Surgery – Endoscope – Having auxiliary channel
Reexamination Certificate
2001-07-12
2003-05-06
Mulcahy, John (Department: 3739)
Surgery
Endoscope
Having auxiliary channel
C600S159000
Reexamination Certificate
active
06558317
ABSTRACT:
BACKGROUND OF THE INVENTION
This application claims the priority of Japanese Patent Application Nos. 10-89403 and 10-89404 filed on Mar. 17, 1998, Nos. 10-100097, 10-100098 and 10-100099 filed on Mar. 27, 1998 which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an air and water supply system for endoscopes, and more particularly, to an arrangement for flow control of air and water supply through air feed tubes and water feed tubes installed in endoscopes.
2. Description of the Prior Art
Endoscopes are conventionally provided with air feed tubes, water feed tubes, etc. through which air and water (liquid) are supplied to the tip of the endoscope to clean the viewing window (objective lens surfaces) at the tip or remove water-drops from it as well as to inflate a body cavity such as the stomach by the air sent into the body of the subject under observation. After use, endoscopes are cleaned and drained through the water feed tubes before storage.
FIG. 12
shows the configuration of a solenoid valve unit of a conventional endoscope. The water feed tube
2
A and air feed tube
3
A on the endoscope side are connected to the solenoid valve unit
1
. The solenoid valve unit
1
comprises a water feed tube
2
B, solenoid valve Va for controlling the opening and closing of the water feed tube
2
B, air feed tube
3
B, and solenoid valve Vb for controlling the opening and closing of the air feed tube
3
B, wherein the water feed tube
2
B is connected to a feed water tank
4
through a water feed tube
2
C.
The solenoid valve unit
1
also contains an air and water supply pump
5
, which is connected with the air feed tube
3
B and a tube (air feed tube) for water supply
3
C, which in turn is connected to the feed water tank
4
through a tube
3
D. Furthermore the pump
5
is connected with an atmospheric escape pipe
6
, which is equipped with a solenoid valve Vc. The control switch for air/water supply is installed, for example, on the operating section of the endoscope.
In the above configuration, when the air/water supply switch is not actuated, only the solenoid valve Vc remains open and the air sent from the pump
5
is released to the atmosphere through the atmospheric escape pipe
6
. When the air/water supply switch is manipulated to supply water, the solenoid valve Va opens and the solenoid valves Vb and Vc close, allowing water to be supplied from the feed water tank
4
to the endoscope through the water feed tubes
2
C,
2
B, and
2
A. When it is manipulated to supply air, the solenoid valve Vb opens and the solenoid valves Va and Vc close, allowing air to be supplied through the air feed tubes
3
B and
3
A.
BRIEF SUMMARY OF THE INVENTION
Object of the Invention
The conventional air and water supply systems of endoscopes are not able to regulate flow rates (quantities of flow per unit time): they control only the on/off operation of air/water supply. They are not capable of providing optimum air/water (liquid) supply individually according to application. Although the system in
FIG. 12
described above is capable of adjusting the flow rates of air and water by changing the supply air pressure (capacity) of the pump
5
itself, it has a problem that is impossible to control air supply and water supply separately because changing the supply pressure of the pump
5
for air flow control will also change the flow rate of water.
For example, shooting out water at a relatively high flow rate (in the state of a large quantity of water per unit time) produces good results when cleaning the viewing window, whereas for subsequent drying, it is better to inject air at a relatively low flow rate, which will eliminate tiny droplets on the objective lens surfaces. Also, when inflating a body cavity such as the stomach (pneumoperitoneum) to apply an endoscope, it is necessary to feed air, taking into consideration the condition of the patient. Therefore, it is desirable if air and water can be supplied at a proper flow rate to suit the specific purposes of individual procedures. Besides, changing the supply pressure of the pump
5
in
FIG. 12
between air supply and water supply may obstruct procedures because of time lags.
Furthermore, the endoscope is drained through the water feed tube
2
A and air feed tube
3
B after use, but there is a disadvantage that the supply air pressure during draining depends on the capacity of the pump
5
, making optimum draining impossible.
Summary of the Invention
The present invention has been made in view of the above problems. The object of the present invention is to provide an air and water supply system for endoscopes that makes it possible to control air flow and water flow rates independently and supply air and water according to each application.
On the other hand, endoscopes have a flush water inlet port and an injection water inlet port installed on a operating section or the like. That is, the flush water inlet port is connected to the water channel of the endoscope. And water supplied through the flush water inlet port under high pressure with a syringe or the like can remove a high level of contamination from the objective lens surfaces of the viewing window. Also, an injection channel is installed in the endoscope to inject water to the object of observation. It is connected with the injection water inlet port installed on the operating section or the like. A liquid such as physiological saline is supplied through the injection water inlet port with a syringe or the like to remove foreign matters which would obstruct observation or treatment by adhering to objects under observation.
However, high-speed water injection and lens surface flushing, which are carried out by the use of accessories such as a syringe from the flush water inlet port and injection water inlet port installed on the operating section, involve complicated operations. Besides, injection with a syringe requires skill and experience of the physician. Moreover, these operations require a fast and ample flow of water, which conventional pumps cannot provide.
Another object of the present invention is to provide an air and water supply system for endoscopes that will allow high-speed water injection and lens surface flushing to be performed with simple switch operations.
Furthermore, the air and water supply system for endoscopes shown in
FIG. 12
employ flexible tubing made of polyvinyl chloride (PVC) or the like for the water feed pipe
2
A and air feed pipe
3
A which connect the solenoid valve unit
1
with, for example, the light source fitted to the endoscope. And it has a problem that these flexible pipes (
2
A and
3
A) may deform during air or water supply, changing the flow rate and failing to dry the lens surface of the viewing window sufficiently.
That is, the diameters of the water feed pipes
2
and the like used in the endoscope increase with approach to the solenoid valve unit
1
, for example, the channel diameter inside the endoscope being approximately 1 mm, the tube diameter in the cable being approximately 2 mm, and the diameters of the above-mentioned flexible connecting pipes (
2
A and
3
A) being approximately 5 mm. The walls of the flexible pipes are subject to some internal pressure. Thus the flexible pipes (
2
A and
3
A) expand under this pressure during air or water supply, changing the flow rate at the start or end of air or water supply.
Furthermore, after supplying water to the lens surfaces to clean the viewing window, the pressure produced by the expanded connecting pipe
6
C returning to the original shape will cause a small amount of water to leak from the nozzle at the distal end of the endoscope, resulting in poor water removal.
Still another object of the present invention is to provide an air and water supply system for endoscopes that can prevent changes in the flow rate and correct insufficient water removal by suppressing the expansion of the connecting pipes between the endoscope and channel control unit.
To attain the above objects, the present invention is characterized by
Akiba Haruo
Sugikawa Etsuko
Takahashi Kazuaki
Fuji Photo Optical Co., Ltd.
Mulcahy John
Snider Ronald R.
Snider & Associates
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