A wireless power transmission system for an active capsule endoscope for colon inspection

Abstract

Multipurpose active capsule endoscopes (ACE) have drawn considerable attention in recent years, but these devices continue to suffer from energy limitations. In order to deliver stable and sufficient energy safely, a wireless power transmission system based on inductive coupling is presented. The system consists of a double-layer solenoid pair primary coil outside and a multiple secondary coils inside the body. At least 500 mW usable power can be transmitted under the worst geometrical conditions and the safety restraints in a volume of Φ13 × 13 mm. The wireless power transmission system is integrated to an ACE and applied in animal experiments. The designed wireless power transmission is proved to be feasible and potentially safe in a future application.

Application of Wireless Power Transmission Systems in Wireless Capsule Endoscopy: An Overview

“…The power amplifier amplifies the TC driving signal that is usually in the form of a square wave [36,58] (with 50% duty cycle) or a sinusoidal wave [59]. The transmitting coil induces magnetic fields when the driving signal is applied to it and the intensity of the induced magnetic field depends on the magnitude of the TC driving signal.…”

“…Although, the intensity of the generated magnetic field depends on the magnitude of the TC driving signal, the uniformity of the field depends completely on the type and the design structure of the TC [64]. In general, they are two types of TC which include solenoid coils [12,36,61–63,65–69] and Helmholtz coils [30,33,70]. The solenoid coil can be arranged in four different forms: (i) single solenoid [65]; (ii) a pair of solenoids [67]; (iii) a pair of double layer solenoids [12] and (iv) segmented solenoids [63].…”

“…Moreover, a pair of double layer solenoids as reported by Jia et al [36] further increases the magnetic field sufficiently to obtain overall efficiency of up to 5.04%. However, after optimization of this double layer solenoid coil based WPT system in terms of size and safety consideration, the efficiency was reduced to 4.08% [76].…”

“…Accordingly, it can be concluded that the peak power requirement for the new generation of WCE is becoming much higher than that of the existing WCE units and the battery capacity may not be sufficient [30,34,35]. This is the main bottleneck in realizing the new generation of WCE devices [36,37]. …”

Application of wireless electrical non-fiberoptic endoscope: Potential benefit and limitation in endoscopic surgery

“…Application of wireless transmission in endoscope was confined in the capsule endoscopy in the past [8,9]. The application was neglected in rigid endoscope [10,11].…”