27 research outputs found

    Development of a Hybrid Stereotactic Guidance System For Percutaneous Liver Tumour Ablation

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    Stereotactic Image-Guided Surgical Navigation System (IGSNS) supports percutaneous procedures by using medical imaging and tracking information, to assist the surgeons in the preprocedural planning and intraprocedural steps. This thesis describes the development of a stereotactic IGSNS for percutaneous liver tumour ablation, the goal of which is to assist in positioning the tip of the ablation applicator accurately to ensure complete tumour coverage. The main system improvement is the employment of a mini stereotactic patient-attach aiming device that is used as a pointer to ensure needle tip position prior to needle insertion. The thesis chapters describe the development and validation of the components of the stereotactic IGSNS. An anthropomorphic phantom development for validation and training is also presented. We hypothesize that the combination of spatial tracking, real-time ultrasound, mechanical stabilization provided by the mini-stereotactic device and image-to-image registration will improve the targeting accuracy for the focal treatment and reduce the needle repositioning

    Bio-Micro-Systems for Diagnostic Applications, Disease Prevention and Creating Tools for Biological Research

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    This thesis, divided into two parts, describes the development of 5 novel Bio-Micro-System devices. The term Bio-Micro-System has been used here to describe BioMEMS and 3D printed devices, with the dimensions of key components ranging from micrometers to a millimeter. Part A is focused on ‘Medical’ Micro-System devices that can potentially solve common medical problems. Part B is focused on ‘Biological’ Micro-System devices/tools for facilitating/enabling biological research. Specifically, Part A describes two implantable, electronics-free intraocular pressure (IOP) microsensors for the medical management of glaucoma: 1) Near Infrared Fluorescence-based Optomechanical (NiFO) technology - Consists of an implantable, pressure sensor that ‘optically encodes’ pressure in the near infrared (NIR) regime. A non-implantable, portable and compact optical head is used to excite the sensor and collect the emitted NIR light. The thesis discusses optimized device architecture and microfabrication approaches for best performance commercialization. 2) Displacement based Contrast Imaging (DCI) technology - A proof of concept, fluid pressure sensing scheme is shown to operate over a pressure range of 0–100 mbar (∼2 mbar resolution between 0–20 mbar,∼10 mbar resolution between 20–100 mbar), with a maximum error of <7% throughout its dynamic range. The thesis introduces the DCI technology and discusses its application as an IOP sensor. Moreover, Part A also describes a Touch-activated Sanitizer Dispensing (TSD) system for combating community acquired infections. The TSD can be mounted on any surface that is exposed to high human traffic and consists of an array of human-powered, miniaturized valves that deliver a small amount of disinfectant when touch actuated. The device disinfects the person’s hand that is touching it while being self-sterilized at the same time. The thesis describes the design and implementation of a proof of concept TSD that can disinfect an area equivalent to the size of a thumb. A significant (~ 10 fold) reduction in microbiological load is demonstrated on the fingertip and device surface within the first 24 hours. The size and footprint of the TSD can be scaled up as needed to improve hand hygiene compliance. In Part B, we developed a microfluidic chip for immobilizing Drosophila melanogaster larva by creating a cold micro-environment around the larva. After characterizing on chip temperature distribution and larval body movement, results indicate that the method is appropriate for repetitive and reversible, short-term (several minutes) immobilization. The method offers the added advantage of using the same chip to accommodate and immobilize larvae across all developmental stages (1st instar-late 3rd instar). Besides the demonstrated applications of the chip in high resolution observation of sub cellular events such as mitochondrial trafficking in neurons and neuro-synaptic growth, we envision the use of this method in a wide variety of biological imaging studies employing the Drosophila larval system, including cellular development and other studies. Finally, Part B also describes a 3D printed millifluidic device for CO2 immobilization of Caenorhabditis elegans populations. We developed a novel 3D printed device for immobilizing populations of Caenorhabditis elegans by creating a localized CO2 environment while the animals are maintained on the surface of agar. The results indicate that the method is easy to implement, is appropriate for short-term (20 minutes) immobilization and allows recovery within a few minutes. We envision its use in a wide variety of biological studies in Caenorhabditis elegan, including cellular development and neuronal regeneration studies.PHDBiomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/144050/1/amritarc_1.pd

    Control techniques for mechatronic assisted surgery

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    The treatment response for traumatic head injured patients can be improved by using an autonomous robotic system to perform basic, time-critical emergency neurosurgery, reducing costs and saving lives. In this thesis, a concept for a neurosurgical robotic system is proposed to perform three specific emergency neurosurgical procedures; they are the placement of an intracranial pressure monitor, external ventricular drainage, and the evacuation of chronic subdural haematoma. The control methods for this system are investigated following a curiosity led approach. Individual problems are interpreted in the widest sense and solutions posed that are general in nature. Three main contributions result from this approach: 1) a clinical evidence based review of surgical robotics and a methodology to assist in their evaluation, 2) a new controller for soft-grasping of objects, and 3) new propositions and theorems for chatter suppression sliding mode controllers. These contributions directly assist in the design of the control system of the neurosurgical robot and, more broadly, impact other areas outside the narrow con nes of the target application. A methodology for applied research in surgical robotics is proposed. The methodology sets out a hierarchy of criteria consisting of three tiers, with the most important being the bottom tier and the least being the top tier. It is argued that a robotic system must adhere to these criteria in order to achieve acceptability. Recent commercial systems are reviewed against these criteria, and are found to conform up to at least the bottom and intermediate tiers. However, the lack of conformity to the criteria in the top tier, combined with the inability to conclusively prove increased clinical benefit, particularly symptomatic benefit, is shown to be hampering the potential of surgical robotics in gaining wide establishment. A control scheme for soft-grasping objects is presented. Grasping a soft or fragile object requires the use of minimum contact force to prevent damage or deformation. Without precise knowledge of object parameters, real-time feedback control must be used to regulate the contact force and prevent slip. Moreover, the controller must be designed to have good performance characteristics to rapidly modulate the fingertip contact force in response to a slip event. A fuzzy sliding mode controller combined with a disturbance observer is proposed for contact force control and slip prevention. The robustness of the controller is evaluated through both simulation and experiment. The control scheme was found to be effective and robust to parameter uncertainty. When tested on a real system, however, chattering phenomena, well known to sliding mode research, was induced by the unmodelled suboptimal components of the system (filtering, backlash, and time delays). This reduced the controller performance. The problem of chattering and potential solutions are explored. Real systems using sliding mode controllers, such as the control scheme for soft-grasping, have a tendency to chatter at high frequencies. This is caused by the sliding mode controller interacting with un-modelled parasitic dynamics at the actuator-input and sensor-output of the plant. As a result, new chatter-suppression sliding mode controllers have been developed, which introduce new parameters into the system. However, the effect any particular choice of parameters has on system performance is unclear, and this can make tuning the parameters to meet a set of performance criteria di cult. In this thesis, common chatter-suppression sliding mode control strategies are surveyed and simple design and estimation methods are proposed. The estimation methods predict convergence, chattering amplitude, settling time, and maximum output bounds (overshoot) using harmonic linearizations and invariant ellipsoid sets

    NASA SBIR abstracts of 1992, phase 1 projects

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    The objectives of 346 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1992 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 346, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1992 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

    Biomedical Engineering

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    Biomedical engineering is currently relatively wide scientific area which has been constantly bringing innovations with an objective to support and improve all areas of medicine such as therapy, diagnostics and rehabilitation. It holds a strong position also in natural and biological sciences. In the terms of application, biomedical engineering is present at almost all technical universities where some of them are targeted for the research and development in this area. The presented book brings chosen outputs and results of research and development tasks, often supported by important world or European framework programs or grant agencies. The knowledge and findings from the area of biomaterials, bioelectronics, bioinformatics, biomedical devices and tools or computer support in the processes of diagnostics and therapy are defined in a way that they bring both basic information to a reader and also specific outputs with a possible further use in research and development

    MEMS Technology for Biomedical Imaging Applications

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    Biomedical imaging is the key technique and process to create informative images of the human body or other organic structures for clinical purposes or medical science. Micro-electro-mechanical systems (MEMS) technology has demonstrated enormous potential in biomedical imaging applications due to its outstanding advantages of, for instance, miniaturization, high speed, higher resolution, and convenience of batch fabrication. There are many advancements and breakthroughs developing in the academic community, and there are a few challenges raised accordingly upon the designs, structures, fabrication, integration, and applications of MEMS for all kinds of biomedical imaging. This Special Issue aims to collate and showcase research papers, short commutations, perspectives, and insightful review articles from esteemed colleagues that demonstrate: (1) original works on the topic of MEMS components or devices based on various kinds of mechanisms for biomedical imaging; and (2) new developments and potentials of applying MEMS technology of any kind in biomedical imaging. The objective of this special session is to provide insightful information regarding the technological advancements for the researchers in the community

    Advances in Bioengineering

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    The technological approach and the high level of innovation make bioengineering extremely dynamic and this forces researchers to continuous updating. It involves the publication of the results of the latest scientific research. This book covers a wide range of aspects and issues related to advances in bioengineering research with a particular focus on innovative technologies and applications. The book consists of 13 scientific contributions divided in four sections: Materials Science; Biosensors. Electronics and Telemetry; Light Therapy; Computing and Analysis Techniques

    Applications and Experiences of Quality Control

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    The rich palette of topics set out in this book provides a sufficiently broad overview of the developments in the field of quality control. By providing detailed information on various aspects of quality control, this book can serve as a basis for starting interdisciplinary cooperation, which has increasingly become an integral part of scientific and applied research

    Research and technology highlights, 1993

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    This report contains highlights of the major accomplishments and applications that have been made by Langley researchers and by our university and industry colleagues during the past year. The highlights illustrate both the broad range of the research and technology activities supported by NASA Langley Research Center and the contributions of this work toward maintaining United States leadership in aeronautics and space research. This report also describes some of the Center's most important research and testing facilities
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