JPS58146334A - Apparatus for measuring flow amount of liquid for living body - 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 The present invention is designed to non-invasively measure the flow rate of cerebrospinal fluid in the brain within a shunt tube after a ventricular-peritoneal shunt tube installation surgery, which is mainly used for the treatment of hydrocephalus. Conventionally, in order to measure the flow rate of cerebrospinal fluid in the brain within such a ventricle-peritoneal shunt tube, a part of the shunt tube is artificially separated from the skin, that is, the skin is separated. Cool the brain from above, place a thermometer such as a thermistor on the skin downstream of the shunt tube, and measure the time it takes for cerebrospinal fluid to reach the thermometer from the cooling part of the cooled brain. A method has been proposed in which the flow rate of the liquid in the short-circuit tube is known, but in this case, since the short-circuit tube is cooled through the skin, the transmission rate of this cooling within the body is not constant, and therefore the This method has the disadvantage that measurement becomes inaccurate and is not practical.

Another method is to inject a radioactive isotope into the ventricles of the brain using a syringe and measure the movement speed of this isotope externally using a Geiger counter, but there is a risk of bacterial infection when injecting radioisotopes. In addition, considering the side effects caused by radioactivity,
It has the disadvantage that it is difficult to measure frequently. It is also undeniable that bacterial infection has serious consequences for the brain.

The present invention avoids the above-mentioned drawbacks, and makes it possible to embed the necessary equipment under the skin of the living body during the surgery to install the shunt tube, and to perform measurements continuously and non-invasively from outside the living body after the surgery. Therefore, there is no need to worry about infection or other side effects. still,
The device according to the present invention is not limited to measuring the flow rate of cerebrospinal fluid in the brain as described above, but can also be used to measure the flow rate of urine in the ureter from the kidney to the bladder.

An example of the device according to the invention will be described below with reference to the drawings.

In Figure 1, (1) is the living body, (2) is its skin, and (3
) shows the skull, (4) shows the ventricle, and (5) shows the abdominal cavity.

As mentioned above, in the treatment of hydrocephalus, there is a so-called short circuit between the ventricle (4) and the abdominal cavity (5), which is called a fluid flow tube! (6), and the brain that accumulates in the ventricle is treated by releasing cerebrospinal fluid into the abdominal cavity (5). This short-circuit tube (6) may be made of silicone rubber and have an inner diameter of, for example, 1.2 m1A.

In the present invention, for such a short circuit pipe (6), a bubble generating means (7) and a bubble detecting means (8) located downstream of the short circuit pipe (6) are provided.
).

First, an example of the bubble generating means (7) will be explained. As shown in FIG. 1, this bubble generating means (7) includes an external device (7a) and an internal device (
7b). The external device (7a) includes an oscillator (9) that oscillates a signal at a predetermined frequency, for example, 200KH2, and an external coil (10) to which the output is supplied.
) and more.

Next, the internal equipment (7b) will be explained with reference to FIG. α1) is an embedding body that encloses this internal device (7b), and can be made of silicone rubber, for example. Inside it is a coil 0211 diode +131. A constant voltage element (14) etc. are embedded, and the output of the coil (12) is rectified by a diode (13), and the voltage is maintained at a constant voltage by a constant voltage element such as a Zener diode 04. There is. The voltage in this case is, for example, about 20V. A through hole (6 holes) having an inner diameter similar to that of the short-circuit tube (6) is formed in a part of the short-circuit tube (6), and a pair of electrolytic electrodes (15a) are formed inside the hole.
and (15b) are attached.

The voltage across the Zener diode Oa mentioned above is applied between the electrodes (15a) and (15b). As shown in the drawing, both electrodes (15a) and (15b) are each formed into an annular shape so that a liquid can pass therethrough. A pair of such electrolytic electrodes (15a) (15b) are sandwiched between them.

Furthermore, the current collecting electrodes (16a) and (16b) are connected to the through hole (6).
These two electrodes (16a) are attached to both ends of the
(16b) are electrically short-circuited by short-circuit wire 07). And such electrodes (16a) and (16b)
is connected to a short-circuit pipe (6) outside the embedded body.

In addition, a commonly known syringe may be used as the bubble generating means (7), and in this case, air may be simply injected into the short-circuit pipe (6) using this syringe.

Next, the bubble detection means (8) will be explained. This detection means (8) similarly includes an external device (8a) and an internal device (8b).
It is composed of. First, the internal device (8b) will be explained. This includes a plurality of (two in the illustrated embodiment) first and second electrical gaps (18
a) and (18b) are provided, and these are electrically connected in series. For this purpose, as shown in the figure, a short-circuit tube (6") made of the same material as the short-circuit tube (6) is provided, its length is selected to be slightly smaller than t, and the above-mentioned electrical connection is made at both ends. This forms gaps (18a) and (18b).

Since both of these electrical gaps are formed in the same way in this example, only the gap (isa) will be explained, and the other is the electrode 0 connected to the short-circuit pipe (6) and the above-mentioned The electrodes attached to the tip of the short-circuit tube (6") are connected to each other at a predetermined interval by a connecting tube (c) made of an electrically insulating material such as polyethylene. → and (20
) have through holes in each of them so that liquid can pass through,
That is, it is formed into a cylindrical shape. Also, these electrodes 01
and (20) can each be made of stainless steel. Also, the electrodes +20 provided at both ends of the short-circuit tube (6")
are electrically connected to each other by electrical conductor portions (a) buried inside the short-circuit pipes (6'), thereby connecting the electrical gaps (18a) and (18b) in series. As shown in the figure, the outer electrode has no scratches, so the outer surface is largely curved, that is, the outer surface is made into a spherical shape as a whole. This is because the surface can be configured to be wide, and the position of the electrode H can be easily determined from the skin.

On the other hand, as is clear from FIGS. 1 and 3, the external device (8a) has an impedance detector (c), and skin electrodes (24a) and (24b) are connected to both ends of the impedance detector (c). This impedance detector is well known in the past.
Since there is, I will omit the detailed explanation, but for example, 100K.
A high frequency of about Hz No. 48 is applied to the electrodes (24a) and (24b).
), and by measuring the value of the high-frequency current flowing therethrough, the so-called impedance between the electrodes (24a) and (24b) can be detected. (c) is a flow rate indicator.

The above-described device according to the present invention is to be implanted at a depth of 1111 times under the skin of a living body during a ventricular-peritoneal shunt tube installation surgery.

Next, its usage and operation will be explained.

First, the oscillator (9) of the external device (7a) is operated to supply a signal of, for example, 200 KHz to the coil Cl0). This coil H is placed opposite the coil of the internal device (7b), and a voltage is thereby induced across the coil of the internal device (7b). This voltage is rectified by the diode (13). , and Zener diode (
The electrolysis electrode (15a) is controlled to a constant voltage by Ia.
.

(15b) is supplied between. Therefore, the shunt duct (6
), the fluid flowing towards the abdominal cavity, in this case cerebrospinal fluid, is electrolyzed between the electrodes (15a) and (15b). That is, oxyhydrogen bubbles are generated by electrolysis.

When such bubbles reach a size that fills the inner chamber of the through hole (6'), they are swept downstream from the brain by the flow of cerebrospinal fluid. In the unlikely event that this bubble becomes the electrode for electrolysis (15a).

(15b), the current generated between these two electrodes may travel through the brain in the shunt tube through the cerebrospinal fluid and stimulate the brain or important organs such as the heart. so as to sandwich the electrodes (15a) and (15b),
Since the current collecting electrodes (16a) and (16b) are provided and these are short-circuited by the short-circuit wire 0η, the above-mentioned current passes through this short-circuit circuit and there is no risk of it reaching the above-mentioned organs, so the accuracy of the local detection is It can be prevented automatically.

- In the internal device (8b) of the male air bubble detection means (8), cerebrospinal fluid is sequentially flowing through the shunt tubes (6) and (6"), which causes the electrode OI and (201 to be electrically connected to each other). is almost short-circuited, i.e., there is a pair of electrical gaps (18
The impedance between a) and (18b) is in a very low state f.

Therefore, the skin electrode (24) of the impedance detector (c)
a) and (24b) as the internal device (8b)+7 described above.
) When the skin electrodes (24a) and (24b) are placed opposite each other, the impedance between the skin electrodes (24a) and (24b) is measured, and a low impedance value Z1 is obtained as shown before time tl in FIG. shows.

When the above-mentioned bubble reaches the first electrical gap (18a) in the internal device (8b) of the detection means (8) in this state, the impedance between the electrodes 01 and a1 increases rapidly. . This value is expressed as Z2 in Figure 4.
It is shown as When this bubble enters the short-circuit tube (6"), the liquid short-circuits the electrodes OI and (A) again, and the impedance between them decreases and becomes Zl. In this way, the bubbles are pushed out one after another, When this further reaches the second electrical gap (18b) K, the impedance becomes Z again.
0 which rises in 2 ma This point is indicated by 12. By knowing the time T for the bubble to pass through the first gap (18a) and the second gap (18b) in this way,
Since the inner diameter of the tubes (6) and (6) are known, the flow rate of liquid through the tubes can be known.

The above-mentioned flow rate indicator (c) is a device that automatically displays the value based on the conversion. The configuration of this device is also not directly related to the gist of the present invention and can be configured using well-known technology, so detailed explanation thereof will be omitted.

The above is a case where two electrical gaps are provided as the first and second (18a) and (18b), but the present invention is not limited to this. Three or more electrical gaps are provided, and the electrodes (24a) and (24b) are placed on the outermost side, respectively. The electrical gaps (18a) and (18b) are arranged opposite to the outer electrodes of the electrical gaps (18a) and (18b), respectively.
In..., pulses as shown in Figure 4 are obtained in sequence, and therefore each passing time can be averaged and detected.Therefore, it is possible to know the average velocity and more accurate flow rate. It becomes possible to detect.

Conventionally, the Doppler method using ultrasonic waves has been used to measure the moving speed of bubbles, but this Doppler method has the disadvantage that it cannot detect when the flow rate is low and the moving speed of the bubbles is slow. There was a drawback that measurement was not possible when the flow rate was 0.033 ml per minute or less, but the present invention described above avoids this conventional drawback and provides a more accurate V.
It has the feature of being able to perform C measurements.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram, partially in cross section, showing the state of use of the device according to the VC of the present invention, FIGS. 2 and 3 are longitudinal sectional views showing some of the equipment, and FIG. FIG. 3 is a waveform diagram used to explain the invention. (1) is a living body, (4) is a ventricle of the brain, (5) is a peritoneal cavity, (6) is a shunt tube, (7) is a bubble generating means, (8) is a bubble detecting means, (18a) and (18b) are The first and second electric gaps, 09 and wire are electrodes, (c) is an impedance detector, and (24a) and (24b) are skin electrodes thereof. Agent Hidenori Matsukuma, Toko Ito

Claims (1)

[Scope of Claims] (1) A bubble detection means for detecting bubbles in the liquid flow pipe generated by the bubble generation means, the bubble detection means comprising an external device and an internal device, the internal device comprising: The device is connected to a part of the liquid distribution tube and buried in the living body together with the liquid distribution tube, and is connected to a plurality of electric currents at a predetermined distance along the flow direction of the liquid through the liquid distribution tube. Each of these electrical gaps is configured with electrodes facing each other, each forming a light, and the external device is configured to connect the living body to the outermost electrode of the electrical gap. 1. A biological fluid flow measuring device comprising: a pair of skin electrodes that are placed facing each other on the skin of a patient; and a device that measures impedance between the pair of skin electrodes. 2. The bubble generating means described in claim 1 above includes a coil in which a voltage is induced by electromagnetic waves, and a voltage generated by the coil is applied, and - in contact with the liquid flowing through the liquid flow pipe. A pair of electrodes for electrolysis arranged as shown in FIG. A biological liquid flow rate measuring device characterized by the following.