Conventional endoscopes are the “gold standard” for investigating and evaluating mucosal disease of the esophagus. Free-swimming camera pills are large because they must carry camera, batteries, memory, illumination, and some level of image processing power on board. A typical camera pill may measure 11 x 26 mm and may be priced at $1500 per pill — and the pill is not reusable. Camera pills are difficult if not impossible to steer from outside the body. Both camera pills and conventional endoscopes require an expensive external support system. Camera pills may not return information for over 24 hours, until the body eliminates them.

The PicoEndo lens system.
The PicoEndo endoscope is the smallest tethered endoscope in the world (4.5 x 12.0 mm). It is also inexpensive enough to use and discard. It provides a dramatic cost reduction in equipment requirements from conventional endoscope or pill camera systems, which can cost upwards of $30,000 USD. PicoEndo delivers more images at an improved quality, including images processed into 3D. This system is applicable to medical tasks such as photographing the surface of the esophagus and to applications in any other industry that needs to place a tiny electronic camera eye in a location that is difficult to view, such as inspecting the interiors of assembled engines.

PicoEndo is an improvement over conventional camera pills for several reasons. A camera pill is used primarily to scan the colon; it passes through the esophagus very quickly. Because of PicoEndo’s tethered nature, and because it photographs at 30 fps, it can pass very slowly through the esophagus and similar biological passages (such as the bronchi). Camera pills — even those with a camera at each end — take images at half the rate of

PicoEndo. Also, there is no need to attach wires to the human body (a single wire is attached to the endoscope). There is no need for 24-hour monitoring, as the camera can be withdrawn by the operator and does not have to make its way out through the body. There is no need to wear a harness for 24 hours and wait for capsule recovery and image processing. Image processing can take place in real time.

An example of an optical biopsy: (a) ordinary endoscopic image, (b) synthesized image by assigning spectral images at 500 nm, 450 nm, and 410 nm to R, G, B planes, respectively.
Because of its string (or tether), which also acts as an electronic connection and steering cable, the body of the endoscope does not have to contain batteries, memory, or processing electronics, unlike much larger camera pills. The size of the camera and lens system determines the size of the unit. PicoEndo currently uses a camera and lens system 2.55 mm across, and is small enough for even children to swallow easily without sedation. The attached electronic tether string allows the camera capsule to be withdrawn or steered after it has entered as far as the operator needs. The tether connects PicoEndo to a special signal processing unit that in turn connects to a standard office PC. The system offers 160,000 pixel resolution at 30 fps (about that of a conventional endoscope) in a camera head that is far smaller and that requires no sedation; it offers a 140-degree field of view that allows it to “see around corners,” which a conventional endoscope cannot do. An onboard sensor shows the exact location of the camera, which is important for identifying any problems detected in an image.

PicoEndo is about to produce a functional prototype. An even smaller camera sensor than the current 2.55 mm is under development. The processing software exists. The developers believe that by using a combination of white, UV, and NIR LEDs in the lens holder, that it may be possible to conduct an optical biopsy in situ instead of (or in addition to) a physical biopsy. A search for suitably sized UV and NIR LEDs is underway.

This technology is offered by yet2.com. For more information, view the yet2.com TechPak at http://info.hotims.com/28059-153 .