RU112618U1 - ACOUSTIC MEDICAL DIAGNOSTIC INSTRUMENT - Google Patents

Abstract

An acoustic medical diagnostic device containing a contact probe and an electronic unit, connected to each other via a USB cable, two structurally combined tuning forks are placed inside the contact probe housing, each of which consists of: a steel electrode, a bimorph piezoacoustic plate and a tuning forks attachment to the probe housing; the electrodes go out through a threaded bushing with a lock nut, a replaceable support nozzle made of a biologically inactive material is put on the bushing, replaceable tips are attached to the steel electrodes, on the side of the probe body opposite to the bushing, a USB cable is fixed through a sealed lead to connect the probe to the electronic unit; the electronic unit is made in a plastic case, which has a compartment for installing a power battery, a connector for connecting a probe and a connector for connecting a computer, on the front panel of the unit there is a matrix indicator for displaying information and a control button for the device, a harmonic signal generator, a signal preprocessing unit and computing device.

Description

The device relates to medical devices and can be used in dermatology, surgery, plastic surgery, cosmetology.

In medicine, mechanical waves are used to diagnose a large list of diseases, including the state of a substance or the location of various inclusions in a medium by wave propagation.

The closest analogue of the proposed device is the device "ASA" (Sarvazyan A.P. Et fl. Method and device for acoustic testing of elasticity of biological tissues. United States Patent No. 947851, 08/14/1990), the device allows you to measure the propagation velocity of a surface shear wave.

However, the known device has several disadvantages, namely:

- poor acoustic isolation of the emitting and receiving piezoelectric transducers from the device design, which leads to unacceptably large phase distortions,

- low sensitivity of the device and a small dynamic range of work on different tissue densities,

- control of piezoelectric transducers does not have galvanic isolation, which is not always acceptable for operation and practically does not provide the ability to sterilize the device and change contact probes.

The technical result is the determination of the complex resistance of elastic tissues, which is achieved due to the following:

- the use of tuning forks provides a decoupling of at least 26 dB, which minimizes phase distortion,

- the use of a resonant tuning fork scheme increases the sensitivity by more than 40 dB, which can dramatically reduce the mechanical effect on the tissue and expand the spectrum of the studied tissues in hardness,

- ensuring repeated measurements without violating the characteristics of tissue elasticity, which affects the result of repeated measurements, the repeatability of the measurement conditions.

The proposed device provides a definition of the complex resistance of elastic tissues in the form of measuring the propagation delays of a longitudinal wave of mechanical excitation in terms of the speed of wave propagation. Propagation delay is measured as the phase shift between the excitation signal and the longitudinal wave response signal. The device allows measuring the wave propagation velocity in the range from 10 to 290 m / s, provides a programmable setting of the gap between the probe electrodes in the range from 1 to 3 mm, as well as automatic calibration by the standard and variable data input. In addition, the device provides a measurement of the operating frequency automatically.

The characteristics of the device:

- frequency of wave excitation 1300-1600 Hz.

- the shape of the tips to the electrodes may be different: ball B = 1 ± 0.1 mm; plates L <1.0-3.0, h = 0.5 ± 0.1 mm; cone D = 0.5 ± 0.1 mm,

- the distance between the sensor elements from 1.0 to 3.0 mm,

- the penetration depth into the fabric is adjustable from 0.1 to 2.5 mm.

A general view of the proposed device is shown in Fig. 1. The device (Fig. 1), the functional diagram of which is shown in Fig. 3, consists of a contact probe (1) and an electronic unit (2). The electronic unit is connected to the contact probe via a USB cable (3), structurally integrated with the probe.

The contact probe (Fig. 2) is made in the form of two structurally combined tuning forks placed in a housing (4) with a cover (5), each of which consists of: a steel electrode (9), a bimorph piezoacoustic plate (actuator), and tuning fork attachment points to probe body.

Steel electrodes of tuning forks exit the housing through a threaded sleeve (6) with a lock nut (7) providing adjustment of the magnitude of the protrusion of the electrodes (this adjustment allows you to select the depth of deformation of the tissue under study by the electrodes). A replaceable support nozzle (8) of biologically inactive material is put on the sleeve, which eliminates measurement distortions arising from the edge effects of reflection or of the drain (damping) of excited vibrations.

Replaceable tips of the required shape are mounted on the steel electrodes (9). On the opposite side of the probe body (relative to the sleeve), a “USB” cable is fixed through the hermetic outlet, which ensures the connection of the probe to the electronic unit, with the aim of supplying excitation signals to the bimorph plate of the tuning fork (10), which ensures the formation of deformations of the tissue under study and removing the response signal from the bimorph plate of the tuning fork that provides a response signal.

The excitation tuning fork provides the formation of a longitudinal wave in the sample under study, of stabilized amplitude, converting the electrical excitation signal into mechanical vibrations.

A tuning fork for receiving a response provides reception of a mechanical delayed wave and converts it into an electrical signal.

The tuning forks of signal excitation and reception, being high-quality resonant systems, provide high sensitivity of signal reception and low excitation energy.

The design of tuning forks, namely, that the active parts of the tuning forks are actuators, and the passive parts that are directly in contact with the tissues under investigation are made as steel electrodes and are not galvanically connected with the active parts, provides:

- full galvanic isolation of the electrodes directly acting on the fabric, with electrical circuits of the device and probe,

- high sensitivity of the reception signal response of mechanical vibrations,

- the ability to perform contacting electrodes of complex geometric shape,

- low energy level of excited vibrations, providing minimal impact on the studied tissue,

- execution of electrodes with replaceable tips of the required shape,

- sterilization of electrodes,

- deep acoustic isolation of the excitation actuator and receiver actuator.

The electronic unit (Fig. 1) is made in a plastic case with a compartment for installing a power accumulator (11), a connector for connecting a probe and a PC connector. Inside the electronic unit there is a harmonic signal generator (13), a signal preprocessing unit (14) and a computing device (15).

On the front panel of the unit is a matrix indicator (12) for displaying information and a control button (17) for the device. Functional diagram of the device is shown in Fig. 3

The device operates as follows:

The generator (13) of the electronic unit generates a harmonic excitation signal, which is supplied to the actuator (20) of the tuning fork for excitation of the longitudinal wave, consisting of poses 19, 20, 21, 22. A mechanical wave excited by the electrode (22), passing through the studied tissue area (18) is recorded by the electrode (25) of the tuning fork of the signal pos. 23, 25, 24, 16 and is converted by the actuator (24) into an electrical signal.

The electric signal of the actuator (24) is processed by the signal preprocessing unit (14) of the electronic unit and then compared in the computing device (15) with the excitation signal. The result of the comparison, namely the phase shift of the response signal and the excitation signal, is converted into the velocity of the longitudinal wave according to the formula:

where

V is the speed of the wave,

L is the distance between the emitting and receiving electrodes,

ω is the circular excitation frequency.

On the matrix indicator of the electronic unit, service information is displayed:

- longitudinal wave propagation velocity,

- condition of the power source,

- excitation frequency,

- response signal level,

- distance between electrodes

Claims (1)

An acoustic medical diagnostic device containing a contact probe and an electronic unit interconnected via a USB cable, two structurally integrated tuning forks are placed inside the contact probe case, each of which consists of: a steel electrode, a bimorph piezoacoustic plate and a tuning fork attachment unit to the probe case; the electrodes exit through a threaded sleeve with a lock nut, a replaceable support nozzle of biologically inactive material is put on the sleeve, replaceable tips are attached to the steel electrodes, a USB cable is fixed on the opposite side of the probe housing from the sleeve through the cable outlet for connecting the probe to the electronic unit; the electronic unit is made in a plastic case that has a compartment for installing a power accumulator, a connector for connecting a probe and a computer connector, on the front panel of the unit there is a matrix indicator for displaying information and instrument control buttons, a harmonic signal generator, a signal preprocessing unit are placed inside the electronic unit and computing device.