29 research outputs found
Image-Based Force Estimation and Haptic Rendering For Robot-Assisted Cardiovascular Intervention
Clinical studies have indicated that the loss of haptic perception is the prime limitation of robot-assisted cardiovascular intervention technology, hindering its global adoption. It causes compromised situational awareness for the surgeon during the intervention and may lead to health risks for the patients. This doctoral research was aimed at developing technology for addressing the limitation of the robot-assisted intervention technology in the provision of haptic feedback. The literature review showed that sensor-free force estimation (haptic cue) on endovascular devices, intuitive surgeon interface design, and haptic rendering within the surgeon interface were the major knowledge gaps. For sensor-free force estimation, first, an image-based force estimation methods based on inverse finite-element methods (iFEM) was developed and validated. Next, to address the limitation of the iFEM method in real-time performance, an inverse Cosserat rod model (iCORD) with a computationally efficient solution for endovascular devices was developed and validated. Afterward, the iCORD was adopted for analytical tip force estimation on steerable catheters. The experimental studies confirmed the accuracy and real-time performance of the iCORD for sensor-free force estimation. Afterward, a wearable drift-free rotation measurement device (MiCarp) was developed to facilitate the design of an intuitive surgeon interface by decoupling the rotation measurement from the insertion measurement. The validation studies showed that MiCarp had a superior performance for spatial rotation measurement compared to other modalities. In the end, a novel haptic feedback system based on smart magnetoelastic elastomers was developed, analytically modeled, and experimentally validated. The proposed haptics-enabled surgeon module had an unbounded workspace for interventional tasks and provided an intuitive interface. Experimental validation, at component and system levels, confirmed the usability of the proposed methods for robot-assisted intervention systems
Medical Robotics
The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently âmedical roboticistsâ or not
A novel three-finger IPMC gripper for microscale applications
Smart materials have been widely used for control actuation. A robotic hand can
be equipped with artificial tendons and sensors for the operation of its various joints
mimicking human-hand motions. The motors in the robotic hand could be replaced with
novel electroactive-polymer (EAP) actuators. In the three-finger gripper proposed in this
paper, each finger can be actuated individually so that dexterous handling is possible,
allowing precise manipulation.
In this dissertation, a microscale position-control system using a novel EAP is
presented. A third-order model was developed based on the system identification of the
EAP actuator with an AutoRegresive Moving Average with eXogenous input (ARMAX)
method using a chirp signal input from 0.01 Hz to 1 Hz limited to 7 ĂĂÂą V. With the
developed plant model, a digital PID (proportional-integral-derivative) controller was
designed with an integrator anti-windup scheme. Test results on macro (0.8-mm) and
micro (50-ĂĂÂźm) step responses of the EAP actuator are provided in this dissertation and its
position tracking capability is demonstrated. The overshoot decreased from 79.7% to 37.1%, and the control effort decreased by 16.3%. The settling time decreased from 1.79
s to 1.61 s. The controller with the anti-windup scheme effectively reduced the
degradation in the system performance due to actuator saturation. EAP microgrippers
based on the control scheme presented in this paper will have significant applications
including picking-and-placing micro-sized objects or as medical instruments.
To develop model-based control laws, we introduced an approximated linear
model that represents the electromechanical behavior of the gripper fingers. Several chirp
voltage signal inputs were applied to excite the IPMC (ionic polymer metal composite)
fingers in the interesting frequency range of [0.01 Hz, 5 Hz] for 40 s at a sampling
frequency of 250 Hz. The approximated linear Box-Jenkins (BJ) model was well matched
with the model obtained using a stochastic power-spectral method. With feedback control,
the large overshoot, rise time, and settling time associated with the inherent material
properties were reduced. The motions of the IPMC fingers in the microgripper were
coordinated to pick, move, and release a macro- or micro-part. The precise manipulation
of this three-finger gripper was successfully demonstrated with experimental closed-loop
responses
Advanced Applications of Rapid Prototyping Technology in Modern Engineering
Rapid prototyping (RP) technology has been widely known and appreciated due to its flexible and customized manufacturing capabilities. The widely studied RP techniques include stereolithography apparatus (SLA), selective laser sintering (SLS), three-dimensional printing (3DP), fused deposition modeling (FDM), 3D plotting, solid ground curing (SGC), multiphase jet solidification (MJS), laminated object manufacturing (LOM). Different techniques are associated with different materials and/or processing principles and thus are devoted to specific applications. RP technology has no longer been only for prototype building rather has been extended for real industrial manufacturing solutions. Today, the RP technology has contributed to almost all engineering areas that include mechanical, materials, industrial, aerospace, electrical and most recently biomedical engineering. This book aims to present the advanced development of RP technologies in various engineering areas as the solutions to the real world engineering problems
Magnetic navigation in percutaneous coronary and non-coronary interventions
There is no question that Percutaneous Coronary Intervention has revolutionized the way we
manage coronary artery disease. Over the past two decades we have witnessed maturity in
several techniques and equipment enabling the interventional cardiologist to manage lesions
that have previously been entirely in the domain of the cardiac surgeon. Despite these remarkable
achievements there still remain lesions that are complex enough to create a challenge
in the most experienced hands.The inherent tortuosity in complex vascular anatomies,
branching segments and chronically occluded vessel have been all associated with lower
procedural success and higher complication rates when compared to the âstraight forward vesselsâ. The Magnetic Navigation System (MNS) is a novel and versatile technology that allows
the re-orientation of a wire within the patientâs body. This unique ability means that the âtrial
and errorâ method of externally re-shaping the tip of the wire and re-engaging the vessel can
be effectively eliminated. As such previously âunreachable areasâ in the heart or within the
vascul
Enhancement of spatial awareness in natural orifice transluminal endoscopic surgery
Natural orifice transluminal endoscopic surgery (NOTES) represents a challenging concept to pursue in minimally invasive procedures, with a promise of becoming even less invasive, but with the additional issues of being team dependent and more technology intensive.
The safety of patients undergoing any surgical procedure is of principal importance. When a surgeon performs laparoscopic procedures, he only has a two dimensional field of view and as a result, his spatial awareness is diminished. A surgeon operating under conditions of reduced spatial awareness poses an increased risk to a patient.
Spatial awareness is deemed a necessary skill for the safe deployment of NOTES procedures. Understanding the surgeonâs situational and spatial awareness during NOTES investigation is therefore of paramount importance for the safe performance of this type of procedures. Enhancing scene visualisation, for instance by means of additional viewpoints or electromagnetic tracking, seems a feasible strategy for augmenting spatial awareness in NOTES. This study aims to propose novel approaches involving electromagnetic tracking and additional off-axis visualisation in an attempt to assess, as well as enhance spatial awareness of the operating field in NOTES.
The original contributions of this thesis include:
⢠Validation of an outlining approach to characterise spatial awareness in minimally invasive surgery particularly in NOTES
⢠Qualitative and quantitative assessment of spatial awareness n NOTES
⢠Identification of certain navigation behavioural patterns in NOTES
⢠Design and evaluation of spatial awareness enhancement tool for NOTES
The value of the research presented in this thesis, as well as the potential for further development is also discussed in the context of spatial awareness in MIS in general