Variation of exterior telemetry links of capsule antenna ingested in human body

Many factors such as the type and the orientation of capsule antenna, the position of the capsule antenna in gastrointestinal tract, the dielectric properties of human body tissues and so on can influence the radiation characteristics of Ingestible Wireless Devices (IWDs). This paper analyses the uncertainty of the radiation characteristics of IWD and how these factors influence the performance of IWD. It is notable that the electric intensity outside human body models where a helix antenna is implanted is larger than that exposed to a dipole antenna. The link performance of helix antenna is influenced by the ground. The dielectric properties of human body tissues and the orientation of IWD also influence the radiation characteristics of IWD. However, among these factors, the position of IWD has the most important influence.