waves of a certain frequency based on the received modulated electrical signal and convert the received echo signal into an electrical signal.
[0026] The signal amplification unit of this invention is electrically connected to the signal modulation and transmission unit, and is used to receive and amplify the electrical signal converted by the ultrasonic transducer. The signal amplification unit of this invention includes a non-inverting amplifier circuit and a filtering circuit. The non-inverting amplifier circuit has at least one non-inverting amplifier, which is used to amplify the electrical signal converted by the ultrasonic transducer to obtain an amplified analog electrical signal. More preferably, the non-inverting amplifier circuit also includes a filtering resistor or a filtering capacitor disposed on the positive input line of the non-inverting amplifier to stabilize the input electrical signal and reduce or avoid fluctuations caused by external factors. The input terminal of the filtering circuit is connected to the output terminal of the non-inverting amplifier, and the filtering circuit includes a low-pass filtering operational amplifier. The output terminal of the low-pass filtering operational amplifier is connected to the signal receiving and demodulation unit.
[0027] The signal receiving and demodulation unit of this invention includes at least one demodulation filter circuit and a quadrature demodulator circuit. The quadrature demodulator circuit includes a quadrature demodulation chip. This invention does not impose any special limitations on the specific selection of the quadrature demodulation chip; single-pole double-throw chips well-known to those skilled in the art can be used, including but not limited to TMUX1133 and TMUX1134. At least one demodulation filter circuit is connected after the quadrature demodulator circuit in this invention. Preferably, two demodulation filter circuits are connected. The two demodulation filter circuits further perform clutter filtering on the differential analog signal processed by the quadrature demodulation circuit and the filtered differential analog signal processed by the first-stage demodulation filter circuit, respectively.
[0028] Example 1
[0029] This embodiment provides a modulation and demodulation device for a hemorrhoidal artery detector, which includes a signal modulation and transmission unit, a signal amplification unit, and a signal receiving and demodulation unit; the signal modulation and transmission unit includes a processor and an ultrasonic transducer, the processor modulates a control electrical signal and transmits ultrasonic waves through the ultrasonic transducer; the ultrasonic transducer receives the echo signal and converts it into an electrical signal.
[0030] The signal amplification unit receives and amplifies the electrical signal converted by the ultrasonic transducer, and the signal amplification unit includes a non-inverting amplifier circuit; see appendix. Figure 1The in-phase amplifier circuit includes an in-phase amplifier U16A (using an OPA2626 amplifier), whose SHIFT-IN input is connected to an ultrasonic transducer. A filter resistor R50 is installed on the positive input line of the in-phase amplifier U16A, with the other end of R50 grounded. A filter capacitor C70 is connected in parallel with the filter resistor R50 and can be used for debugging. The negative input line of the in-phase amplifier U16A is grounded through a resistor R49, the other end of which is connected to a resistor R48, and the other end of R48 is connected to... A redundant capacitor C69 is connected in parallel with resistor R48 to the output terminal of the non-inverting amplifier U16A for debugging and other operations. The positive voltage input terminal of the non-inverting amplifier U16A is connected to the positive terminal of an external power supply through parallel-connected voltage-stabilizing capacitors C65 and C66, with the other ends of C65 and C66 grounded. The negative voltage input terminal of the non-inverting amplifier U16A is connected to the negative terminal of an external power supply through parallel-connected voltage-stabilizing capacitors C67 and C68, with the other ends of C67 and C68 grounded. The specifications of the resistors, capacitors, and other components used in the above non-inverting amplifier circuit can be the values marked in the attached diagram.
[0031] The signal amplification unit further includes a filtering circuit. The input terminal of the filtering circuit is connected to the output terminal of the inverting amplifier U16A. The filtering circuit includes a low-pass filtering operational amplifier U16B (using an OPA2626 amplifier). The output terminal of the low-pass filtering operational amplifier U16B is connected to the signal receiving and demodulation unit. See Appendix. Figure 2 The non-inverting amplifier circuit is connected to the filter circuit via resistor R52. The other end of resistor R52 is connected to the positive input terminal 5 of the low-pass operational amplifier U16B via resistor R51. The connection between resistors R52 and R51 is connected to the output terminal of the low-pass operational amplifier U16B via capacitor C71. The negative input terminal of the low-pass operational amplifier U16B is connected to its output terminal. Resistor R51 is grounded to the positive input terminal of U16B via capacitor C72. The specifications of the resistors, capacitors, and other components used in the above filter circuit can be those marked in the attached diagram.
[0032] The signal receiving and demodulation unit receives the amplified electrical signal from the signal amplification unit, performs quadrature demodulation processing, and transmits the quadrature demodulated signal to the processor for analysis and processing. The signal receiving and demodulation unit includes at least one demodulation filter circuit and a quadrature demodulator circuit. The quadrature demodulator circuit uses a single-pole double-throw (TPD) chip TMUX1134. The output of the low-pass operational amplifier U16B is connected to the TPD chip TMUX1134, which performs quadrature demodulation on the amplified analog electrical signal to obtain differential analog signals I and Q after removing the carrier signal. These differential analog signals I and Q serve as inputs to the demodulation filter circuit, which performs filtering processing to output filtered differential analog signals I and Q containing Doppler signals. The demodulation filter circuit includes two primary filtering modules: one filtering module filters clutter signals in the differential analog signal I, and the other filtering module filters clutter signals in the differential analog signal Q. (See Appendix) Figure 3 The first-stage filtering module includes an operational amplifier U19B. The differential analog signal I is connected to the positive input terminal of the operational amplifier U19B through resistors R63 and R64 connected in series. Resistor R64 is grounded to the positive input terminal of U19B through capacitor C88. The connection between resistors R64 and R63 is connected to the output terminal of U19B through capacitor C84. A redundant capacitor C85 is also provided in parallel with capacitor C84 for debugging. The positive voltage input terminal of the operational amplifier U19B is connected to resistor R... R65 is connected to an external power supply and grounded through parallel capacitors C75 and C77; the negative voltage input terminal of operational amplifier U19B is connected to an external power supply through resistor R66 and grounded through parallel capacitors C86 and C87; the output terminal of operational amplifier U19B outputs a filtered differential analog signal I; another primary filtering module circuit for filtering noise signals in the differential analog signal Q is the same as the above filtering module circuit, and the filtered signal is output as a filtered differential analog signal Q through the output terminal of the operational amplifier. The filtered differential analog signal Q and the filtered differential analog signal I are respectively input into the processor for analysis and processing to obtain target information such as blood flow velocity and arterial depth.
[0033] Example 2
[0034] This embodiment provides a modulation and demodulation device for a hemorrhoidal artery detector, which includes a signal modulation and transmission unit, a signal amplification unit, and a signal receiving and demodulation unit. The difference from Embodiment 1 is that the signal receiving and demodulation unit includes an orthogonal demodulator circuit and a two-stage demodulation and filtering circuit. The first-stage demodulation and filtering circuit is the same as in Embodiment 1, and the filtered differential analog signal Q and filtered differential analog signal I output from the first-stage demodulation and filtering circuit are used as inputs to the second-stage demodulation and filtering circuit for further noise filtering. (See attached diagram) Figure 4 The filtered differential analog signal I is connected to the negative input terminal of operational amplifier U22A through resistor R82. The negative input terminal of operational amplifier U22A is also connected to the output terminal of operational amplifier U22A through resistor R86 and capacitor C109 connected in parallel. Diodes D7 and D6 are connected in forward and reverse directions between the negative input terminal and the output terminal of operational amplifier U22A, with the anode of diode D7 connected to resistor R82. The positive input terminal of operational amplifier U22A is connected to the output terminal of operational amplifier U22B through resistor R90. The output terminal of operational amplifier U22A is connected to the output terminal of operational amplifier U22B through resistors R88 and R89 connected in series. The negative input terminal of amplifier U22B is connected to ground via resistor R88 and resistor R87. The positive input terminal of operational amplifier U22B is grounded via resistor R85 and capacitor C107 connected in parallel. The negative input terminal of operational amplifier U22B is connected to its output terminal via capacitor C110. The positive voltage input terminal of operational amplifier U22A is connected to an external power supply via resistor R78 and grounded via capacitors C101 and C103 connected in parallel. Its negative voltage input terminal is also connected to an external power supply via a resistor of the same specification and grounded via a capacitor of the same specification in the same way. The output terminal of operational amplifier U22A outputs a further filtered differential analog signal I (Filtered-IA). The other secondary filtering module circuit used to process and filter noise signals in the differential analog signal Q is the same as the above filtering module circuit. After filtering, the further filtered differential analog signal Q is output through the output terminal of the operational amplifier. The further filtered differential analog signal Q and the further filtered differential analog signal I are respectively input into the processor for analysis and processing to obtain target information such as blood flow velocity and arterial depth.
[0035] Finally, it should be noted that the above description is only a part of the preferred embodiments of this utility model and is not intended to limit this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A modulation and demodulation device for a hemorrhoidal artery detector, characterized in that, It includes a signal modulation and transmission unit, a signal amplification unit, and a signal receiving and demodulation unit; The signal modulation and transmission unit modulates the control electrical signal and transmits ultrasonic waves through the ultrasonic transducer; the ultrasonic transducer receives the echo signal and converts it into an electrical signal. The signal amplification unit receives and amplifies the electrical signal converted by the ultrasonic transducer. The signal amplification unit includes a non-inverting amplifier circuit and a filtering circuit. The non-inverting amplifier circuit has at least one non-inverting amplifier and is connected to the ultrasonic transducer. The non-inverting amplifier amplifies the electrical signal converted by the ultrasonic transducer to obtain an amplified analog electrical signal. The input terminal of the filtering circuit is connected to the output terminal of the non-inverting amplifier. The filtering circuit includes a low-pass operational amplifier, and the output terminal of the low-pass operational amplifier is connected to the signal receiving and demodulation unit. The signal receiving and demodulation unit receives the amplified electrical signal from the signal amplification unit, performs quadrature demodulation processing, and transmits the information after quadrature demodulation processing to the processor for analysis and processing.
2. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 1, characterized in that, The non-inverting amplifier circuit further includes a filter resistor or a filter capacitor disposed on the positive input line of the non-inverting amplifier. One end of the filter resistor or filter capacitor is connected to the positive input line of the non-inverting amplifier, and the other end of the filter resistor or filter capacitor is grounded. The negative input line of the non-inverting amplifier is grounded through a first gain resistor. The other end of the first gain resistor is connected to the output terminal of the non-inverting amplifier through a second gain resistor.
3. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 2, characterized in that, The positive input terminal of the low-pass filter operational amplifier is connected to the output terminal of the non-inverting amplifier through two sets of gain resistors connected in series; the two sets of gain resistors include a third gain resistor and a fourth gain resistor, and the output terminal of the third gain resistor is connected to the output terminal of the low-pass filter operational amplifier through a first capacitor; the negative input terminal of the low-pass filter operational amplifier is connected to the output terminal of the low-pass filter operational amplifier.
4. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 2, characterized in that, The positive and negative voltage input terminals of the in-phase amplifier are connected to the positive and negative terminals of an external power supply through two sets of parallel-connected voltage-stabilizing capacitors, respectively.
5. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 4, characterized in that, The positive voltage input terminal of the non-inverting amplifier is connected to one end of the two sets of voltage-stabilizing capacitors, and is connected to an external power source through this end; the other end of the two sets of voltage-stabilizing capacitors is grounded.
6. The modulation and demodulation device for the hemorrhoidal artery detector according to any one of claims 1 to 5, characterized in that, The signal receiving and demodulation unit includes at least one demodulation filter circuit and a quadrature demodulator circuit; the output of the low-pass filter operational amplifier is connected to the input of the quadrature demodulator circuit, and the amplified analog electrical signal is quadraturely demodulated by the quadrature demodulator circuit to obtain a differential analog signal with the carrier signal removed; the demodulation filter circuit includes at least one set of operational amplifiers, the demodulation filter circuit receives the differential analog signal, and filters the differential analog signal respectively to remove higher harmonics, and outputs a filtered differential analog signal containing Doppler signals.
7. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 6, characterized in that, The signal receiving and demodulation unit includes a two-stage demodulation and filtering circuit. The two-stage demodulation and filtering circuit consists of a first-stage demodulation and filtering circuit and a second-stage demodulation and filtering circuit. The first-stage demodulation and filtering circuit is connected to the output terminal of the quadrature demodulator circuit, and the second-stage demodulation and filtering circuit is connected to the output terminal of the first-stage demodulation and filtering circuit, and further filters the filtered signal output by the first-stage demodulation and filtering circuit.
8. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 7, characterized in that, The first-stage demodulation and filtering circuit includes two primary filtering modules, each of which contains an operational amplifier; the second-stage demodulation and filtering circuit includes two secondary filtering modules, each of which contains two operational amplifiers.
9. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 8, characterized in that, The positive and negative voltage input terminals of the operational amplifier are connected to the positive and negative terminals of an external power supply through voltage-regulating resistors, respectively.
10. The modulation and demodulation device for the hemorrhoidal artery detector according to claim 8, characterized in that, The secondary filtering module includes a first operational amplifier and a second operational amplifier. The positive input terminal of the first operational amplifier is connected to the output terminal of the second operational amplifier through a buffer resistor.