Waterjet is a cold cutting device that uses high-pressure water jets. It was first applied to the industrial field for cutting metal plates, ore, etc., and it was not really used in clinical operations until 1990. The pressure of the medical water knife is much lower than that of the industrial water knife, but its working principle is similar to that of the industrial water knife. It uses a high-pressure pump to pump out sterile saline, passes through the catheter to the operating handle, and sprays out through the small nozzle on the handle. Local high pressure is used to cut human tissues.
The biggest feature of the medical water knife is that it selectively cuts and finely separates the tissue structures of different strength and toughness, so that the specific tissue can be protected to the greatest extent, and it has the advantages of clear vision and less bleeding. At the same time, because the water knife is not Generate heat, and will not cause heat damage to surrounding tissues caused by other surgical instruments such as high-frequency electrosurgical knife, laser, ultrasonic knife, etc. In recent years, medical water knives rely on their unique advantages and are widely used internationally in clinical specialties such as hepatobiliary surgery, neurosurgery, rectal surgery, otolaryngology, head and neck surgery, and laparoscopic surgery.
The German company has disclosed a medical waterjet with complex structure, low pressure accuracy, high production cost and high cost of disposable consumables. The Institute of Medical Equipment of the Academy of Military Medical Sciences of the Chinese People’s Liberation Army developed the first domestic prototype in 2009. The prototype uses a hydraulic pump as a pressure source and uses a variety of spray guns to achieve waterjet cutting of tissues under high pressure and low pressure. It is often used for wound cleaning, but the prototype is large in size and heavier; there are many hydraulic pipelines and many valves, which are not conducive to sealing; the waterjet spray gun uses a medical cleaning spray gun, which is not ideal for high-pressure tissue cutting. In 2010, the second-generation prototype was developed. The development of the prototype realized the miniaturization and light weight of the water jet, and adopted a new type of medical pump to meet the requirements for cutting tissue at high pressure and cleaning wounds at low pressure. , But its medical pump uses a reciprocating plunger pump driven by a lead screw. When the two plungers change direction, pressure fluctuations will occur, and the design of the disengagement mechanism is unreasonable, which cannot meet the disposable and aseptic requirements of medical pumps. Require.
The design and development of a surgical water knife with compact structure, simple operation and low cost is of positive significance for promoting medical progress and reducing the cost of patients seeking medical treatment.
