Surgery – Endoscope – Having auxiliary channel
Reexamination Certificate
1999-07-02
2001-12-11
Freay, Charles G. (Department: 3746)
Surgery
Endoscope
Having auxiliary channel
C600S158000, C417S044200, C417S028000
Reexamination Certificate
active
06328690
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an air feeding device for an endoscope to feed air into body cavity.
Conventionally, an air feeding device for an endoscope has been known. The air feeding device has an air compressor which compresses the air, and by opening/closing a valve, the air is fed to the human cavity through a tube such as a forceps channel of an endoscope. In such an air feeding device, in order to control the pressure of the air fed therefrom, a pressure control valve is provided. The pressure control valve varies the cross sectional area of a path where the air flows to vary the pressure of the discharged air.
In the air feeding device, the pressure control valve only lowers the pressure of the discharged air. Therefore, in order to control the pressure over a relatively wide range, a large compressor, which is capable of feeding the air at a relatively high pressure, should be provided. Generally, such a compressor should be driven all the time, which generates continuous noise when the endoscope is used for operation. Further, in such a conventional air feeding device, due to a structure of the pressure control valve, it is impossible to feed the air so as to strike an object at a very small pressure, and thus, it is impossible to control the air pressure accurately within a wide range between a very low pressure and a very high pressure.
There has been known a method for detecting hardness of a foreign body in the human cavity by applying air. There has also been known a method for diagnosing organs inside the human cavity by applying air intermittently. In order to use the air feeding device for such diagnosing system, the air feeding device is required to be able to generate a stable and continuous air flow or intermittent air flow, at a relatively low pressure.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved air feeding device which is capable of generating a stable and continuous air flow or intermittent air flow, at a relatively low pressure.
For the above object, according to the present invention, there is provided an air feeding device for an endoscope system, which is provided with: an air compressor that compresses air and feeds the air into a sealed space; a pressure sensor that detects air pressure in the sealed space; a pressure setting device through which a pressure value in the sealed space to be adjusted is set; a pressure controller that turns the compressor ON and OFF in accordance with the air pressure detected by the pressure sensor and the pressure value set by the pressure setting device; and a main valve, an inlet of the main valve being connected to the sealed space, an outlet of the main valve being connected to an outlet of the air feeding device.
Since the air is once compressed in the sealed space, the feeding system does not require a large compressor. Further, the feeding device is capable of adjusting the pressure of the air discharged from the outlet.
Optionally, the pressure controller may include a comparator which compares output of the pressure sensor with a reference value which is determined based on the pressure value set by the pressure setting device, and wherein the pressure controller turns ON or OFF the compressor depending on the comparison result of the comparator.
With this configuration, since the compressor is not continuously operating, the noise can be reduced.
In a particular case, the pressure controller defines first and second reference values based on the pressure value set by the pressure setting device. The first reference value is greater than the pressure value, and the second reference value is less than the pressure value.
Further, the pressure controller includes a comparator, and turns OFF the compressor if the pressure detected by the pressure sensor is increasing and the pressure detected by the pressure sensor reaches the first reference value. Further, the pressure controller turns ON the compressor if the pressure is decreasing and the pressure reaches the second reference value.
With this configuration, a so-called hysteresis characteristic can be achieved, and thus, a hunting phenomenon in turning ON and OFF the compressor can be avoided.
According to another aspect of the invention, there is provided an air feeding device for endoscope system which is provided with: an air compressor that compresses air and feeds the air in a sealed space; an air tank forming part of the sealed space; a pressure sensor that detects air pressure in the sealed space; a pressure setting device through which a pressure value in the sealed space to be adjusted is set; a pressure controlling valve that releases air in the sealed space; a pressure controller that turns ON or OFF the compressor and/or turns ON or OFF the pressure controlling valve in accordance with the air pressure detected by the pressure sensor and the pressure value set by the pressure setting device; an air feeding valve, an inlet of the air feeding valve being connected to the sealed space, an outlet of the air feeding valve being connected to an outlet of the air feeding device.
Optionally, the sealed space may be defined as a space between the compressor and the air feeding valve, the air tank being arranged between the compressor and the air feeding valve, wherein the air feeding device is further provided with tube members for connecting the compressor and the air tank, and for connecting the air tank and the air feeding valve.
Preferably, a volume of the air tank is greater than a volume of the sealed space excluding the volume of the air tank.
Optionally, the air feeding device may be provided with an air filter which is inserted within the sealed space.
In particular case, the pressure controller defines first and second reference values based on the pressure value set by the pressure setting device, the first reference value being greater than the pressure value, the second reference value being less than the pressure value. The pressure controller turns OFF the compressor if the pressure detected by the pressure sensor is greater than the first reference value, and turns ON the compressor if the pressure detected by the pressure sensor is less than the second reference value.
Optionally or alternatively, the pressure controller may control the pressure control valve to open if the pressure detected by the pressure sensor is greater than the first reference value, and may control the pressure control valve to close if the pressure detected by the pressure sensor is less than the second reference value.
According to a further aspect of the invention, there is provided an air feeding device for endoscope system which is provided with an air compressor that compresses air and feed the air in a sealed space; a pressure sensor that detects air pressure in the sealed space; a pressure controller that turns ON and OFF the compressor in accordance with the air pressure detected by the pressure sensor and a predetermined pressure value; and a main valve, an inlet of the main valve being connected to the sealed space, an outlet of the main valve being connected to an outlet of the air feeding device. The air feeding device is further provided with a pressure setting device through which a pressure value in the sealed space to be adjusted is set; and an enter switch that is manually operated to make the pressure value set by the setting device effective. In this case, when the pressure value is set by the pressure setting device and the enter switch is operated, the pressure controller controls the compressor in accordance with the air pressure detected by the pressure sensor and the pressure value set by the pressure setting device.
With this configuration, until the enter switch is operated, the newly set or currently set pressure value will not be made effective, and therefore unnecessary change of the pressure can be avoided. Further, the pressure can be adjusted upon operation of the enter switch, the pressure control operation can be performed effectively.
Acco
Takahashi Noriaki
Takami Satoshi
Yamazaki Kazuhiro
Asahi Kogaku Kogyo Kabushiki Kaisha
Freay Charles G.
Greenblum & Bernstein P.L.C.
Torrente David J.
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