JPH0530729Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultrasonic sensor such as a birth monitoring device, and particularly relates to a sensor suitable for an ultrasonic Doppler sensor for measuring heartbeat information of a fetus.

[Prior art]

The present inventors have already proposed an ultrasonic Doppler sensor for a birth monitoring device in Japanese Patent Application No. 141928/1982. This ultrasonic Doppler sensor 1 uses a polymer piezoelectric element to widen the area of the ultrasonic transmitter and receiver, making it possible to collect fetal heartbeat information without changing the sensor position even if the fetus moves. It is.

[Problem that the invention attempts to solve]

In the preceding example, an ultrasonic Doppler sensor is attached to the abdominal wall of the mother's body near the heart of the fetus in order to obtain information about the heartbeat of the fetus, but if there is even a slight air layer between the sensor body and the mother's body, , the ultrasonic waves are not emitted from the sensor body due to the difference in acoustic impedance and do not enter the mother body.

Therefore, in order to detect the fetal heartbeat, it is essential to send and receive ultrasonic waves to the mother's body (input and radiation), so a contact medium is usually used to avoid creating an air layer between the sensor body and the mother's body. There is.

The contact medium used is a paste-like gel or a water-absorbing polymer containing a large amount of water.

When a contact medium is applied or attached to the ultrasonic emission surface (often flat) of the sensor body in the preceding example, the base body to which the sensor body is attached with the contact medium may move for some reason or change its shape. When this occurs, the sensor body is likely to shift or come off. That is, leakage of the contact medium due to sensor displacement occurs, and an air layer is formed between the sensor body and the mother body, making it impossible to transmit and receive ultrasonic waves, making it impossible to collect heartbeat information.

[Summary of the idea]

In order to solve the above problems, the ultrasonic sensor of the present invention uses a polymer piezoelectric element 5 to transmit and receive ultrasonic waves, and a liquid reservoir 3 is provided on the ultrasonic emission surface of the sensor body 2. A contact medium 4 for transmitting and receiving ultrasonic signals is attached to the liquid reservoir 3 side.

With this configuration, the sending and receiving contact medium 4 is attached to the liquid reservoir 3 side of the sensor body 2, so when the sensor body 2 is attached to the abdominal wall surface of the mother's body,
There is no risk of movement or leakage,
It becomes possible to send and receive ultrasonic waves and collect heartbeat information.

[Specific explanation of the idea]

Embodiments of the present invention will be described below based on the drawings.

1A and 1B are a sectional view and a perspective view of the sensor body, respectively, showing a first embodiment of the ultrasonic sensor of the present invention.

In FIG. 1, 1 is the ultrasonic Doppler sensor of the present invention, and 2 is the sensor body, which is configured to transmit and receive ultrasonic waves using a polymer piezoelectric element. This sensor body 2 has, for example, film-like electrodes 6a and 6b formed on one surface of a polymer piezoelectric element 5, lead wires 7a and 7b connected to both electrodes 6a and 6b, and the entire sensor body 2 is made of a flexible material such as silicone rubber. It is molded with a rubber-like elastic body 8 having excellent properties.

A rectangular liquid reservoir 3 is provided on the ultrasonic emission surface (plane) of the sensor body 2, and this liquid reservoir 3
A contact medium 4 for transmitting and receiving ultrasonic signals is installed inside.

The height of the sensor body 2 is approximately 4 to 6 mm, and the height of the sensor body 2 is approximately 4 to 6 mm.
Considering the attenuation of ultrasonic waves, the depth is preferably about 1 to 2 mm.

The contact medium 4 can be attached to the liquid reservoir 3 by providing an annular groove 9 on the circumferential surface of the liquid reservoir 3 as shown in FIG. 2a, or by providing an annular projection 10 as shown in FIG. 3b. The contact medium 4 may be mounted on the liquid reservoir 3 side using these grooves 9 or projections 10.

The shape and number of the grooves 9 and the protrusions 10 are not limited, and they may be provided continuously or discontinuously.

The sending/receiving contact medium 4 is a gel or water-absorbing polymer, and is a solid contact medium made of a crosslinked copolymer containing water and/or a polyhydric alcohol.

FIG. 3 is a sectional view showing the second embodiment.
In the embodiment, membrane electrodes 6 are provided on both sides of a polymer piezoelectric element 5.
a, 6b are formed, and a shield electrode 11 is provided above the upper electrode 6a, and these electrodes 6a, 6b are formed.
The sensor body 2 is constructed by connecting lead wires 7a to 7c to the terminals b and 11, and molding the entire body with a highly flexible rubber-like elastic body 8 such as silicone rubber. A liquid reservoir 3 is provided on the surface so that the thickness on the lower electrode 6b side is a thin layer of about 0.5 to 1.0 mm, and a sending/receiving contact medium 4 is installed in this liquid reservoir 3.

FIG. 4 is a sectional view showing the third embodiment.
In the second embodiment, a protective film 13 made of polyester or the like having a thickness of about 50 μm to 100 μm is attached to the lower electrode 6b with an adhesive 12, and a liquid reservoir 3 is formed on the side of the protective film 13. The sensor body 2 is constructed by molding a rubber-like elastic body 8 with excellent flexibility such as silicone rubber, and the contact medium 4 is installed in the liquid reservoir 3 formed on the ultrasonic emission surface side of the sensor body 2. This is what I did.

In addition, the ultrasonic Doppler sensor 1 of the present invention is
As in the prior art of No. 62-141928, a common electrode is attached to the back surface of the polymer piezoelectric element, and a transmitting electrode constituting the transmitting section and a receiving electrode constituting the receiving section are slightly separated from each other on the top surface. The transmitting electrode and the receiving electrode are arranged in a comb shape and fitted into each other, and a liquid reservoir is provided on the ultrasonic emission surface side, and the transmitting and receiving contact medium is placed in this liquid reservoir. It may also be configured such that it is attached.

The ultrasonic Doppler sensor 1 of any of the embodiments is fitted to the abdominal wall surface 14 of the mother's body as shown in FIG.
When a high frequency voltage is applied to a and 6b at predetermined time intervals via a cable 15 connected to each lead wire, an ultrasonic wave is generated, and this ultrasonic wave is irradiated to the heart of the fetus within the mother's body. It reflects off the fetal heart surface and valves,
A Doppler signal (acoustic signal) modulated by the movement of the heart is converted into a fetal heartbeat signal (electrical signal) by the polymer piezoelectric element 5 of the sensor body 2 and extracted.
The sensor main body 2 is entirely covered with a flexible rubber-like elastic body 8, and since the area of the polymer piezoelectric element 5 is large, it is possible to collect fetal heartbeat information over a very wide range.

Further, the ultrasonic Doppler sensor 1 of the present invention can be attached to the abdominal wall surface 14 of the mother's body by pressing it with the contact medium 4 side facing the mother's body as shown in FIG.

As described above, according to the present invention, the sending/receiving contact medium 4
is attached to the liquid reservoir 3 side of the sensor body 2, so when the sensor body 2 is attached to the abdominal wall of the mother's body,
There is no risk of movement or leakage,
It becomes possible to transmit and receive ultrasound, and heartbeat information can be collected.

Furthermore, if the polymer piezoelectric material is made into an array type, it can be used as an ultrasonic probe for observing internal structures.

[Brief explanation of the drawing]

1A and 1B are a sectional view and a perspective view of the sensor body, respectively, showing a first embodiment of the ultrasonic sensor of the present invention, and FIGS. 2A and 2B are a sectional view and a perspective view of a modification of the first embodiment, respectively. 3 is a sectional view of the second embodiment, FIG. 4 is a sectional view of the third embodiment, and FIG. 5 is a simplified sectional view showing the ultrasonic Doppler sensor of the present invention attached to the abdominal wall surface of the mother's body. 1... Ultrasonic Doppler sensor of the present invention, 2... Sensor body, 3... Liquid reservoir, 4... Sending/receiving contact medium, 5...
...Polymer piezoelectric element.

Claims (1)

[Scope of utility model registration request] In an ultrasonic Doppler sensor that transmits and receives ultrasonic waves using a polymer piezoelectric element, a liquid reservoir is provided on the ultrasonic emission surface of the sensor body, and a contact medium for transmitting and receiving ultrasonic signals is attached to this liquid reservoir side. Sonic sensor.