Biopsy is a technique that removes diseased tissue from the patient's body for pathological examination by cutting, clamping or puncturing for differential diagnosis and treatment as needed. Biopsy forceps are indispensable for gastrointestinal endoscopic biopsy and are also one of the most commonly used accessories by endoscopic nurses.
1. Types of biopsy forceps
There are many types of endoscopic biopsy forceps, including standard type, side opening type, needle type at the tip, round cup type, toothed cup type, etc. Typically, laser welding of biopsy forceps can be achieved with continuous or pulsed laser beams. Laser radiation first heats the surface to be processed, and then the surface heat diffuses to the interior through thermal conduction by controlling laser parameters such as laser pulse width, energy, peak power and repetition frequency.
The energy conversion mechanism is accomplished through a "keyhole" structure. Under laser irradiation with a high enough power density, the material will evaporate and form small holes. This small hole filled with water vapor is like a black hole, which can absorb almost all the incident beam energy, and the equilibrium temperature in the hole cavity will reach about 2500°C. Heat is then transferred from the outer walls of this high-temperature hole to melt the metal surrounding the cavity. Then, the small hole will be filled with high-temperature steam generated by the continuous evaporation of the lower wall material illuminated by the beam, and the four walls of the hole will be surrounded by molten metal. The liquid metal will be surrounded by solid material (whereas in most traditional welding processes and laser-conducted welding, energy is first deposited on the surface of the workpiece and then transferred to the interior). The liquid flow and wall surface tension outside the pore wall will maintain and dynamically balance with the continuously generated vapor pressure in the pore cavity. As the light beam continuously enters the small hole, the material outside the hole continues to flow. As the light beam moves, the inside of the hole is always in a stable flow state. That is to say, when the molten metal around the small hole and the hole wall moves forward with the forward speed of the front beam, the molten metal will immediately fill the gap left after the small hole is removed and condense with it, and the weld is formed. . Then it was formed.
All of the above processes can occur very quickly, allowing biopsy forceps to be welded at speeds of several meters per minute easily. This is the mechanism by which we see the threaded cavity of the biopsy forceps forming. Therefore, once the biopsy clamp thread breaks, normal welding processes will not solve the problem because metal barbs may form. In recent years, most biopsy forceps have adopted a rigid four-bar structure, making the use of biopsy forceps more convenient.
2. Details of using biopsy forceps
The key to making full use of biopsy forceps mainly relies on mastering the correct force. When using biopsy forceps, it is important to use moderate force. Do not use force to open or close the biopsy forceps; otherwise, not only will the biopsy forceps not be able to clamp the diseased tissue well, but the biopsy forceps will be easily damaged. It can be seen that mastering the biopsy forceps is actually the basis for mastering the use of many other medical accessories, and this is a truth that is generally difficult to feel. However, if you are removing a foreign object, especially a coin, you will find that it is difficult to keep the coin stable if the alligator jaws are opened too wide. So how do we deal with this situation? It is the experience of many endoscopic nurses to open the forceps opening slightly wider than the edge of a coin. When the tweezers can go over the edge of the coin, they can apply a steady force. This will allow you to hold the coin securely. Therefore, during the practice of biopsy forceps, you must pay attention to the strength of the forceps.
