Endoscopy today and tomorrow George BERCI, M.D.

Director, Department of Endoscopy

Cedars-Sinai Medical Center Los Angeles Clinical Assistant Professor of Surgery

Department of Surgery School ol Medicine

UCLA Medical Center

The alloted time allows only to outline the present stage and indicate some promising de- velopments in an abstracted form.

There are only a few diagnostic or treatment procedures available where we are so instru- ment dependent as in endoscopy.

Our achievements, apart from the clinical results, can be classified in the following larger groups :

Optics

The invention of the rod-lens system by Hopkins created a new image transmitting prin- ciple, which triggered the exploration of many new areas previously inaccessible for rigid ins- truments. Especially in the field of miniaturiza- tion (pediatrics). We reported the first clini- cal results in the field of urology (Beret and Kont, 1969). The optical parameters are signi- ficantly improved compared with the standard lens system. The invention is now accepted worldwide in many subspecialties (some examples were demonstrated by 16 mm film strips).

Light transmission

To conduct light from an external source to the working end of the endoscope by incoherent fibers was a great step forward compared with the old light carriers and miniature distal elec- tric globes. On the other hand we had to take into consideration that the light absorption of a 6-foot (180 cm.) bundle is in the vicinity of 60-70 %. Furthermore, the yellowish tint of the bundles create a compression in the light red spectrum interferring with the natural ap-

pearance e.g. of slight inflammation. The pro- blems of this high loos during transmission be- came even more emphasized if the same fiber bundle was employed with a high intensity light source or flash, for timing or still photography.

A new flexible light transmitting medium was developed which in size, shape, and weight, is similar to the glass fibers but does not consist of fibers at all and is a new concept in light transmission. The advantages over glass fibers, plastic, etc. are that the efficiency (transmission) is approximately twice as much as our present fiber, and the color is white. This new light transmitter is promising and if the initial re- sults will prove its effectiveness, it will have the same impact in endoscopy as the invention of the new image transmitting system.

Permanent film record

We came to a stage where we had to realize that the production of films or slides are not of importance, only to show it on various lectures or meetings, but to produce an objective record of our visual findings for the patient's chart. A good analogy is the progress in diagnostic radiology between the pioneer typewritten des- cription of a fluoroscopic examination and the availability of an x-ray film.

Still Photography

With the new transmitting medium mentio- ned above, it is possible to transmit more effi- ciently a flash discharge. The presently em- ployed U-shaped flash globes are not ideal for the entrance angle or the match the aperture of the fiber and therefore a great loss is encoun- tered.

Acta Endoscopica et Radiocinematographica Tome VI - N ~ I - 1976 1

A new flash is under development where the entire power output can be conducted in a flexible transmitter. This will provide the pos- sibility in a flexible transmitter. This will pro- vide the possibility that more energy (W/sec) will be employed for still photography.

Still Cameras

A miniature 35 mm. full framed camera weighing only 340 gms. with an electric motor drive incorporated, was developed which will help significantly to avoid interference in cou- pling a heavy camera to a light endoscope.

High Intensity Light Sources

The employed Xenon globes are efficient and presented an improvement over the previous mercury pressure globes but still are far from ideal. The large size, the complexity and cos- tly equipment, restricted it's application from wider acceptance.

A new miniature explosion-proof Xenon light has been developed, which is approxima- tely l /5th of the size of the existing models and can be adapted to every brand of telescope or endoscope (rigid and flexible).

Movie Camera

A light-weight 16 mm. movie camera with interchangeable pre-loaded magazines was in- troduced with a larger shutter opening time (270 o) which improves our individual frame exposure.

Flexible Fiber Endoscopes

In this area the double channel operating scopes are under testing conditions to evaluate their usefulness in bleeding or under polypec- tomy conditions.

R e]erences

Berci, et al., Endoscopy, Part I and II. Ap- pleton-Century-Crofts, New York, 1975.

�9 XII" Congr~s de la S.M.I.E.R., Constance, 16- 19/IV/1975.

�9 II ~ Europ~iischer Kongress Fiir Endoskopie, Konstanz, 16-19/IV/1975.

�9 Received for publication 20-2-1976.

2 Tome VI - N" 1 - 1976 Acta Endoscopica et Radiocinematographica