EC-funded collaboration draws on microelectronic improvements to bring low-cost, less invasive endoscopy devices into mass production. Christopher Sell reports
A GROUND-BREAKING medical device is set for mass production thanks to common sensor technology and advances in miniature components.
A collaborative European project led by the Institute for Microelectronics, Stuttgart, is drawing on recent improvements in microelectronics to develop low-cost, less invasive alternatives to traditional endoscopy devices.
The EC-funded intracorporeal videoprobe (IVP) project, due to finish in September, is developing two prototype imaging systems capable of high- quality, wireless data transmission. The first of these, IVP1, is a small wired videoprobe with a CMOS imaging sensor, while a more advanced model (IVP2) is an autonomous video-capsule with a telemetric link for image data transfer to an external PC
Project co-ordinator Christine Harendt explained that the development of a tiny image sensor just 1.7mm x 1.3mm has enabled the team to produce one of the world’s smallest endoscopes.
With an outer size of 3mm-4mm, smaller than a matchstick head, one advantage is that the sensor is located in the head of the endoscope, which will provide a better image for the surgeon. Endoscopes with head- mounted sensors are typically much larger than this, while those with set-back sensors tend to suffer a loss of resolution due to additional fibre-optic link needed to the head.
Harendt said that the common CMOS sensor technology integrated into the two systems enables it to be manufactured for large scale, low-cost production. The ultimate aim, she said, is to produce the devices at a cost which can make them disposable, eliminating the need for expensive sterilisation. ‘Once the system has been tested and mass marketed it will be cheap,’ she added.
IVP2 will capture images as they pass through the system. And, while the direction travelled cannot be controlled, a motor inside the pill can rotate the sensor to access views in varying directions. This, combined with the anticipated low cost of the device, offers considerable advantages over existing passive, pill-shaped devices. The data collected is transmitted wirelessly to a PC. This steering mechanism was developed by engineers from the Sant’Anna School of Advanced Studies in Pisa, Italy.
Just like IVP1, IVP2 transmits colour images at a high pixel rate and takes 10 images/sec, but it must do this wirelessly and high data transmission rates have been problematic. The challenge of compressing the data to reduce the bandwidth fell to one of the project partners, the University of Leuven in Belgium.
This group, also responsible for developing the power system for IVP2, developed a special chip called endocom that can compress data without losing too much information.
Such high data rates, combined with the nature of the course taken by IVP2 leads to a significant number of images being taken through the course of one movement through the body. As a result, researchers at the University of Westminster have been working on software capable of rapidly recognising the tell-tale features of diseases.
- ‘If you have something moving through the body, you produce many images. nobody will want to look at them all, so the software will scan them for you,’ said Harendt.
- Researchers have been working with doctors to gain a better understanding of what to look for in the images, such as modified tissue structures and on a simpler level, bleeding.
- The commercial applications of non-invasive, high-imaging probes are numerous. Harendt said that one of the project partners, endoscope manufacturer Karl Storz, has shown an interest in developing the product further.