Ekawahyu Susilo

Propeller-based wireless device for active capsular endoscopy in the gastric district

An innovative approach to active locomotion for capsular endoscopy in the gastric district is reported in this paper. Taking advantage of the ingestion of 500 ml of transparent liquid by the patient, an effective distension of the stomach is safely achieved for a timeframe of approximately 30 minutes. Given such a scenario, an active swallowable capsule able to navigate inside the stomach thanks to a four propeller system has been developed. The capsule is 15 mm in diameter and 30 mm in length, and it is composed of a supporting shell containing a wireless microcontroller, a battery and four motors. The motors enable the rotation of propellers located in the rear side of the device, thus obtaining a reliable locomotion and steering of the capsule in all directions in a liquid. The power consumption has been properly optimized in order to achieve an operative lifetime consistent with the time of the diagnostic inspection of the gastric district, assumed to be no more than 30 minutes. The capsule can be easily remotely controlled by the endoscopist using a joystick together with a purposely developed graphical user interface. The capsule design, prototyping, in vitro, ex vivo and preliminary in vivo tests are described in this work.

Wireless therapeutic endoscopic capsule: in vivo experiment.

BACKGROUND AND STUDY AIM Capsule endoscopy is becoming well established as a diagnostic technique for the gastrointestinal tract. Nevertheless swallowable capsule devices that can effectively perform surgical and therapeutic interventions have not yet been developed. Such devices would also be a valuable support for natural orifice transluminal endoscopic surgery (NOTES). The objective of this study was to assess the feasibility of using a swallowable wireless capsule to deploy a surgical clip under remote control. MATERIALS AND METHODS A wireless endoscopic capsule, diameter 12.8 mm and length 33.5 mm, was developed. The device is equipped with four permanent magnets, thus enabling active external magnetic steering. A nitinol clip is loaded on the topside of the capsule, ready to be released when a control command is issued by an external operator. Repeated ex vivo trials were done to test the full functionality of the therapeutic capsule in terms of efficiency in releasing the clip and reliability of the remote control. An in vivo test was then carried out in a pig: the capsule was inserted transanally and steered by means of an external magnetic arm towards an iatrogenic bleeding lesion. The clip, mounted on the tip of the capsule, was released in response to a remote signal. The procedure was observed by means of a flexible endoscope. RESULTS A wireless capsule clip-releasing mechanism was developed and tested. During ex vivo trials, the capsule was inserted into the sigmoid section of a phantom model and steered by means of the external magnet to a specific target, identified by a surgical suture at a distance of 3 cm before the left flexure. The capsule took 3 to 4 minutes to reach the desired location moving under external magnetic guidance, while positioning of the capsule directly on the target took 2 to 3 minutes. Successful in vivo clipping of an iatrogenic bleed by means of a wireless capsule was demonstrated. CONCLUSIONS This study reports the first successful in vivo surgical experiment using a wireless endoscopic capsule, paving the way to a new generation of capsule devices able to perform both diagnostic and therapeutic tasks.

A reconfigurable modular robotic endoluminal surgical system: Vision and preliminary results

Miniaturized surgical devices are promising for the future development of minimally invasive and endoluminal surgery. However, the dexterity and therapeutic functions of these devices are limited. In this paper, a reconfigurable modular robotic system is proposed to perform screening and interventions in the gastrointestinal tract. In the proposed system, millimeter-sized robotic modules are ingested and tasked to assemble into an articulated mechanism in the stomach cavity. The modules are assembled according to the target location to perform precise intervention. Based on this concept, a preliminary report is presented covering the robotic schemes for the endoluminal reconfigurable platform, the design with structural functions, the control strategy, and the interval-based constraint satisfaction algorithm to determine the suitable topologies of the reconfigurable robot for the given task.

Wireless reconfigurable modules for robotic endoluminal surgery

In this paper, a reconfigurable modular robotic system is proposed to augment the dexterity of endoluminal interventions in the gastrointestinal tract. In the proposed system, miniaturized robotic modules are ingested and assembled in the stomach cavity. The assembled robot can change its configuration according to the target location, thus enabling complicated surgical tasks. The robotic assembly, the robotic configuration and the surgical tasks are controlled via wireless bidirectional communication. Based on this concept, early prototypes of the robotic modules were designed and fabricated. The developed module has 2DOF (±90° of bending and 360° of rotation), measures 15.4 mm in diameter and 36.5 mm in length. It weighs 5.6 g and contains a Li-Po battery, two brushless DC motors, and a custom-made control board capable of wireless communication. The performance of the bending and rotational motion was evaluated and the future work has been discussed.

Wireless Implantable Electronic Platform for Chronic Fluorescent-Based Biosensors

The development of a long-term wireless implantable biosensor based on fluorescence intensity measurement poses a number of technical challenges, ranging from biocompatibility to sensor stability over time. One of these challenges is the design of a power efficient and miniaturized electronics, enabling the biosensor to move from bench testing to long term validation, up to its final application in human beings. In this spirit, we present a wireless programmable electronic platform for implantable chronic monitoring of fluorescent-based autonomous biosensors. This system is able to achieve extremely low power operation with bidirectional telemetry, based on the IEEE802.15.4-2003 protocol, thus enabling over three-year battery lifetime and wireless networking of multiple sensors. During the performance of single fluorescent-based sensor measurements, the circuit drives a laser diode, for sensor excitation, and acquires the amplified signals from four different photodetectors. In vitro functionality was preliminarily tested for both glucose and calcium monitoring, simply by changing the analyte-binding protein of the biosensor. Electronics performance was assessed in terms of timing, power consumption, tissue exposure to electromagnetic fields, and in vivo wireless connectivity. The final goal of the presented platform is to be integrated in a complete system for blood glucose level monitoring that may be implanted for at least one year under the skin of diabetic patients. Results reported in this paper may be applied to a wide variety of biosensors based on fluorescence intensity measurement.

Design of a brushless micro motor driver for a locomotive endoscopic capsule

In this paper is presented the design of a driver for a Namiki micro motor. The micro motor is used as a basic element for the locomotion of an endoscopic capsule to explore the entire gastrointestinal tract. The driver is based on the basic 3-phase structure with synchronous rectification and is designed in a full-custom ASIC in the h35 automotive technology of Austriamicrosystems.

Systematic Design of Medical Capsule Robots

Medical capsule robots that navigate inside the body as diagnostic and interventional tools are an emerging and challenging research area within medical CPSs. These robots must provide locomotion, sensing, actuation, and communication within severe size, power, and computational constraints. This paper presents the first effort for an open architecture, platform design, software infrastructure, and a supporting modular design environment for medical capsule robots to further this research area.

Control electronics integration toward endoscopic capsule robot performing legged locomotion and illumination

Miniaturization of sensors and actuators up to the point of active features in endoscopic capsules, such as locomotion or surgery, is a challenge. VECTOR endoscopic capsule has been designed to be the first endoscopic capsule with active locomotion. It is equipped with mini-legs driven by Brushless DC (BLDC) micro motors. In addition it can be also equipped with some other sensors and actuators, like a liquid lens, that permits to enable advanced functions. Those modules are managed by an ASIC specifically designed for the VECTOR capsule. The ASIC is a complete System-On-Chip (SoC) and integrates all the electronics needed to enable the legged locomotion and the sensing and actuating functions of the capsule in an unique chip. The SoC also enables other functions for endoscopic capsules such as drug delivery and a biopsy system. The size of the SoC is 5.1 mm × 5.2 mm in a 0.35 um high voltage CMOS technology.

Modular Robotic Approach in Surgical Applications – Wireless Robotic Modules and a Reconfigurable Master Device for Endoluminal Surgery –

The trend in surgical robots is moving from traditional master-slave robots to miniaturized devices for screening and simple surgical operations (Cuschieri, A. 2005). For example, capsule endoscopy (Moglia, A. 2007) has been conducted worldwide over the last five years with successful outcomes. To enhance the dexterity of commercial endoscopic capsules, capsule locomotion has been investigated using legged capsules (Quirini, M. 2008) and capsules driven by external magnetic fields (Sendoh, M. 2003; Ciuti, G. 2010; Carpi, F. 2009). Endoscopic capsules with miniaturized arms have also been studied to determine their potential for use in biopsy (Park, S.-K. 2008). Furthermore, new surgical procedures known as natural orifice transluminal endoscopic surgery (NOTES) and Single Port Access surgery are accelerating the development of innovative endoscopic devices (Giday, S. 2006; Bardaro, S.J. 2006). These advanced surgical devices show potential for the future development of minimally invasive and endoluminal surgery. However, the implementable functions in such devices are generally limited owing to space constraints. Moreover, advanced capsules or endoscopes with miniaturized arms have rather poor dexterity because the diameter of such arms must be small (i.e. a few millimeters), which results in a small force being generated at the tip. A modular surgical robotic system known as the ARES (Assembling Reconfigurable Endoluminal Surgical system) system has been proposed based on the aforementioned motivations (Harada, K. 2009; Harada, K. 2010; Menciassi, A. 2010). The ARES system is designed for screening and interventions in the gastrointestinal (GI) tracts to overcome the intrinsic limitations of single-capsules or endoscopic devices. In the proposed system,

Enabling multiple robotic functions in an endoscopic capsule for the entire gastrointestinal tract exploration

Commercial endoscopic capsules are passive. Nevertheless, active capabilities such as active locomotion, drug delivery or biopsy, among others, can now be offered with the aid of robotics. New robotic functions require additional electronics for control purposes, as well as for the sensors and actuators. To avoid increasing the capsule size as a consequence, it is useful to incorporate all the electronics into the minimum number of elements, preferably in a single ASIC. This paper describes the ASIC included in a robotised capsule with the abovementioned active functions. The ASIC is a system-on-chip (SoC) integrating all the electronics needed to control the other electronic elements in the capsule. It also enables the movement of two BLDC motors, illuminates the exploration region and focuses a liquid lens used to achieve advanced vision capabilities. Details of the complete system integration are also given.