Safely tracking the location of the tip of an endoscope while it’s inside the body has posed a serious challenge for biomedical engineers. The benefit of tracking can help to guide an endoscope to its target quickly and accurately. X-rays can be used, but unnecessary radiation is not advised.
Now researchers from University of Edinburgh and Heriot-Watt University in Scotland have devised a method of seeing the endoscope tip through the body by detecting the light emitted at its tip. The technology relies on a camera able to detect individual photons and to elucidate how long they took to travel from the light source.
By parsing individual photons for whether they came in a straight line from the endoscope tip or traveled in a more circuitous path, the system is able to separate photons that have been scattered from ones that have not. Only a few directly projected photons are necessary to spot their source and to measure its location with centimeter-level resolution.
The accuracy is sufficient for a lot of clinical use cases, but it’s unclear whether all the lights in the same room have to be extinguished in order for the system to be used.
Top image: Camera is detecting light emitted from an endomicroscope whilst in use in sheep lungs. Left half shows light emitted from the tip of the endomicroscope, revealing its precise location in the lungs. Right half shows the picture that would be obtained using a conventional camera, with light scattered through the structures of the lung.
Study in Biomedical Optics Express: Ballistic and snake photon imaging for locating optical endomicroscopy fibres…
