A hydraulically driven colonoscope

BACKGROUND: Conventional colonoscopy requires a high degree of operator skill and is often painful for the patient. We present a preliminary feasibility study of an alternative approach where a self-propelled colonoscope is hydraulically driven through the colon. METHODS: A hydraulic colonoscope which could be controlled manually or automatically was developed and assessed in a test bed modelled on the anatomy of the human colon. A conventional colonoscope was used by an experienced colonoscopist in the same test bed for comparison. Pressures and forces on the colon were measured during the test. RESULTS: The hydraulic colonoscope was able to successfully advance through the test bed in a comparable time to the conventional colonoscope. The hydraulic colonoscope reduces measured loads on artificial mesenteries, but increases intraluminal pressure compared to the colonoscope. Both manual and automatically controlled modes were able to successfully advance the hydraulic colonoscope through the colon. However, the automatic controller mode required lower pressures than manual control, but took longer to reach the caecum. CONCLUSIONS: The hydraulic colonoscope appears to be a viable device for further development as forces and pressures observed during use are comparable to those used in current clinical practice

Molecular Tagging Velocimetry (MTV) and Its Automotive Applications

This work provides an overview of the technique of Molecular Tagging Ve-locimetry (MTV) and some of its automotive applications. The various ele-ments of MTV implementation are briefly described in terms of the available molecular tracers, methods of tagging, detection, and processing schemes. The automotive applications of this velocimetry technique are demonstrated in mapping the velocity field of the intake flow into a “steady flow rig ” model of an internal combustion engine and flow mapping of cycle-to-cycle variation in late compression of a motored IC engine. 1