DTA

Digital Theses Archive

 

Tesi etd-02092023-183434

Type of thesis
Dottorato
Author
REN, XUYANG
URN
etd-02092023-183434
Title
Soft Robotic Devices for Endoluminal Diagnosis and Intervention
Scientific disciplinary sector
ING-IND/34
Course
Istituto di Biorobotica - PHD IN BIOROBOTICA
Committee
relatore Prof. DARIO, PAOLO
Tutor Prof. CIUTI, GASTONE
Keywords
  • Endoluminal Devices
  • Endoluminal Diagnosis and Intervention
  • Endoscopy
  • Medical Robotics
  • Soft Robotics
Exam session start date
26/04/2023;
Availability
parziale
Abstract
In the recent years, soft robotic devices for the diagnosis and treatment of the gastrointestinal tract are drawing significant attention in research, and they exhibit a great potential to obtain better outcomes during inspection and surgery. The common favourable feature of these tools, being compliant, allows them interacting with the tissues or organs safely. However, the effectiveness and low invasiveness of such devices is still challenging. Therefore, application-based requirements and proper engineering approaches are needed for the development of effective robotic endoscopic devices.<br>In this context, the goal is to develop soft robotic devices which can perform inspection, diagnosis, and treatment in a safer and more effective manner. To this purpose, my Ph.D. activity focused on the development of different diagnostic and interventional robotic platforms, i.e.: i) a soft gastroscope with an ultrathin diameter tether to perform inspection inside the stomach; ii) an adjunct robotic tool compliant with conventional colonoscopes to accomplish surgery inside the colorectal tract; iii) an origami-inspired colonoscope with a large pulling/pushing force and bending angle to improve locomotion with a limited invasiveness inside the colon; and iv) an assistive device with a two-phase anchoring mechanism for supporting locomotion of soft-tethered colonoscopes with “front-wheel” locomotion. The contents of the thesis are organized into 7 chapters:<br>Chapter 1 reports the motivation of the whole thesis and a general background concerning the devices for the diagnosis and treatment inside the gastrointestinal tract. <br>Chapter 2 reviews the literatures of the proposed devices including those for the upper and lower gastrointestinal tract. Apart from summarizing the state of the art, open issues, potential research limitations and challenges are also discussed.<br>Chapters 3 is about the design of a soft robotic gastroscope for low/middle-income countries. The gastroscope with a small diameter tether and its allied operating controller are described; the mechanical performance is characterized in the laboratory setting, comparing performance with the mathematic analysis and the numerical simulation. Experiments are conducted to validate functionalities in in-vitro and ex-vivo environments.<br>Chapters 4 is about the design of a robotic platform for micro-surgery in the colorectal tract. The soft robotic platform is designed to be compliant with a standard colonoscope; besides, the mapping principle between the master device and slave device is established. After that, the performance of the end effector and the tether is investigated, and the workspace is constructed. Finally, in-vitro and ex-vivo experiments were conducted to demonstrate the function in different scenarios.<br>Chapters 5 is about the design of a self-propelling dexterous origami-based soft robot for colonoscopy. The origami-based central actuator and the dumbbell-shaped anchor actuator are developed, the mathematic modelling and anchoring mechanism are investigated, and then the pushing force, bending angle and anchoring force are characterized. Functionalities are also validated in ex-vivo setting.<br>Chapters 6 is about the design of a flexible assistive device for soft-tethered robotic colonoscopes. The main concept of the mechanism is introduced, and several designs are presented. Then, with a model-based design approach, utilizing both analytical and numerical models, the performance is characterized. Furthermore, functionalities are experimentally evaluated both in laboratory and ex-vivo conditions.<br>Chapter 7 sketches out the conclusions of this Ph.D. thesis and highlights future perspectives, by describing possible trends and strategies to address scientific and medical issues still hampering the wide adoption of soft robots in the clinical practice.
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