JPH11332824A - Gas feeding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air feeding apparatus which is provided with a measuring means of a measurable flow rate at a higher accuracy upto a large flow rate. SOLUTION: A shunt branch member 304 which has a branch outlet 306 and a branch inlet 307 of a gas flowing through a pipeline 204 is connected in series in the course thereof 204. The branch outlet 306 and the branch inlet 307 of the shunt branch member 304 are made to communicate by a bypass pipeline 308 equipped with a flowrate sensor 310 in the course thereof. The shunt branch member 304 is provided with a shunt ratio adjusting means 404 which makes variable the distance between the branch outlet 306 and the branch inlet 307 to adjust a shunt ratio of the gas shunted to the bypass pipeline 308 from the pipeline 204.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air supply device for reducing the pressure of a high-pressure gas supplied from a gas cylinder as a gas supply source to a predetermined pressure and sending it to the abdominal cavity.

[0002]

2. Description of the Related Art In recent years, a trocar for guiding an observation endoscope into a body cavity and a trocar for guiding a treatment tool to a treatment site are punctured into the abdomen of a patient without opening the laparotomy to reduce the invasion of the patient. In addition, laparoscopic surgery for performing a therapeutic treatment while observing a treatment tool and a treatment site with an endoscope is performed. In this method, an insufflation device that sends insufflation gas such as carbon dioxide gas into the abdominal cavity is used to secure a visual field of an endoscope and a space area for treatment.

A conventional example of an air supply device will be described with reference to FIG. In a conventional insufflation apparatus, when, for example, carbon dioxide gas (hereinafter also referred to as carbon dioxide gas or CO2 gas) is supplied as gas into the abdominal cavity of a patient, the high-pressure CO2 gas stored in a high-pressure cylinder is removed from the apparatus. This was achieved by controlling the manifold valve through ON / OFF control through a primary pressure reducer and a secondary pressure reducer.

[0004] As shown in FIG.
2 A CO2 cylinder (referred to as a gas cylinder) 202 as a gas supply source is connected via a high-pressure hose 203.
The high-pressure carbon dioxide gas sent from the gas cylinder 202
The input is made to a main conduit 204 that passes through the insufflation device main body. In the main pipeline 204, from the upstream side,
In order, the pressure of the CO2 gas in the gas cylinder 202 is reduced to about 1 /
A primary decompressor 205 for reducing the pressure to 20, a closing valve 206,
A secondary pressure reducer 207 for further reducing the pressure of CO2 gas to about 1/30, a flow sensor 208 for monitoring the amount of CO2 gas sent into the abdominal cavity, and a solenoid valve manifold 209 are inserted in series.

[0005] A cylinder pressure sensor 211 for monitoring the pressure value of CO2 gas sent from the CO2 cylinder 202 is provided in the main pipe 204 on the input side to which the high-pressure hose 203 is connected. The solenoid valve manifold 209 is provided with an abdominal cavity pressure sensor 212 for monitoring the pressure in the abdominal cavity. This abdominal cavity pressure sensor 212
And the cylinder pressure sensor 211 and the flow rate sensor 208
Is electrically connected to a control circuit 213, and the shut-off valve 206 and the solenoid valve manifold 209 are connected to the drive circuit 2.
14, and is electrically connected to the control circuit 213. The drive circuit 214 is connected to a pinch valve 215 for controlling a smoke exhaust function. This pinch valve 2
The suction tube 216 and the exhaust tube 217 are connected to 15, and the foot switch 218 electrically connected to the control circuit 213 can exhaust the smoke filled in the abdominal cavity during the operation.

[0006] A power supply power supply cord 219 connected to a medical outlet in the facility extends from the air supply device 201, and is connected to a power supply 222 via a power switch 221. Then, power is supplied from the power supply unit 222 to the control circuit 213 and the drive circuit 214.

A panel display switch input 223 provided with an input unit and a display unit comprising a panel is provided on the front surface of the main body of the air supply device 201, and is set via the input unit of the panel display switch input 223. The various setting values to be performed are input to the control circuit via the panel controller 224.

The panel display switch input 223
The control circuit 213 and the panel controller 224
The power is supplied via the. Reference numeral 225 denotes a system connector used when the air supply device 201 is controlled by, for example, an external controller (not shown).

The air supply device 20 configured as described above
1 will be described. First, before operation, trocar 220,
The air supply tube 210, the foot switch 218 for exhausting smoke as required, the suction tube 216, and the exhaust tube 217 are prepared in a predetermined state.

Next, the power switch 22 of the air supply device 201
Operate 1 to turn on the power. Then, the control circuit 213
Operates to set the air supply device 201 to the initial state. In this initial state, the closing valve 206 is closed, so that the high-pressure CO2 gas supplied from the gas cylinder 202
Next, in the state where the pressure is reduced by the
Closed at the stage before 6.

Next, the output setting suitable for the surgical procedure is set by the panel display switch input 223, the setting of the air supply start is performed, and the air supply switch (not shown) provided on the panel display switch input 223 is operated. To the “ON state”. Then, the closing valve 206 is opened, and the CO2 gas flows into the main pipeline 204 after the secondary decompressor 207. Then, the CO2 gas whose flow rate and pressure are controlled with high precision is sent to the air supply tube 210 connected to the air supply device 201, and sent into the abdominal cavity through the trocar 220 punctured in the abdominal cavity. Go. At this time, the amount of CO2 gas supplied from the air supply device 201 into the abdominal cavity was about 20 liters per minute.

In recent years, an insufflation device capable of quickly injecting a desired amount of CO 2 gas into the abdominal cavity during surgery has been desired.
There has been a demand for a high flow rate air supply device capable of continuously supplying air at 40 liters per minute.

[0013]

As described above, 40 minutes per minute
In order to be able to send gas at a high flow rate higher than the liter, flow rate measuring means corresponding to the high flow rate is required.
However, a flow sensor capable of measuring a range of about 40 liters per minute is generally expensive, and a method of directly measuring the flow rate of the main pipe by inserting the flow sensor in series with the main pipe as described above. However, when the air supply device is configured to be able to supply gas at a high flow rate, there is a problem that the cost of the entire device increases.

On the other hand, German Patent DE 423384 describes
No. 9 and Japanese Patent Application Laid-Open No. 5-207970, an orifice is provided in the main pipe as means for measuring the flow rate of gas flowing through the main pipe, and a differential pressure at both ends thereof is measured. A method of calculating and calculating the flow rate of the main pipeline from the pressure is used.

According to such a method of calculating the flow rate from the differential pressure, the pressure sensor for measuring the differential pressure is inexpensive and the cost can be reduced. However, when calculating the flow rate from the differential pressure, the flow rate is proportional to the square root of the differential pressure, so that the calculation formula is complicated, and there is a problem that a large load is applied to the control software.

According to such a method of obtaining a flow rate from a differential pressure, when a measurement error of the differential pressure is converted into a flow rate from the characteristic of the square root, the flow rate error is proportional to the square of the differential pressure error. There is also a problem that an error in a low flow rate region becomes large.

In addition, as another method for obtaining the flow rate of the gas flowing through the main pipe of the air supply device, the flow of the gas in the main pipe is divided and the flow rate on the branch side is measured. There is known a method of calculating the entire flow rate by calculation.

However, in this type of flow rate measurement, the flow rate on the branch side (hereinafter referred to as the flow ratio) with respect to the flow rate of the main pipeline changes depending on the shape of the portion where the branch flow is taken out. There was a problem that it led to the deterioration of.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an air supply device having a flow rate measuring means capable of measuring a large flow rate with high accuracy.

[0020]

In order to solve the above problems, an air supply device according to the present invention is a gas supply device for injecting a gas such as carbon dioxide gas into a body cavity of a living body. And a branching branch member having a branch outlet and a branch inlet for the gas flowing through the main pipeline, which are connected in series in the middle of the main pipeline, and the branch outlet and the branch inlet communicate with each other. A bypass pipe for bypassing a part of the gas flowing through the main pipe at a predetermined split ratio, a flow sensor connected in series with the bypass pipe and measuring a flow rate of the gas in the bypass pipe; Calculating means for deriving the flow rate of the gas in the main pipeline based on the split flow ratio of the gas flow rate in the bypass pipeline measured by the flow rate sensor,
And a flow dividing ratio adjusting means for changing a ratio of a flow rate of gas diverted from the main pipe to the bypass pipe.

That is, by adjusting the gas flow ratio from the main line to the bypass line by the flow ratio adjusting means, the accuracy of the gas flow rate of the main line guided by the calculating means is improved.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 relate to a first embodiment of the present invention, FIG. 1 is an explanatory diagram showing a configuration of an air supply device,
FIG. 2 is an explanatory view showing the configuration of the flow rate measuring means, FIG. 3 is an exploded perspective view showing the appearance of the branching member, and FIG. 4 is a sectional view of the branching member.

As shown in FIG. 1, the air supply device 301 has C
A CO2 cylinder (referred to as a gas cylinder) 202 as a supply source of O2 gas is connected via a high-pressure hose 203. The high-pressure carbon dioxide gas sent from the gas cylinder 202 is input to a pipe 204 (hereinafter, also referred to as a main pipe) passing through the insufflation apparatus main body. The C in the gas cylinder 202 is sequentially connected to the pipeline 204 from the upstream side.
Primary decompressor 20 for reducing the pressure of O2 gas to about 1/20
5. The closing valve 206 further reduces the pressure of the CO2 gas by about 1 /
A secondary decompressor 207 for reducing the pressure to 30, a flow rate measuring means 302 for monitoring the amount of CO2 gas supplied into the abdominal cavity, and a solenoid valve manifold 209 are inserted in series.

A cylinder pressure sensor 2 for monitoring the pressure value of the CO 2 gas sent from the CO 2 cylinder 202 is provided on the input side pipeline 204 to which the high-pressure hose 203 is connected.
11 are provided. The solenoid valve manifold 209 has an abdominal cavity pressure sensor 2 for monitoring the pressure in the abdominal cavity.
12 are provided. The abdominal cavity pressure sensor 212, the cylinder pressure sensor 211, and the flow rate measuring means 302 are electrically connected to a control circuit 213, and the closing valve 206 and the solenoid valve manifold 209 are connected to the driving circuit 21.
4, and is electrically connected to the control circuit 213. The drive circuit 214 is connected to a pinch valve 215 for controlling a smoke exhaust function. This pinch valve 21
A suction tube 216 and an exhaust tube 217 are connected to 5. A foot switch 218 electrically connected to the control circuit 213 can exhaust the smoke filled in the abdominal cavity during the operation.

A power supply power supply cord 219 connected to a medical outlet in the facility extends from the air supply device 301, and is connected to a power supply 222 via a power switch 221. Then, power is supplied from the power supply unit 222 to the control circuit 213 and the drive circuit 214.

A panel display switch input 223 having an input unit and a display unit comprising a panel is provided on the front of the main body of the air supply device 301, and is set via the input unit of the panel display switch input 223. The various setting values to be performed are input to the control circuit via the panel controller 224.

The panel display switch input 223
The control circuit 213 and the panel controller 224
The power is supplied via the. Reference numeral 225 denotes a system connector used when the air supply device 201 is controlled by, for example, an external controller (not shown). Reference numeral 210 denotes an air supply tube, and reference numeral 220 denotes a trocar, which are prepared in a predetermined state before the operation.

The above-mentioned air supply device 301 is, for example, 40
The CO2 gas can be supplied at a flow rate higher than the liter, and the flow rate measuring means 302 can measure a flow rate of 40 liters or more per minute.

In the air supply device, the control circuit 21
In 3, the closing valve 206 and the solenoid valve manifold 20 are determined based on the flow rate data measured by the flow rate measuring means 302 and the pressure data measured by the abdominal cavity pressure sensor.
9 to automatically control the pressure in the abdominal cavity and the air supply flow rate.

Next, the flow rate measuring means 302 capable of measuring in a high range will be described in detail with reference to FIGS. As shown in FIG.
A branching branch member having a branch outlet 306 inserted in the middle of the pipe 204 and branching a part of the gas flowing through the pipe 204, and a branch inlet 307 returning a part of the branched gas to the pipe 204. 304, a bypass line 308 that communicates with the branch outlet 306 and the branch inlet 307 to bypass the line 204, and is connected in series with the bypass line 308 to reduce the flow rate of gas in the bypass line 308. And a flow sensor 310 for measuring.

The branching member 304 is formed by connecting a first branching member 401 having the branching outlet 306 and a second branching member 402 having the branching inlet 307 to each other.

The first branch member 401 is formed of a cylindrical member (see FIG. 3).
The branch outlet 30 is provided in a through hole 305a as a conduit of
6 are open (see FIG. 4).

One end of the first branching member 401 is formed in a tapered shape, and is configured as a connecting portion 403 that can be connected to the upstream side of the pipeline 204.

An external thread 404a is threaded on the outer periphery of the other end of the first branch member 401.

The second branch member 402 is formed of a cylindrical member (see FIG. 3).
In the through hole 305b as a pipeline of the branch inlet 30
7 is opened (see FIG. 4). Here, the through hole 305b is formed to have the same diameter as the through hole 305a.

The inner circumference of one end of the second branch member 402 has a female screw 4 screwed with the male screw 404a.
04b is threaded. Here, the male screw 404a
And the female screw 404b are configured as a flow dividing ratio adjusting unit 404 that changes the ratio of the flow rate of the gas flowing into the bypass pipe 308.

The other end of the second branch member 402 is formed in a tapered shape, and is configured as a connection portion 405 that can be connected to the downstream side of the pipe 204.

The first branch member 401 and the second branch member 402 have through holes 305a and 305b.
May be any material as long as it is not deformed by a pressure of about 100 mmHg, and is made of, for example, metal such as stainless steel or resin such as plastic.

The first branch member 401 and the second branch member 402 are connected to each other as a branching branch member 304 by screwing a male screw 404a and a female screw 404b. The through hole 3
A pipeline (hereinafter, also referred to as a main pipeline) 305 is formed by 05a and the through hole 305b (see FIG. 4).

The branching member 304 is connected in series in the middle of the pipe 204 (see FIG. 2), and the upstream and downstream sides of the pipe 204 communicate with each other by the pipe 305 of the branching member 304. Have been. That is, the connection portion 4
03 is connected to the upstream side of the pipeline 204, and the connection portion 405 is connected to the downstream side of the pipeline 204.

The branch outlet 306 and the branch inlet 307 of the branch member 304 are connected to the flow sensor 310 in the middle.
Are connected by a connected bypass pipeline 308. That is, the branch outlet 306 and the upstream side of the flow sensor 310 are connected by the bypass pipe 308a, and the downstream side of the flow sensor 310 and the branch inlet 307 are connected by the bypass pipe 308b.

Further, the flow sensor 310 is electrically connected to the control circuit 213 having a function as a calculating means.

Here, as the flow sensor 310, for example, a sensor having a small flow rate range of 1 liter per minute is used. In this case, the bypass line 30
8 is set to 1: 100, the flow rate of the gas flowing through the main conduit 204 is set to 1: 100.
From the relationship between the measured value by 10 and the flow ratio, the flow rate measuring means 302 can measure the flow rate up to 100 liters per minute.

In the flow rate measuring means 302 having the above-described structure, the ratio of the gas divided into the main line 305 and the bypass line 308 by the branching member 304 is determined by the diameter of the main line 305, the branch outlet 306, and the branch. Entrance 30
7 has a fixed diameter, and varies depending on the relative distance D between the branch outlet 306 and the branch inlet 307 (see FIG. 4).

That is, when the distance D is long, the main pipeline 30
Since the flow path resistance of No. 5 increases, the flow rate on the branch side increases. Conversely, when the distance D is short, the flow resistance of the main conduit 305 is small, so that the flow rate on the branch side is small.

The flow rate measuring means 3 utilizing the above characteristics will be described below.
A method of correcting the initial error 02 will be described.

The tube 21 is connected to the gas outlet of the air supply device 301.
0 is connected, and a reference flow meter (not shown) is connected to supply carbon dioxide gas. The branch members 401 and 402 are set so that the relationship between the flow meter reading and the output of the flow sensor 310, which is the reference at this time, is a preset relationship.
Are rotated relative to each other to adjust the distance D.

As described above, the flow rate measuring means 302 applied to the air supply device 301 is
The shunt ratio can be easily adjusted. This makes it possible to prevent the accuracy from being deteriorated due to the offset error of the flow rate sensor 310, the variation in the pipe diameter, and the like, so that the flow rate measuring means 302 can perform the measurement with high accuracy.

Since the flow sensor 310 used for the flow measuring means 302 is of a low flow type and is inexpensive, the cost of the entire apparatus can be kept low.

Further, by greatly changing the flow division ratio by the flow branching member 304, the flow measurement range can be changed using a flow sensor of one measurement range. Therefore, when models of flow rate measuring means having different maximum flow rates are assumed, there is also an effect that a pipe configuration including the flow rate sensor 310 can be shared.

Next, FIGS. 5 and 6 relate to a second embodiment of the present invention. FIG. 5 is an exploded perspective view showing the appearance of the branching member, and FIG. 6 is a sectional view of the branching member. . The air supply device according to the present embodiment is different from the above-described first embodiment in the configuration of the branching member. In addition, the same components are denoted by the same reference numerals, and description thereof is omitted.

The branching member 407 according to this embodiment
A first branch member 501 having a branch outlet 306;
A second branch member 502 having a branch inlet 307 is connected to each other.

The first branch member 501 is formed of a cylindrical member (see FIG. 5).
The branch outlet 30 is provided in a through hole 305a as a conduit of
6 is opened (see FIG. 6).

One end of the first branch member 501 is formed in a tapered shape, and is configured as a connection portion 403 that can be connected to the upstream side of the pipeline 204.

A plurality of circumferential grooves 503 having a semicircular cross section are provided around the outer periphery of the other end of the first branch member 501 at predetermined intervals.

The second branch member 502 is formed of a cylindrical member (see FIG. 5).
A branch inlet 307 is opened in the through hole 305b as a conduit (see FIG. 6). Here, the through hole 30
5b has the same diameter as the through hole 305a.

A circumferential groove 50 having a shape corresponding to the circumferential groove 503 is formed on the inner circumference at one end of the second branch member 502.
4 are provided around. Here, the peripheral groove 504 can be engaged with any one of the peripheral grooves 503 via an O-ring 505, and these peripheral grooves 503, 504 and the O-ring 505 are connected to the bypass conduit. It is configured as a split ratio adjusting means 506 for changing the ratio of the flow rate of the split gas.

The other end of the second branch member 502 is formed in a tapered shape, and is formed as a connection portion 405 that can be connected to the downstream side of the pipe 204.

The first branch member 501 and the second branch member 502 have through holes 305a and 305b.
May be any material as long as it is not deformed by a pressure of about 100 mmHG, and is made of, for example, metal such as stainless steel or resin such as plastic.

The first branch member 501 and the second branch member 502 are separated from each other by the peripheral groove 504 and one of the peripheral grooves 503 being engaged via an O-ring 505. The branching member 407 is connected to the conduit (hereinafter, also referred to as a main conduit) 30 by the through hole 305a and the through hole 305b.
5 are formed (see FIG. 6).

At this time, the O-ring 505 serves as a seal against a gas leak at a connecting portion between the first branch member 501 and the second branch member 502 and a position for relative positioning of these two members. The role will be shared.

In the flow rate measuring means 302 having the above-described configuration, the ratio of the gas divided into the main pipe 305 and the bypass pipe 308 by the splitting / branching member 407 is determined by the pipe diameter of the main pipe 305, the branch outlet 306, and the branch. Entrance 30
7 has a fixed diameter, and varies depending on the relative distance D between the branch outlet 306 and the branch inlet 307 (see FIG. 6).

In the branching member 407, the branching member 5
01 of the peripheral grooves 503 provided in the O-ring 5
05, the branch outlet 306 and the branch inlet 3
07 changes. Therefore, each circumferential groove 50
If the flow division ratio when using No. 3 is measured, the flow division ratio can be adjusted by changing the circumferential groove 503 to be used. Therefore, also in such an embodiment, substantially the same effects as in the first embodiment can be obtained.

Next, FIGS. 7 and 8 relate to a third embodiment of the present invention, and FIG. 7 is a perspective view showing an appearance of a branching member, and FIG. 8 is a sectional view of the branching member. The air supply device according to the present embodiment is different from the above-described first embodiment in the configuration of the branching member. In addition, the same components are denoted by the same reference numerals, and description thereof is omitted.

The branching member 601 according to this embodiment
Is formed of a cylindrical member (see FIG. 7), and a through hole of the branching member 601 is formed as a pipe (hereinafter, also referred to as a main pipe) 606 (see FIG. 8).

Both ends of the branching member 601 are formed in a tapered shape, and are configured as connecting portions 403 and 405 which can be connected to the upstream side and the downstream side of the pipeline 204, respectively.

The connecting portion 4 of the branching member 601
A screw hole 603 communicating with the pipe 606 is formed on the downstream side of the pipe 03.

The screw hole 603 has a screw hole 6 around its outer periphery.
A cylindrical branching member 602 having a screw portion corresponding to 03 is screwed.

A flexible tube 604 is connected to an end of the branch member 602 on the side facing the conduit 606. The flexible tube 604 is in contact with the wall of the conduit 606 inside the conduit 606 and is bent downstream. The flexible tube 604 is made of a material such as silicon.

Further, a branch inlet 605 is provided downstream of the screw hole 603 of the branching branch member 601.

Here, in this embodiment, the branch member 602 to which the flexible tube 604 is connected and the branch inlet 605 are connected by a bypass conduit 308 having a flow sensor 310 in the middle. I have.

In the branching member 601, the main conduit 60
6 to the bypass line 308 is determined by the distance D between the distal end of the flexible tube 604 and the branch inlet 605.
Varies by.

Therefore, in this embodiment, the amount of screwing of the branch member 602 into the screw hole 603 is changed to change the position of the distal end of the flexible tube 604 in the conduit 606 in the thrust direction. The split ratio can be adjusted, and substantially the same effects as in the first embodiment can be obtained.

Next, FIG. 9 is a sectional view of a main part of a branching member according to a fourth embodiment of the present invention. The air supply device according to the present embodiment is different from the above-described first embodiment in the configuration of the branching member. In addition, the same components are denoted by the same reference numerals, and description thereof is omitted.

The branching member 70 in this embodiment
1 is constituted by a cylindrical member,
One through hole is configured as a pipeline (hereinafter, also referred to as a main pipeline) 707.

The branch outlet 306 and the branch inlet 307 are opened at predetermined intervals from each other in the branching member 701.

The branch outlet 306 and the branch inlet 30
7 is provided with a membrane 704 made of rubber or the like and filled with a magnetic fluid. Further, electrodes 703 and 703 are provided at an upstream position and a downstream position of the membrane 704, respectively.

A power supply 705 is connected to the electrodes 703 and 703 via a variable resistor 706.

In the branching member 701, the electrode 7
03, 703, and the voltage value is changed by the variable resistor 706, whereby the membrane 704 is changed.
Is deformed. As a result, the cross-sectional area of the main conduit 707 between the branch outlet 306 and the branch inlet 307 changes, and the flow resistance of the main conduit 707 changes.

As a result, the branch ratio can be changed, and substantially the same effects as those of the first embodiment can be obtained.

Next, FIG. 10 is a sectional view of a main part of a branching member according to a fifth embodiment of the present invention. In addition,
The air supply device according to the present embodiment is different from the first embodiment in the configuration of the branching member. In addition, the same components are denoted by the same reference numerals, and description thereof is omitted.

The branching member 71 in this embodiment
Reference numeral 0 denotes a cylindrical member,
The 0 through-hole is configured as a pipeline (hereinafter, also referred to as a main pipeline) 714.

The branch outlet 306 and the branch inlet 307 are opened at a predetermined interval from each other in the branching branch member 710.

The branch outlet 306 and the branch inlet 30
7 is provided with a screw hole 7 communicating with the outside.
13 are drilled.

The main conduit 714 has a rubber film 711 for closing the screw hole 713 inside the main conduit 714.
Is provided.

The screw hole 713 has a screw 712
Is screwed.

In the branching member 710, the screw 712
Is changed, the shape of the rubber film 711 in the main pipeline 714 is changed. As a result, the cross-sectional area of the main pipe 714 between the branch outlet 306 and the branch inlet 307 changes, and the flow resistance of the main pipe 714 changes.

As a result, the branch ratio can be changed, and substantially the same effects as in the first embodiment can be obtained.

Next, FIG. 11 is a sectional view of a main part of a branching member according to a sixth embodiment of the present invention. In addition,
The air supply device according to the present embodiment is different from the first embodiment in the configuration of the branching member. In addition, the same components are denoted by the same reference numerals, and description thereof is omitted.

The branching member 72 in this embodiment
0 is constituted by a cylindrical member,
The through-hole 0 is configured as a pipeline (hereinafter, also referred to as a main pipeline) 724.

The branch outlet 720 has a branch outlet 306 and a branch inlet 307 which are open at predetermined intervals.

The branch outlet 306 and the branch inlet 30
7 is provided with a through-hole 7 communicating with the outside.
23 are drilled.

The main conduit 724 is provided with a rubber film 721 for closing the through hole 723 inside the main conduit 724.
Is provided.

The through-hole 723 has a pressure source 72
2 are connected.

The branching member 720 includes a pressure source 72
The shape of the rubber film 721 in the main conduit 724 is changed by changing the pressure on the rubber film 721 by the pressure change 2. Thereby, the branch outlet 306 and the branch inlet 307 are formed.
Between the main line 724 and the main line 72
The flow path resistance of No. 4 changes.

As a result, the branch ratio can be changed, and substantially the same effects as those of the first embodiment can be obtained.

Incidentally, a differential pressure sensor is used in the air supply device disclosed in Japanese Patent Application Laid-Open No. Hei 5-207970.
A method for measuring flow is shown, but in this method,
When the differential pressure sensor breaks down, there is no means for detecting the abdominal cavity pressure, which may be dangerous to the patient. In addition, since an orifice for measuring the flow rate needs to be provided, there is a problem that the cost increases.

FIG. 12 is an explanatory view showing the structure of an air supply device according to the seventh embodiment of the present invention. In the above-described embodiments, the flow rate of the gas flowing through the main pipeline is obtained from the flow rate of the gas diverted from the main pipeline. The difference is that the flow rate is determined based on the flow rate. In addition, the same components are denoted by the same reference numerals, and description thereof is omitted.

In the middle of the pipe 204 of the air supply device 801, the primary pressure reducer 205 and the secondary pressure reducer 2
07, a first solenoid valve 802, and a second solenoid valve 803 are connected in series.

Further, a branch pipe 804 is provided in the pipe 204 downstream of the first solenoid valve 802 and upstream of the second solenoid valve 803. Is connected to a first pressure sensor 805 for measuring the line pressure of the line 204.

A branch pipe 806 is provided downstream of the second solenoid valve 803 in the pipe 204, and the pressure of the pipe 204 is measured in the branch pipe 806. The second pressure sensor 807 is connected.

The first and second solenoid valves 802 and 803
Are electrically connected to a control circuit 213 via a drive circuit 214, and are connected to the first and second pressure sensors 805 and 805.
Reference numeral 806 is electrically connected to the control circuit 213.

Next, a method of controlling the abdominal cavity pressure by the air supply device 801 having the above configuration will be described. When the first and second solenoid valves 802 and 803 are released, gas from the gas cylinder 202 flows through the pipeline 204, and the air supply is started.

At this time, the first pressure sensor 805 measures the pipeline pressure P1, and the second pressure sensor 807 measures the pipeline pressure P2. Here, the pipeline pressure P2 is lower than P1 because the pressure is reduced by the pipeline resistance of the second solenoid valve 803.

The first and second pressure sensors 805 and 80
The pipeline pressures P1 and P2 measured at step 7 are input to a control circuit 213, which controls the pipeline pressures P1 and P2.
The difference between the two is calculated as the differential pressure ΔP between both ends of the second solenoid valve 803 in the pipeline 204.

Next, the control circuit 213 determines the flow rate of the gas flowing through the pipeline 204 based on the differential pressure ΔP.
Here, at both ends of the solenoid valve 803, the pipeline 204
Is proportional to the square root of the differential pressure ΔP at both ends of the solenoid valve 803, and can be obtained by multiplying the square root of the differential pressure ΔP by a constant measured in advance.

When measuring the abdominal cavity pressure, when the air supply is stopped, that is, when the first solenoid valve 802 is closed and the second solenoid valve 803 is opened, the first and the second solenoid valves are opened. The pipeline pressures P1 and P2 by the pressure sensors 805 and 806 are read. When the air supply by the pipeline 204 is stopped, the values of the two pipeline pressures P1 and P2 usually indicate the same value. However, when one of the two fails, the two values are different. Can be determined to be a failure.

The above operation is performed by a microcomputer (not shown) equipped with software in the control circuit 213.
Is controlled by

According to such an air supply device 801, the flow rate can be measured only by the pressure sensor without using the flow rate sensor, so that the cost can be greatly reduced.

Further, since two pressure sensors are used instead of the differential pressure sensor for measuring the flow rate, the failure of one of the sensors can be detected, and the safety is improved.

[Appendix] According to the above-described embodiment of the present invention, the following configuration can be obtained.

(1) In an air supply device for injecting a gas such as carbon dioxide into a body cavity of a living body, a main pipe for introducing a gas from a supply source to the body cavity is connected in series with the main pipe. A branching member having a main pipe and a branch outlet and a branch inlet for the gas flowing through the main pipe, and a part of the gas flowing through the main pipe communicating with the branch outlet and the branch inlet at a predetermined split ratio. A bypass line to be bypassed, a flow sensor connected in series with the bypass line to measure a flow rate of gas in the bypass line, and a bypass line measured by the flow ratio sensor and a split ratio of the bypassed gas. Calculating means for deriving the gas flow rate in the main pipeline based on the gas flow rate;
An air supply device, comprising: a flow dividing ratio adjusting unit that changes a ratio of a flow rate of gas diverted from the main pipe to the bypass pipe.

(2) The air supply device according to appendix 1, wherein the flow dividing ratio adjusting means is configured to change a length of a main pipeline between the branch outlet and the branch inlet.

(3) The branching member is divided into a first branching member having the branching outlet and a second branching member having the branching inlet.
And the first branch member and the second branch member are screwed together and connected to each other.
3. The air supply device according to claim 2, wherein the length of the main conduit between the branch outlet and the branch inlet is made variable by the amount of screwing between the branch member and the second branch member.

(4) The branching member is divided into a first branch member having the branch outlet and a second branch member having the branch inlet.
A plurality of peripheral grooves are provided at predetermined intervals on the downstream outer periphery of the first branch member, and a peripheral groove is provided on the upstream inner periphery of the second branch member. By connecting any one of the peripheral grooves of the branch member to the peripheral groove of the second branch member via an O-ring, the length of the main conduit between the branch outlet and the branch inlet can be reduced. The air supply device according to claim 2, wherein the air supply device is variable.

(5) At least one of the branch outlet and the branch inlet has a screw hole communicating the outer periphery of the branching member and the main conduit, and a screw portion corresponding to the screw hole on the outer periphery. A cylindrical branch member screwed into the screw hole, and connected to an end of the branch member facing the main pipeline, abutted against a wall surface of the main pipeline inside the main pipeline and bent. The branch outlet and the branch by changing the screw-in amount of the branch member to move the distal end of the flexible tube in the thrust direction in the main pipeline. The air supply device according to claim 2, wherein the length of the main conduit between the inlet and the inlet is variable.

(6) The air supply device according to appendix 1, wherein the flow dividing ratio adjusting means is configured to change a flow path resistance of a main conduit between the branch outlet and the branch inlet.

(7) The air supply device according to appendix 1, wherein the flow dividing ratio adjusting means is configured to change a cross-sectional area of a main pipeline between the branch outlet and the branch inlet.

(8) In an air supply device for injecting a gas such as carbon dioxide into a body cavity of a living body, a pipe for introducing a gas from a supply source into the body cavity is connected in series with the pipe. At least one conduit opening / closing unit, and conduit pressure measuring means connected to at least both ends of the upstream and downstream sides of the conduit opening / closing unit via branch conduits to measure the conduit pressure of the conduit, Wherein the flow rate of the gas flowing through the pipeline is measured from the pressure difference between the pipeline pressures measured by the two pipeline pressure measuring means.

[0120]

As described above, according to the present invention,
It is possible to provide an air supply device provided with a flow rate measuring means capable of measuring a large flow rate with high accuracy.

[Brief description of the drawings]

FIGS. 1 to 4 relate to a first embodiment of the present invention, and FIG. 1 is an explanatory diagram showing a configuration of an air supply device.

FIG. 2 is an explanatory diagram showing a configuration of a flow rate measuring unit.

FIG. 3 is an exploded perspective view showing the appearance of a branching member;

FIG. 4 is a sectional view of a branching member;

FIGS. 5 and 6 relate to a second embodiment of the present invention, and FIG. 5 is an exploded perspective view showing the appearance of a branching member;

FIG. 6 is a sectional view of a branching member;

7 and 8 relate to a third embodiment of the present invention, and FIG. 7 is a perspective view showing the appearance of a branching member;

FIG. 8 is a cross-sectional view of a branching member;

FIG. 9 relates to a fourth embodiment of the present invention, and is a sectional view of a main part of a branching member;

FIG. 10 relates to a fifth embodiment of the present invention, and is a sectional view of a main part of a branching member;

FIG. 11 relates to a sixth embodiment of the present invention, and is a sectional view of a main part of a branching member;

FIG. 12 relates to a seventh embodiment of the present invention, and is an explanatory diagram showing a configuration of an air supply device,

FIG. 13 is an explanatory diagram showing a configuration of a conventional air supply device,

[Explanation of symbols]

 201 ... air supply device 204 ... pipe (main pipe) 213 ... control circuit (calculation means) 301 ... air supply device 304 ... branching branch member 306 ... branch outlet 307 ... branch inlet 308 ... bypass line 310 ... flow sensor 404 ... Dividing ratio adjusting means 407 ... Dividing branch member 506 ... Dividing ratio adjusting means 601 ... Dividing branch member 701 ... Dividing branch member 710 ... Dividing branch member 720 ... Dividing branch member

Claims (1)

[Claims] An insufflation apparatus for injecting a gas such as carbon dioxide into a body cavity of a living body, comprising: a main pipe for introducing a gas from a supply source to the body cavity; A branching member having a branch outlet and a branch inlet for a gas flowing through the main pipeline; and a bypass pipe communicating with the branch outlet and the branch inlet to bypass a part of the gas flowing through the main pipeline at a predetermined branch ratio. And a flow sensor connected in series to the bypass line and measuring a flow rate of gas in the bypass line; and a flow ratio of the bypass line gas measured by the flow ratio sensor and a flow dividing ratio of the bypassed gas. Calculating means for guiding the flow rate of the gas in the main pipe based on the following, and split flow rate adjusting means for changing the ratio of the flow rate of the gas split from the main pipe to the bypass pipe. apparatus.