43 research outputs found
Wireless capsule endoscope for targeted drug delivery
The diagnosis and treatment of pathologies of the gastrointestinal (GI) tract are performed routinely by gastroenterologists using endoscopes and colonoscopes, however the small intestinal tract is beyond the reach of these conventional systems. Attempts have been made to access the small intestines with wireless capsule endoscopes (WCE). These pill-sized cameras take pictures of the intestinal wall and then relay them back for evaluation. This practice enables the detection and diagnosis of pathologies of the GI tract such as Crohn's disease, small intestinal tumours such as lymphoma and small intestinal cancer. The problems with these systems are that they have limited diagnostic capabilities and they do not offer the ability to perform therapy to the affected areas leaving only the options of administering large quantities of drugs or surgical intervention.
To address the issue of administering therapy in the small intestinal tract this thesis presents an active swallowable microrobotic platform which has novel functionality enabling the microrobot to treat pathologies through a targeted drug delivery system. This thesis first reviews the state-of-the-art in WCE through the evaluation of current and past literature. A review of current practises such as flexible sigmoidoscopy, virtual colonoscopy and wireless capsule endoscopy are presented. The following sections review the state-of-the-art in methods of resisting peristalsis, drug targeting systems and drug delivery. A review of actuators is presented, in the context of WCE, with a view to evaluate their acceptability in adding functionality to current WCEs.
The thesis presents a novel biologically-inspired holding mechanism which overcomes the issue of resisting natural peristalsis in the GI tract. An analysis of the two components of peristaltic force, circumferential and longitudinal peristaltic contractions, are presented to ensure correct functionality of the holding mechanism. A detailed analysis of the motorised method employed to deploy the expanding mechanism is described and a 5:1 scale prototype is presented which characterises the gearbox and validates the holding mechanism.
The functionality of WCE is further extended by the inclusion of a novel targeting mechanism capable of delivering a metered dose of medication to a target site of interest in the GI tract. A solution to the problem of positioning a needle within a 360 degree envelope, operating the needle and safely retracting the needle in the GI tract is discussed. A comprehensive analysis of the mechanism to manoeuvre the needle is presented and validation of the mechanism is demonstrated through the evaluation of scale prototypes.
Finally a drug delivery system is presented which can expel a 1 ml dose of medication, stored onboard the capsule, into the subcutaneous tissue of the GI tract wall. An analysis of the force required to expel the medication in a set period of time is presented and the design and analysis of a variable pitch conical compression spring which will be used to deliver the medication is discussed. A thermo mechanical trigger mechanism is presented which will be employed to release the compressed conical spring. Experimental results using 1:1 scale prototype parts validate the performance of the mechanisms.Open Acces
Design, Actuation, and Functionalization of Untethered Soft Magnetic Robots with Life-Like Motions: A Review
Soft robots have demonstrated superior flexibility and functionality than
conventional rigid robots. These versatile devices can respond to a wide range
of external stimuli (including light, magnetic field, heat, electric field,
etc.), and can perform sophisticated tasks. Notably, soft magnetic robots
exhibit unparalleled advantages among numerous soft robots (such as untethered
control, rapid response, and high safety), and have made remarkable progress in
small-scale manipulation tasks and biomedical applications. Despite the
promising potential, soft magnetic robots are still in their infancy and
require significant advancements in terms of fabrication, design principles,
and functional development to be viable for real-world applications. Recent
progress shows that bionics can serve as an effective tool for developing soft
robots. In light of this, the review is presented with two main goals: (i)
exploring how innovative bioinspired strategies can revolutionize the design
and actuation of soft magnetic robots to realize various life-like motions;
(ii) examining how these bionic systems could benefit practical applications in
small-scale solid/liquid manipulation and therapeutic/diagnostic-related
biomedical fields
Weakly Calibrated Stereoscopic Visual Servoing for Laser Steering: Application to Phonomicrosurgery.
International audienceThis paper deals with the study of a weakly calibrated multiview visual servoing control law for microrobotic laser phonomicrosurgery of the vocal folds. It consists of the development of an endoluminal surgery system for laserablation and resection of cancerous tissues. More specifically, this paper focuses on the part concerning the control of the laser spot displacement during surgical interventions. To perform this, a visual control law based on trifocal geometry is designed using two cameras and a laser source (virtual camera). The method is validated on a realistic testbench and the straight point-to-point trajectories are demonstrated
Measurement of Z-Directional Individual Fibre-Fibre Bond Strength and Microfibril Angle Using Microrobotics
The use of microrobotics in high throughput and precise characterization of objects at microscale has been noticeably increased during recent years. Microrobotics has provided a significant added value to multiple realms e.g. biomedical research, bio-based industry, microassembly of miniature products, etc. Recently, the use of microrobotic technology in paper industry has been also commenced for measuring properties at the single fibre level.
There is a large interest in the measurement of different loading modes of individual fibre-fibre bonds in pulp and paper/board industry. Among the four different modes of loading, it would be desirable for papermaking companies and paper converting companies to obtain the Z-directional strength of pulp and paper. Indeed, the Z-directional properties affect compressive properties, and accordingly the performance of structural paperboard products. Several methods have been developed to measure the Z-directional strength at a handsheet level; however, there is not any reported device capable of the Z-directional fibre-fibre bond strength measurement at a fibre level. This thesis work presents a novel method for the experimental evaluation of the Z-directional bond strength using microrobotics and a Polyvinylidene fluoride (PVDF) film microforce sensor. Due to the special dynamics of PVDF microforce sensors, the effect of the deformation rate on the performance of the sensor is studied. The Z-directional fibre-fibre bond strength experiments have been performed successfully for unrefined and refined bleached softwood Kraft pulp fibres.
Besides, paper scientists are interested in microfibril angle changes during and after application of the Z-directional force. Indeed, there is interest in simultaneous measurement of microfibril angle and mechanical properties such as Z-directional bond strength. To address this need, a microfibril angle measurements system based on microscopic transmission ellipsometry is developed and integrated to the microrobotic platform. The results from both Z-directional bond strength and microfibril angle measurement are promising.
In summary, the first concept for simultaneous measurement of microfibril angle and mechanical properties such as Z-directional bond strength at the individual fibre level is developed during this thesis work which has a high practical impact on the fibre characterization research field
Design of an Autonomous Swimming Miniature Robot Based on a Novel Concept of Magnetic Actuation
Abstract-In this work, we propose a new concept for locomotion of a miniature jellyfish-like robot based on the interaction of mobile permanent magnets. The robot is 35 mm in length and 15 mm in width, and it incorporates a rotary actuator, a magnetic rotor, several elastic magnetic tails and a polymeric body embedding a wireless microcontroller and power supply. The novel magnetic mechanism is very versatile for numerous applications and can be tailored and adapted on the basis of different specifications. An analytical model of the magnetic mechanism allows to shape the robot design based on the specific application. The working principle of the robot together with the design, prototyping and testing phases are illustrated in this paper
SINGLE SITE ROBOTC DEVICE AND RELATED SYSTEMS AND METHODS
The embodiments disclosed herein relate to various medical device components, including components that can be incor porated into robotic and/or in vivo medical devices. Certain embodiments include various medical devices for in vivo medical procedures
From Concept to Market: Surgical Robot Development
Surgical robotics and supporting technologies have really become a prime example of modern applied
information technology infiltrating our everyday lives. The development of these systems spans across
four decades, and only the last few years brought the market value and saw the rising customer base
imagined already by the early developers. This chapter guides through the historical development of the
most important systems, and provide references and lessons learnt for current engineers facing similar
challenges. A special emphasis is put on system validation, assessment and clearance, as the most
commonly cited barrier hindering the wider deployment of a system