JPH058964Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an endoscope with improved air and water supply means for supplying air and water to a tip nozzle.

Prior Art and its Problems In general, it has always been desired that the insertion portion of an endoscope be made thinner in order to alleviate patient pain, and it is preferable that the insertion portion be as thin as possible. Therefore, in order to make the distal end portion of the insertion portion as thin as possible, a type in which the nozzles for supplying air and water are combined into one has been proposed. (Japanese Utility Model Publication No. 52-7997) In addition, this type also has a connecting part between the air supply path and the water supply channel near the tip, and the length of the common passage on the tip side is made as short as possible to facilitate draining after water supply. It is designed to be easy and quick. However, when this format is actually used, it has been found that the following problems occur. In other words, because the body cavity into which the endoscope is inserted normally swells, the pressure inside the body cavity is 10 to 30.
It becomes higher than the outside pressure by about cmH ₂ O. In particular, when a patient burps, the pressure can reach up to 120 cmH ₂ O, and these pressures can cause mucus and the like to flow back from the nozzle into the passageway. In the above-mentioned type of endoscope, the air and water supply channel on the distal end side is short, about 1 to 2 cm, so backflowing mucus, etc., avoids the water-filled channel, although a check valve is installed. Invades air passages filled with compressible air. This backflow of mucus, filth, etc. remains in the air passage,
Even when air is supplied, it is difficult to get out of the nozzle. Also,
When a water supply operation is performed in this state, a portion of the water, which has been increased in pressure to be strongly jetted from the tip nozzle, also flows into the air supply path, further pushing up mucus, dirt, and the like. As a result, phenomena such as clogging of the air supply path or liquid substances gradually descending to the tip nozzle part when the endoscope is suspended and stored, solidify in the nozzle part, and clog the nozzle part occur.

Purpose of the invention This invention aims to prevent the passage and nozzle from becoming clogged with mucus, etc. flowing back from the tip nozzle in an endoscope in which the air supply path and the water supply path are connected and communicated with the tip nozzle via a common passage. The purpose of the present invention is to provide an endoscope that can perform air and water supply operations well.

Summary of the invention This invention is based on the idea that the central position of the connecting part that communicates the downstream ends of the water supply channel and the air supply channel should be set at 0.1040L or more along the common passage from the tip of the tip nozzle (however, L is the tip of the nozzle). Distance from check valve to check valve) is characterized by being installed within a range of 40 cm or less.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a direct-viewing endoscope, in which an operating section 1 is connected to the proximal end of an insertion section 2 to be inserted into a body cavity. Further, a base end of a light guide cord 3 is connected to the operating section 1. An observation window 5 is provided on the distal end surface 4 of the insertion section 2, and the observation window 5 is optically connected to the eyepiece section 7 of the operation section 1 via an image guide 6.

Furthermore, an air supply tube 8 forming an air supply path and a water supply tube 9 forming a water supply channel are inserted and arranged in parallel across the insertion section 2, the operation section 1, and the light guide cord 3. . and,
The air supply tube 8 supplies air sent from the light guide cord 3 side, and the water supply tube 9 supplies water sent from the light guide cord 3 side. The operation unit 1 is provided with an air/water switching valve device 10 that opens and closes the air tube 8 and the water tube 9 midway, and selects air feeding operation through the air feeding tube 8 and water feeding operation through the water feeding tube 9. I'm starting to be able to do it. In addition, air supply tube 8
A check valve 11 is inserted downstream of the air/water supply switching valve device 10 .

Furthermore, the downstream ends of the air supply tube 8 and the water supply tube 9 are connected to each other by a connecting portion 12, and a common path 13 is formed.
It communicates with the tip nozzle 14 via. The tip nozzle 14 is provided protruding from the tip surface 4 in close proximity to the observation window 5 so as to be able to spray water or air onto the outer surface of the observation window 5.

The length of the common path 13 from the connecting portion 12 of each tube 8, 9 to the tip nozzle 14 is l. The length l is determined by the intra-body cavity pressure under various conditions. Normally, the intrabody cavity pressure during endoscopy is 10 to 30 cmH ₂ O, but when the patient burps, it reaches as high as 120 cmH ₂ O. At this pressure nozzle 14
Figure 2 shows an experiment to determine the distance that water flows backwards. FIG. 2 shows the check valve 1 from the nozzle 14.
The distance from the nozzle opening x (cm) to the body cavity gauge pressure ΔP (cmH ₂ O) when L = 130 cm and 210 cm is shown. This relationship can be expressed as follows: X=ΔP/1033+ΔP·L. However, the atmospheric pressure is assumed to be 1033 cmH ₂ O.
From this experiment and the relational expression, it was confirmed that the backflow distance was not affected by the diameter of the tube, but depended on the intrabody cavity pressure and the distance from the nozzle opening to the check valve. According to the above relational expression, when L=120cm,
If ΔP=30cmH ₂ O, a backflow of X=3.4cm will occur, and if ΔP=120cmH ₂ O at the time of burping, a backflow of X=12.5cm will occur. This backflow distance is for water, and due to the influence of viscosity of mucus etc. that actually flows back, the backflow distance will be shorter even if the internal body cavity pressure is the same.

Therefore, in determining the length l, in order to prevent mucus etc. from flowing back into the air supply tube 8, it is determined that l>X=ΔP/1033+ΔP·L. During normal use of the endoscope, the maximum pressure within the body cavity is 30 cmH ₂ O, so it is necessary that l>0.0282L. Furthermore, taking into account the time of burping, the pressure inside the body cavity at the time of burping is 120 to 150 cmH ₂ O.
Therefore, taking this into consideration, it is sufficient to set l>0.1040L. Furthermore, the maximum length l is preferably 40 cm, as will be described later.

If the surface of the observation window 5 becomes dirty with mucus, filth, etc. in the body cavity while using this endoscope, the air/water supply switching valve device 10 of the operating section 1 is operated to connect the water supply tube 9 and the common Water is conveyed through channel 13.
This water feeding operation causes water to be jetted from the tip nozzle 14 to clean the surface of the observation window 5. Next, the air/water supply switching valve device 10 is switched to the air supply position to supply air through the air supply tube 8 and the common path 13, and air is blown onto the surface of the observation window 5 from the tip nozzle 14 so that it remains on the surface. Blow out the water.

By the way, during normal use of this endoscope, the pressure inside the body cavity is increased by about 10 to 30 cmH ₂ O, so the tip nozzle 14 has a distance of L from the opening to the check valve 11.
= 120 cm, ΔP = 30 cm H ₂ O, and during use, there is a possibility that about 3.4 cm may flow backward into the common path 13 and enter.

However, the length l of the common path 13 is 0.0282L
As above, if L=120cm, l>
The length is 3.4 cm, and mucus etc. that have entered from the nozzle 14 do not flow back up to the joint 12, thereby preventing entry into the air supply tube. Mucus and the like that have entered the common channel 13 in this way can be constantly washed away by operating the air/water supply switching valve device 10 and performing a water supply operation, and the mucus and the like that remain in the common channel 13 and the nozzle 14 can be washed away.
It never sticks.

Furthermore, if we take into account the case where the patient burps during the examination for greater safety, the intra-body cavity pressure at the time of burping is similarly set to ΔP=120 cmH ₂ O, and l is set to 0.1040 L or more. When L=120cm, the backflow distance during burping is 12.5cm, but l>12.5cm, which prevents the air from entering the air tube 8 and allows it to be flushed away by the water supply operation.

Also, if the above length l is 40cm or more,
Since water tends to remain in the common path 13 and drainage becomes difficult, it is preferable that the length l is 40 cm or less.

3 and 4 show other embodiments of the invention. This embodiment is applied to a side-viewing endoscope. That is, one side 2 of the distal end portion of the insertion section 2
1 includes a tip nozzle 14, an observation window 5, and an illumination window 22.
are arranged adjacently in parallel along the longitudinal direction of the insertion section 2,
A forceps opening 23 is provided next to these. Furthermore,
The tip nozzle 14 has a common path 1 as in the first embodiment.
The air supply tube 8 and the water supply tube 9 are connected via 3. And the length l of the common path 13 in this case
is determined in the same way as in the first embodiment.

Effects of the invention According to the invention, even if mucus and dirt in the body cavity flow back from the tip nozzle during burping, it remains in front of the connection between the air supply path and the water supply channel, and does not enter the air supply path. Therefore, mucus and dirt are constantly flushed away during water supply, preventing clogging in the air supply path and nozzle portion. Further, the water does not drain easily during the water supply operation.

[Brief explanation of the drawing]

Fig. 1 is a schematic structural explanatory diagram of an endoscope showing one embodiment of the present invention, Fig. 2 is a diagram showing the relationship between body cavity pressure and backflow distance, and Fig. 3 is a diagram showing another embodiment of the present invention. FIG. 4 is a plan view of the insertion section and a side view of its distal end. 8...Air supply tube, 9...Water supply tube, 1
DESCRIPTION OF SYMBOLS 1...Check valve, 12...Connection part, 13...Common path, 14...Tip nozzle.

Claims (1)

[Scope of utility model registration request] In an endoscope in which the downstream ends of a water supply channel and an air supply channel provided with a check valve on the upstream side are connected to each other and connected to a common passage leading to a tip nozzle, the water supply channel and the air supply channel are The center position of the connecting part that communicates each downstream end of the channel, from the tip of the tip nozzle to the common path, is 0.1040L or more (L is the distance from the nozzle tip to the check valve) or less than 40cm. An endoscope characterized in that the endoscope is installed at a distance within the range of .