So, you are developing an externally mounted camera system. The camera (you call it image sensor) is mounted on to the eyepiece through which the surgeons use to see. This is what I made out from your posting. Correct me if I am wrong.

If the following is known to you, bear with me. There are two types of scopes i.e., rigid and flexible. The flexible is further divided into fibre optic and video endoscopes.

In the flexible type, image is carried by a fibre optic (image) bundle to an eyepiece assembly for the surgeon to see. A separate fibre optic light guide bundle carries the light from the base unit. These are first generation endoscopes. To extend their usefulness, CCD cameras are mounted on the eyepiece and output is used for viewing, video grabbing and archiving, etc. I understand this what you are trying to do.

The video type is similar to flexible type except a miniature camera assembly is mounted at the distal end (i.e., the end going into the body) and there is no eyepiece. An image processor processes the signals from the camera and its output is used for viewing, video grabbing and archiving, etc. The most difficult part is the miniature camera assembly (aka CHA) and it’s mounting, which is monopolised by three major players Pentex, Olympus and Fujinon and they won't sell the CHAs to anybody. Or, this what you are trying to make? (BTW, if you know the source to get these please, let me. I would like to buy some).

If it is the first method, I would suggest you to make use of off-the-shelf camera module (OEM versions are available) and concentrate on processing the video signal.

However, whichever way you choose to go, please take extr.....a care on the electrical safety. The threshold limits requirements are very very low for these types of equipment. Please, refer to IEC standards.

All the best.