Ultrasonic Scalpel Series (Ⅱ) Structure, Working Principle and Precautions for Use

01 Structure

The Ultrasonic Scalpel consists of the main parts such as the generator, transducer, handle piece, scalpel and foot switch.

The generator provides energy for the transducer and scalpel, and the foot switch and manual control device on the scalpel are used to control the output energy of the generator.

02 Working Principle

The ultrasonic soft tissue cutting and hemostasis system, by setting different output power levels, can simultaneously cut and coagulate tissues. The high power level can cut tissues more quickly, while the low power level can better coagulate tissues. The ultrasonic frequency current in the main unit is transmitted to the transducer, which converts the electrical energy into mechanical energy of forward and backward vibration. This vibration is transmitted and amplified through the tip of the device, causing the tip to vibrate at a certain frequency (e.g., 55.5 kHz). The friction generates heat, causing the water in the tissue cells in contact with the tip to vaporize, breaking the hydrogen bonds in proteins. This leads to cell disintegration and re-fusion, and the tissue is cut after coagulation. When cutting blood vessels, the tip comes into contact with tissue proteins, and mechanical vibrations generate heat, which destroys the collagen structure in the tissue, causing protein coagulation and thus sealing the blood vessel to achieve hemostasis.

03 Precautions for Use

When using the ultrasonic scalpel under thoracoscopic surgery, it should be avoided to directly contact other metal instruments, such as suction devices, vascular clamps, staplers, or metal staples, to prevent secondary damage to surrounding tissue structures and damage to the energy devices.

For tissues of normal thickness, the ultrasonic scalpel can be used in the "fast mode" for cutting. However, for thicker tissues and tissues at critical locations, coagulation should be performed first in the "slow mode" before cutting. It is important to use both fast and slow modes of cutting appropriately. For thicker blood vessels, pre-coagulate both sides of the vessel in the "slow mode" without cutting, then cut the vessel in the middle. When working near large blood vessels or normal organs, first try to separate a safe gap before performing precise coagulation and cutting.

To ensure effective tissue coagulation and cutting, hold the tissue with the front two-thirds of the scalpel tip. This will ensure the scalpel has enough room for effective vibration. When holding the handle, apply appropriate force and make sure there is enough time for tissue coagulation and cutting.

During use, the scalpel should be placed in sterile water for cleaning at regular intervals, using the "fast mode" for vibration cleaning to ensure the tip works within the normal oscillation frequency.

If severe adhesion is encountered in the surgical field or when the anatomical planes are unclear, additional instruments such as an electrocautery hook, scissors, or other devices may be used to leverage the advantages of various instruments.