Medical Pump

Abstract

Medical pumps for water jet surgery are known. The invention relates to a pump comprising at least two pistons provided with piston rods for displacing the pistons in cylinders and for coupling to a pump actuation device, a cylinder head for closing the cylinders, and valve means for respectively connecting a pressure chamber in the cylinder to at least one fluid inlet and at least one fluid outlet. Said fluid outlet is connected to the fluid inlet in a communicating manner by means of an adjustable pressure regulating valve, in such a way that the pressure in the fluid outlet can be limited to a predetermined maximum value so that operation of the pump can be.

Description

RELATED U.S. APPLICATIONS[0001]Not applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not applicable.REFERENCE TO MICROFICHE APPENDIX[0003]Not applicable.FIELD OF THE INVENTION[0004]The invention relates to a medical pump, in particular for water jet surgery.BACKGROUND OF THE INVENTION[0005]Water jet surgery has been used for some time in liver surgery as this organ, like no other, has tissue structures of different firmness (parenchyma, blood vessels and bile ducts) and the applied water jet separates the tissue being cut, yet leaves the blood vessels and bile ducts undamaged. Naturally, a precise control of the cutting pressure is required for this.[0006]A further problem of water jet surgery is that the cutting medium must be totally sterile (e.g. Ringer solution) as the liquid comes into contact with body tissue in the closest and most intensive way possible. Ordinary problems such as high reliability, simplicity and economic manufacture must also be...

AI Technical Summary

Benefits of technology

The invention is a medical pump for water jet surgery that improves cutting performance with a simple construction and suitability for single use. It includes two pistons with piston rods for displacing the pistons in the cylinders and for coupling to a pump actuation device. The pump has valve means for connecting the pressure control valve in such a way that the pressure in the fluid outlet can be limited to a predetermined maximum value. The valve means and / or the pressure control valve comprise an elastic or elastically pressurized valve membrane, which enables very economic manufacture and high operational safety. The pressure control valve is preferably constructed as a power driven valve in such a way that the maximum value is adjustable by means of actuating power on a regulator of the pressure control valve. The pistons or pistons rods are securely and sterilely connected via non-slip seals to the cylinders, which prevents germs from entering. The valve devices and / or the pressure control valve are housed in the cylinder head, simplifying the setup. The outlet has fittings for irreversible connection to a pressure hose, preventing faulty installation and non-permissible re-use. An accumulator is provided to smooth fluid pressure fluctuations at the fluid outlet and improve the equipment cutting function. The accumulator is preferably connected to the fluid outlet in a way that smooths out fluid pressure fluctuations due to a low pass function.

Problems solved by technology

A further problem of water jet surgery is that the cutting medium must be totally sterile (e.g. Ringer solution) as the liquid comes into contact with body tissue in the closest and most intensive way possible.

Ordinary problems such as high reliability, simplicity and economic manufacture must also be considered.

The pump efficiency as well as its adjustment, however, are unsatisfactory.

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