Endoscope sees through blood

17 Jun 2002

A US company has developed infrared endoscopic technology that allows surgeons to see through blood

Researchers from US-based company Cardio-optics have developed an infrared endoscopic imaging system capable of resolving cardiac structures in flowing blood. Bruce Ferguson, medical director of Cardio-optics, said: "Using infrared illumination will significantly aid surgical procedures that require surgeons to work through blood such as heart surgery."

As in military applications, infrared technology can image through particulates in media that are impenetrable in the visible spectrum such as smoke and fog. In this case, blood consists of particles (red blood cells) suspended in an otherwise clear medium (plasma).

The basic principle behind this application is that one can see "through" particles when the wavelength of illumination is comparable to the particle dimensions. Cardio-optics' Trans Blood Vision (TVB) system uses pulsed laser emission from diodes operating at 1550 nm or 1820 nm to provide real-time images of blood flow and the walls of coronary arteries.

An endoscope containing separate illumination and imaging fiber bundles is inserted into the blood vessels of the patient. Reflected and scattered light is collected and transmitted through the imaging fibers to an infrared camera.

TVB offers a minimally invasive technique capable of providing direct high-quality images in real time. This is in contrast to the current gold-standard treatment of angiography, in which a contrast medium is injected into the artery and a rapid series of X-ray recordings is made in order to obtain images.

The company has completed a series of successful animal experiments and will be presenting its results at the American Heart Association meeting in Anaheim, California in November. The firm now plans to perform further animal trials and begin human clinical trails.

Cardio-optics also plans to improve the output power from the infrared sources and the optics in the endoscope. Larry Blankenship, CEO of Cardio-optics said: "We remain on track to have our first products ready for market late next year."