JPH0792397B2 - Fluid information measuring tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluid information measuring tube for measuring the flow velocity of a fluid to be measured flowing inside a tube main body using ultrasonic waves.

[Prior Art] Conventionally, when the flow velocity and flow rate of a fluid to be measured flowing in the tube are measured by using ultrasonic waves, a probe such as an ultrasonic flow meter is fixed to the outer wall of the tube and used. . Further, in recent years, during open heart surgery and other operations, development of an artificial heart-lung machine, an auxiliary heart, or an artificial heart device for assisting the heart or cardiopulmonary function externally or temporarily outside the body has been advanced. There is. Further, such an artificial heart-lung machine, assist heart, or artificial heart device is also effective in clinical application to patients during actual treatment.

In such clinical applications, especially blood flow measurement,
An important monitoring element, ultrasonic flow meters allow the measurement of flow without direct contact with blood.
It is said to be effective.

[Problems to be Solved by the Invention] When using such an ultrasonic flowmeter, a probe having an ultrasonic transducer is bonded to the outer wall of the tube via an adhesive, or a band or a special holder is attached. It must be attached to the outer wall of the tube through the operation, which is very troublesome to operate. Especially, between the ultrasonic transducer and blood,
Substances having different acoustic impedances, such as the outer wall of the tube and the adhesive layer of the probe, are interposed. Therefore, the ultrasonic waves transmitted from the ultrasonic transducer are attenuated or reflected, and it becomes difficult to effectively receive the echo from the blood.
In this way, there is a problem that the flow velocity cannot be accurately measured by utilizing this echo. In addition, it has been pointed out that an error in the ultrasonic wave transmission angle or the like occurs due to a defect in the mounting method of the probe, which adversely affects the measurement accuracy.

The present invention has been made in view of the above problems,
The object of the present invention is to quickly measure the flow velocity of a fluid to be measured,
Moreover, it is an object of the present invention to provide a fluid information measuring tube capable of reliably improving the measurement accuracy.

[Means for Solving Problems] In order to solve the above problems and achieve the object, a fluid information measuring tube according to the present invention includes a tube main body through which a fluid to be measured having high cleanliness flows, A sensor holding portion integrally provided on the outer wall of the tube body, and a fixed state of the sensor holding portion, which outputs ultrasonic waves to a fluid to be measured flowing in the tube body and reflects the ultrasonic wave. It is characterized by comprising a detecting means for receiving at least the ultrasonic waves and detecting at least data relating to the flow velocity.

Further, the first of the fluid information measuring tubes according to the present invention is provided.
According to an embodiment of the present invention, the tube main body is formed of a resin material capable of transmitting ultrasonic waves in a portion where the detecting means is arranged, and the detecting means is fixedly arranged on the resin material. As a result, the input / output direction of the ultrasonic waves input / output from the detection means is maintained constant.

In addition, the second embodiment of the fluid information measuring tube according to the present invention.
According to another embodiment, the tube main body through which the fluid to be measured flows constitutes a part of a blood circuit connected to the artificial heart-lung machine, artificial heart apparatus, or auxiliary heart apparatus.

Also, the third embodiment of the fluid information measuring tube according to the present invention.
According to another embodiment of the present invention, the inner peripheral surface of the tube body is antithrombogenic.

[Operation] In the fluid information measuring tube configured as described above, when measuring the flow velocity of the fluid to be measured flowing in the tube main body, the detecting means for outputting ultrasonic waves is previously integrated with the outer wall of the tube main body in advance. Since it is arranged in a fixed state on the provided sensor holding portion, this detection operation is started with the start of the output of the ultrasonic wave from the detection means, and a quick detection operation is realized. Further, between the detection means that outputs ultrasonic waves and the blood, there is no substance such as the outer wall of the tube or the adhesive layer of the probe with different acoustic impedance, so the ultrasonic waves output from the detection means are attenuated or reflected. As a result, the state where it becomes difficult to effectively receive the echo from the blood is improved. In this way, the flow velocity can be accurately measured by utilizing this echo. Further, since the disposition state of the detecting means is fixed, an error such as an ultrasonic wave transmission angle does not occur and the measurement accuracy is not adversely affected.

[Embodiment] A configuration of an embodiment of a fluid information measuring tube according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, the flow rate measuring tube 10 has a tube main body 12 through which blood as a fluid to be measured flows, and a sensor holding portion 14 integrally attached to an outer wall of the tube main body 12. As shown in FIGS. 2A and 2B, the sensor holding portion 14 has an ultrasonic sensor as a detecting means for detecting the flow velocity of blood flowing in the tube main body 12 via ultrasonic waves.
16 is disposed with its mounting state fixed.

This ultrasonic sensor 16, as shown in FIG.
It is electrically connected to the arithmetic unit 20 via 18, and the arithmetic unit 20 is configured to calculate the flow rate of the blood flowing in the tube main body 12 based on the flow velocity detected by the ultrasonic sensor 16. ing.

The ultrasonic sensor 16 described above has a sensor holding portion 14 integrally attached to the outer wall of the tube main body 12 through which blood as a fluid to be measured flows, as shown by different cross sections in FIGS. 2A and 2B. A recess 22 is formed on the inner surface of the tube main body 12. A sensor block 24 made of acrylic resin, which is fixed to the tube main body 12, is arranged in the recess 22. The ultrasonic sensor 16 described above,
The recess 22 and the sensor block 24 constitute the detection means of the present invention.

On the sensor block 24, an ultrasonic transmitter 16a that outputs ultrasonic waves toward the blood flowing in the tube body 12,
An ultrasonic receiver 16b that receives ultrasonic waves reflected in flowing blood and detects data relating to the flow velocity is provided with their axes crossing each other. One end of the above-described cable 18 is connected to the ultrasonic transmitter 16a and the ultrasonic receiver 16b, respectively.

The ultrasonic wave transmitter 16a and the ultrasonic wave receiver 16b constitute an ultrasonic wave sensor 16 for detecting data relating to the flow velocity.

On the other hand, the tube main body 12 to which such an ultrasonic sensor 16 is attached is made of a soft vinyl chloride resin. In addition, the bottom of the sensor block 24 is
It is composed of a curved surface along the inner peripheral surface of. Further, an antithrombotic agent 26 is attached to the entire inner peripheral surface of the tube main body 12 so that blood flowing in the tube main body 12 does not coagulate, and so-called antithrombotic treatment is applied.

In this embodiment, the fluid information measuring tube 14
Constitute a part of a blood circuit duct in the heart-lung machine 28. That is, in this artificial heart-lung machine 28, venous blood removed from the patient's vein via the blood removal line 30 and blood bleeding from the patient's incision site during the open-heart surgery are aspirated and cardiovascular. The blood that has been defoamed in the Tommy reservoir 32 and then sent from here is stored together in one end in the venous reservoir 34.
The venous blood stored in 34 is heat-exchanged by the drive of the blood pump 36 through the heat exchanger 38 and the artificial lung 40 sequentially, and oxygen is added thereto, and thereafter, via the blood supply line 42. It is configured to return blood to the patient's artery.

The fluid information measuring tube 10 is not only applied to such an artificial heart-lung machine 28, but may be, for example, the fourth
As shown as a modified example in the figure, the blood circuit 44 for the auxiliary heart
In, it can also be used to measure blood flow velocity. That is, a part of the blood removal cannula 48 that sends blood from the patient to the auxiliary heart pump 46 is adopted as the tube 10 through which blood as the fluid to be measured flows. In addition, the pump 46 for the assisting heart is provided with a blood feeding cannula for returning the blood energized here to the patient.
50 is installed. The fluid information measuring tube 10 can also be used as a part of the blood supply cannula 50 in the pump 46 for the auxiliary heart.

The operation of the fluid information measuring tube 10 in the heart-lung machine 28 configured as above will be described.

In the open-heart surgery, when the heart-lung machine 28 is used, the flow rate of the blood removed is measured by the flow rate measurement tube 10 in order to control the driving state of the blood pump 36. In this measurement, first, the arithmetic unit 20
Is turned on. Here, the ultrasonic sensor 16 is arranged in a fixed state in the tube wall of the pre-strain tube main body 12. Therefore, in this detection operation, it is necessary to apply a preliminary jelly-like liquid in order to prevent air or bubbles from entering between the tube main body 12 and the sensor block 24 and increasing the attenuation of ultrasonic waves. Lost. Also,
After the application of the jelly, it is not necessary to fit the probe for measuring fluid information into the tube body in which the blood as the fluid to be measured flows in the tube body, as in the conventional case.

In addition, since the probe mounting operation is omitted in this way, the operator does not make a mistake in the mounting position.

In this way, by starting the operation of the arithmetic device 20, ultrasonic waves from the ultrasonic transmitter 16a of the ultrasonic sensor 16,
For example, it is transmitted as a continuous wave of 5 MHz. The ultrasonic waves thus transmitted are reflected by the blood flowing in the tube main body 12, and the ultrasonic waves reflected by the ultrasonic receiver 16 have different frequencies due to the Doppler effect.
Received at b.

The data regarding the flow velocity at the place received by the ultrasonic receiver 16b is sent to the arithmetic unit 20 via the cable 18, and the arithmetic unit 20 performs information processing to determine the flow rate of blood flowing in the tube main body 12. It is calculated.

As described above in detail, in this embodiment, in the fluid information measuring tube 10, the tube body 12 in which blood as the fluid to be measured flows and the ultrasonic sensor 16 are integrally formed. is doing. In this way, it is possible to minimize the presence of materials having different acoustic impedances from the ultrasonic transducer 16a to the blood. Therefore, according to this embodiment, the measurement accuracy in measuring the flow velocity is significantly improved.

Further, in this embodiment, the ultrasonic sensor 16 is arranged in a fixed state in the tube wall of the tube body 12. In this way, the emission angle of the ultrasonic wave output from the ultrasonic transducer 16a is always constant, and an accurate measurement state is realized.

Here, it is generally known that if there is a step or a discontinuous portion in the blood flow path, such as a connecting portion between the tube and the connector, thrombus is likely to occur at the step or the discontinuous portion. Has been. However, in this one embodiment, as described above, since the fluid information measuring tube 10 includes the tube main body 12 that constitutes a part of the blood circuit, it is necessary to separately install it when incorporating it into the blood circuit. It is not necessary to use a connecting member such as a connector, and the connecting portion to the blood circuit can be minimized. Therefore, according to this embodiment, it is possible to minimize the possibility of thrombus in the blood flow path.

It goes without saying that the present invention is not limited to the configuration of the above-described embodiment and can be variously modified without departing from the scope of the present invention.

[Effect of the Invention] As described in detail above, the fluid information measuring tube according to the present invention is integrally provided on the tube main body through which the fluid to be measured having high cleanliness flows and the outer wall of the tube main body. The sensor holding part and the sensor holding part are fixedly arranged to output ultrasonic waves toward the fluid to be measured flowing in the tube body and receive the reflected ultrasonic waves to detect at least data on the flow velocity. And a detecting means for

Therefore, according to the present invention, a fluid information measuring tube capable of promptly measuring the flow velocity of the fluid to be measured and surely improving the measurement accuracy is provided.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an embodiment of a fluid information measuring tube according to the present invention; FIGS. 2A and 2B show the fluid information measuring tube cut along different cutting planes. Front sectional view and side sectional view; FIG. 3 is a circuit diagram schematically showing a blood circuit of an artificial heart-lung machine to which this fluid information measuring tube is applied; FIG. 4 is a fluid of one embodiment according to the present invention. Information measurement tube,
It is a perspective view showing a modification when applied to a pump of an auxiliary heart. In the figure, 10 ... tube for measuring fluid information, 12 ... tube body, 14 ... sensor holder, 16 ... ultrasonic sensor, 16a
...... Ultrasonic transmitter, 16b …… Ultrasonic receiver, 18 …… Cable, 20 …… Computer, 22 …… Recess, 24 …… Sensor block, 26 …… Antithrombotic agent, 28 …… Artificial cardiopulmonary Device, 30 ... Blood removal line, 32 ... Cardiotomy reservoir, 34 ... Venous blood reservoir, 36 ... Blood pump, 38 ... Heat exchanger, 40
…… Artificial lung, 42 …… Blood supply line, 44 …… Blood circuit for assisting heart, 46 …… Pump for assisting heart, 48 …… Blood removal canister, 50 …… Blood sending canister.

Claims (4)

[Claims] 1. A tube main body in which a fluid to be measured having high cleanliness flows, an sensor holding portion integrally provided on an outer wall of the tube main body, and a sensor holding portion fixed to the sensor holding portion. A fluid information measuring tube comprising: a detecting means for outputting an ultrasonic wave toward the fluid to be measured flowing in the main body of the tube and for receiving the reflected ultrasonic wave to detect at least data relating to the flow velocity. 2. The tube main body is formed of a resin material capable of transmitting ultrasonic waves in a portion where the detecting means is provided, and the detecting means is fixedly provided on the resin material. The fluid information measuring tube according to claim 1, characterized in that the input and output directions of the input and output ultrasonic waves are kept constant. 3. A tube main body through which the fluid to be measured flows,
The fluid information measuring tube according to claim 2, which constitutes a part of a blood circuit connected to the artificial heart-lung machine, artificial heart apparatus, or auxiliary heart apparatus. 4. The fluid information measuring tube according to claim 3, wherein an inner peripheral surface of the tube body is antithrombogenic.