Which instrument uses light in place of a scalpel to cut or treat tissue?

• A. Surgical Laser
• B. Electrosurgical Unit
• C. Medical Ventilator
• D. Heart-Lung Machine

Answer: (A)

Light-based cutting is done with a surgical laser. A laser emits a highly focused beam of light that is absorbed by tissue, quickly heating and sometimes vaporizing or sealing as it cuts. This allows precise removal or treatment of tissue with minimal physical contact and often reduces bleeding because the energy can coagulate small vessels as it works. Different wavelengths interact with tissue in different ways, giving versatility for various applications.

The other tools serve different purposes: an electrosurgical unit uses high-frequency electrical current to cut or cauterize tissue through heat, not light; a medical ventilator helps a patient breathe; a heart-lung machine temporarily takes over circulation and oxygenation during surgery.