Internal arteriovenous fistula tremor measuring method and device based on capacitance sensing principle

Abstract

The invention provides an internal arteriovenous fistula tremor measurement method and device based on a capacitance sensing principle. The method comprises the steps of collecting a tremor signal generated when blood flows through an internal fistula through a capacitance sensor, converting the tremor signal into a capacitance value, and outputting the capacitance value; and performing reducing through continuous capacitance value signals to obtain the tremor signal generated when the blood flows through the internal fistula. The device comprises a measuring unit and a signal processing unitwhich are connected through a shielded wire, wherein the measuring unit comprises an arc-shaped support, a sliding block, a telescopic rod and a capacitive sensor; an arc-shaped through groove is formed in the arc-shaped support to serve as a sliding rail, and the sliding block is in sliding connection with the sliding rail; the capacitive sensor comprises a fistula sensing polar plate and a fixedsensing polar plate; the telescopic rod penetrates through the sliding block and is fixedly connected with the fixed sensing polar plate at the end located on the circle center side of the arc-shapedsupport, of the telescopic rod. The device has the advantages of low cost, high precision, high sensitivity and free from risks to patients.

Description

technical field [0001] The invention relates to the field of signal detection methods and equipment, in particular to a method and device for measuring arteriovenous fistula tremor based on the principle of capacitive sensing, which can measure the vibration signal transmitted to the skin surface when the arteriovenous fistula trembles. Background technique [0002] Explanation of terms: [0003] Arteriovenous fistula: Arteriovenous fistula is one of the surgical procedures, mainly used in hemodialysis treatment. Arteriovenous fistula is a small operation of vascular anastomosis. The artery near the wrist of the forearm and the adjacent vein are sutured, so that arterial blood flows in the anastomotic vein, forming an arteriovenous fistula. [0004] Hemodialysis: Hemodialysis is one of the renal replacement therapy methods for patients with acute and chronic renal failure. It uses the principle of semi-permeable membranes to remove various harmful and redundant metabolic wa...

AI Technical Summary

Problems solved by technology

[0013] In the above scheme 1, angiography and Doppler ultrasound are mainly used in medicine. Angiography needs to inject a contrast agent into the blood vessel, which is an invasive examination; cause measurement error

Both are expensive and require equipment, site and operator experience

[0014] In the above scheme two, although the stethoscope measurement method can collect the acoustic characteristics of the internal fistula, it is obviously affected by the environment, and it is easy to mix the noisy signal of the external environment with the normal signal, which affects the judgment of the internal fistula state

[0015] In the above scheme three, due to the acceleration principle, the acceleration sensor cannot collect the constant velocity part or the part with small acceleration in the tremor signal of the internal fistula, and the collected signal cannot correctly reflect the state of the internal fistula

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