Towards tactile sensing active capsule endoscopy

Examination of the gastrointestinal(GI) tract has traditionally been performed using tethered endoscopy tools with limited reach and more recently with passive untethered capsule endoscopy with limited capability. Inspection of small intestines is only possible using the latter capsule endoscopy with on board camera system. Limited to visual means it cannot detect features beneath the lumen wall if they have not affected the lumen structure or colour. This work presents an improved capsule endoscopy system with locomotion for active exploration of the small intestines and tactile sensing to detect deformation of the capsule outer surface when it follows the intestinal wall. In laboratory conditions this system is capable of identifying sub-lumen features such as submucosal tumours.Through an extensive literary review the current state of GI tract inspection in particular using remote operated miniature robotics, was investigated, concluding no solution currently exists that utilises tactile sensing with a capsule endoscopy. In order to achieve such a platform, further investigation was made in to tactile sensing technologies, methods of locomotion through the gut, and methods to support an increased power requirement for additional electronics and actuation. A set of detailed criteria were compiled for a soft formed sensor and flexible bodied locomotion system. The sensing system is built on the biomimetic tactile sensing device, Tactip, \cite{Chorley2008, Chorley2010, Winstone2012, Winstone2013} which has been redesigned to fit the form of a capsule endoscopy. These modifications have required a $360^{o}$ cylindrical sensing surface with $360^{o}$ panoramic optical system. Multi-material 3D printing has been used to build an almost complete sensor assembly with a combination of hard and soft materials, presenting a soft compliant tactile sensing system that mimics the tactile sensing methods of the human finger. The cylindrical Tactip has been validated using artificial submucosal tumours in laboratory conditions. The first experiment has explored the new form factor and measured the device's ability to detect surface deformation when travelling through a pipe like structure with varying lump obstructions. Sensor data was analysed and used to reconstruct the test environment as a 3D rendered structure. A second tactile sensing experiment has explored the use of classifier algorithms to successfully discriminate between three tumour characteristics; shape, size and material hardness. Locomotion of the capsule endoscopy has explored further bio-inspiration from earthworm's peristaltic locomotion, which share operating environment similarities. A soft bodied peristaltic worm robot has been developed that uses a tuned planetary gearbox mechanism to displace tendons that contract each worm segment. Methods have been identified to optimise the gearbox parameter to a pipe like structure of a given diameter. The locomotion system has been tested within a laboratory constructed pipe environment, showing that using only one actuator, three independent worm segments can be controlled. This configuration achieves comparable locomotion capabilities to that of an identical robot with an actuator dedicated to each individual worm segment. This system can be miniaturised more easily due to reduced parts and number of actuators, and so is more suitable for capsule endoscopy. Finally, these two developments have been integrated to demonstrate successful simultaneous locomotion and sensing to detect an artificial submucosal tumour embedded within the test environment. The addition of both tactile sensing and locomotion have created a need for additional power beyond what is available from current battery technology. Early stage work has reviewed wireless power transfer (WPT) as a potential solution to this problem. Methods for optimisation and miniaturisation to implement WPT on a capsule endoscopy have been identified with a laboratory built system that validates the methods found. Future work would see this combined with a miniaturised development of the robot presented. This thesis has developed a novel method for sub-lumen examination. With further efforts to miniaturise the robot it could provide a comfortable and non-invasive procedure to GI tract inspection reducing the need for surgical procedures and accessibility for earlier stage of examination. Furthermore, these developments have applicability in other domains such as veterinary medicine, industrial pipe inspection and exploration of hazardous environments

蠕動運動を用いた月・惑星の地中探査ロボットの開発

【学位授与の要件】中央大学学位規則第4条第1項【論文審査委員主査】中村　太郎（中央大学理工学部教授）【論文審査委員副査】梅田　和昇（中央大学理工学部教授）、大隅　久（中央大学理工学部教授）、國井　康晴（中央大学理工学部准教授）、久保田　孝（宇宙航空研究開発機構教授）博士（工学）中央大

Robotics 2010

Without a doubt, robotics has made an incredible progress over the last decades. The vision of developing, designing and creating technical systems that help humans to achieve hard and complex tasks, has intelligently led to an incredible variety of solutions. There are barely technical fields that could exhibit more interdisciplinary interconnections like robotics. This fact is generated by highly complex challenges imposed by robotic systems, especially the requirement on intelligent and autonomous operation. This book tries to give an insight into the evolutionary process that takes place in robotics. It provides articles covering a wide range of this exciting area. The progress of technical challenges and concepts may illuminate the relationship between developments that seem to be completely different at first sight. The robotics remains an exciting scientific and engineering field. The community looks optimistically ahead and also looks forward for the future challenges and new development

Worm blobs as entangled living polymers:From topological active matter to flexible soft robot collectives

Recently, the study of long, slender living worms has gained attention due to their unique ability to form highly entangled physical structures, exhibiting emergent behaviors. These organisms can assemble into an active three-dimensional soft entity referred to as the “blob”, which exhibits both solid-like and liquid-like properties. This blob can respond to external stimuli such as light, to move or change shape. In this perspective article, we acknowledge the extensive and rich history of polymer physics, while illustrating how these living worms provide a fascinating experimental platform for investigating the physics of active, polymer-like entities. The combination of activity, long aspect ratio, and entanglement in these worms gives rise to a diverse range of emergent behaviors. By understanding the intricate dynamics of the worm blob, we could potentially stimulate further research into the behavior of entangled active polymers, and guide the advancement of synthetic topological active matter and bioinspired tangling soft robot collectives.</p

Modelling the neuromechanics of exploration and taxis in larval Drosophiila

The Drosophila larva is emerging as a useful tool in the study of complex behaviours, due to its relatively small size, its genetic tractability, and its varied behavioural repertoire. The larva executes a stereotypical exploratory routine that appears to consist of stochastic alternation between straight peristaltic crawling and reorientation events through lateral bending. The larva performs taxis by biasing this behavioural pattern, allowing it to move up or down attractive and aversive stimulus gradients. Existing explanations of exploration and taxis behaviour often neglect the larva's embodiment, focusing on central pattern generation and decision making circuits within the nervous system. In Chapter 1 of this thesis, I review the current state of knowledge regarding larval peristalsis, exploration, and taxis behaviours, as well as existing theories of their generation. I argue that an understanding of the animal's embodiment should lead to a deeper understanding of its behaviour. In Chapter 2, I present a model of the axial mechanics of the larva, and demonstrate how the animal's body physics can be exploited to produce peristalsis by using segmentally localised, positive feedback of strain rate. The mechanical model includes viscoelastic tissue mechanics, muscular inputs, and substrate interaction while sensory feedback is modelled as a linear feedback control law. In Chapter 3, I extend the mechanical model to study motion in the plane, including both axial and transverse deformations of the body. The feedback law is replaced by a simple model of the larval nervous system. The model includes both a segmentally localised reflex arc as well as long-range, mutual inhibition between segments. The complete model is capable of generating both peristalsis and spontaneous reorientation, leading to emergent exploration behaviour in the form of a deterministic superdiffusion process grounded in the chaotic mechanics of the larva's body. In Chapter 4, I consider taxis behaviour. I introduce a transverse reflex capable of modulating the effective transverse viscosity of the larval body. When the larva is experiencing an increasing attractive (aversive) stimulus, the reflex acts to increase (decrease) the effective transverse viscosity, causing bending to occur less (more) easily. As a result, the model larvae approach attractive stimuli and avoid aversive stumuli. On a population level, I show that the transverse reflex can be thought of as biasing the model animals towards sub- or super-diffusion. I compare the statistics of this behaviour to those of the real larva. In Chapter 5, I shift focus to engineered soft systems. Having successfully deployed an energy-based modelling approach in Chapters 2--4, I argue for the adoption of an energy-focused (specifically, port-Hamiltonian) approach within the field of soft robotics. In Chapter 6, I present some initial theoretical extensions to the models presented in chapter 2--4. I first focus on the mechanics of self-righting and rolling behaviours, before modelling the ventral nerve cord of the larva using a ring attractor architecture. Finally, in Chapter 7, I summarise the results of the previous chapters and discuss directions for future research

An analysis of the locomotory behaviour and functional morphology of errant polychaetes

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Mathematical models for biological motility: From peristaltic crawling to plant nutations

In this thesis we propose mathematical models for the motility of one-dimensional crawlers moving along a line and for growing slender plant organs, which are applied to the study of peristaltic crawling and nutations of plant shoots, respectively. The first chapter contains a theoretical analysis of metameric worm-like robotic crawlers, and it investigates optimal actuation strategies. Our main result is that peristalsis, i.e., muscle extension and contraction waves propagating along the body, is an optimal actuation strategy for locomotion. We give a rigorous mathematical proof of this result by solving analytically the optimal control problem in the regime of small deformations. We show that phase coordination arises from the geometric symmetry of a 1D system, exactly in the periodic case and approximately, due to edge-effects, in the case of a crawler of finite length. In the second chapter we introduce the general framework of morphoelastic rods to model elongating slender plant organs. This chapter is intended as preparatory to the third one, where we derive a rod model that is exploited to investigate the role of mechanical deformations in circumnutating plant shoots. We show that, in the absence of endogenous cues, spontaneous oscillations might arise as system instabilities when a loading parameter exceeds a critical value. Moreover, when oscillations of endogenous nature are present, their relative importance with respect to the ones associated with the former mechanism varies in time, as the biomechanical properties of the shoot change. Our findings suggest that the relative importance of exogenous versus endogenous oscillations is an emergent property of the system, and that elastic deformations play a crucial role in this kind of phenomena