JP3626037B2 - Blood pressure device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration analysis type blood pressure apparatus that injects vibrations having a frequency of about an audible frequency or less into the body from the surface of a living body and detects the injected vibrations on the surface of the living body.
[0002]
[Prior art]
Conventionally, a vibration analysis type blood pressure device is disclosed in Japanese Patent Application Laid-Open No. 9-506024. The operation principle will be described below with reference to the block diagram shown in FIG. In FIG. 6, the excitation circuit 1 generates an excitation waveform, and drives the excitation conversion element 3 attached to the arm 2 as the subject via the cable 4. The excitation conversion element 3 injects vibrations of several hundred hertz or more into the arm 2 and the vibrations propagated through the artery of the arm 2 are detected by the reception conversion element 5 to obtain a reception signal. The received signal is received by the receiving circuit 7 of the apparatus main body 9 via the cable 6 and further signal-processed by the signal processing unit 8 to obtain biological information such as blood pressure.
[0003]
[Problems to be solved by the invention]
However, the cables 4 and 6 connected to the excitation conversion element 3 and the reception conversion element 5 in the conventional blood pressure apparatus connect the living body on the bed and the apparatus main body 1 generally placed on another table. However, if the weights or swings of the cables 4 and 6 are applied to the excitation conversion element 3 and the reception conversion element 5, the position interval between the conversion elements changes, and further, the force on the artery of the arm 2 is also increased. It was difficult to accurately measure blood pressure.
[0004]
The present invention solves such a conventional problem, and provides a highly accurate blood pressure device in which the weight and swing of the cable do not affect the conversion elements for excitation and reception. It is the purpose.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is provided with a position restricting means for restricting the movement of the cable to prevent the weight and swing of the cable from affecting the conversion element for excitation and reception, as well as the excitation. A blood pressure apparatus with high accuracy is realized by making the attachment state and the attachment interval of the conversion element for reception and the conversion element for reception constant .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, there is provided an excitation cable and a reception cable respectively connected to an excitation conversion element and a reception conversion element mounted on an artery of a subject, and a support for supporting the subject. A cable guide provided on the base, and position restriction means for preventing the axial movement of each cable in cooperation with the cable guide, from the position restriction means to the excitation conversion element and the reception A predetermined difference is provided in the length of each cable to the conversion element, and the excitation conversion element and the reception conversion element are arranged so that each cable is substantially collinear with the direction of the artery. a blood pressure device for a vibration analysis method of the weight and the swinging of the cable no longer affect the transducer for and receiving excitation, excitation transducer and reception transducer It can be an attachment state and the attachment interval constant, such an action can highly blood pressure measurement precision.
[0012]
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
(Embodiment 1)
FIG. 1 is a schematic block diagram of the configuration of the measurement unit and the apparatus main body of the blood pressure apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a schematic diagram showing the positional relationship between the conversion element and the subject. The excitation conversion element 11 converts an electrical signal into mechanical vibration. The excitation cable 12 is connected to the excitation conversion element 11. The receiving conversion element 13 converts mechanical vibration into an electric signal. The receiving cable 14 is connected to the receiving conversion element 13. The common cable 15 bundles the excitation cable 12 and the reception cable 14. The relay connector 21 connects the common cable 15 and the relay connector 22. The relay connector 22 is connected to the main cable 23. The main cable 23 is connected to the apparatus main body 40 via the connector 24.
[0013]
The excitation circuit 31 generates an electrical signal for exciting the excitation conversion element 11. The amplifier circuit 32 amplifies the reception signal generated by the reception conversion element 13. The clock generation circuit 34 generates an excitation clock for the excitation circuit 31, and an in-phase clock and a quadrature clock synchronized with the excitation clock. The quadrature detection circuit 33 obtains detection outputs I and Q using the in-phase clock and the quadrature clock with respect to the output of the amplifier circuit 32. The signal processing unit 35 calculates a continuous blood pressure output from the detection outputs I and Q. The cuff sphygmomanometer 36 measures the maximum and minimum blood pressure of the subject 2 at predetermined time intervals, and sends the measurement result to the signal processing unit 35.
[0014]
FIG. 2 shows the positional relationship between the conversion elements 11 and 13 and the subject 2. 2A is a front view, FIG. 2B is a side view, and FIG. 2C is a bottom view. The support table 16 supports the subject 2, in this example, the arm. The position of the artery of the subject 2, the radial artery in this example, is indicated by the symbol P, and the excitation conversion element 11 and the reception conversion element 13 are attached on the artery. A cable guide 17 is provided on the support base 16. The cable guide 17 is provided with a V-shaped guide groove 19. In the guide groove 19, a common cable 15 in which the cables 12 and 14 are combined is disposed. One end of a cable presser 18 that is a position restricting means for the cable is fixed to the cable guide 17. The buffer body 20 is placed between the subject 2 and the cable guide 17.
[0015]
Next, the operation of the blood pressure apparatus in the present embodiment will be described. In FIG. 1, an excitation circuit 31 generates a sine wave electric signal of about 1 kHz, and the excitation signal is applied to the excitation conversion element 11 via the main cable 23, the common cable 15, and the excitation cable 12. The excitation conversion element 11 converts an electrical signal into mechanical vibration. As an example of such a conversion element 11, a monomorph vibrator is desirable. For a 1 kHz electrical signal, the desired diameter of the monomorph vibrator is, for example, about 1 centimeter to 3 centimeters. The excitation conversion element 11 is mounted on the artery of the subject 2, and the mechanical vibration generated by the conversion element 11 is injected into the subject 2, and at the same time, part of it propagates along the artery. It is known that when mechanical vibration of about 1 kHz or less propagates along an artery, the propagation speed depends on blood pressure. Next, the mechanical vibration propagated through the subject 2 is received by the receiving conversion element 13 and converted into a received signal. Examples of such a conversion element 13 include a monomorph vibrator, a bimorph vibrator using a piezoelectric polymer film, and a thickness longitudinal vibrator. Typical dimensions of these vibrators are also about 1 centimeter to 3 centimeters. The received signal is input to the amplifier circuit 32 via the receiving cable 14, the common cable 15, and the main cable 23. The output of the amplifier circuit 32 is phase-detected by the quadrature detection circuit 33. Since the propagation speed of the mechanical vibration transmitted through the artery changes due to the pulsation of the artery of the subject 2, the change in the propagation speed can be obtained by analyzing the outputs of the phase detection outputs I and Q of the quadrature detection circuit 33. The cuff blood pressure device 36 measures the maximum and minimum blood pressure of the subject at a predetermined time interval, for example, every few minutes. A continuous blood pressure output can be obtained from the phase detection outputs I and Q by obtaining the correspondence between the maximum and minimum blood pressures at this time and the phase detection outputs I and Q in the signal processing unit 35.
[0016]
In order to obtain an accurate continuous blood pressure output by the above-described method, it is necessary to keep the excitation conversion element 11 and the reception conversion element 13 attached to the living body constant or to attach the conversion elements 11 and 13 to the living body. It is necessary to keep the interval constant. In particular, it is important that the weight or oscillation of the cable connecting the subject 2 and the apparatus main body 40 is added to the conversion elements 11 and 13 and does not affect the state of attachment to the living body. For this reason, in this embodiment, as shown in FIG. 2, a cable guide groove 19 is formed in the cable guide 17 attached to the support base 16, and the common cable 15 is inserted into the guide groove 19, By pressing the cable presser 18 from above, the movement of the common cable 15 in the axial direction is restricted. Therefore, the depth of the guide groove 19 must be smaller than the diameter of the common cable 15. By restraining the movement of the common cable 15 in this way, the weight and swinging of the main cable 23 and the common cable 15 connected to the apparatus main body 40 are transferred to the conversion elements 11 and 13 via the cables 12 and 14. It is possible to prevent transmission.
[0017]
The height from the surface of the support 16 to the guide groove 19 is preferably 5 centimeters or more. Further, the mounting position interval between the conversion elements 11 and 13 is preferably about 3 to 10 centimeters, for example. In the example of FIG. 2, the direction of the artery and the direction of each cable 12, 14, 15 can be positioned on substantially the same straight line, so that a difference Dc is given to the length of the cables 12, 14 separated from the common cable 15. Thus, the distance between the conversion elements can be set to Dc. The cable length difference Dc is set so that the conversion elements 11 and 13 are covered by setting the effective opening diameter Le of the shorter one of the cables 12 and 14, in this case, the conversion element connected to the cable 12. There is no contact on the specimen 2, which is convenient for attaching the conversion elements 11 and 13. Effective opening size Le of the conversion elements 11 and 13 is approximately 1 cm on than is preferred. Thus, by providing the cable guide 17 and giving the length difference Dc to the cables 12 and 14, the distance between the mounting positions of the conversion elements 11 and 13 can be made substantially Dc. It becomes easy to attach at regular intervals.
[0018]
As described above, according to the first embodiment, the cable guide 17 provided on the support base 16 that supports the subject 2, the guide groove 19 formed in the cable guide 17, and the guide groove 19 are inserted. Since the cable presser 18 for preventing the common cable 15 from moving in the axial direction is provided, the cables 12 and 14 are not subjected to weight or swinging on the conversion elements 11 and 13, and highly accurate blood pressure measurement can be performed. can do. Further, by configuring the cable presser 18 with, for example, a leaf spring, the common cable 15 can be easily detached by pulling the common cable 15 upward. Further, by providing the difference Dc in the lengths of the cables 12 and 14, the conversion elements 11 and 13 can be easily attached at a predetermined interval.
[0019]
(Embodiment 2)
FIG. 3 shows another example of the cable position regulating means in the second embodiment of the present invention. The excitation conversion element 11, the excitation cable 12, the reception conversion element 13, the reception cable 14, the common cable 15, the support base 16, the cable guide 17, and the guide groove 19 are the same as those in the first embodiment. Note that the depth of the guide groove 19 may be deeper than the diameter of the common cable 15. Reference numeral 38 denotes a stopper ring fixed to the common cable 15. The outer diameter of the stopper ring 38 is made wider than the width of the guide groove 19. Therefore, even when the common cable 15 receives a tensile force from the apparatus main body 40 side, the stopper ring 38 stops at the guide groove 19 of the cable guide 17, so that the conversion elements 11 and 13 are not affected.
[0020]
As described above, according to the second embodiment, the cable guide 17 provided on the support base 16 that supports the subject 2, the guide groove 19 formed in the cable guide 17, and the guide groove 19 are inserted. Since the stopper ring 38 that is fixed to the common cable 15 and prevents the common cable 15 from moving in the axial direction is provided, the weights and swings of the cables 12 and 14 may be applied to the conversion elements 11 and 13. The blood pressure can be measured with high accuracy. Further, since the stopper ring 38 does not fix the common cable 15 to the cable guide 17, for example, the common cable 15 can be easily removed by pulling the cable 15 upward.
[0021]
(Embodiment 3)
FIG. 4 shows still another example of the cable position regulating means in the third embodiment of the present invention. Excitation converter 11, excitation cable 12, reception converter 13, reception cable 14, common cable 15, support 16, cable guide 17, and relay connectors 21 and 22 for connecting the common cable 15 to the main cable 23. Is the same as in the first embodiment. Reference numeral 39 denotes a stopper groove as a cable position restricting means, and a portion 39b for accommodating the common cable 15 on both sides and a portion 39c for accommodating the main cable 23 are formed narrower than the portion 39a for accommodating the relay connectors 21 and 22. ing. Therefore, even when the main cable 23 receives a tensile force from the apparatus main body 40 side, the relay connector pins 21 and 22 stop at the stopper groove 39, so that the conversion elements 11 and 13 are not affected.
[0022]
As described above, according to the third embodiment, the cable guide 17 provided on the support base 16 that supports the subject 2 and the common cable 15 and the main cable 23 connected to each other are provided on the cable guide 17. Since the relay connector 21 and 22 are accommodated and the stopper groove 39 is provided to prevent the common cable 15 and the main cable 23 from moving in the axial direction, the weight and swing of the common cable 15 are applied to the conversion elements 11 and 13. The blood pressure can be measured with high accuracy. Further, since the stopper groove 39 does not firmly fix the common cable 15, these cables can be easily detached by pulling the common cable 15 or the main cable 23 upward, for example.
[0023]
A cover may be provided above the stopper groove 39. Accordingly, there is an advantage that the relay connectors 21 and 22 can be protected from various dirt. Further, the stopper groove 39 may accommodate a stopper ring 38 fixed to the common cable 15 as in the second embodiment, instead of accommodating the relay connectors 21 and 22.
[0024]
(Embodiment 4)
FIG. 5 shows still another example of the position regulating means in the fourth embodiment of the present invention. The excitation conversion element 11, the excitation cable 12, the reception conversion element 13, the reception cable 14, the common cable 15, the support base 16, the cable guide 17, the guide groove 19, the relay connectors 21, 22 and the main cable 23 are implemented as described above. This is the same as Form 1. The stopper ring 38 is the same as that of the second embodiment, and is fixed to one end of the common cable 15. Therefore, even when the common cable 15 receives a tensile force from the apparatus main body 40 side, the stopper ring 38 stops at the guide groove 19 of the cable guide 17, so that the conversion elements 11 and 13 are not affected. Reference numerals 50 and 51 denote fixed bands that are attached to the support 16 and restrain the subject 2. The fixed band 50 loosely fixes the palm of the subject 2, and the fixed band 51 is an elbow. And loosely fix the middle of the mounting portion of the conversion element. Therefore, by fixing the subject 2 with the fixing bands 50 and 51, the subject 2 can be prevented from moving from the support base 16 or rotating on the support base 16. Therefore, the movement of the subject 2 prevents the conversion elements 11 and 13 from pulling the cables 12 and 14, that is, the force is not applied from the cable to the conversion element as the reverse action.
[0025]
Thus, according to the fourth embodiment of the present invention, the cable guide 17 provided on the support base 16 that supports the subject 2, the guide groove 19 formed in the cable guide 17, and the guide groove 19 A stopper ring 38 that is fixed to the common cable 15 that is inserted into the common cable 15 to prevent the common cable 15 from moving in the axial direction, and fixing bands 50 and 51 for fixing the subject 2 to the support base 16 are provided. Further, since the weight and the swing of the common cable 15 are not applied to the conversion elements 11 and 13 and the movement of the subject 2 is also restrained, blood pressure can be measured with high accuracy.
[0026]
【The invention's effect】
As described above, the present invention provides an excitation cable and a reception cable respectively connected to the excitation conversion element and the reception conversion element that are in contact with the subject, and a cable provided on the support base that supports the subject. A guide and a position restricting means for preventing the movement of each cable in the axial direction in cooperation with the cable guide, and the length of each cable from the position restricting means to the excitation converting element and the receiving converting element. Since the excitation conversion element and the reception conversion element are arranged so that a predetermined difference is provided, and the cables are substantially collinear with each other in the direction of the artery , the weight and oscillation of the cable there is no influence to the conversion element for receiving an attachment state and the attachment spacing of the excitation transducer and the reception transducer can be made constant, accurate blood pressure measurement An effect that can be.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a configuration of a blood pressure device and a main body of a blood pressure device according to a first embodiment of the present invention. FIG. 2A is a front view showing a positional relationship between a conversion element and a subject in the first embodiment. (B) Side view showing the positional relationship between the conversion element and the subject in Embodiment 1 (c) Bottom view showing the positional relationship between the conversion element and the subject in Embodiment 1. FIG. FIG. 4A is a front view showing the positional relationship between the conversion element and the subject in Embodiment 3. FIG. 4B is a front view showing the positional relationship between the conversion element and the subject in Embodiment 3. FIG. FIG. 5A is a front view showing the positional relationship between the conversion element and the subject in the fourth embodiment. FIG. 5B is a side view showing the positional relationship between the conversion element and the subject in the fourth embodiment. Side view [Fig. 6] Measurement of blood pressure device in conventional example Schematic block diagram of a configuration of the apparatus main body EXPLANATION OF REFERENCE NUMERALS
2 Subject 11 Excitation conversion element 12 Excitation cable 13 Reception conversion element 14 Reception cable 15 Common cable 16 Support base 17 Cable guide 18 Cable retainer 19 Guide grooves 21, 22 Relay connector 23 Main cable 24 Connector 38 Stopper ring 39 Stopper groove 50, 51 Fixed band

Claims (1)

An excitation cable and a reception cable connected to an excitation conversion element and a reception conversion element attached to the artery of the subject, a cable guide provided on a support base that supports the subject, and the cable guide And a position restricting means for preventing the axial movement of each cable, and a predetermined length of each cable from the position restricting means to the excitation converting element and the receiving converting element. A vibration analysis type blood pressure apparatus , wherein the excitation conversion element and the reception conversion element are arranged so that a difference is provided and the cables are substantially collinear with each other in the direction of the artery .

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