JP6376937B2 - Electronic auscultation device and cover member used in this device - Google Patents

Description

  The present invention relates to an electronic auscultation apparatus that monitors biological sounds such as vital signs (biological information) and a cover member used in the apparatus.

  Artificial hemodialysis, which is one of the treatment methods for renal failure patients, is a treatment method that is currently widely used. In this treatment method, a shunt is created by joining the artery and vein under the skin of the arm of a hemodialysis patient, and a large amount of arterial blood flows through the vein by this shunt, and the blood is guided to the dialyzer. To purify blood and remove water.

  By the way, it is well known that blood pressure of hemodialysis patients decreases in the second half of dialysis treatment. The cause of this is said to be that water movement called plasma refilling from the interstitium does not catch up with the water removal rate and occurs because the blood volume temporarily decreases. The decrease in blood pressure during hemodialysis causes a change in condition such as loss of patient's consciousness, and is regarded as a problem in clinical practice of dialysis. For this reason, there is an increasing interest in continuously monitoring vital signs in order to quickly know sudden changes in conditions such as blood pressure drop in hemodialysis patients during dialysis.

  As one of the methods for monitoring vital signs in this way, a method of auscultating a shunt sound with a stethoscope is known. According to this method, a patient's condition can be easily known from a shunt sound in a dialysis room. Is possible. For example, Patent Document 1 discloses a method for estimating blood pressure during hemodialysis from an auscultated shunt sound. However, in patent document 1, since the device which reduces noise in the auscultation part of an electronic stethoscope is not made | formed, it causes a patient to put a blanket on an auscultation part or to turn over during continuous monitoring. The influence of noise caused by physical stimulation on the auscultation part cannot be prevented.

  On the other hand, Patent Document 2 and Patent Document 3 disclose a method of attaching a cover to avoid noise and separating it from the microphone, or filling a material in a gap between the housing and the microphone. .

Japanese Patent No. 513003 JP 2008-142112 A JP 2013-74915 A

  It is known that there are solid vibration sound and air vibration sound, and when the sound is collected by an electronic stethoscope, the solid vibration sound appears more as noise than the air vibration sound. For this reason, it is necessary to avoid that something touches the auscultation part (microphone) of the electronic stethoscope directly.

  In this respect, in the method of Patent Document 2 in which the cover is attached and separated from the microphone, the solid vibration sound due to the impact on the cover is not directly transmitted to the microphone, but the impact is converted into the air vibration sound and is passed through the air in the gap. The effect of noise cannot be prevented.

  Further, in the method of filling the gap between the housing and the microphone disclosed in Patent Document 3, external environmental noise and sliding noise are taken into consideration, but impact on the housing is not taken into consideration. Therefore, since all the shock applied to the casing is transmitted to the microphone as solid vibration sound, it is difficult to prevent the generation of noise due to the external shock during continuous monitoring.

  The present invention has been made to solve the above problems, and an electronic auscultation apparatus that reduces noise that may be mixed when continuously monitoring sound from a living body such as vital signs, and a cover member used in the apparatus. The purpose is to provide.

The present invention, which has been conceived to solve such a problem, is an electronic auscultation apparatus for detecting a body sound, and is a body sound sensor that is directly or indirectly attached to a living body and continuously detects the body sound. And a cover member that is provided so as to form a gap between the biological sound sensor and reduces noise mixed into the biological sound sensor by an external physical stimulus to the biological sound sensor. The cover member is formed with an opening that further reduces noise mixed into the biological sound sensor due to the physical stimulus.

  In the electronic auscultation apparatus having such a configuration, the gap between the biological sound sensor and the cover member is not filled with a material or the like, and air is interposed. For this reason, even if a physical stimulus from the outside is applied to the cover member, the solid vibration sound is not transmitted to the biological sound sensor through the material.

  Further, in this electronic auscultation apparatus, as described above, since the gap between the living body sound sensor and the cover member remains air, an opening is formed in the cover member. The air vibration sound that can be generated when a mechanical stimulus is applied can be released to the outside through the opening. According to this, it is possible to reduce the air vibration sound that is converted into solid vibration sound through the cover member and the like, and thereby it is possible to reduce the mixing of noise into the biological sound sensor.

  In this electronic auscultation apparatus, it is preferable that the ratio of the aperture area of the aperture portion to the surface area of the cover member is at least 6%.

  The electronic auscultation apparatus may further include a sheet-like member having flexibility that is interposed between the biological sound sensor and the living body.

  The sheet-like member may have adhesiveness on at least a part of its surface.

  In the electronic auscultation apparatus, the bottom of the cover member that contacts the living body or the side that contacts the flexible sheet-like member interposed between the living body sound sensor and the living body has a flange shape. It is preferable that

  The relationship between the distance Z between the auscultation part of the biological sound sensor and the cover member in the direction perpendicular to the plane defined by the bottom part and the shortest distance X between the auscultation part and the bottom part of the cover member is X It is preferable that> Z.

  Furthermore, in the electronic auscultation apparatus, it is preferable that the bottom part, which is the side of the cover member that contacts the sheet-like member, has a hem-opening shape with an increased inner diameter.

  The cover member may have a shape with a narrowed inner diameter as it is closer to the top opposite to the bottom.

  Alternatively, the cover member may have a shape in which the outer diameter is narrowed toward the top on the side opposite to the bottom.

  The cover member may be formed with a conduction portion that guides the blood circuit of the living body and / or the cable of the biological sound sensor to the outside of the cover member.

  The cover member may be formed with a cable clamp capable of fastening the biological sound sensor cable.

  The cover member according to the present invention is used for the electronic stethoscope device described above.

  ADVANTAGE OF THE INVENTION According to this invention, the noise which can be mixed when monitoring the sound from living bodies, such as a vital sign, can be reduced.

It is a figure showing an example of use of an electronic auscultation device in a hemodialysis patient showing the use image of continuous monitoring of vital signs. It is a perspective view which shows the structural example of the monitor sensor which comprises an electronic auscultation apparatus. It is a perspective view which shows the usage example of an electronic auscultation apparatus. It is a figure which shows the structural example of a noise reduction member. It is a perspective view which shows the structural example of a noise reduction member. It is a figure which shows the structural example of a cover fixing member. It is a perspective view which shows the structural example of a cover fixing member. It is a figure which shows 2nd Embodiment of an electronic auscultation apparatus. It is a figure which shows the example of an internal structure of an electronic auscultation apparatus. It is a figure which shows another example in 2nd Embodiment of an electronic auscultation apparatus. It is a graph which shows the result of having carried out the noise mixing test by blocking the opening part of a noise reduction member. It is a graph which shows the result of having conducted the noise mixing test using various vibration-proof sheets, and evaluating it. It is a graph which shows the result of having evaluated the noise mixing test using the noise reduction member which changed the internal diameter of the cover member. It is a figure which shows the structural example of a circuit connection jig.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings. The electronic auscultation apparatus 1 according to the present invention is a biological sound monitoring apparatus including a noise reduction member 30 including a noise reduction cover member 31 and a monitor sensor (biological sound sensor) 16.

<First form of electronic auscultation device>
FIG. 1 is a diagram showing an example of use of an electronic auscultation apparatus 1 in a hemodialysis patient. Under the skin of the patient's arm 100, a shunt is created by joining the artery and vein so that a large amount of arterial blood flows and guides the blood to the dialyzer. The electronic auscultation apparatus 1 shown in FIG. 1 is installed in the venous blood circuit 13 in order to continuously monitor the vital signs of the patient, but is not limited to the venous side, and is installed in the arterial blood circuit 12. It can be installed in both the arterial blood circuit 12 and the venous blood circuit 13. The monitor sensor 16 (the auscultation unit 23) is connected to a cable 24 for transmitting a monitored body sound signal. In addition, the code | symbol 14 in FIG. 1 represents the artery side puncture part, 15 represents the vein side puncture part.

  2 and 14 are diagrams showing a configuration example of the monitor sensor 16 constituting the electronic auscultation apparatus 1. The auscultation unit 23 is connected to the blood circuit 22 by a circuit connection jig 26. The circuit connection jig 26 has a groove 26a that is hollowed out, and the blood circuit 22 is fitted into the groove 26a (see FIG. 14). A cable 24 is connected to the auscultation unit 23. The auscultation unit 23 collects a shunt blood flow sound from the blood circuit 22 as a biological sound.

  FIG. 3 is a perspective view showing an example of use of the electronic auscultation apparatus 1. The monitor sensor 16 described above is provided with a noise reduction member 30 constituted by a noise reduction cover member 31. The cover member 31 is attached so as to cover the auscultation part 23. The blood circuit 22 and the cable 24 are guided to the outside from the passage opening (conduction portion) 33 of the cover member 31.

  FIG. 4 is a diagram showing a configuration example of the noise reduction member 30, and FIG. 5 is a perspective view thereof. FIG. 6 is a diagram showing a configuration example of the cover fixing member 35, and FIG. 7 is a perspective view thereof.

  The noise reduction member 30 includes a cover member 31 having an opening 32 and a vibration-proof sheet 34.

  The cover member 31 is provided so as to cover the monitor sensor 16 in a state of being separated from the monitor sensor 16 so as to reduce noise that may be mixed into the monitor sensor 16 due to an external physical stimulus to the electronic auscultation apparatus 1. . The gap between the cover member 31 and the monitor sensor 16 is not filled with a material or the like, and air is interposed. For this reason, even if an external physical stimulus is applied to the cover member 31, the solid vibration sound is not transmitted to the monitor sensor 16 through the material. Further, an opening 32 is formed in the cover member 31.

  The opening 32 allows air vibration sound that can be generated when a physical stimulus is applied to the cover member 31 to escape to the outside through the opening 32. Therefore, the cover member 31 including the opening 32 can further reduce noise mixed into the monitor sensor 16 due to physical stimulation.

  Moreover, if the hole area ratio which occupies the surface area of the cover member 31 is made high, such as increasing the diameter of the hole portion 32, the air vibration sound is more likely to escape to the outside, so that noise can be easily reduced. The ratio of the aperture area of the aperture portion to the surface area of the cover member 31 is at least 6%.

  In addition, the shape, size, and number of the opening portions 32 shown in each drawing are only suitable examples. The configuration of the holes is not limited to that illustrated, and in short, a mesh shape may be used as long as the air vibration sound can escape to the outside.

  The cover member 31 is provided with a passage port 33 that conducts the blood circuit 22 and the cable 24 of the monitor sensor 16 and leads them to the outside. The specific configuration of the passage port 33 is not particularly limited, and may be cut out in a hole shape or cut out from the bottom edge as shown in FIG. I do not care.

  In the present specification, of the cover member 31 described above, the side attached to the patient's arm 100 or the vibration isolation sheet 34 is referred to as a bottom portion, and is denoted by reference numeral 31b in FIG. Further, the side opposite to the bottom 31b (the side facing upward in FIG. 4 and the like) is referred to as a top, and is denoted by reference numeral 31a in FIG.

  The monitor sensor 16 may be directly attached to the patient's arm 100 or indirectly attached with a sheet-like material, preferably a vibration-proofing sheet 34 interposed between the monitor sensor 16 and the patient's arm 100. Also good. By interposing a sheet-like material, it becomes possible to attach the monitor sensor 16 in a more stable state or to suppress skin irritation or the like that may occur when the monitor sensor 16 or the like is directly attached. The vibration-proof sheet 34 employed in the present embodiment is made of a flexible sheet-like member that reduces vibration or vibration, and attenuates the fixed vibration sound transmitted from the cover member 31 to the auscultation unit 23. If an example of the range of the suitable thickness and hardness of the vibration-proof sheet 34 is given, it is 1-5 mm in thickness and hardness Shore A12 or less.

  Further, as the vibration-proof sheet 34, a material having adhesiveness on at least a part of the surface or the entire surface can be adopted. According to the vibration-proof sheet 34 having such an adhesive property, it can be easily attached to the surface of a living body such as the patient's arm 100 and the monitor sensor 16 can be easily fixed by being attached to the vibration-proof sheet 34. There is also. Furthermore, the adhesiveness prevents movement of the blood circuit, and the movement of the blood circuit due to the movement of the patient or the like can reduce noise and instability of the hearing sound generated between the circuit connection jig 26 and the like. It becomes possible.

  When such an adhesive vibration-proof sheet 34 is used, the contact area with the vibration-proof sheet 34 is increased if the bottom 31b of the cover member 31 that is in contact with the vibration-proof sheet 34 has a flange shape. Makes it easier to fix. Further, the cover member 31 having the flange 31 at the bottom 31b as described above has a large contact area and is likely to be stable when attached directly to the patient's arm 100, and reduces the pressure on the surface of the arm 100.

  The cover member 31 is disposed at a position covering the auscultation part 23 and the blood circuit 22 on the vibration-proof sheet 34 and then fixed on the vibration-proof sheet 34 with a medical tape. However, this is only an example of a fixing method of the cover member 31. In addition, for example, a cover fixing member 35 that allows the cover member 31 to be attached and detached is bonded to the vibration-proof sheet 34 in advance, and the cover member 31 is fitted into a fitting cut 36 (shown only in FIG. 6). (See FIG. 6).

For example, the anti-seismic sheet A can be used as the anti-vibration sheet 34 (note that a specific product name or the like is not shown here), but is not limited to this. Urethane, olefin, styrene, amide, isobutylene, vinyl chloride, and silicone materials may be used (see Table 1).

<Second form of electronic auscultation device>
FIG. 8 and FIG. 9 are diagrams showing another form (second form) of the electronic auscultation apparatus 1. The noise reduction member 30 of the electronic auscultation apparatus shown in FIG. 8 includes a cover member 31 having an opening portion 32 and a passage opening 33, and a vibration-proof sheet 34. The cover member 31 has a stepped (step-shaped) divergent shape in which the outer diameter in the vicinity of the bottom 31b is larger than that in the vicinity of the top 31a, and the inner diameter is also formed to be larger in the vicinity of the bottom 31b. As described above, when the inner diameter of the cover member 31 in contact with the vibration-proof sheet 34 (or the surface of the living body) is large, it is difficult for the solid vibration sound to be transmitted to the auscultation unit 23. That is, the longer the distance (creeping distance) when the solid vibration sound is transmitted through the surface, the more the vibration sound is attenuated. However, when the inner diameter of the bottom 31b of the cover member 31 is large as in this embodiment, the auscultation unit 23 and The distance (distance) from the inner surface of the cover member 31 is increased, and the solid vibration sound is attenuated.

  As described above, if the inner diameter of the bottom portion 31b of the cover member 31 is large, the distance (distance) between the auscultation portion 23 and the inner surface of the cover member 31 is increased, and the solid vibration sound is further attenuated. Further, the outer shape and the outer diameter of the cover member 31 have little influence on the attenuation of the solid vibration sound.

  From the viewpoint of downsizing the electronic auscultation apparatus 1, the bottom 31b of the cover member 31 has a shape with a larger inner diameter (a shape with a wider base), and the inner diameter is narrowed closer to the top 31a. It is preferable that the shape is different. Alternatively, the cover member 31 having a shape in which the outer diameter is narrowed toward the top portion 31a is also preferable in terms of miniaturization.

  Here, an example of a preferable distance relationship is shown. Assuming a plane defined by the bottom 31b of the cover member 31 (for example, the surface of the vibration-proof sheet 34 with which the bottom 31b comes into surface contact), the auscultation unit 23 in a direction perpendicular to the plane (or a vertical direction if the plane is a horizontal plane) Let Z be the distance along the vertical direction between the top 23c and the cover member 31 when the top is 23c. Further, the shortest distance between the auscultation portion 23 and the bottom portion 31b of the cover member 31 is X (see FIG. 9). In such a case, from the viewpoint of further attenuating the solid vibration sound transmitted to the auscultation unit 23, it is preferable that X> Z. If X> Z, there is an advantage that miniaturization is easier than in the case of X ≦ Z.

  FIG. 10 is a diagram showing another example of the electronic auscultation apparatus 1 in the second embodiment. The cover member 31 in the electronic auscultation apparatus 1 has a divergent shape in which the inner diameter gradually increases as it approaches the bottom 31b. Further, the outer peripheral shape of the cover member 31 is a dome shape. However, as described above, the influence of the outer shape and the outer diameter of the cover member 31 is small in attenuating the solid vibration sound. You can set it.

  Further, the cover member 31 in the electronic auscultation apparatus 1 of the present embodiment is formed with a passage port (conduction part) 33 and is connected to the blood circuit 22 and / or the monitor sensor 16 using the passage port 33. The cable 24 can be guided to the outside of the cover member 31.

  Further, the cover member 31 is formed with a cable clamp 37 capable of fastening the cable 24. By fastening the cable 24 here, vibration of the cable 24 is suppressed and noise is less likely to be mixed. be able to. That is, since the auscultation unit 23 of the electronic auscultation apparatus 1 has a cable 24 for transmitting a signal, an impact (physical stimulation) when touching the cable 24 is transmitted as vibration to the auscultation unit 23 and easily appears as noise. Measures to prevent this (for example, measures such as fixing the cable 24 with a tape) are required. In this regard, according to the electronic auscultation apparatus 1 of the present embodiment, the cable 24 can be fixed using the cable clamp 37 so that vibration from the cable 24 does not appear as noise (see FIG. 10). Incidentally, if a wireless communication technology such as Bluetooth (registered trademark) is used, the cable 24 of the auscultation unit 23 can be omitted.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the electronic auscultation apparatus 1 that detects vital signs and monitors vital signs has been described as an example. However, the application of the present invention is not limited to monitoring vital signs in this way. As another application, for example, it is possible to detect the occurrence of occlusion due to a blood clot or the like by observing the shunt sound itself using the electronic auscultation apparatus 1. Alternatively, the present invention can be applied as a device for “home action monitoring” for watching a patient at home. Furthermore, not only for medical purposes, but also when monitoring the sound of any device in the factory or outdoors, it can also be applied as a device that can reduce external stimuli (such as tree branches touching outside). It is.

  In the above-described embodiment, the monitor sensor 16 in which the auscultation unit 23 faces the bottom 31b is exemplified as a configuration example suitable for detecting a body sound with the patient's arm 100. However, this is only a preferable example. In addition, it is also possible to configure the auscultation unit 23 so as to face upward, for example, when detecting a body sound using an extracorporeal circulation tube.

  A noise mixing test was performed by hitting the top portion 31a of the cover member 31 at an interval of about 1 second with a force of about 0.4 N for a fixed time (1 minute, 30 seconds, 20 seconds, 10 seconds, 5 seconds). The sound power was calculated from the obtained sound waveform and evaluated. Here, the sound power is obtained by squaring the amplitude of the sound waveform output from the electronic auscultation apparatus 1. In addition, the calculation method of the sound power followed the method described in Patent Document 1.

  FIG. 11 shows the result of the noise mixing test performed by covering the opening 32 of the noise reduction member 30 shown in FIGS. 4 and 5. It can be seen that the sound power in the cover member 31 is increased by blocking the opening 32, and noise is mixed. From this result, it was found that the provision of the opening portion 32 in the cover member 31 was effective for noise reduction.

  A noise mixing test was performed using various vibration-proof sheets 34 shown in Table 1 and evaluated. The result is shown in FIG. There was a tendency that noise was less likely to be mixed as the softness of the vibration-proof sheet 34 was softer. It was found that the vibration-proof sheet 34 is preferably a soft sheet that easily attenuates solid vibration sound.

  FIG. 13 shows the result of evaluating the noise mixing test using the noise reduction member 30 in which the inner diameter of the cover member 31 is changed. It can be seen that as the inner diameter of the cover member 31 increases, noise is less likely to be mixed.

  The present invention is suitable for application to an electronic auscultation apparatus that continuously monitors biological sounds such as vital signs.

DESCRIPTION OF SYMBOLS 1 Electronic auscultation apparatus 12 Arterial side blood circuit 13 Vein side blood circuit 14 Arterial side puncture part 15 Vein side puncture part 16 Monitor sensor (biological sound sensor)
22 Blood circuit 23 Auscultation part 23c Top part 24 of auscultation part Cable 26 Circuit connection jig 26a Groove 30 for blood circuit insertion Noise reduction member 31 Noise reduction cover member (cover member)
31a Top part 31b Bottom part 32 Opening part 33 Passage opening (conduction part)
34 Anti-vibration sheet (sheet-like member)
35 Cover fixing member 36 Insertion cut 37 Cable clamp 100 Arm X Shortest distance Z between the auscultation part and the bottom part of the cover member Auscultation part (top part) of the biological sound sensor and the cover member in a direction perpendicular to the plane defined by the bottom part Distance to

Claims (12)

An electronic auscultation device for detecting body sounds,
A biological sound sensor that is directly or indirectly attached to a living body and continuously detects the biological sound;
A cover member that is provided so as to form a gap with the biological sound sensor and reduces noise mixed into the biological sound sensor by an external physical stimulus to the biological sound sensor;
With
An electronic auscultation apparatus according to claim 1, wherein the cover member is formed with an opening that further reduces noise mixed into the biological sound sensor due to the physical stimulus.   The electronic auscultation apparatus according to claim 1, wherein a ratio of an opening area of the opening portion to a surface area of the cover member is at least 6%.   The electronic auscultation apparatus according to claim 1, further comprising a sheet-like member having flexibility interposed between the biological sound sensor and the biological body.   The electronic auscultation apparatus according to claim 3, wherein the sheet-like member has adhesiveness on at least a part of a surface thereof.   The bottom part which is the side which contacts the sheet-like member provided with the flexibility which interposes between the living body sound sensor and the living body, or the side which contacts the living body of the cover member is flanged. The electronic auscultation apparatus according to any one of 1 to 4.   The relationship between the distance Z between the auscultation part of the biological sound sensor and the cover member in the direction perpendicular to the plane defined by the bottom part and the shortest distance X between the auscultation part and the bottom part of the cover member is X> Z. The electronic auscultation device according to any one of claims 1 to 5, wherein   The electronic auscultation apparatus according to claim 6, wherein a bottom portion of the cover member that is in contact with the sheet-like member has a hem-expanding shape with an increased inner diameter.   The electronic auscultation apparatus according to claim 6 or 7, wherein the cover member has a shape in which an inner diameter is narrowed toward a top portion opposite to the bottom portion.   The electronic auscultation apparatus according to claim 6 or 7, wherein the cover member has a shape in which an outer diameter is narrowed toward a top portion opposite to the bottom portion.   10. The electron according to claim 1, wherein the cover member is formed with a conduction portion that guides the blood circuit of the living body and / or the cable of the biological sound sensor to the outside of the cover member. Auscultation device.   The electronic auscultation apparatus according to any one of claims 1 to 10, wherein a cable clamp capable of fastening the biological sound sensor cable is formed on the cover member.   A cover member used in the electronic stethoscope device according to claim 1.