A surgical robot is a machine through which a surgeon operates with small instruments inside the patient, controlled from a console a few metres away. It is also called a robotic surgical system, and the method is called robot-assisted surgery. It is used mainly for operations on soft organs, such as removing the prostate, the womb, part of a kidney or part of the bowel.
The system has three parts. The patient cart stands beside the operating table and carries three or four robot arms. Each arm holds an instrument or a camera, which goes into the body through a cut about 8 to 12 mm wide. The surgeon console has a 3D viewer and two hand controls. The surgeon looks into the viewer, sees a magnified 3D picture from the camera inside the body, and moves the hand controls. A third cart holds the computers, and a screen for the rest of the theatre team.
The robot's software sits between the surgeon's hands and the instruments. It does three things. It scales each movement down. It filters out the small tremor that every human hand has. And it moves an instrument tip that can bend like a wrist inside the body. The long, straight tools of ordinary keyhole surgery, called laparoscopy, cannot bend like that.
Imagine a urologist at a hospital in Kolkata removing a patient's prostate. She sets the motion scaling to 3 to 1. So when her hand moves 3 cm at the console, the instrument tip moves 1 cm inside the patient. She stitches the bladder to the urethra, the tube that carries urine out, with stitches a few millimetres apart. Each instrument has a chip that counts how many times it has been used. After a set number of operations, the robot no longer accepts it. Surgical instrument tracking records those uses, and sends each instrument for cleaning between operations.
The robot never operates on its own. It moves the instruments only while the surgeon is at the viewer and holding the controls. If the surgeon looks away, the instruments stop where they are.
A robot costs several crore rupees, and each operation uses expensive instruments. So hospitals plan carefully which operations use it, through operating room scheduling. Before a difficult operation, the team may study a 3D model of the organ, made from the patient's scans. Afterwards, the operation notes and the robot's log go into the hospital EHR.
In India, robotic surgery began in large hospitals in the metros, and is now spreading to smaller cities. An Indian maker now sells a surgical robot of its own. Operations on bones use a different kind of robot, the orthopaedic surgical robot.