JPS61253046A - Convertible electronic stethoscope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to medical and testing instruments, and more specifically to converting a standard acoustic stethoscope into an electronic@diagnostic device and converting an electronic stethoscope into an acoustic stethoscope. Concerning a convertible electronic stethoscope that can be converted into a.

[Conventional technology]

For many years, acoustic stethoscopes have been used by doctors, nurses, etc. to diagnose abnormalities in the body. Later, electronic stethoscopes were introduced to isolate and amplify specific sounds, making it easier to diagnose certain medical conditions.

[Problem that the invention seeks to solve]

However, research has shown that most doctors, nurses, etc. can hear the diagnostician clearly and louder than traditional acoustic stethoscopes, and that they are similar in appearance, feel, and operation to the standard acoustic stethoscopes they have used for many years. It turned out that he was asking for a stethoscope. It was also found that doctors, nurses, etc. are very busy and often forget to turn off the electronic stethoscope after use.

As a result, the battery often ran out, the electronic stethoscope did not work when needed, and doctors, etc., were frustrated and never used it again. Also, the weakest part of a standard acoustic stethoscope is the rubber tube. Stethoscope chest pieces are precisely made from expensive materials to meet standards.
However, when the cheap rubber tube broke, I had no choice but to throw away the entire stethoscope.

[Means for solving problems]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a convertible electronic stethoscope that can easily convert a standard acoustic stethoscope to an electronic stethoscope, and an electronic stethoscope to an acoustic stethoscope. The specific means for this purpose is a convertible electronic stethoscope that converts a standard acoustic stethoscope into an electronic stethoscope, which consists of a chest piece, a binaural device, and multiple duplex means connecting the chest piece and the binaural device. a housing having upper and lower sidewalls;
lower connecting means extending downwardly from said lower side wall and connected to a lower portion of said chest piece means; and lower connecting means located within said housing and acoustically connected within said housing to said lower connecting means for transmitting sound waves. a microphone for converting the electrical signal into an electrical signal; an amplifier installed in the housing and electrically connected to the microphone to amplify the electrical signal; and an amplifier installed in the housing and electrically connected to the amplifier to amplify the electrical signal. and an upper connecting means that is acoustically connected to the speaker, extends upwardly from the upper side wall, and is connected to the binaural.

[For production]

The tubes are connected to the upper and lower connecting means of the housing containing the microphone, amplifier and speaker respectively, and the chest piece is connected to the other end of the lower tube connected to the lower connecting means, while the upper connecting means is connected to the chest piece. By connecting the binaural to the other end of the upper tube connected to the means, an electronic stethoscope is formed, and by connecting the upper and lower tubes without going through an amplifier module, a standard acoustic stethoscope is formed. Yes, when used as an electronic stethoscope, sound waves such as heart sounds transmitted from the chest piece reach the microphone through the lower tube, where they are converted into electrical signals, and then amplified by an amplifier. The amplified electrical signal is converted into sound waves by the speaker and transmitted to the user's vision via the upper tube and binaural.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the invention. Module 10 is connected to a standard acoustic stethoscope 18.

The acoustic stethoscope 18 includes a chest piece 12 for pinking up the patient's heart sounds, and the chest piece 1
2 is acoustically coupled to one end of a pliable lower tube 14 and the other end of the tube 14 is coupled to an amplifier module 10 for transmitting heart sounds transmitted from the chest piece 12 to the amplifier module 10. 1. Electronically amplify the heart sounds using an amplifier. One end of the pair of binaurals 19 is joined to the flexible upper tube 16 to form a figure 7 shape. The other end of the tube 16 is acoustically connected to the amplifier module 10, and the other end of the pinaural 19 is provided with an earpiece 20, which the user places in his or her ear to listen to the heartbeat. There is.

The preferred chest piece 12 is a standard unit having a membrane 22 that vibrates when applied to the patient's body, creating sound waves within the chest piece 12. This type of chest piece 12 is widely used in standard acoustic stethoscopes and allows doctors to easily use the stethoscope of the present invention and utilize the knowledge gained with standard stethoscopes. It is. The chest piece 12 is designed to be removable from the lower tube 14 so that the user can replace it with a chest piece that is optimal in terms of shape, size, weight, etc., depending on the patient's body and medical condition. It is being The preferred tubes 14 and 16 are made of rubber and connect the chest piece 12 and binaural 19 to the amplifier module 10 to form a sound system.

FIG. 2 shows the internal structure of the amplifier module 10 excluding the top cover. The module 10 has a housing 24
It is about half the size of a cigarette case,
Made of materials such as plastic. Microphone 2
6 is attached to the bottom of the lower connecting pipe 28.

The connecting pipe 28 is attached to the lower (left side in the drawing) side wall of the housing 24 and is acoustically connected to the lower tube 14. The connecting pipe 28 is tapered from the bottom to the tip to facilitate insertion into the tube 14. Further, an annular projection 29 is provided between the bottom and the tip to prevent the tube from falling off. A preferred microphone is of the electret type and has its own field effect transistor amplifier (E F T). The connecting pipe 28 can be made of metal, plastic, or other materials. A printed circuit board 30 is mounted approximately centrally in the housing 24 and is electrically connected to the microphone 26 and supports various electrical components as described below. The speaker 32 is attached to the bottom of the upper connecting pipe 34. The connecting pipe 34 is connected to the housing 2
The printed circuit board 3 is attached to the upper (right) side wall of 4.
electrically connected to the 0 output. A preferred speaker 32 uses a Guinamisoku microphone as a speaker and is connected to the upper tube 16 through a connecting pipe 34 to form a sound system. Connection pipe 34
is tapered from the bottom to the tip to facilitate insertion of the tube 16. Further, an annular protrusion 35 is provided between the bottom and the tip to prevent the amplifier module 10 from falling off. The connecting pipe 34 can be made of metal or plastic.

An on-off switch 36 is mounted on the upper right side of the housing 24 and electrically connected to the printed circuit board 30. This on/off switch is preferably a small pushbutton type. A tone switch 38 is mounted centrally at the top of the housing 24 and is connected to the printed circuit board 30. This tone switch 38 is preferably of a sliding type.

A volume control 40 is mounted on the lower right side of the housing 24 and is electrically connected to the printed circuit board 30. The preferred volume control 40 consists of a variable resistance 42 and a rotatable knob 44 that articulates the resistance. The auxiliary jack 46 is attached to the lower left side of the housing 24. The preferred auxiliary jack 46 is a standard jack commonly used for connecting auxiliary amplifiers and tape recorders. A battery 48 is provided on the upper left side of the housing 24 and provides power to the printed circuit board 30. A preferred battery 48 voltage is 7v.

The electronic circuitry of amplifier module 10 is shown as a block diagram in FIG. The on-off timer circuit 50 is connected to the amplifier circuit 52 of the microphone 26 and is powered by the battery when on.

・On the other hand, in the off state, the power supply is automatically cut off after the scheduled time. Amplifier circuit 52, which normally operates as a high band amplifier, operates as a low band amplifier when connected to high band filter 54 through tone switch 38. The speaker 32 is connected to the amplifier circuit 52 and receives power to provide sound to the binaural 19.

In FIG. 4, the on-off timer circuit 50 includes two Schmitt triggers 56, 58 and a transistor 60.
includes a Schmitt trigger integrated circuit. The two Schmitt triggers 56 and 58 are connected to the Schmitt trigger 58 when pin 3 of the Schmitt trigger 58 has a low voltage.
The output of pin 4 of is configured to always be at a high voltage. Pin 4 connects to Schmitt trigger 5 through resistor 62
It is connected to the gate of 6 by pins 1 and 2. Pin 3 is connected in parallel to two series circuits consisting of a resistor 64, a capacitor 66, a capacitor 68, and a resistor 70.

Meanwhile, it is connected to pin 6 of the Schmitt trigger 58 by a wire. Pin 5 of Schmitt trigger 58 is connected to the connection point of capacitor 68 and resistor 70. Bush button switch 36 is connected between pin 2 of Schmitt trigger 56 and the connection point of resistor 64 and capacitor 66. Pins 14.7 of Schmitt trigger 58 are connected to the positive and negative terminals of battery 48, respectively. The base and emitter of the transistor 60 are each connected to a resistor 72.
through pin 4 of Schmitt trigger 58 and battery 4
It is connected to the positive (+TV) of 8. The collector of transistor 60 is connected to the negative terminal of battery 48 through capacitor 74. Microphone 26 is resistor 76
It is connected between the collector of the transistor 60 and the negative terminal of the battery 48 through the terminal.

Amplification circuit 52 includes an operational amplifier 80 with EFT high input impedance. The non-invert input at pin 3 of the operational amplifier 80 is connected to the output of the microphone 26 through the connection point of the series connection of two resistors 82, 84 and a capacitor 86. Resistors 82, 84 form a voltage divider and bias the non-inverting input of operational amplifier 80 at half the value of the supply voltage. Pin 2 of the operational amplifier 80 is connected to the negative terminal of the battery 48 through a fixed resistor 88, a variable resistor 90, and a capacitor 92. Pins 7.4 of the operational amplifier are connected to the collector of transistor 60 and the negative of battery 48, respectively. Pin 6 of the operational amplifier is connected to pin 2 through resistor 94 (12), which together with resistors 88 and 90 determines the gain of the amplifier. The gain is about 3 when changing the variable resistor 90 from maximum to minimum.
Preferably, the resistance values are chosen to vary from 300 to 300.

Filter 54 selectively connects capacitance 96.98 across resistor 94 through switch 38 . In the figure, the switch 38 is closed to the high tone side, and a capacitor 96 smaller than the capacitor 98 is connected.

The speaker 32 and the auxiliary jack 46 are connected between the negative of the battery 48 and the pin 6 of the operational amplifier 8° through the capacitor 100, completing the amplifier unit. The speaker has a resistance of approximately 200 ohms.

In use, the rubber tube of a standard acoustic stethoscope is first cut near the connection point of the binaural 19 to create the upper and lower rubber tubes 14 and 16. Next, the connecting pipe 28.3 of the amplifier module 10 of the invention
4 into the rubber tubes 14 and 16 respectively to connect. The connecting pipe 28.34 has a taper so that it can be easily inserted into rubber tubes of different diameters. An annular projection 29.35 on the connecting pipe 28.34 prevents the rubber tube 14.16 from falling out. Thus, an ordinary acoustic stethoscope can be easily converted into an advanced electronic stethoscope using the inexpensive amplifier module 10 of the present invention.

Next, to explain the function of the convertible electronic stethoscope configured as described above, the user can use the binaural 19
to the patient's ears, and the chest piece 12 is placed against the patient's body as if using an ordinary acoustic stethoscope. Since the chest piece 12 can be removed from the rubber tube 14, a chest piece suitable for the purpose can be selected from a variety of standard chest pieces.

Then, when the on-off switch is pressed, the charge on capacitor 66 is transferred through pin 1.2 of Schmitt trigger 56. When the voltage on pin 3 is low, the charge on capacitor 66 is Ov, and the resistor 62 that brings pin 1°2 to Ov tries to charge capacitor 66, but this happens before pin 3 becomes high voltage. I don't have time. When pin 3 becomes high voltage, the input of pin 6 of the gate of Schmitt trigger 58 becomes high voltage immediately because it is connected by a wire. The charge on capacitor 68 is also transferred to pin 5 or other input of Schmitt trigger 58. The input of this charge bin 6.5 goes high and pin 4 goes low, quasi-biasing transistor 60 and turning on amplifier 52.

Microphone 26 is supplied with current through resistor 76 . The voltage across resistor 76 is connected through capacitor 86 to the non-inverting input of operational amplifier 80 at pin 3. The output of the operational amplifier 80 is connected to the speaker 32 through the capacitor 100, so that the AC portion is transmitted to the speaker while the DC portion is blocked. Amplifier 52 is disconnected from the power input by capacitor 74, grounding the AC portion and stabilizing amplifier circuit 52. The loudspeaker forms a closed air system with binaural 19 as described above.

Since resistor 88 is used in series with volume control resistor 90, operational amplifier 80 will not saturate even if volume control resistor 90 is adjusted to its minimum value for maximum volume. Without this resistor, the amplifier would be in open loop at the minimum value of the volume control resistor.

The amplifier amplifies the sound level of the diagnostician, so the patient's heartbeat can be heard even in a noisy room or through a kimono.

When the volume adjustment resistor 90 is set from the minimum volume to the maximum value,
The electronic stethoscope's volume is comparable to that of a traditional acoustic stethoscope, allowing doctors to compare the sounds heard with a standard acoustic stethoscope.

Resistor 94 is a feedback resistor for operational amplifier 52 and is normally bypassed by capacitor 96 .

This limits high frequencies and optimizes the frequency response of the amplifier 52 to all sounds made by a breathing person, allowing a physician to use the electronic stethoscope to measure respiration. In other words, when tone control 38 is in the "high" position, capacitor 96 provides a high frequency response. When the tone control 38 is in the "low" position, the capacity is 98
bypasses high frequencies and gives a low frequency response. In other words, the electronic@diagnostic instrument is in a state suitable for listening to heart sounds.

At this time, the low voltage pin 4 is connected to the pin 1 through the resistor 62.
, 2, keeping pins 1.2 at a low voltage even after the on-off switch is released.

At this point, pin 3 is at a high voltage, but capacitor 66 is charged through resistor 64. In this way, the next on/off
When the switch 36 is pressed, the previous state of the switch is remembered. Charge gradually leaks from capacitor 68 through resistor 70 for a time determined by the values of capacitor 68 and resistor 70 until pin 4 becomes high voltage again and transistor 60
and turns off the amplifier 52. Preferably, the values of capacitor 68 and resistor 70 are selected such that the time is 2 minutes and 45 seconds. This high voltage at pin 4 is connected to pin 1 by resistor 62.
Connected to 2.

If the on-off switch 38 is pressed again while the amplifier 52 is still on, the charge on the capacitor 66 at the high voltage will be transferred to pins 1.2.
to high voltage. This causes output bin 3 to be at a low voltage and momentarily bin 4 to be at a high voltage.

This charge is connected through resistor 62 to pin 1.2.

Transistor 60 and amplifier 52 are turned off. Therefore, repeatedly pressing switch 36 will cause amplifier module 1 to
0 repeats on and off. However, if module 10 is left on, capacitor 68 will discharge through resistor 70, turning module 10 off after 2 minutes and 45 seconds.

Resistor 72 connects the output of pin 4 to the base of transistor 60 to limit its current. The dark current of module 10 when there is no signal to microphone 26 is approximately 3n+A. Leakage current when the module is turned off is approximately 0.1A
It is. Therefore, one small battery can power the module for a long time.

FIG. 5 shows a standard acoustic stethoscope 18 with the upper and lower rubber tubes 16, 14 connected by the straight connector 102 of the present invention. This straight connector is shown in detail in FIG. It is a piece of metal or plastic pipe with a flange 104 in the middle. Flange 104 is optional, but rubber tube 14.
16 to facilitate connection and removal. The outer wall of the pipe 103 is tapered from the center to the tip so that it can be easily fitted into rubber tubes 14, 16 of various inner diameters. Pipe 103 of straight connector 102
has an annular protrusion 106 between the center and the tip to prevent the rubber tube 14, 16 from slipping out of the connector. This linear connector 102 allows the combined acoustic/electronic stethoscope to be easily converted into a standard acoustic stethoscope.

Of course, two straight connectors can be used for a two-tube stethoscope.

FIG. 7 shows a standard acoustic stethoscope including lower and upper rubber tubes 14, 16 and binaural 19, and upper and lower rubber tubes.
Amplifier module 10 inserted between tubes 14.16 and binaural 19 inserted into upper rubber tube 14.1
6 shows a convertible electronic stethoscope 108 consisting of a hexagonal connector 110 that connects to a hexagonal connector 110. Amplifier module 10
The connections between the rubber tubes 14 and 14, 16 are made in the same manner as in the embodiment described with reference to FIG.

Connector 110, shown in detail in FIG. 8, has a hexagonal base 112 with a hexagonal cavity 111. The cavity may have other shapes, such as circular. Three short metal or plastic pipes 114 connect to the hexagonal base 11
It is screwed into every other side of 2. The pipe 114 is tapered from the bottom to the tip so that it can be easily fitted into rubber tubes of various inner diameters.

Additionally, one or more annular protrusions 116 between the bottom and the tip prevent the rubber tube from slipping out of the connector. In this embodiment, the connector 110 is always attached to the acoustic stethoscope, so there is no need to carry a separate connector as shown in FIG. 6 to convert an electronic stethoscope to an acoustic stethoscope. For a two-tube stethoscope, four pipes 114 are used: 1. Use two for the binaural 19 and the remaining two for the upper rubber tube.

〔Effect of the invention〕

As described above, in the present invention, the lower tube connected to the chest piece and the upper tube connected to the binaural are easily connected to the upper and lower connecting means of the housing containing the microphone, amplifier and speaker. When an electronic stethoscope can be formed and the electronic stethoscope is replaced with an acoustic stethoscope, the upper and lower tubes are removed from the upper and lower connecting means, respectively, and the upper and lower tubes are connected directly by appropriate means. By connecting them, an acoustic stethoscope can be easily formed, and interchange between an electronic stethoscope and an acoustic stethoscope can be performed extremely easily.

Furthermore, it is possible to provide an electronic stethoscope that has no change in appearance, feel, operation, etc. from conventional acoustic stethoscopes, and allows the diagnostician to hear more clearly and with greater clarity.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of an amplifier module of the embodiment, and FIG. 2 is a plan view 1 of the amplifier module of FIG. 1 with the cover removed to show the internal structure. 3 is a block diagram of the electrical circuit of the amplifier module of FIG. 1, FIG. 4 is a circuit diagram of the amplifier module of FIG. 1, and FIG. 5 shows a standard acoustic stethoscope, after removing the amplifier module. An explanatory diagram showing how the tubes are connected by a linear connector, FIG. 6 is an enlarged side view of the linear connector in FIG. 5, FIG. 7 is a plan view of a convertible electronic stethoscope having a hexagonal connector, and FIG. FIG. 7 is an enlarged side view of the hexagonal connector of FIG. 7; 10--one amplifier module; 12-chest piece;
14- lower tube (tube means), 16- upper tube (tube means), 19- binaural, 24-
Housing, 26-microphone, 2B--lower connecting pipe, 32-speaker, 34-upper connecting pipe, 36
-On-off switch, 3 B-)-on switch, 4
〇-Volume control, 46-Auxiliary jack, 102-
Straight connector, 108 - Convertible electronic @ medical device, 110 - Hexagonal connector. Figure ε 7

Claims (4)

[Claims] (1) A convertible electronic stethoscope for converting a standard acoustic stethoscope, such as a chest piece, a binaural, and a plurality of tube means connecting the chest piece and the binaural, into an electronic stethoscope, a housing having upper and lower side walls; a lower connecting means extending downwardly from the lower side wall and connected to the chest piece; and acoustically connected within the housing to the lower connecting means installed in the housing. a microphone that converts sound waves into electrical signals; an amplifier installed within the housing and electrically connected to the microphone to amplify the electrical signal; and an amplifier installed within the housing and electrically connected to the amplifier. A convertible electronic stethoscope, comprising: a speaker for converting the amplified electrical signal into a sound wave; and upper connection means acoustically connected to the speaker, extending upwardly from the upper side wall and connected to the binaural. (2) The convertible electronic stethoscope according to claim 1, wherein the upper and lower connecting means include a pipe connected to the lower or upper portion of at least one of the tube means. 3. A convertible electronic stethoscope according to claim 1, wherein said lower and upper connecting means are tapered from the bottom to the top to facilitate insertion of said tube means. 4. A convertible electronic stethoscope according to claim 1, wherein said lower and upper connecting means have at least one annular protrusion to prevent said tube means from slipping out of said connecting means.