GB2198948A

GB2198948A - Body cavity pressure adjusting device in endoscope

Info

Publication number: GB2198948A
Application number: GB08717639A
Authority: GB
Inventors: Yuzuru Doi; Hitoshi Osawa
Original assignee: Asahi Kogaku Kogyo Co Ltd
Current assignee: Pentax Corp
Priority date: 1986-12-25
Filing date: 1987-07-24
Publication date: 1988-06-29
Anticipated expiration: 2007-07-24
Also published as: FR2608910A1; GB2198948B; GB8717639D0; JPS63161929A; JPH0257928B2; FR2608910B1

Abstract

An endoscope system in which air is pumped into a first channel 12 in the endospace to pressurize the body cavity and a second channel 13 is connected to a suction pump 16 to drain the body cavity of fluid, air and debris. Either a second suction pump 34 or a second supply of air is connected to the channel 13 along with a pressure detector 32 for controlling the suction. <IMAGE>

Description

BODY CAVITY PRESSURE ADJUSTING DEVICE IN ENDOSCOPE BACKGROUND OF THE INVENTION Field of the Invention This invention relates to a body cavity pressure adjusting device which is so designed as to automatically adjust the pressure in a body cavity (hereinafter referred to as "body cavity pressure") during medical examination or treatment with an endocope.

Background of the Invention In a medical examination or treatment with an endoscope, air is supplied into a body cavity such as the stomach to spread the wall of the body cavity or to clean the obJective lens of the endoscope.

In general, a body cavity internal organ such as the stomach or intestine automatically contracts itself.

Therefore, in a medical examination of a body cavity with an endoscope, gas like air is supplied into the body cavity through a gas supplying pipe line built in the endoscope to inflate the body cavity so that the operator can observe the body cavity sufficiently. However, if the stomach is excessively filled with air, then the following difficulties are caused. The gastric wall may be so greatly spread that the small blood vessels are broken, with the result that the stomach hemorrhages. As the stomach is greatly strained, the patient may belch. Thus, the supplying of air into the stomach inflicts pain on the patient. Since the gastric wall may be excessively spread, as was described above, it is difficult to accurately detect the delicate change of the mucous membranes, with the result that the diagnosis or medical treatment of gastritis under the endoscope is not always correct.

In order to eliminate the above-described difficulties, the following method has been employed. The forceps channel of the endoscope is connected through a manual valve with a suction device (or suction bottle).

The operator operates the manual valve while watching the patient so that the pressure in the body cavity may not become excessively high. However, for instance in the medical examination of the large intestine, escessive increase of the pressure in the large intestine is hazardous because the wall of the large intestine is weaker than the gastric wall. Especially in the case of a patient who is liable to hesitate to complain of pain, the worst case may occur that the wall of the large intestine is broken.

At any rate, in the conventional medical examination with an endoscope, suppression or control of the increase of the pressure in a body cavity is carried out according to the experience of the operator. There has been presented no idea of maintaining the pressure in a body cavity constant.

Even if a pressure detector for detecting a pressure in the suction pipe line of the endoscope is provided to detect the pressure in the body cavity through the suction pipe line, and a suction device connected to the suction pipe line is operated in response to the output signal of the pressure detector, to suck gas out of the body cavity, thereby to automatically decrease the pressure in the body cavity.

In this latter operation, not only air but also mucus, blood and other debris are sucked into the suction pipe line of endoscope, and they may often clog up the suction pipe line. In this case, the pressure in the body cavity can no longer be detected by the pressure detector in such body cavity pressure adjusting device with a pressure sensor. Therefore, even when the pressure in the body cavity has become higher, the suction is not carried out. Accordingly, it is impossible for the operator to observe the mucous membrane in detail, and the inner wall of the body cavity may be damaged.

SUMMARY OF THE INVENTION Accordingly, an. object of this invention is to eliminate the above-described difficulties accompanying a conventional body cavity pressure adjusting device in an endoscope.

More specifically, an object of this invention is to maintain the pressure in a body cavity within a predetermined range thereby to ease the pain of the patient in a medical examination or treatment with an endoscope.

A further object of the invention is to provide a body cavity pressure adjusting device for an endoscope which, even if the suction pipe line is clogged up with debris or the like, can automatically remove it so as to maintain the pressure in a body cavity constant at all times.

One specific feature of the invention resides in that the forceps channel of an endoscope is connected to an automatic suction device adapted to maintain the pressure in a body cavity in a predetermined range. The automatic suction device is provided in addition to the conventional suction device which is communicated through the manual valve with the forceps channel. The conventinal suction device is used to suck debris out of a body cavity.

In the case when the automatic suction device is used as was described above, the air suppling pump can be operated at all times to supply air into a body cavity through the air supplying pipe of the endoscope at all times. The air supplying pipe is formed in the endoscope body generally in such a manner that its end confronts with the objective lens at the end of the image fiber.

Therefore, the objective lens is maintained clean at times to allow the clear observation of objects.

If the air supplying pump for supplying air into the body cavity and the automatic suction device are provided in a power source unit for the illuminating fiber of the endoscope, then the device of the invention can be obtained merely by modifying part of the endoscope system.

That is, the device of the invention can be realized at low manufacturing cost without changing the system itself.

According to another aspect of the invention, a gas supplying pipe line connected to first gas supplying means and a suction pipe line connected to suction means separately open at the end of the inserting part of the endoscope. A second gas supplying means supplies gas into the suction pipe line. A pressure detector detects the pressure in the suction pipe line. The operation of the suction means is controlled according to the output of the pressure detector.

Normally, the pressure in the body cavity is detected through the suction pipe line by the pressure detector. When the pressure in the body cavity is excessively high, in response to the output signal of the pressure detector the suction means operates to suck gas out of the body cavity through the suction pipe line, to thereby maintain the pressure in the body cavity constant at all times.

In the case when the suction pipe line is clogged up with debris or the like, the gas from the second gas supplying means increases the pressure in the suction pipe line. The pressure thus increased is detected by the pressure detector. As a result, similarly as in the case where the pressure in the body cavity is increased, the suction means is activated to automatically remove the debris or the like out of the suction pipe line.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory diagram of a first embodiment of the invention for a body cavity pressure adjusting device in an endoscope.

Fig. 2 is an explanatory diagram of a second embodiment.

Fig. 3 is a detailed diagram of part of Fig. 2.

Fig. 4 is a flow diagram of the operation of the body cavity pressure adjusting device.

DETAILED DESCRIPTION OF THE PREFEERRED EMBODIMENTS A first embodiment of this invention will be described with reference to the accompanying drawings.

As shown in Fig. 1, an endoscope body 11 has an air supplying pipe 12 and a forceps channel 13 which can reach a body cavity. The endoscope body further includes conventional elements such as an image fiber for observation and an illuminating fiber. However, these elements are not shown because they are not directly related to the invention. As was described before, the air supplying pipe 12 is so formed in the endoscope body 11 that its end confronts with the objective lens at the end of the image fiber.

The forceps channel 13 is communicated through a manual valve 14 and a suction pipe 15 with a suction device 16. When an operating button 14a is depressed by the operator, the manual valve 14 is opened to communicate the forceps channel 13 with the suction device 16. The suction device 16 is made up of a suction bottle 16a and a suction pump 16b. This suction system is used to suction the debris in a body cavity into the suction bottle 16a, and is provided for the conventional endoscope.

A light source unit 20 is used to apply light to the illuminating fiber and is made up of an illuminating lamp 21, an air supplying pump 22 and an automatic suction device 30 in which the specific feature of the invention resides. The air supplying pump 22 is communicated with the above-described air supplying pipe 12 through an air supplying pipe 24 extending along a light guide cable 23 and through a control valve 25 for switching an air supplying operation and a water supplying operation. The control valve 25 is so designed that normally, or when the operating button 25a is not depressed, air from the air supplying pump 22 is delivered into the air supplying pipe 12. On the other hand, when the operating button 25a is depressed, water is delivered with the flow of air from the air supplying pump 22.A method of carrying water with a flow of air is well known in the endoscope field.

The principal aspects of the invention are not concerned with a water supplying mechanism nor with the arrangement thereof.

The automatic suction device 30 is communicated with the forceps channel 13 through an automatic suction pipe 31 connectd to a forceps inserting port 26 into which the forceps are inserted and operated. The automatic suction device 30 operates to control the amount of suction so that the pressure in the forceps channel 13, i.e., the pressure in the body cavity, is maintained within a predetermined range. The automatic suction device 30 comprises a pressure sensor 32, a control cirucit 33, and a suction pump 34. The pressure sensor 32 detects the pressure in the body cavity (as measured in the forceps channel 13 and the automatic suction pipe 31) and controls the suction pump 34 through the control circuit 33 so that the pressure thus detected is maintained in the predetermined range. The set pressure of the pressure sensor 32 can be adjusted.The suction pump 34 may be controlled by an on-off control method, a valve control method, or a continous suction control method.

In the body cavity pressure adjusting device thus constructed, during examination with the endoscope, the air supplying pump 22 is driven continuously to supply air into the air supplying pipe and, thus, into the body cavity through the air supplying pipe 24 and the control valve 25. Accordingly, the pressure in the body cavity increases with time. The pressure sensor 32 detects when the pressure in the body cavity reaches a predetermined value, thereby -to drive the suction pump 34 via the control circuit 33. As the suction pump 34 sucks the air out of the body cavity, the pressure in the body cavity is decreased. When the pressure in the body cavity becomes lower than the predetermiend value, the suction by the suction pump 34 is suspended or the amount of suction is decreased.The above-described suction control is continously carried out to maintian the body cavity pressure in a certain range. Experiments indicate that the pressure in the body cavity could be maintained in a small range of the order of i10% of the set pressure of the pressure sensor 32.

As is apparent from the above description, the adjustment of the pressure in a body cavity, which is heretofore done according to the experience of the operator who views the pain or expression of the patient, can be automatically achieved according to the invention.

Therefore, with the device of the invention, the examination of the large intenstine or the like which is small in wall thickness can be safely carried out with a burden to the patient lessened. At the same time, it is unnecessary for the operator to apply attention to the increase or decrease of the pressure in the body cavity.

It is further unneccessary for the operator to pay special attention at all times to an abnormal increase. That is, the burden to the operator is also reduced, and therefore the operator can concentrate his ability on the examination or medical treatment. Thus, with the device of the invention, the examination and the medical treatment can be performed more correctly.

A second embodiment of this invention will be described with refrence to Fig. 2.

As shown in Fig. 2, an inserting part 1 of an endoscope is inserted into a body cavity. The inserting part 1 is controlled by an operating part 2. A connector 3 is connected to an external light source unit 4 in which an illuminating lamp 21 and gas supplying means 22, namely, a gas supplying pump are provided. Light from the illuminating lamp 21 is applied to an illuminating light guide 7, while gas such as air is supplied by the gas supplying means 22 into a gas supplying pipe 24 which is inserted into the endoscope. The gas supplying pipe 24 extends from the connector 3 into the operating part 2 and the inserting part 1, and is open at its end. A control valve 25 is provided in the operating part 2 in such a manner that it protrudes therefrom. The control valve 25 is a conventional one, and therefore no detailed description will be made thereof. However, it should be noted that the control valve 25 is so designed that normally, or until it is manually depressed, the gas supplying pipe 24 is communicated with the atmosphere so that air supplied from the air supplying means 22 is discharged into the atmosphere. However, when the valve 25 is manually depressed, the communication of the gas supplying pipe 25 with the atmosphere is interrupted so that the air from the gas supplying means 22 is delivered into the body cavity through the opening at the end of the gas supplying pipe 25. The manual control valve 25 may be replaced by an electrical switch. The gas supplying means 22 may be such that gas is supplied continuously or the gas supplying operation is automatically controlled.

Further in Fig. 2, a medical tool is inserted into a forceps channel 13. The forceps channel 13 is open at the end face of the inserting part 1, and is communicated through its base end with a forceps inserting port 26 which is formed in the endoscope body below the operating part 2. A conventional forceps plug 26a is engaged with the forceps inserting port 26. That is, when no medical tool is inserted into the forceps channel 13, i.e., the forceps channel 13 is not used, the forceps inserting port 26 is closed with the forceps plug 26a. Near the forceps inserting port 26, a suction tube 31 is connected to the forceps channel 13. The suction tube 31 thus connected to the forceps inserting port 26 is further connected at its other end to external suction means 16. The forceps channel 13 and suction tube 31 form a suction pipe line which opens at the end face of the inserting part 1.The suction means 16 comprises a suction pump 16a, a suction tank 16b which pools things which have been sucked up and an electromagnetic valve 16c. In the embodiment, the suction of the suction means 16 is controlled by operating the electromagnetic valve 16c.

A pressure detector 32 is connected to the suction tube 31 to detect the pressure the suction tube 31, so that the pressure in the body cavity is detected through the suction pipe line (the suction tube 31 and the forceps channel 13). A second gas supplying means 17 for supplying gas into the suction tube 31 is provided near the pressure detector 16. The second gas supplying means 17 is for instance a small gas supplying pump which operates to continuously or intermittently supply a small amount of gas into the suction tube 31. A large gas supply pump may be employed to utilize high pressure to discharge debris out of a body cavity. However, if a large amount of gas is supplied with the large gas supplying pump, then the output of the pressure detector 16 is adversely affected so that it is impossible to detect the pressure in the body cavity with high accuracy.

Accordingly, the amount of gas delivered by the second gas supplying means should be less than a certain value. On the other hand, the amount of gas supplied should be more than a certain value in order to effectively operate the device of the invention. It has been proved through experiments that the value satisfying the two requirements is in a range of 30 to 70 milliliters per minute.

Further in Fig. 2, a pressure setting circuit 18 sets a body cavity pressure which is clinically suitable.

The output terminals of the pressure setting circuit 18 and the pressure detector 32 are connected to the input terminals of a control circuit 19, the output terminal of which is connected to the input terminal of the electromagnetic valve 16c. In the control circuit 19, the pressure in the body cavity is compared with a reference value set by the pressure setting circuit 18. When the pressure in the body cavity is higher than the reference value, the control circuit 19 provides an output signal to open the electromagnetic valve 16c. When the pressure in the body cavity is lower than the reference velue, the control circuit 19 produces an output signal to close the electromagnetic valve 16c. The suction means 16 may be so designed that its operation is effected by the on-off control of the suction pump or continous control of the amount of suction.

The control circuit 19 is shown in detail in Fig. 3. It contains a CPU 19a which receives a digitized pressure signal Px from an analog-to-digital (A/D) converter 19b which converts an analog signal Vx received from the pressure detector 32. The CPU 19a compares the digitized pressure signal Px with the reference pressure value PREF provided by the pressure setting circuit 18 and thereby controls the opening of the electromagnetic valve 16c through an electromagnetic valve driver 19c.

The CPU 19a executes a control program stored in its internal ROM, the flow of which is illustrated in Fig. 4. At the beginning of operation of the pressure control circuit 19, an internal reference value PO is initialized in Step S1 to a value stored in the ROM, for instance, 5mmHg. This internal reference value PO is stored in a RAM internal to the CPU 19a. In Step S2, the digitized detected pressure Px is read from the A/D converter 32 and is compared with the internal reference value PO in Step S3. If the detected pressure Px is greater than the internal reference value PO; then, in Step Sar the CPU 19a outputs a pulse of a predetermined time width Tx to the electromagnetic valve driver 19c.

The effect is to open the electromagnetic valve 16c for this predetermined time Tx. ~ During this time, the suction pump 16b is pumping the internal cavity so this time is the period of absorption. If the detected pressure Px is less than or equal to the internal reference value Po, the electromagnetic valve 16c is not opened. In Step sir it is determined if the internal reference value PO agrees with the externally provided reference pressure Tx supplied from the pressure setting circuit 18. If the two values disagree, the internal reference value PO is reset to the reference pressure Tx from the pressure setting circuit 18.Thereby, the pressure setting circuit 18 can be reset during the operation of the pressure control circuit 19. Thereafter, the loop is repeated with a new reading of the detected pressure Px.

Although the apparatus shown in Fig. 1 is so arranged that the operation of the absorption pump 34 is controlled by the control circuit 33, the control program for the control circuit 33 is the same as that in Fig. 4.

With the body cavity pressure adjusting device thus constructed, normally the pressure in the body cavity is detected by the pressure detector 32. The pressure in the body cavity thus detected is compared with the set pressure value (reference value), and according to the result of the comparison the suction means 16 is controlled thereby -to maintain the pressure in the body cavity constant.

If the suction pipe 31 from the open end of the forceps channel 13 near to the pressure detector 32 is clogged up with debris or the like, then the pressure in the suction pipe 31 is increased with the operation of the second gas supplying means 17. The pressure thus increased is detected by the pressure detector 32. As a result, similarly as in the case where the pressure in a body cavity is increased, the pressure detector 32 applies the detection signal to the control circuit 19, so that the electromagnetic valve 16c is opened and the suction is started. Thus, the debris or the like is automatically sucked out of the suction pipe line.In the case where the part of the suction pipe 31 which is located between the suction means 16 and the connecting point of the pressure detector 32 is clogged up with debris or the like, the pressure adjusting function is performed normally, and therefore when the pressure in the body cavity increases, the suction means is started to automatically remove the debris or the like.

As was described above, with the body cavity pressure adjusting device of the invention, when the suction pipe is clogged up with debris or the like, then the suction means is automatically operated to remove it from the suction pipe line. Therefore, in the case where the endoscope is operated in the body cavity in which mucus, blood and other debris are mixed, the pressure in the body cavity can be maintained at a predetermined value. Therefore, the operator can observe the mucous membrane in detail for correct diagnosis without inflicting pain on the patient.

Claims

1. An endoscope system, comprising: a endoscope having an inserting part for insertion into a body cavity, said inserting part containing at least a first and a second channel communicating with said body cavity; first negative pumping means communicating with said first channel for suctioning said body cavity; first positive pumping means communicating with said second channel for pumping a gas into said body cavity; pressure means communicating through a third channel with said first channel for controllably adjusting a pressure in said body cavity; and a pressure sensor communicating with said third channel, an output of said pressure sensor controlling a pressure of said body cavity.

2. An endoscope system as recited in Claim 1, wherein said pressure means is a second negative pumping means for reducing said pressure in said body cavity automatically controlled by said output of said pressure sensor.

3. An endoscope system as recited in Claim 2, further comprising a light fiber included in said inserting part of said endoscope and a light unit for supplying light to said light fiber, said first positive pumping means and said second negative pumping means being included in said light unit.

4. An endoscope system as recited in Claim 2, wherein said first positive pumping means alternatively supplies a first air flow and water included in said first air flow in a first operational mode or a second air flow in a second operational mode and further comprising a control valve interposed between said first positive pumping means and said second channel for switching said first positive pumping means between said first and second operational modes.

5. An endoscope system as recited in Claim 2, wherein said first channel is a forceps channel into which a medical tool is insertable.

6. An endoscope system as recited in Claim 1, wherein said pressure means is a second positive pumping means for supplying a gas into said second channel and said output of said pressure detector controlling said first negative pumping means.

7. An endoscope system as recited in Claim 6, wherein said second positive pumping means supplies said gas at a rate of 30 to 79 milliliters per minute.

8. An endoscope system as recited in claim 6, wherein said first channel is a forceps channel in which a medical tool is insertable.

9. An endoscope system substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

10 An endoscope system substantially as hereinbefore described with reference to Figures 2, 3 and 4 of the accompanying drawings.