22 research outputs found
Tactile Sensing System for Lung Tumour Localization during Minimally Invasive Surgery
Video-assisted thoracoscopie surgery (VATS) is becoming a prevalent method for lung cancer treatment. However, VATS suffers from the inability to accurately relay haptic information to the surgeon, often making tumour localization difficult. This limitation was addressed by the design of a tactile sensing system (TSS) consisting of a probe with a tactile sensor and interfacing visualization software. In this thesis, TSS performance was tested to determine the feasibility of implementing the system in VATS. This was accomplished through a series of ex vivo experiments in which the tactile sensor was calibrated and the visualization software was modified to provide haptic information visually to the user, and TSS performance was compared using human and robot palpation methods, and conventional VATS instruments. It was concluded that the device offers the possibility of providing to the surgeon the haptic information lost during surgery, thereby mitigating one of the current limitations of VATS
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 cylindrical sensing surface with 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
Towards Continuous Acoustic Tactile Soft Sensing
Acoustic Soft Tactile (AST) skin is a novel sensing technology that uses deformations of the acoustic channels beneath the sensing surface to predict static normal forces and their contact locations. AST skin functions by sensing the changes in the modulation of the acoustic waves travelling through the channels as they deform due to the forces acting on the skin surface. Our previous study tested different AST skin designs for three discrete sensing points and selected two designs that better predicted the forces and contact locations. This paper presents a study of the sensing capability of these two AST skin designs with continuous sensing points with a spatial resolution of 6 mm. Our findings indicate that the AST skin with a dual-channel geometry outperformed the single-channel type during calibration. The dual-channel design predicted more than 90% of the forces within a ± 3 N tolerance and was 84.2% accurate in predicting contact locations with ± 6 mm resolution. In addition, the dual-channel AST skin demonstrated superior performance in a real-time pushing experiment over an off-the-shelf soft tactile sensor. These results demonstrate the potential of using AST skin technology for real-time force sensing in various applications, such as human-robot
interaction and medical diagnosis
OPTICAL-BASED TACTILE SENSORS FOR MINIMALLY INVASIVE SURGERIES: DESIGN, MODELING, FABRICATION AND VALIDATION
Loss of tactile perception is the most challenging limitation of state-of-the-art technology for minimally invasive surgery. In conventional open surgery, surgeons rely on their tactile sensation to perceive the tissue type, anatomical landmarks, and instrument-tissue interaction in the patient’s body. To compensate for the loss of tactile feedback in minimally invasive surgery, researchers have proposed various tactile sensors based on electrical and optical sensing principles. Optical-based sensors have shown the most compatibility with the functional and physical requirements of minimally invasive surgery applications. However, the proposed tactile sensors in the literature are typically bulky, expensive, cumbersome to integrate with surgical instruments and show nonlinearity in interaction with biological tissues. In this doctoral study, different optical tactile sensing principles were proposed, modeled, validated and various tactile sensors were fabricated, and experimentally studied to address the limitations of the state-of-the-art. The present thesis first provides a critical review of the proposed tactile sensors in the literature with a comparison of their advantages and limitations for surgical applications. Afterward, it compiles the results of the design, modeling, and validation of a hybrid optical-piezoresistive sensor, a distributed Bragg reflecting sensor, and two sensors based on the variable bending radius light intensity modulation principle. The performance of each sensor was verified experimentally for the required criteria of accuracy, resolution, range, repeatability, and hysteresis. Also, a novel image-based intensity estimation technique was proposed and its applicability for being used in surgical applications was verified experimentally. In the end, concluding remarks and recommendations for future studies are provided
Tactile sensing using elastomeric sensors
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 99-111).GelSight, namely, elastomeric sensor, is a novel tactile sensor to get the 3D information of contacting surfaces. Using GelSight, some tactile properties, such as softness and roughness, could be gained through image processing techniques. In this thesis, I implemented GelSight principle to reconstruct surface geometry of tested surfaces, based on which, the roughness comparison and lump detection experiment are conducted. Roughness of five different types of sandpapers are successfully compared using GelSight Ra value. In the lump detection experiment, a visual display for tactile information is presented. To get binary feedback of lump presence or not, a simple threshold method is introduced in this thesis. To evaluate the performance of GelSight sensor, human psychological experiments are conducted. In similar tasks, GelSight sensor outperforms humans in lump detection.by Xiaodan (Stella) Jia.S.M
Advances in Human-Robot Interaction
Rapid advances in the field of robotics have made it possible to use robots not just in industrial automation but also in entertainment, rehabilitation, and home service. Since robots will likely affect many aspects of human existence, fundamental questions of human-robot interaction must be formulated and, if at all possible, resolved. Some of these questions are addressed in this collection of papers by leading HRI researchers
Development of deep learning methods for head and neck cancer detection in hyperspectral imaging and digital pathology for surgical guidance
Surgeons performing routine cancer resections utilize palpation and visual inspection, along with time-consuming microscopic tissue analysis, to ensure removal of cancer. Despite this, inadequate surgical cancer margins are reported for up to 10-20% of head and neck squamous cell carcinoma (SCC) operations. There exists a need for surgical guidance with optical imaging to ensure complete cancer resection in the operating room. The objective of this dissertation is to evaluate hyperspectral imaging (HSI) as a non-contact, label-free optical imaging modality to provide intraoperative diagnostic information. For comparison of different optical methods, autofluorescence, RGB composite images synthesized from HSI, and two fluorescent dyes are also acquired and investigated for head and neck cancer detection. A novel and comprehensive dataset was obtained of 585 excised tissue specimens from 204 patients undergoing routine head and neck cancer surgeries. The first aim was to use SCC tissue specimens to determine the potential of HSI for surgical guidance in the challenging task of head and neck SCC detection. It is hypothesized that HSI could reduce time and provide quantitative cancer predictions. State-of-the-art deep learning algorithms were developed for SCC detection in 102 patients and compared to other optical methods. HSI detected SCC with a median AUC score of 85%, and several anatomical locations demonstrated good SCC detection, such as the larynx, oropharynx, hypopharynx, and nasal cavity. To understand the ability of HSI for SCC detection, the most important spectral features were calculated and correlated with known cancer physiology signals, notably oxygenated and deoxygenated hemoglobin. The second aim was to evaluate HSI for tumor detection in thyroid and salivary glands, and RGB images were synthesized using the spectral response curves of the human eye for comparison. Using deep learning, HSI detected thyroid tumors with 86% average AUC score, which outperformed fluorescent dyes and autofluorescence, but HSI-synthesized RGB imagery performed with 90% AUC score. The last aim was to develop deep learning algorithms for head and neck cancer detection in hundreds of digitized histology slides. Slides containing SCC or thyroid carcinoma can be distinguished from normal slides with 94% and 99% AUC scores, respectively, and SCC and thyroid carcinoma can be localized within whole-slide images with 92% and 95% AUC scores, respectively. In conclusion, the outcomes of this thesis work demonstrate that HSI and deep learning methods could aid surgeons and pathologists in detecting head and neck cancers.Ph.D
Development of a freehand three-dimensional radial endoscopic ultrasonography system
Oesophageal cancer is an aggressive malignancy with an overall five-year survival of 5-10% and
two-thirds of patients have irresectable disease at diagnosis. Accurate staging of oesophageal cancer is
important as survival closely correlates with the stage of the tumour, nodal involvement and presence
of metastases (TNM staging). Endoscopic ultrasonography (EUS) is currently the most reliable
modality for providing accurate T and N staging. Depending on findings of the staging, various
treatment options including endoscopic, oncological, and surgical treatments may be performed.
It was theorised that the development of three-dimensional radial endoscopic ultrasonography would
reduce the operator dependence of EUS and provide accurate dimensional and volume measurements
to aid planning and monitoring of treatment. This thesis investigates the development of a three
dimensional endoscopic ultrasound technique that can be used with the radial echoendoscopes.
Various agar-based tissue mimicking material (TMM) recipes were characterised using a scanning
acoustic macroscope to obtain the acoustic properties of attenuation, backscatter and speed of sound.
Using these results, a number of endoscopic ultrasound phantoms were developed for the in-vitro
investigation and evaluation of 3D-EUS techniques.
To increase my understanding of EUS equipment, the imaging and acoustic properties of the EUS
endoscopes were characterised using a pipe phantom and a hydrophone. The dual ‘single element’
mechanical and ‘multi-element’ electronic echoendoscopes were investigated. Measured imaging
properties included dead space, low contrast penetration, and pipe length. The measured acoustic
properties included transmitted beam plots, active working frequency and peak pressures.
Three-dimensional ultrasound techniques were developed for specific application to EUS. This
included the study of positional monitoring systems, reconstruction algorithms and measurement
techniques. A 3D-EUS system was developed using a Microscribe positional arm and frame grabber
card, to acquire the 3D dataset. A Matlab 3D-EUS toolbox was written to reconstruct and analyse the
volumes. The 3D-EUS systems were evaluated on the EUS phantom and in clinical cases.
The usefulness of the 3D-EUS systems was evaluated in a cohort of patients, who were routinely
investigated by conventional EUS for a variety of upper gastrointestinal pathology. 3D-EUS
accurately staged early tumours and provided the necessary anatomical information to facilitate
treatment. With regards to more advanced tumours, 3D-EUS was more accurate than EUS in T and N
staging. 3D-EUS gave useful anatomical details in a variety of benign conditions such as varicies and
GISTs
Mastering Endo-Laparoscopic and Thoracoscopic Surgery
This is an open access book. The book focuses mainly on the surgical technique, OR setup, equipments and devices necessary in minimally invasive surgery (MIS). It serves as a compendium of endolaparoscopic surgical procedures. It is an official publication of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA). The book includes various sections covering basic skills set, devices, equipments, OR setup, procedures by area. Each chapter cover introduction, indications and contraindications, pre-operative patient’s assessment and preparation, OT setup (instrumentation required, patient’s position, etc.), step by step description of surgical procedures, management of complications, post-operative care. It includes original illustrations for better understanding and visualization of specific procedures. The book serves as a practical guide for surgical residents, surgical trainees, surgical fellows, junior surgeons, surgical consultants and anyone interested in MIS. It covers most of the basic and advanced laparoscopic and thoracoscopic surgery procedures meeting the curriculum and examination requirements of the residents