Smart optical CMOS sensor for endoluminal applications

Abstract

A custom CMOS image sensor designed for low power endoluminal applications is presented. The fabricated chip includes a 320 × 240 pixel array, a complete read-out channel, a 10-bit ADC converter, a series of DACs for internal references and digital blocks for chip control. The complete functionality of the chip is guaranteed through 7 signal pins, used for the I 2 C-like input and LVDS output interfaces. Prototypes were produced using UMC 0.18 m-CIS (CMOS Image Sensor) technology for both monochrome and colour-RGB versions. Due to its high sensitivity, a pinned photodiode was implemented. The imager was electrically and optically characterized and preliminary ex-vivo tests were performed. Characterization results show state-of-the-art performance in terms of power consumption (<40 mW for the core), which is less than half compared to off-the-shelf sensors, and light sensitivity (0.1 lux@555 nm for the monochrome imager), which makes sensor performance comparable to CCD technology performance for single chip endoluminal applications.

Design, Fabrication, and Testing of a Capsule With Hybrid Locomotion for Gastrointestinal Tract Exploration

“…Although a system with these features is not commercially available, on-going efforts toward this goal are provided in literature [24]. In particular, our group is developing a 20 fps real-time wireless camera system for capsule endoscopy, weighing 3.5 g and measuring 450 mm 3 in volume [25].…”

“…4) Real-time vision system: Since the devised procedure is based on a real-time visual feedback from the capsule, a wireless vision module with adequate frame rate needed to be integrated. Despite research in this field [24], no miniaturized real-time vision system was available at the time of the work, therefore an estimated volume (450 mm 3 as the ongoing efforts [25] toward a wireless vision module) for this module was left available in the hybrid capsule for future integration. 5) User-friendly control interface: Since capsule steering is obtained by applying two synergetic approaches, the endoscopist must be able to switch between the two easily and intuitively.…”

Mesoscale mobile robots for gastrointestinal minimally invasive surgery (MIS)

“…current commercial imaging chips must compromise between image quality and power consumption (Vatteroni et al, 2010). several researchers have been working to develop smaller, more efficient image acquisition chips.…”

CMOS image sensor with tunable dynamic range for catheter based endoluminal applications

“…This is a big step forward if compared to traditional instruments where the camera is generally placed outside the body and illumination and images acquisition are guaranteed by a complicated lens system or optical fibers [2]. To make deep miniaturization possible, the interest on CMOS technology for the sensor fabrication is much increased because of the capability to integrate on a single piece of silicon the sensitive part and the control electronics [3].…”