The implantable cardioverter defibrillator (ICD) is a reliable, cost-effective implanted device designed to terminate life-threatening cardiac arrhythmias and prevent sudden death. The recent exponential increase in implantation rates emphasises the need for nurses, doctors and other clinicians to understand the experience of living with an ICD for patients and partners. Current knowledge of patient experiences is mostly derived from overseas studies of specific variables, including physical problems, psychosocial outcomes, ICD shocks and quality of life issues. Studies of partner experiences focus on psychosocial concerns. Using van Manen's (1990) hermeneutic phenomenological approach, this study describes the experience of living with an ICD for seven Australian patients and six partners. Experiential descriptions, obtained in tape-recorded conversational interviews, were subjected to three levels of analysis. The first descriptive analysis summarised individual experiences of living with an ICD. The second, thematic analysis phenomenologically described the collective lived experience of being a patient, and of being a partner. Each description identified a challenging and changing experience through the themes of Being Disrupted and Distressed, Reconstructing Life, Appreciating and Celebrating Life, and Accommodating the ICD. For the patient, various everyday interactions, events and activities meant either being able to trust the ICD as a reassuring protection or experiencing it as an inescapable intrusive object. For the partner, a trusting reliance on the ICD's protective security eased the vulnerability and onerous perceived responsibility for the patient's survival and well-being. Threats to the partner's restored sense of normality, security and hope occurred when the patient wanted the ICD removed or discontinued. The third hermeneutic analysis specifically explored how the ICD, as an implanted biomedical device, was perceived, embodied and comprehended by patients. This analysis disclosed the varied, ambiguous existential meanings derived from and accorded to the ICD's presence, power and potential. The interpretation concluded that the ICD was either embodied as a trusted and reassuring friend, or existentially rejected as an intruder that thwarted meaningful possibilities. Theoretical and practical implications of this understanding of living with an ICD included several recommendations for improving staff education, as well as practical interventions for informing and supporting patients and partners. A proposal for implementing these recommendations concluded with suggestions for future inquiries that would extend understanding of this increasingly common human phenomenon.

Thesis (Ph.D.)--York University, 2008. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 99-127). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR51759

Thesis (M.Sc.Eng.) / The use of implantable neural probes has become common, both for stimulation and recording, and their applications range from chronic pain treatment to implementation of brain machine interfaces (BMI). Studies have shown that signal quality of implanted electrodes decays over time mainly due to the immune response. Characterization of the tissue-electrode interface is critical for better understanding of the physiological dynamics and potential performance improvement of the electrode itself and its task. This work describes the fabrication of an implantable electrode with optical measurement capabilities for providing means to characterize the tissue-electrode interface using optical spectroscopy. The electrode has a set of waveguides embedded in its shanks, which are used to inject white light into tissue and then collect the light reflected from the tissue surrounding the shanks. The collected light was analyzed with a spectrometer and the spectra processed to detect changes in optical properties, information that allows to track physiological changes. It is believed that the immune response can be correlated to changes in scattering as more cells are recruited to the injury site. The increased cell density in local injury/implantation sites increases the amount of scattering due to the increased number of cell nuclei and membranes that light encounters in its path. Investigation of scattering and absorption coefficients in such interface and their change over time can provide useful data for modeling and determining physiological parameters like blood oxygenation while the actual shape of the acquired spectra might highlight particular phenomena that can be indicative of scaring process or hemorrhaging. Validation of this system was done using optical phantoms based on polystyrene spheres and solutions with various concentrations of fat emulsion, which yielded scattering coefficients similar to those of brain tissue. Results suggest that the developed optrodes are able to detect differences between samples with different scattering coefficients. Improvements of fabrication process are discussed based on experimental results and future work includes attempting to perform fluorescence measurements of voltage reporters for optogenetic applications. The ultimate goal of this project was to create a novel device that is capable of satisfying the unmet need of tissue characterization at the implanted electrode interface as well as a tool for the optogenetics field suitable for greater depths than those a microscope can achieve.

Η χρήση της προηγμένης τεχνολογίας για την παροχή υγειονομικής περίθαλψης από απόσταση έχει τη δυνατότητα να είναι μία από τις πιο καθοριστικές ιατρικές επαναστάσεις του 21ου αιώνα. Είναι κοινώς αποδεκτό ότι η σύγχρονη ασύρματη τεχνολογία θα διαδραματίσει σημαντικό ρόλο στην εξέλιξη της προηγμένης τηλεϊατρικής. Η ανάπτυξη των εμφυτεύσιμων ιατρικών συσκευών (IMDs) είναι μία από τις πιο σημαντικές πτυχές για την εγκαθίδρυση ενός τέτοιου προηγμένου συστήματος υγειονομικής περίθαλψης. Σημαντικό στοιχείο των εμφυτεύσιμων συσκευών είναι κεραίες που ενσωματώνονται σε τέτοια συστήματα και επιτρέπουν την ανταλλαγή δεδομένων μεταξύ των εμφυτεύσιμων συσκευών με το εξωτερικό περιβάλλον. Η εν λόγω εργασία έγινε σε συνεργασία με την ερευνητική ομάδα της MediWise Ltd. Η λύση που προτείνεται στην παρούσα εργασία είναι μια βελτιστοποιημένη εμφυτεύσιμη κεραία για ασύρματη δοσιμετρία ακτινοβολίας για χρήση σε ακτινοθεραπεία εξωτερικής δέσμης, που έχει ως στόχο να αναπτυχθεί περαιτέρω στο μέλλον, προκειμένου να παραχθεί ένα εμπορικά βιώσιμο προϊόν. Η διατριβή παρουσιάζει το σχεδιασμό των δύο τύπων των εμφυτεύσιμων δομών κεραίας που είναι πιο κατάλληλα για την ελαχιστοποίηση των διαστάσεων, και επικεντρώνεται στην ανάπτυξη ενός εμφυτεύσιμου σχεδιασμού της κεραίας που είναι μικρότερο από 5 x 5 χιλιοστά σε μέγεθος το οποίο λειτουργεί στα 402 - 405 MHz MICS μπάντα και στην βελτιστοποίηση της επιλεγμένης εμφυτεύσιμης κεραία για εύρος ζώνης, απώλεια επιστροφής, ακτινοβολία, κλπ. και αποσκοπεί στην περαιτέρω σμίκρυνση της κεραίας σε μέγεθος 1 x 1 χιλιοστά. / The use of advanced technology to deliver healthcare from a distance has the potential to be one of the defining medical revolutions of the 21st century. It is commonly recognized that modern wireless technology will play an important role in making advanced telemedicine possible. The development of implantable medical devices (IMDs) is one of the most important aspects towards establishing such an advanced healthcare system. Essential element of implantable devices are antennas embedded in such systems, which enable the exchange of data between implantable devices and external environment. The underlying project was ran in collaboration with MediWise Ltd. The solution proposed in this dissertation is an optimised implantable antenna, for wireless radiation dosimetry for usage within external-beam radiotherapy, which aims to be further developed in the future in order to produce a commercially viable product. The dissertation presents the design of two types of implantable antenna structures that are suitable for miniaturisation, and focuses on the development of an implantable antenna design that is smaller than 5 x 5 mm in size which operates at 402 - 405 MHz MICS band and on the optimization of the chosen implantable antenna for bandwidth, return loss, radiation, etc. and aim to miniaturise further the antenna at 1 x 1 mm in size.

For several decades of years, the electrical stimulation has been applied on rehabilitation of motional recovery for quadriplegic and paraplegic patients such as walking, standing, and cycling exercise. As the advancement of VLSI (very large scale integration) technology, the implantable micro-stimulators become feasible in recent years. This thesis presents an implantable system including an inductively coupling transceiver of power & data, a protocol of communication, and the implementation of a FES (Functional Electrical Stimulation ) SOC (System-On-chip). The first part of this thesis discusses the architecture of the proposed implantable FES system, including the theory of wireless power transmission, the implementation of mixed-signal circuits, the RS232 protocol, and two encoding methods of Manchester code and NRZ code. The second part of this thesis is focused on the multi-frequency stimulation of the implantable FES system, which comprises an advanced communication protocol suitable for multi-frequency stimulation function and a novel arrangement of interconnections for the chip.

The first topic of this thesis is to propose a design of an all-digital low¡Vpower PLL (ADPLL). This design is implemented by only using standard cell library. The design cycle is effectively reduced. Furthermore, the portability and reusability of the proposed design is significantly raised. The large power consumption, glitch hazards, and timing violations of prior ADPLL designs are avoided by the proposed control method and modified DCO with multiplexers. The proposed design is implemented by only using the standard cell library of TSMC (Taiwan Semiconductor Manufacturing Company) 0.18 um 1P6M CMOS process. The feature of power saving is verified by measurement, which shows that the power consumption of the proposed ADPLL is merely 1.45 mW at 166 MHz output. The second topic of this thesis is a load shift keying wireless modulator circuit for implantable biomedical SOC. We successfully realize data and power transmission between outer controller and an implantable chip via wireless RF transmission interface. The convenience and the safety of using the implantable biomedical chip are significantly improved. The proposed on-chip LSK modulator consumes less power and area than those of traditional designs. Hence, the design margin of the implantable biomedical chip will be relaxed. The proposed LSK modulator is implemented with TSMC 0.35um 2P4M mixed-signal process. The proposed wireless RF transmission interface is implemented on PCB with discrete components.

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2004. / Titre provenant de l'écran-titre.

A multi-channel wireless implantable neural recording (WINeR) system for electrophysiology and behavioral neuroscience research applications was proposed. The system is composed of two units: a system-on-a-chip (SoC) transmitter (Tx) unit and a receiver (Rx) unit. In the Tx unit, the outputs are combined with marker signals and modulated into pulse widths after the neural signals are amplified and filtered by an array of low-noise amplifiers (LNA). The next step involves time-division multiplexing (TDM) of pulse-width modulation (PWM) signals. The TDM-PWM signal drives RF transmitter block and is transmitted by an antenna. To satisfy the needs of neuroscientists during animal experiments, the proposed WINeR system provides long-term recording with inductive powering and stimulus-artifact rejection for closed-loop operations, which requires simultaneous stimulation and recording. The Rx is another critical unit for wireless-link communication. To increase the area of wireless coverage, multiple antennas are used for the Rx. In addition, the automatic frequency-tracking method is used to track free-running Tx frequencies, and a smart time-to-digital conversion method is used to reduce noise and interference. A high-throughput computer interface and software are also developed to continuously receive and store neural data. The WINeR system is a potential tool for neuroscientists due to several advantages, such as a reliable wireless link with large coverage and no blind spots, low power consumption, an unlimited power source, and a stimulation function.

Thesis (M.S.)--University of Michigan, 1994. / Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves [159]-165).