Design And Experimental Research Of A Micropower Wireless Capsule Endoscopy System

Intestine diseases are conventionally lack of efficent inspecting method so thattreatment level against them is low. Aiming at those diseases, capsule endoscopy came outwith development of technology. As an intelligent small-intestine diseases inspectingsystem, research on it relates to scientific achievements of micro-electronics, RF circuit,commmunication theory, optics, micro-mechanics machining etc.In this paper, optimization and improvement on the OV6920-based capsule endoscopysystem based on the existing achievements of our research group are studied. Byimplementing theoretical analysis and experimental research, a capsule endoscopy withlower power comsuption and long working hours has been developed.In this paper, the following tasks are accomplished.First, construction and working principle of the system are introduced in detail and thecapsule is deconstructed. For the main modules inside the capsule, the parameters of achosen imaging sensor as well as design and fabrication of the emitting circuit, opticalsystem, powering system etc are presented.Second, the photographing module, especially the crystal oscillator circuit in it, isstudied. Several different kinds of crystal oscillators are chosen by the theory. Schematicsand PCB are designed. Then comparing experiments are carried out to test performance ofeach design. The cylinder-shaped crystal is finally chosen for the system because it makesthe module work longer and its dimension smaller.Third, LED illuminating system is studyed. Aiming to improve the original directpowering mode, several different LED driving cicuits are designed and then experimentscarried out to test their function. Finally the MAX1916driving chip is chosen and the newcircuit integrated into the system with a new photographing module PCB designed.Fourth, material objects of each module are made and assembled into a model machine.Compared with the original design, power consumption of the new model is42.2%lowerand whole working hours87.5%longer. Then, the clear and stable images obtained duringexperiments verify practicability of the above design in this paper. Fifth, some problems and parts that may be improved of the design are brieflyintroduced. And the using of the new imaging sensor in research is presented as outlook ofthe following research.