RU81061U1 - ELECTRONIC-ACOUSTIC INTERFACE FOR STETHOSCOPE - Google Patents

Abstract

The utility model relates to the field of acoustic technology and can be used for professional auscultation in medicine, mainly for diagnostic monitoring of the lungs in the presence of external sound interference in a hospital and intensive care unit, in emergency situations for the sound search of living people in ruins and inaccessible places, localization of leak points gas and liquid, directed observation of the sounds of animals, birds, fish, etc.

EFFECT: creation of a noise-resistant interface with the possibility of detachable connection to any acoustic head of a standard stethoscope, increasing its maintainability, ease of assembly and providing versatility for the detection and observation of weak sound signals (medical diagnostics, training, transmission to another user, in emergency and technical situations )

The electronic-acoustic interface is detachable and consists of an acoustic transducer 1, containing flexible first and second tubes 2, 3 with microphones 7, 6 and elastic plugs 8 for the formation of the main and compensating channels, respectively, an electronic transducer 11, comprising a housing 12 in which the amplifier 13, the inputs of the amplifier 13 are connected to the terminals of the balance controller 17, made in the form of a variable resistor with the ability to select (switch) channels, and the housing 12 has an input and output jacks 18, 19 for connecting Nia respectively acoustic transducer 1 and the acoustic console 20 or headphone. The interface is affordable, versatile, has a simple noise-resistant robust design that provides diagnostics in different frequency ranges, and can be easily connected to any head and headset of a standard stethoscope or headphones. The universality of the application of the interface is ensured by the simplicity of its detachable design, which allows you to modify the components of the interface independently of each other.

Description

The utility model relates to the field of acoustic technology, to acoustic devices that convert, under conditions of external and (or) internal interference, the initial acoustic signal into selectively amplified electronic and acoustic signals with the characteristics necessary for analysis and can be used for:

- professional auscultation in medicine, mainly for diagnostic monitoring of the lungs in the presence of external sound interference in a hospital and intensive care unit;

- in emergency situations for the sound search of living people in ruins and inaccessible places, localization of places of leakage of gas and liquid;

- directional observation of the sounds of animals, birds, fish, etc.

The closest analogues to the proposed utility model for the functional purpose and configuration of the main elements include the interfaces of electronic stethoscopes. The main distinguishing feature of the interface of electronic stethoscopes is the presence of an electronic channel containing electronic devices: a microphone, an amplifier-converter, a mini speaker (telephone), a power source, which are structurally integrated with an integral connection to the head and headset of the stethoscope.

An interface is known as part of an electronic stethoscope, in which an acoustic transducer with a microphone is located inside the housing, connected on one side by a flexible tube to the head of the stethoscope, and on the other hand is connected by an electric cable to the electronic transducer of the stethoscope. In order to reduce the influence (compensation) of external sounds on the useful signal coming to the microphone through a flexible tube from the side of the stethoscope head, a special omnidirectional microphone with a circular

(two-way) radiation pattern, on the other (opposite) side of which external sounds come through the holes in the transducer housing. Thus, on the microphone membrane, the acoustic signals are subtracted - sounds coming from opposite sides, and a useful signal is extracted, the gradient principle of the differential pressure gauge is used (see US patent No. 5909495, class A61B 7/04, published June 1, 1999). , Fig. 1,2).

The well-known acoustic transducer of the electronic stethoscope interface is notable for its simplicity of design, which has some drawbacks: assembly complexity, original individual elements, lack of tightness - open holes in the housing, which contributes to the pollution of the internal cavity and microphone from the external environment.

The main disadvantage of the interface is the lack of compensation (reduction - suppression) of infra-low and undesirable low sound frequencies, for example, the main heart tone, present in the initial acoustic signal from the head of the stethoscope.

The known interface in the electronic stethoscope, in which an acoustic transducer with a microphone is located inside the head of an electronic stethoscope.

The microphone is mounted on a cylinder of heavy metal - "load", which is surrounded on all sides by a shell of elastic porous material - "spring". The elastic shell and the metal cylinder, firstly, protect the microphone and the diaphragm of the head from external sounds and, secondly, form a mechanical oscillatory system similar to the spring-load system. The oscillation system is tuned to a low resonant frequency within 50-150 hertz (main heart tone) and oscillates synchronously (in phase) with acoustic vibrations in the cavity of the diaphragm of the head, thereby reducing the effect of low frequencies on the microphone membrane.

The cavity of the diaphragm of the head is connected to the external medium (atmosphere) in series by two through holes of small diameter and an air chamber (cavity) between them. The openings - "chokes" and the camera - "capacitance" form an acoustic low-pass filter with a transmission frequency of 0-150 hertz, similar to an electric filter. Acoustic vibrations come out (shunted) through the filter from the diaphragm cavity — sounds of an infralow frequency of 0-50 hertz, as well as a low frequency of 50-150 hertz, which reduces the quality factor of the said oscillatory system and makes the resonance characteristic more gentle (see US patent No. 6587564 B1, class A61B 7/04, published July 1, 2003, Fig. 1).

The disadvantages of the known interface include:

- acoustic and mechanical elements designed to reduce external and low-frequency interference are passive elements and are not able to provide a high degree of protection against interference;

- a complex structure in manufacturing, assembly technology, parameter settings - adjustment of mechanical resonance and an acoustic filter, special materials are required;

- the through holes of the filter are not protected from pollution from the external environment, which can lead to a change in the filter parameters.

The closest in purpose, design and used elements is a stand-alone electronic-acoustic interface for a stethoscope, comprising a housing with a flexible tubular element for connection with a stethoscope head with the formation of acoustic and electronic channels, including the first tube, valve, power source, microphone connected in series, adjustable an amplifier and a speaker, wherein a second tube is introduced into the flexible tubular element, the first and second tubes of the flexible tubular element are integrated into the housing with Tew separation respectively of the acoustic and electronic channels, the valve is configured to

the possibility of acoustic correction and switching of these channels, and the adjustable amplifier is made with an electric linear output for connecting external electronic devices, including recording and / or sound analysis (see utility model patent RU No. 70777, class A61B 7/04, publ. February 20, 2008).

The disadvantages of the known interface are as follows:

- there is no compensation for external sounds, infra-low sound frequencies and insufficient adjustment of low frequencies;

- there is no output to the headphone;

- it is inconvenient to use when monitoring lungs due to the relatively large size and weight, when it is necessary to fix the head of the stethoscope motionless for a long time on the patient.

The technical result of the utility model is to create a professional, cost-effective noise-resistant interface with the possibility of detachable connection to any acoustic head of a standard stethoscope, increasing its maintainability, ease of assembly and providing versatility for the detection and observation of weak sound signals (medical diagnostics, training, transmission to another to the user, in emergency and technical situations) when working in electronic or acoustic modes with ope By switching the frequency range and connecting the headphones or the acoustic headset of the stethoscope.

The technical result is achieved in that in the electronic-acoustic interface containing an acoustic transducer, including the first and second flexible tubes, forming respectively the main and compensating channels and made with the possibility of connection with the head of the stethoscope, in series

connected to the first microphone installed in the second tube, an amplifier and a power source located in the housing of the electronic transducer, at least one speaker, introduced a third tube, a second microphone and a balance control, the third tube is integrated in the second tube, the second microphone is placed in the first tube, the first and second microphones are connected in series with the balance control and amplifier. It is advisable to perform the differential amplifier.

Preferably, the acoustic transducer is detachable.

It is advisable to perform the first and second flexible tubes with a length (L) of 60 mm, with one of their ends being closed with elastic plugs, and the other ends can be connected to the head of the user's stethoscope.

It is preferable to install the first and second microphones in the second and first flexible tubes at a distance (S) of 45 mm from one of their ends with the possibility of placement and fixation by elastic plugs of the cable to connect them to an adjustable amplifier.

It is advisable in the acoustic transducer to perform the first tube with the possibility of creating a broadband main channel, and the second and third tubes of it with the possibility of creating a low-frequency compensating channel.

It is preferable to insert and fix the third tube with a sleeve inside the second tube with the possibility of connecting with the head of the stethoscope, with a length of (l) 40 mm with an inner diameter (d) of 1.3-1.5 mm and secure at a distance of at least (h) 5 mm from the first microphone.

Preferably, the first and second microphones are connected to the second and first inputs of the amplifier, respectively.

It is advisable to connect the balance regulator with conclusions to the first and second inputs of the amplifier.

It is preferable to perform the balance regulator with the ability to control the level of suppression of the low-frequency signal and / or external sounds, including interference, as well as the ability to select one of the frequency ranges: low-frequency - "N" (50-150 hertz), mid-frequency - "C" (150 -1500 hertz), broadband "Sh" (50-1500 hertz).

It is preferable to have a balance control in the form of a variable resistor.

It is advisable to integrate the speaker into a removable acoustic set-top box.

The essence of the utility model is that the electronic-acoustic interface is detachable and consists of an acoustic (primary) transducer, an electronic (secondary) transducer and an acoustic set-top box (adapter), connected in series by electrical connectors (plugs), with the possibility of connecting standard extension cords - cables with connectors for stereo phones up to 5 meters long.

When conducting patent research, no solutions were found that are identical to the claimed, and therefore, the claimed utility model meets the criterion of "novelty."

Figure 1 shows a General view of the structure of the interface.

The electronic-acoustic interface is autonomous, detachable and contains (figure 1):

- acoustic transducer 1 containing flexible first and second tubes 2, 3 for the formation of the main and compensating channels, respectively, and in the second tube 3 is fixed with

using a short sleeve 5, a third tube 4 of smaller diameter with the possibility of connecting with a stethoscope head, and inside the indicated second and first tubes 3, 2, the first and second microphones 6, 7 and elastic plugs 8 for tightness and fixation of the electric are installed at their (upper) ends a cable 9, which provides an electrical connection to the first and second microphones 6, 7 through the plug 10 and socket 18 with the electronic transducer 11, and the other (lower) ends of the first and second tubes 2, 3 are made with the possibility of connection with the head of a stethoscope;

- an electronic converter 11, comprising a housing 12, in which an amplifier 13 is placed, made of a differential (selective type) with an electric linear output 14 and a volume control 15, combined with a switch of the power source 16, the first ("+") and the second ("- ") the inputs of the amplifier 13 are connected to the terminals of the balance controller 17, made in the form of a variable resistor with the ability to select (switch) channels, and the housing 12 has input and output sockets 18, 19 for connecting acoustic transducer 1 and acus, respectively nical consoles 20 or headphones (. FIG not shown);

- an acoustic prefix 20, having a housing 21 with acoustic fittings 22 for connecting to the tubes of the acoustic headset of a stethoscope (not shown in FIG.) and one or two miniature speakers 23 (FIG. 1) placed therein, connected to an electrical plug 24 for connection to the socket 19 of the electronic Converter 11.

The first and second flexible tubes 2, 3 are made with a length (L) of 65 mm so that some of their ends (upper) are closed by elastic plugs 7, and the other (lower) ends are made with the possibility of connection with the head of a stethoscope of the user. First and second

microphones 6, 7 are installed inside the second and first flexible tubes 3, 2 at a distance (S) of 45 mm from their other (lower) ends with the possibility of placement and fixing with elastic plugs 8 of cable 9 to connect them to the amplifier 13. Distance (S) to microphones 6, 7 are selected so that the acoustic resonance inside each tube 3, 2 is above 1500 hertz. Elastic plugs 8 serve to seal one (upper) ends of the first and second tubes 2, 3 from the side of the respective microphones 7, 6 and fix the cable 9.

The first flexible tube 2 transmits, without changes, the acoustic signal (sound) from the head of the stethoscope to the second microphone 7 and together with it forms the main - broadband channel in which the specified microphone 7 converts the signal into an electric one and then through cable 9 connected by plug 10 to socket 18 transmits a signal through the balance regulator 17 to the first ("+") input of the amplifier 13.

Inside the second tube 3, a third tube 4 of a smaller diameter (l) 40 mm and an inner diameter (d) of 1.3-1.5 mm is inserted, fixed by a short sleeve 5 at a distance (h) of 5 mm from the first microphone 6. The outer diameter of the third the tube 4 allows, when connected to the head of the stethoscope, to insert (insert) its end into the internal hole of the fitting of the specified head. The third tube 4 transmits an acoustic signal (sound) from the head of the stethoscope through the air cavity inside the second flexible tube 3 to the first microphone 6 and together with it form a compensating - low-frequency channel, in which the first microphone 6 converts the signal into an electric one and then through cable 9, the connector from the plug 10 and the socket 18 transmits a signal through the balance regulator 17 to the second ("-") input of the amplifier 13. The third tube 4 is an analogue of the "throttle", and the air cavity inside the second flexible tube 3 is an analogue of the "capacity" and together they represent acoustic filter of the first order low frequency 0-150 Hz.

External sounds (interference) penetrate through the walls of the first and second flexible tubes 2, 3 and the head of the stethoscope simultaneously. Thus, all the acoustic signals arriving at the second and first microphones 7, 6 in the first 2 and second 3 flexible tubes are in phase - they have the same propagation phase of the acoustic wave.

The balance regulator 17 is designed to change the ratio of amplitudes (values) between the electrical signals of the main and compensating channels supplied to the amplifier 13. In position "W" of the regulator, the compensating channel is connected to the common point (ground) of the amplifier 13 and is zero on the second ("-" ) input of amplifier 13, and at the first ("+") input there will be a maximum of the main - broadband signal. In the "H" position, the situation changes to the opposite and at the second ("-") input of the amplifier 13 there will be a maximum of the compensating-low-frequency signal. In position "C" the amplitude of the signals in each channel at the first and second inputs of the amplifier 13 are approximately equal.

The amplifier 13 is designed to receive the difference and amplification of electrical signals from the first and second microphones 6, 7, the formation of a frequency bandwidth in the range of 50-1500 hertz and the output signal on the output socket 19 with a power sufficient to work with standard 32 ohm headphones. Depending on the position of the balance control 17, after subtracting the common-mode signals, the frequencies will be amplified: in the “H” position - 50-150 hertz, in the “C” position - 150-1500 hertz, in the “Sh” position - 50-1500 hertz. The maximum suppression of low frequencies and / or external sounds is regulated by the regulator 17 balance near the middle position "C".

The amplifier 13 is made differential with an electrical linear output 14 for connecting external electronic devices, including for recording and / or analysis of sound and volume control 15, combined with a power switch.

Thus, the amplifier 13 must be differential and have an active low-pass filter with a cutoff frequency of about 1500 hertz with a decay of 40 decibels / decade, gain control combined with the power supply switch. The minimum cost amplifier 13 is preferably of an analog type, for example, as used in hearing aids.

A power source 16, for example, of a battery type, provides a direct current supply for operation of the electronic converter 11.

It is advisable that the housing 12 of the interface is made of hygienically neutral plastic and the same electrical jack connectors are used for stereo phones.

The interface is used as follows.

The power source 16 is installed in the interface housing 12, the stethoscope head fittings are connected to the first and second flexible tubes 2, 3 of the acoustic transducer 1, and the acoustic headset with the fittings 22 of the acoustic set-top box 20 or headphones are connected to the output of the electronic transducer 11, while the volume control 15 the regulator 17 balance set in the middle position "C" - the middle frequency.

Initially, the interface is set up and checked on a patient who is healthy without pathology, for this, at a characteristic auscultation point (approximately 200-1000 Hz), the ratio of cardiac and pulmonary sounds is compared, then the level of heart sounds is reduced by the balance regulator 17, after which we can proceed to the diagnosis of pathology.

When diagnosing a heart, it is recommended to set the level of heart sounds with the balance control 17 to the extreme position “N” - lower frequencies, the volume control 15 sets a comfortable level

sound for the user's ear. In general, the balance is transferred to the "Sh" position - broadband mode of 50-1500 hertz.

To obtain high-quality diagnostic results in suitable conditions (in a hospital), it is recommended to use a latch for the stethoscope head (patent No. 64495 "Sensor latch and frame for its implementation") mounted on the patient’s body.

The interface is affordable, versatile, has a simple noise-resistant robust design that provides diagnostics in different frequency ranges, and can be easily connected to any head and headset of a standard stethoscope or headphones.

The interface can be used to work together with a standard acoustic stethoscope that the user already has. The quick and quick transition from one diagnostic mode to another allows the user to more accurately configure the interface and quickly master (self-learn) the electronic diagnostic method. In addition, the interface is easy and simple to disconnect from the headset of the stethoscope and transfer to another user, if necessary, extend the cable connection between the components of the interface. However, the interface does not have the disadvantages of the above analogues and prototype.

The electronic-acoustic interface has passed pilot tests, confirming the effectiveness of its application. The cost of manufacturing the interface is slightly higher than the cost of a traditional acoustic stethoscope, while the parameters of the stethoscope comply with modern requirements. The universality of the application of the interface is ensured by the simplicity of its detachable design, which allows you to modify the components of the interface independently of each other.

Claims (5)

1. An electronic-acoustic interface comprising an acoustic transducer comprising first and second flexible tubes, respectively forming the main and compensating channels and configured to connect to a stethoscope head, serially connected to a first microphone installed in the second tube, an amplifier and a power source located in the housing of the electronic transducer, at least one speaker, characterized in that a third tube, a second microphone and a balance control are inserted, the third tube is integrated in a second tube, the second microphone is placed in the first tube, the first and second microphones are connected in series with the regulator, and balance amplifier. 2. The interface according to claim 1, characterized in that the amplifier is made differential. 3. The interface according to claim 1, characterized in that the acoustic transducer is detachable. 4. The interface according to claim 1, characterized in that the first and second flexible tubes are made in length (L) 60 mm, with one of their ends closed by elastic plugs, and the other ends made with the possibility of connection with the head of a stethoscope of the user. 5. The interface according to claim 1, characterized in that the first and second microphones are installed in the second and first flexible tubes at a distance (S) of 45 mm from one of their ends with the possibility of placement and fixation by elastic plugs of the cable for connecting them to an adjustable amplifier.