JPH0751132B2 - Cooling device for ultrasonic endoscope - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cooling device for removing heat generated from an ultrasonic transducer arranged at the tip of an insertion portion of an endoscope.

[Conventional technology]

Conventionally, an ultrasonic transducer is placed at the tip of an endoscope insertion part that is inserted into a body cavity, sends out an ultrasonic wave inside the body cavity, and receives an ultrasonic wave reflected from the inside of the body cavity to obtain a tomographic image inside the body cavity. The ultrasonic endoscope to be obtained is known, and is disclosed in, for example, JP-A-57-
It is described in Japanese Patent No. 168648. In the ultrasonic endoscope described in this publication, an ultrasonic transducer is arranged at the tip of the insertion portion and rotated through a flexible shaft to perform mechanical scanning. In this case, in order to increase the ultrasonic wave propagation efficiency, degassed water, an ultrasonic wave propagation medium such as silicone oil, etc. is housed in a housing chamber that surrounds the ultrasonic vibrator, and the method described in the above publication is also disclosed. In the above, a space is provided between the flexible shaft and the flexible tube surrounding the flexible shaft so as to communicate with the accommodation chamber, and the ultrasonic propagation medium is also accommodated in this space to act as a lubricant to provide friction resistance. Is being reduced.

[Problems to be solved by the invention]

In the above-mentioned conventional ultrasonic endoscope, in order to improve the image quality of the ultrasonic tomographic image, the power of the ultrasonic waves emitted from the ultrasonic transducer is increased. It is necessary to increase the voltage applied to the ultrasonic vibrator, and as a result, the amount of heat generated from the ultrasonic vibrator increases, and the characteristics of the ultrasonic vibrator deteriorate. As described above, the ultrasonic transducer is immersed in the ultrasonic wave propagating medium, but since the ultrasonic wave propagating medium is housed in the closed space, it has no cooling effect. In order to solve such a problem of heat generation, it is conceivable that the ultrasonic wave propagating medium is circulated through a storage chamber that surrounds the ultrasonic vibrator so as to have a cooling function. When circulating, the problem of bubbles entering the fluid arises. When bubbles infiltrate the cooling fluid, which is an ultrasonic wave propagation medium, as described above, the impedance of the bubbles to the ultrasonic waves is significantly different from that of the cooling fluid, which causes a drawback that interference occurs in the ultrasonic tomographic image.

The object of the present invention is to eliminate the above-mentioned drawbacks and to circulate a cooling fluid, which also acts as an ultrasonic wave propagation medium, through a storage chamber that surrounds the ultrasonic wave oscillator to cool the ultrasonic wave oscillator. An object of the present invention is to provide a cooling device for an ultrasonic endoscope, which is configured to reduce interference with an ultrasonic tomographic image.

[Means and Actions for Solving Problems]

The cooling device of the present invention has a first flow path, one end of which is connected to a housing chamber that surrounds an ultrasonic transducer arranged at a distal end portion of an endoscope and through which a cooling fluid for cooling the ultrasonic transducer is passed. A defoaming device connected to the other end of the first flow path to remove bubbles mixed in the cooling fluid; one end of the defoaming device is connected to the defoaming device; And a means for circulating the cooling fluid through the first flow passage, the defoaming device, the second flow passage, and the ultrasonic transducer storage chamber. It is characterized by getting.

According to such a cooling device of the present invention, since the cooling fluid is circulated through the accommodation chamber that surrounds the ultrasonic transducer, the heat generated from the ultrasonic transducer can be effectively dissipated, and the ultrasonic power is large. It is possible to obtain an ultrasonic tomographic image with excellent image quality. Further, since the defoaming device is provided in the circulation path of the cooling fluid, it is possible to effectively eliminate the bubbles that enter the cooling fluid, and there is no fear that the ultrasonic tomographic image is disturbed by the bubbles.

〔Example〕

FIG. 1 is a diagram showing the overall configuration of an ultrasonic endoscopic apparatus including a cooling device according to the present invention. The ultrasonic endoscope, generally designated by reference numeral 1, has a distal end rigid portion 1a and a flexible insertion portion.
1b and operating part 1c. An ultrasonic transducer 2 is arranged inside the tip rigid portion 1a, a flexible shaft 3 having one end connected to the transducer extends in the insertion portion 1b, and the other end is connected to a servomotor 5 via a belt 4. Connect and allow the oscillator to rotate at the desired speed. At the other end of the flexible shaft 3 is a circuit section 6 having a built-in preamplifier.
Is provided, and a rotary transformer 7 is provided at the tip thereof to transmit and receive signals.

The housing chamber 8 formed between the housing that constitutes the tip forming portion 1a and the ultrasonic transducer 2, the flexible shaft 3 that extends inside the insertion portion 1b, and a structure such as a flexible tube that surrounds the flexible shaft 3 The storage chamber 9 formed therebetween is communicated. A mechanical seal 10 is arranged at the boundary between the accommodation chamber 9 and the operating portion 10. Further, a tube 11 having one end connected to the accommodation chamber 9 is provided, and the other end of the tube is provided with a defoaming device.
Connect to 12. A flow path 13 communicating with the accommodation chamber 8 of the ultrasonic transducer 2 is extended through the insertion portion 1b, and a tube is provided in this flow path.
Connect one end of 14.

The defoaming device 12 includes a container 12a, a lid 12b that closes the opening thereof, a tube 12c inserted into the lid, and a vacuum pump 12d connected to the tube. The tube 11 is also inserted into this lid 12b, and the tip thereof is positioned below the liquid level of the cooling fluid 15 contained in the container 12a. The tip of the tube 12c is located above this liquid level.

The tube 16 is further inserted through the lid 12b of the defoaming device 12, and its tip is positioned below the liquid level of the cooling fluid. In the tube 16, a circulation pump 17 such as a roller pump is arranged, and a bubble detector 18 for detecting bubbles that may enter the cooling fluid flowing in the tube 16 is arranged. In this book, this bubble detector 18 comprises a light source 18a that emits light and a light receiver 18b that receives the light transmitted through the tube, and the amount of transmitted light is changed by the bubbles entering the light beam passage. It is assumed that air bubbles are detected and detected. At the other end of the tube 16, a flow path switching valve 19
Is provided and is driven by the output signal of the control circuit 20 which processes the output signal of the light receiver 18b and determines the presence or absence of bubbles. That is, when no bubbles are detected,
The tube 16 is communicated with the tube 21, and the tube 16 is communicated with the tube 22 when air bubbles are detected.
The other end of the tube 21 is connected to a cooling device 23, and multiple ends of the tube 14 are connected to this cooling device. Further, the other end of the tube 22 is inserted into the lid 12b of the defoaming device 12 and is positioned below the liquid level of the cooling fluid.

Next, the operation of the cooling device of this example will be described. First, defoaming device
A predetermined amount of cooling fluid such as water or silicone oil is contained in twelve containers 12a, and the circulation pump 17 is driven. As a result, the cooling fluid 15 in the container 12a passes through the tube 16, the circulation pump 17, the bubble detector 18, the flow path switching valve 19, the tube 21, the cooling device 23, the tube 14 and the flow path 13 and the ultrasonic transducer 2. It is injected into the accommodation chamber 8 in which it is accommodated. When the accommodation chamber 8 is filled with the cooling fluid 15, the cooling fluid is returned to the container 12a via the accommodation chamber 9 and the tube 11. In this way, the cooling fluid 15 cooled by the cooling device 23 can be circulated through the accommodation chamber 8. On the other hand, since the vacuum pump 12d of the defoaming device 12 is driven to reduce the pressure inside the container 12a, the bubbles mixed in the cooling fluid 15 can be quickly discharged from the liquid surface and defoamed. Since the cooling fluid 15 that has been degassed in this way is circulated, there is no risk of bubbles disturbing the ultrasonic tomographic image. Further, a bubble detector 18 is provided in the tube 16 to detect the presence or absence of bubbles, and when a bubble is detected, the switching valve 19 is driven to allow the cooling fluid containing bubbles to pass through the tube 22 and the container 12a of the defoaming device 12. As a result, the cooling fluid supplied into the storage chamber 8 surrounding the ultrasonic transducer 2 does not contain bubbles. Further, if the cooling fluid is taken out from the accommodation chamber 9 provided with the mechanical seal 10 and returned to the defoaming device 12 as in the present embodiment, even if bubbles intrude through the mechanical seal, this will be removed. Since the bubbles are removed by the bubble device 12, the possibility that bubbles are mixed in the cooling fluid supplied to the storage chamber 8 is further reduced.

As described above, the cooling fluid cooled by the cooling device 23
Since 15 is supplied to the accommodation chamber 8 that accommodates the ultrasonic transducer 2 through the tube 14 and the relatively long flow path 13, it may be heated in the middle and the cooling efficiency may decrease. In order to eliminate such a defect, as shown in FIG. 2, a flexible tube having a double structure in which a small-diameter inner tube 31 is arranged inside a large-diameter outer tube 31 is formed of resin, and an outer tube 32 is formed. Used as an insulating tube, inner tube
Suitably the cooling fluid is supplied via 31.

〔The invention's effect〕

According to the cooling device of the present invention described above, since the cooling fluid acting as an ultrasonic propagation medium is circulated through the accommodation chamber that surrounds the ultrasonic transducer disposed in the distal rigid portion of the ultrasonic endoscope, It is possible to effectively dissipate the heat generated from the ultrasonic wave oscillator, and to apply a higher voltage and radiate ultrasonic waves with higher power without deteriorating the characteristics of the ultrasonic wave oscillator. On the other hand, since the defoaming device is provided in the circulation path of the cooling fluid to remove the bubbles that enter the cooling fluid, the bubbles do not enter the accommodation chamber even when the cooling fluid is circulated.

As a synergistic effect of the above two functions, an ultrasonic tomographic image with good image quality can be obtained, and more accurate ultrasonic diagnosis can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an ultrasonic endoscope apparatus including an embodiment of a cooling device according to the present invention, and FIG. 2 is a perspective view showing a configuration of a cooling fluid conduit. 1 ... Ultrasonic endoscope, 1a ... Tip rigid part 1b ... Insertion part, 2 ... Ultrasonic vibrator 3 ... Flexible shaft 8 ... Ultrasonic vibrator housing chamber 9 ... Flexible shaft housing Chamber 11,14,16,21,22 …… Tube 12 …… Defoaming device, 17 …… Circulation pump 18 …… Bubble detector, 19 …… Flow path switching valve 23 …… Cooling device

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroyoshi Fujimori 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Tatsuo Nagasaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Kenji Hirooka 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (56) Reference JP-A-63-242246 (JP, A)

Claims (1)

[Claims] 1. A first flow path, one end of which is connected to a housing chamber surrounding an ultrasonic transducer arranged at a distal end portion of an endoscope, and through which a cooling fluid for cooling the ultrasonic transducer is passed. A defoaming device connected to the other end of the first flow path to remove air bubbles mixed in the cooling fluid, and one end of the defoaming device is connected to the defoaming device and the other end houses the ultrasonic transducer. Second connected to the chamber
And a means for circulating the cooling fluid through the first flow path, the defoaming device, the second flow path, and the accommodating chamber of the ultrasonic transducer. Cooling device for endoscopes.