JPH0330086Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a stethoscope used for auscultation of the internal acoustics of a subject (living body).

(Prior Art) A stethoscope has conventionally been used to auscultate the body sounds of a subject. A stethoscope enables auscultation by guiding body sound obtained by pressing the diaphragm of the stethoscope against the surface of a subject through an auscultation tube to both ears of a doctor or the like. Therefore, 1
Normally, only one person can hear the body sound using a stethoscope, and it is difficult for multiple people to listen to it at the same time. For this reason, cardiac diagram information (heartbeat and heart sound information, etc., hereinafter the same) at the points auscultated by a skilled doctor.
There is a desire to display or record information in real time. However, since the conventional stethoscope output is only an acoustic output for auscultation, it cannot completely meet the above requirements.

(Problems to be Solved by the Invention) As described above, conventional stethoscopes have a problem in that cardiac diagram information at auscultation points cannot be displayed or recorded.

The present invention has been developed in view of the above circumstances, and its purpose is to provide a stethoscope that can display or record cardiogram information at auscultation points.

[Structure of the invention] (Means for solving the problem) In order to achieve the above-mentioned object, the present invention provides a stethoscope for auscultation using the internal sound of the subject obtained through a diaphragm that contacts the surface of the subject. , an orthogonal diagram sensor consisting of a magnetizing body attached to the diaphragm, and a group of inductors arranged radially around the axis on a plane orthogonal to an axis connecting the NS poles of the magnetizing body; The present invention is characterized by being provided with a processing circuit that processes a signal including a plurality of frequency components obtained from the sensor and displays the processed signal.

(Function) The diaphragm is brought into contact with the surface of the subject, and the internal sound of the subject is transmitted through the diaphragm for auscultation. At the same time, cardiac diagram information is detected by the cardiac diagram sensor, and this detection result is outputted to the outside via a different route from the internal body sound used for auscultation, and is used for displaying or recording the cardiac diagram. . Therefore, it is possible to display or record a cardiac diagram at the same time as auscultation. In this case, since a signal including a plurality of frequency components is obtained from the cardiogram sensor, by processing this signal, it is possible to obtain not only heartbeat information but also information regarding heart sounds.

(Example) The present invention will be described in detail below based on the example shown in the drawings.

FIG. 1 is an explanatory diagram of a stethoscope that is an embodiment of the present invention. This stethoscope 1 includes a stethoscope main body 2, a diaphragm 3, and a cardiac image sensor 10.

An auscultation tube attachment portion 8 is formed protruding from the stethoscope body 2, and the auscultation tube 4 is attached to this auscultation tube attachment portion 8. Air vibrations in the hollow portion 5 of the stethoscope main body 2 are configured to propagate through the auscultation tube attachment portion 8 and the auscultation tube 4. A screw 9 is provided on the peripheral surface end of the stethoscope body 2 on the large diameter side, and the diaphragm 3 is screwed into the screw 9. A cardiac image sensor 10 is provided in the gap between the diaphragm 3 and the stethoscope body 2.

The cardiac image sensor 10 detects cardiac information of a subject (not shown) from the vibration of the diaphragm 3, and as will be described in detail later, is a sensor fixed to the center of the inner surface of the diaphragm 3. Magnetizing body M and this magnetic body M
Inductor group 12 that generates an electromotive force according to the displacement of
and a holder 11 for fixing this inductor group. A lead wire drawn out from the inductor group 12 is connected to a sensor terminal 5a attached to the stethoscope body 2. Sensor terminal 5
A sensor cable 7 is attached to a, and information on the electromotive force of the inductor group 12 is transmitted to a processing circuit (described in detail later) via the sensor cable 7.

Next, the configuration of the cardiac image sensor 10 will be explained.

Fig. 2a is a plan view of the cardiac image sensor 10, Fig. 2b
is a sectional view taken along line A-A' in Figure a.

As the magnetizing body M attached to the diaphragm 3, a permanent magnet with a diameter of 3 mm is applied.

The holder 11 is formed by laminating first, second, and third insulating members 11a, 11b, and 11c. 1st
A circular hole 14 is bored in the center of the insulating member 11a, and the magnetic body M is loosely inserted into the hole 14. Moreover, the second insulating member 1
A hole 13 is formed in the center of 1b concentrically with the hole 14, and the inductor group 12 is provided on this insulating member 11b.

This inductor group 12 has a magnetic core made of, for example, an amorphous wire AF (composition Co ₆₈ Fe ₄ Si ₁₃ B ₁₅
The inductors L ₁ to _{L 24} are arranged radially, each having a coil wound therein (at a diameter of 110 μm). Each coil is connected in series to every other inductor, as shown in the wiring diagram in Figure 3.
Lead wires ₂₁ , ₂₂ , and 23 are drawn out from the coil ends of the inductors L1, L2 _, L23, and _L24 . In addition, since two systems of inductor groups are formed by such a connection, the inductors L ₁ , L ₃ , L ₅ , ..., L ₂₃
with the first inductor group 24 and also with the inductor
L ₂ , L ₄ , L ₆ , ..., L ₂₄ are the second inductor group 2
Collectively referred to as 5.

Lead wires 21, 22, 23 drawn out from the first and second inductor groups 24, 25 are connected to the processing circuit 6 via the sensor cable 7. Various circuit configurations are possible for the processing circuit 6, but
Here, as shown in FIG. 4, a combination of a multivibrator circuit and an active filter is applied.

In FIG. 4, 24 and 25 are first and second inductor groups, and lead wires 21 and 23 drawn out from the first and second inductor groups 24 and 25
are connected to the input end of the active filter ACF via transistors Tr ₁ and Tr ₂ and signal lines 31 and 33, respectively. Transistor Tr ₁ ,
The outputs of the commutation circuits (consisting of a capacitor C _B and a resistor R _B ) connected to each signal line are applied to the base of Tr ₂ in a crossed manner. Further, load resistors R _L and R _L are connected in series between the signal lines 31 and 33, and a variable resistor VR is connected in parallel with this, and the connection point between this resistor VR and the resistors R _L and R _L is commonly grounded. ing. Then, a power supply voltage E (positive electrode side) is applied to the lead wire 22, and an output Eout can be taken out from the active filter ACF. That is, this circuit is configured as a multivibrator bridge using the first and second inductor groups 24 and 25.

In addition, the active filter ACF allows selection of filter characteristics, such as cutting frequencies above 50Hz, cutting frequencies above 20Hz, cutting frequencies below 20Hz,
It is possible to select various modes such as passing through both the DC ~ 20Hz band and the 20Hz ~ 50Hz band.

Next, the operation of the stethoscope configured as above will be explained.

The diaphragm 3 is pressed against the surface of the subject. This causes the diaphragm 3 to vibrate in response to body surface vibrations caused by cardiac function. The sound caused by this vibration is transmitted to both ears of the doctor via the hollow part 5, the auscultation tube 4, etc., and is used for auscultation.

On the other hand, the magnetizing body M is displaced by the vibration of the diaphragm 3, and in accordance with this displacement, the inductor group 12 (first
(inductor group 24, second inductor group 25)
generates an electromotive force. This electromotive force information (cardiogram information) is transmitted to the processing circuit 6 via the sensor cable 7, and is output from the active filter ACF.
is obtained. Cardiogram information can be displayed or recorded by the display means or recording means based on the output Eout.

Next, test results of the cardiogram sensor 10 will be explained.

FIG. 5 shows the inductor L ₁ of the cardiogram sensor 10.
~ _L24 This is a plot of the output (output of the processing circuit 6) Eout when a DC magnetic field is applied perpendicularly to the array plane. As is clear from the figure, ±2
Even if a DC magnetic field of [Oe] is applied, no fluctuation is observed in the output Eout.

Moreover, FIG. 6 is a plot of the output Eout when the cardiac image sensor 10 is rotated in a laboratory. In addition, although many electronic devices are arranged in the laboratory, no magnetic shield is provided around the cardiac image sensor 10. inductor
The coil length of L ₁ to _{L 24} is 3 mm, the number of coil turns is 20,
Power supply voltage E is 2.8V. As is clear from the figure, even if the cardiac image sensor 10 is rotated 360 degrees, the output is
The variation of Eout is less than 0.06mV. When a magnetic field is applied parallel to the magnetic core of each inductor L ₁ to _{L 24} by the magnetizing element M, the output Eout is maximum ±150 mV
Therefore, the fluctuation of 0.06 mV mentioned above is 0.04% or less, which is extremely small.

Next, the results of detecting cardiac diagram information using this cardiac diagram sensor 10 will be explained.

Fig. 7 71 shows the sensor output waveform when the diaphragm 3 is pressed lightly against the human chest, and Fig. 7 72 shows the pulsation diagram in which the 0 to 5 Hz components are extracted by filtering the sensor output. be. Also,
Figure 8 81 is a phonocardiogram in which 20 to 50 Hz components have been extracted by filtering, and 82 in the same figure is a 0 to 5 Hz component.
This is an extracted version. All of them are unaffected by disturbance magnetic fields (mainly those generated by earth's magnetism, electronic equipment, etc.) and are highly reliable.

In addition, as shown in FIG. 9, which shows the relationship between the displacement X of the magnetizing body M and the output Eout, the change in the output Eout is large,
Moreover, since there is a region in which it changes linearly, it is preferable to use it within this region. In this embodiment, the magnetic body M is connected from the inductor L ₁ to L ₂₄ array surface
The distance to the end face of is within 1mm (X = 0.7mm). The displacement X can be adjusted by changing the screwing state between the stethoscope body 2 and the diaphragm 3.

As described above, in this embodiment, the stethoscope main body 2
Since the cardiogram sensor 10 is provided in the gap between the diaphragm and the diaphragm 3, the cardiogram can be displayed or recorded at the same time as auscultation. In particular, since it is possible to obtain cardiogram information of auscultation points by a skilled doctor in real time, accurate cardiogram recording can be performed, and it is also effective as a stethoscope for training doctors for auscultation training.

Furthermore, the inductors L ₁ to _{L 24} formed by winding a coil around a magnetic core are arranged radially, and every other inductor L ₁ to _{L 24} are directly connected to form the inductor group 12. , the effects of disturbance magnetic fields can be canceled out, and highly reliable cardiac image information can be obtained without using a magnetically shielded room or the like.

Although one embodiment of the invention has been described above, it goes without saying that the invention is not limited to the above embodiment and can be implemented in various modifications.

For example, in the above embodiment, both the first and second inductor groups 24 and 25 are constructed of 12 inductors, but the number of inductors is not limited to this.

Furthermore, if an amorphous disk or the like is arranged as a yoke by using the steps formed around the holes 13 and 14 in the holder 11, the magnetic path of the lines of magnetic force emitted from the magnet M can be regulated.
There is an advantage that the influence of the movement of the magnetizing body M in the lateral direction can be suppressed.

Furthermore, a magnetizing body corresponding to the magnetizing body M is added via the inductor L ₁ to _{L 24} array surface (opposing surfaces are N pole or S pole), and the magnet is parallel to the inductor L ₁ to _{L 24} array surface. If the magnetic flux is adjusted so that it is, more magnetic flux can be linked to the inductors _L1 to _L24 , and sensor sensitivity can be improved.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a stethoscope that can display or record cardiogram information at auscultation points.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a stethoscope that is an embodiment of the present invention, FIG. 2a is a plan view of a cardiac image sensor applied to the stethoscope of FIG. 1, and FIG.
A′ sectional view, FIG. 3 is a wiring diagram of the inductor group in the cardiac image sensor, FIG. 4 is a circuit diagram showing details of the processing circuit in FIG. 1, and FIG. 5 is a characteristic diagram showing the output Eout with respect to the DC magnetic field. , FIG. 6 is a characteristic diagram showing the output Eout with respect to the rotation angle of the cardiac organ diagram sensor, FIGS. 7 and 8 are cardiac diagrams obtained based on the detection information of the cardiac organ diagram sensor, and FIG. Figure Output in response to displacement of magnetizing body in sensor
FIG. 3 is a characteristic diagram showing Eout. 1... Stethoscope, 3... Vibration plate, 10... Cardiogram sensor, 12... Inductor group, AF... Magnetic core,
_L1 to _L24 ...Inductor, M...Magnetizing body.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A stethoscope for auscultation of the internal sound of a subject obtained through a diaphragm in contact with the surface of the subject, a magnetic body attached to the diaphragm, and the magnetic body. A cardiac diagram sensor consisting of a group of inductors arranged radially around the axis on a plane orthogonal to an axis connecting the NS poles of A stethoscope characterized by being provided with a processing circuit for display. (2) The stethoscope according to claim 1, wherein the inductor group is formed by electrically connecting a plurality of inductors each having a coil wound around a magnetic core. (3) The stethoscope according to claim 2, wherein the electrical connection of the plurality of inductors is a series connection of every other inductor. (4) The stethoscope according to claim 2 or 3, wherein the magnetic core is an amorphous wire. (5) The stethoscope according to any one of claims 1 to 4, wherein the magnetizing body is a permanent magnet.