Tiny endoscopes

Researchers at the

have developed two prototypes of tiny endoscopes that may make life a lot more comfortable for patients who need to undergo an endoscopic procedure. The reason: they’re small.

The first of the two is a small wired endoscope, called IVP1, and the second, a tiny wireless-imaging probe, called IVP2, that can be taken in the form of a pill.

Both prototypes are equipped with optics for illumination as well as mechanical components for swivelling the inbuilt image sensor.

The head of the IVP1 is 3.5 millimetres in diameter - about the size of a match head - and the image sensor itself is a CMOS chip measuring 2.7 by 2.3 millimetres.

‘The great advantage of our prototype is the fact that the image sensor is incorporated into the head of the endoscope, which provides much better images for the surgeon,’ said Christine Harendt from the Stuttgart Institute for Microelectronics.

Existing endoscope heads, with the image sensor integrated into the head, are usually about twice the size. Other types - with the image sensor set back from the head of the probe - tend to suffer image resolution losses due to the additional fibre-optic link to the head that is needed.

While the travel of the pill-sized wireless IVP2 cannot be controlled like the IVP1, a tiny motor in the head enables the image sensor to swivel to provide views in different directions. The pill itself draws power by induction from a vest worn by the patient, which also picks up the images transmitted by the probe, as well as transmitting them wirelessly to a nearby PC.

The high data content colour images from both the sensors means that the researchers are now looking at how to compress the data to reduce the system bandwidth that’s required to transmit the images.

Both prototypes are currently being readied for medical evaluation.