Surgical navigation system refers to a computer assisted technology that provides real-time information to surgeons during complex surgical procedures. It is designed to increase precision and accuracy during surgery by providing 3D visual guidance to the surgeon. The technology has been rapidly evolving and is revolutionizing difficult surgical specialties like neurosurgery, orthopedic surgery and ENT surgery. 

A surgical navigation system consists of three main components — a tracking system, 3D rendered images and surgical instruments that are tracked in real-time. The tracking system typically uses infrared, electromagnetic or ultrasound based technologies to precisely track the position of surgical instruments or implants. Pre-operative 3D images like MRI or CT scans are uploaded into the navigation system software which renders a 3D model of the surgical site. During surgery, the tracked instruments are localized on these 3D images to guide the surgeon. Some key steps involved are:

- Registration of patient anatomy: Landmarks on the patient like bones are registered with the 3D rendered anatomy to integrate the patient into the virtual environment.

- Tracking: Reflective makers or coils are attached to surgical instruments and patient anatomy which are continuously tracked in 3D space using infrared light, electromagnetic fields etc.

- Navigation: The real-time position data from the tracking system is overlaid on the pre-operative images to show instrument position. This provides visual guidance to the surgeon on instrument trajectory.

Benefits in Neurosurgery

Surgical Navigation Systems has found immense use in complex neurosurgical procedures to treat brain tumors, aneurysms, AVMs etc. Some key advantages are:

- Increased accuracy: It helps surgeons navigate intricate brain anatomy with sub-millimeter precision avoiding injury to critical structures.

- Reduced invasiveness: Smaller and targeted openings are made reducing brain shift, blood loss and recovery time for patients.

- Enhanced visualization: 3D rendering of vessels, tumors and surgical pathway provides anatomical orientation and roadmap during surgery.

- Objectification of results: Navigation data like resection margins can be objectively measured intra-operatively and in follow-ups to assess treatment success.

- Training and planning: Trainee surgeons can practice complex cases, analyze surgical plans and identify risk factors better.