The Sterile Eye

This is the first in a series of posts where I’ll go through different ways of shooting surgical video. First out are cameras integrated inside the handle of surgical lights.

The handle-integrated camera is one of the most common solutions used to record video of surgical procedures. Most surgical light manufacturers produce lights with optional cameras. These cameras are not only used for recording video, but is also a way for nurses and students to get a good view of the operation.

Most surgical lights are constructed as parabolic reflectors that concentrates the light into a narrow beam in the center axis of the light. In most cases the center of the lamp will point directly to the center of the operating field. In theory a handle-integrated camera will therefore cover the operation very good.

This is however not always the case.

Framing
The light handle is kept sterile during surgery, so the gloved surgeon can reposition it without becoming contaminated. Consequently the handle-integrated camera can not be positioned by a skilled videographer (unless he is also wearing sterile gloves).

The surgeon, of course, have to focus on the surgery, so all considerations concerning the video always comes second. Good working light is important, and in many cases the best positioning of the light will result in bad framing. In some cases the repositioning of the light can produce viewer confusion as to the orientation of the patient and the anatomical structures.

This is a video still from a lung cancer operation (lobectomy) where the light was positioned in a way that provided good light but bad framing. Approximately 50 % of the footage from this operation was framed similar to this.

Heads
One of the biggest problems when filming surgery is the surgeons’ heads. They get in the way all the time. This is especially the case when using handle-integrated cameras. The light handle is fixed in it’s position to the light. I have yet to see a camera like this that can be panned or tilted. Most of these cameras can not even zoom, but have a fixed focal length (most often quite wide angled as in the video still above). So it’s not possible to adjust the framing without moving the light. Not a very good starting point for quality video production.

Video quality
To fit inside the light handle, the camera has to be relatively small. The cameras most commonly used in surgical light are single CCD, fixed focal length cameras with unsophisticated optics. Compare the video still above with this still from the Panasonic AG-HVX200 (same operation):

The surgical light cam still is blury, has dull colors, and most important, it’s too badly framed and too far away from the wound to show anything of interest.

Broadcast quality 3 CCD-cameras are getting smaller by the day, but when it comes to video integration, surgical light manufacturers are not exactly cutting edge.

Conclusion
Based on my own experiences with handle-integrated cameras, they’re good for showing the operating field on monitors inside the OR (CCTV), but they’re close to useless when it comes to producing quality video of surgical procedures.