RESUMEN
BACKGROUND: A colonoscopy and a gastroscopy are the most important screening measures for malignant diseases in the GI tract. One of the main limitations is the lack of patient adherence to come in for a flexible endoscopy, especially in asymptomatic conditions. OBJECTIVE: The feasibility proof of a new generation of endoscopic capsules based on a novel propelling mechanism that features electromechanical legs. DESIGN: Teleoperated endoscopic 8-legged capsule. SETTING: Scuola Superiore Sant'Anna, Pisa, Italy, and novineon Healthcare Technology Partners GmbH, Tübingen, Germany. MAIN OUTCOME MEASUREMENTS: Successful locomotion in a lower-GI tract (LGI) phantom model and in a porcine colon. RESULTS: The testing session was organized into repetitive ex vivo trials and in vivo tests. The repetitive tests were performed for collecting reproducible data in various small series of individual experiments in standardized conditions, thus defining the best locomotion parameters. In vivo tests were performed in a porcine colon: the capsule, inserted transanally, traveled upward in the oral direction for 15 cm in about 5 minutes, against peristalsis. LIMITATIONS: The current version of the capsule travels curves by bouncing back from the wall and following step by step the direction of the curved bowel. Steering mechanisms are not yet implemented. CONCLUSIONS: This study shows the systematic development and medical assessment of an imaging capsule with self-propelling abilities. A full colonic passage was successfully demonstrated in the ex vivo phantom model. A net movement in in vivo tests has been achieved, thus giving a feasibility proof of the legged locomotion as a possible solution to the problem of self-locomoting endoscopic devices in the LGI.
Asunto(s)
Endoscopía Capsular/métodos , Colonoscopía/métodos , Motilidad Gastrointestinal , Tracto Gastrointestinal , Gastroscopía/métodos , Peristaltismo/fisiología , Animales , Biomimética , Endoscopios en Cápsulas , Diseño de Equipo , Estudios de Factibilidad , Modelos Animales , Fantasmas de Imagen , Sensibilidad y Especificidad , Porcinos , Grabación en VideoRESUMEN
This paper describes a novel approach to capsular endoscopy that takes advantage of active legged locomotion in the gastro intestinal tract. The basic and essential functions that such a microdevice must possess are listed and discussed in details, as well as the specific features required in the different districts of the digestive path. Active legged locomotion was selected to achieve the adequate degree of flexibility and accuracy during the capsule journey. In addition, on-board locomotion mechanisms would allow to avoid bulky external driving systems that are typical of externally actuated devices. Two different prototypes, having 4 and 8 legs respectively, are presented, evaluated and tested. In particular, the 8-leg solution achieved a speed of 6 cm/min during in vitro tests. Moreover, it demonstrated capabilities of backward locomotion, vertical locomotion and locomotion around acute bends.
Asunto(s)
Endoscopía Capsular/métodos , Tracto Gastrointestinal/anatomía & histología , Movimiento (Física)RESUMEN
The impulse given by robotic technologies and imaging techniques to the development of a new way to conceive and perform surgery is clearly visible. Nowadays, minimally invasive surgical (MIS) procedures are often performed with the assistance of robots, such as the Da Vinci master-slave system, the AESOP robot with voice control, etc. In addition, mechatronic technologies are becoming the elective technologies for designing advanced hand-held surgical tools. The introduction of robotic technologies in endoscopy has been slower than in MIS, since the development of miniaturized robotic components for entering the small orifices of the human body is difficult. On the other hand, the large contribution that robotic technologies could bring to endoluminal techniques has been evident since the first development of instrumented catheters. In the 1990s, there was an increasing activity in the application of robotic technologies to improve endoscopic procedures in the gastrointestinal tract. The objective of robotic colonoscopy and gastroscopy was to obtain more effective diagnoses in terms of reduced pain for the patients, and to make uniform the diagnostic procedures, which too often depended on the manual abilities of the endoscopist. Currently, the availability of more reliable robotic technologies for miniaturization of size and integration of functions has allowed to conceive and develop robotic pills for the early screening of the digestive tract, with dramatic potential advantages for patients, endoscopists, and healthcare system.
Asunto(s)
Endoscopía Gastrointestinal/métodos , Miniaturización , Robótica/instrumentación , Endoscopios en Cápsulas , Electrónica Médica/instrumentación , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentaciónRESUMEN
This paper illustrates the problem of active locomotion in the gastrointestinal tract for endoscopic capsules. Authors analyze the problem of locomotion in unstructured, flexible and tubular environments and explain the reasons leading to the selection of a legged system. They present a theoretical simulation of legged capsule locomotion, which is used to define the optimal parameters for capsule design and gait selection. Finally, a legged capsule--about 3 cm3 in volume--is presented; it consists of 4 back legs whose actuation is achieved thanks to a miniaturized DC brushless motor. In vitro tests demonstrate good performance in terms of achievable speed (92 mm/min).