Wireless Intraocular Pressure Sensing Using Microfabricated Minimally Invasive Flexible-Coiled LC Sensor Implant

This paper presents an implant-based wireless pressure sensing paradigm for long-range continuous intraocular pressure (IOP) monitoring of glaucoma patients. An implantable parylene-based pressure sensor has been developed, featuring an electrical LC-tank resonant circuit for passive wireless sensing without power consumption on the implanted site. The sensor is microfabricated with the use of parylene C (poly-chlorop- xylylene) to create a flexible coil substrate that can be folded for smaller physical form factor so as to achieve minimally invasive implantation, while stretched back without damage for enhanced inductive sensor–reader coil coupling so as to achieve strong sensing signal. A data-processed external readout method has also been developed to support pressure measurements. By incorporating the LC sensor and the readout method, wireless pressure sensing with 1-mmHg resolution in longer than 2-cm distance is successfully demonstrated. Other than extensive on-bench characterization, device testing through six-month chronic in vivo and acute ex vivo animal studies has verified the feasibility and efficacy of the sensor implant in the surgical aspect, including robust fixation and long-term biocompatibility in the intraocular environment. With meeting specifications of practical wireless pressure sensing and further reader development, this sensing methodology is promising for continuous, convenient, direct, and faithful IOP monitoring

Critical evaluation and novel design of a non-invasive and wearable health monitoring system

This thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.This study is about developing a non-invasive wearable health-monitoring system. The project aims to achieve miniaturisation as much as possible, using nanotechnology. The achieved results of the project are nothing but conceptual images of a convertible watch. The system is a non-invasive health measurement system. An important part of the study is researching the automation of blood pressure measurement by means of experiments which test the effect of exterior factors on blood pressure level. These experiments have been held to improve the automation and simplicity of BP measurements to establish a 24hr BP monitoring system. This study proposed a medical sensor that is part of the watch system, and that is most compatible with the elderly people product preferences in the UK. The “sensor strip” is in cm range, integrating a number of MEMS sensors, for the non-invasive detection of certain health aspects. The health aspects are chosen according to how close they are from the “health vital signs”, which are the first measurements executed by the doctor, if a patient is to visit him. An applied QFD study showed that the most suitable measurement technology to be used in the proposed sensor strip is the infrared technology. In addition to the sensor strip, EEG health detection is added, which is the reason why the watch is convertible. MEMS sensors, MEMS memory and an embedded processor are selected, since that this project also includes minimising the size of a device where the utilization of nanotechnology is vital. The final result of the study is only a conceptual design of a product with a carefully selected subsystems. The software design of the product will not be further developed to become a physical prototype of a consumer product

Future of smart cardiovascular implants

Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition

Design of a Customized multipurpose nano-enabled implantable system for in-vivo theranostics

The first part of this paper reviews the current development and key issues on implantable multi-sensor devices for in vivo theranostics. Afterwards, the authors propose an innovative biomedical multisensory system for in vivo biomarker monitoring that could be suitable for customized theranostics applications. At this point, findings suggest that cross-cutting Key Enabling Technologies (KETs) could improve the overall performance of the system given that the convergence of technologies in nanotechnology, biotechnology, micro&nanoelectronics and advanced materials permit the development of new medical devices of small dimensions, using biocompatible materials, and embedding reliable and targeted biosensors, high speed data communication, and even energy autonomy. Therefore, this article deals with new research and market challenges of implantable sensor devices, from the point of view of the pervasive system, and time-to-market. The remote clinical monitoring approach introduced in this paper could be based on an array of biosensors to extract information from the patient. A key contribution of the authors is that the general architecture introduced in this paper would require minor modifications for the final customized bio-implantable medical device

Beyond Tissue replacement: The Emerging role of smart implants in healthcare

Smart implants are increasingly used to treat various diseases, track patient status, and restore tissue and organ function. These devices support internal organs, actively stimulate nerves, and monitor essential functions. With continuous monitoring or stimulation, patient observation quality and subsequent treatment can be improved. Additionally, using biodegradable and entirely excreted implant materials eliminates the need for surgical removal, providing a patient-friendly solution. In this review, we classify smart implants and discuss the latest prototypes, materials, and technologies employed in their creation. Our focus lies in exploring medical devices beyond replacing an organ or tissue and incorporating new functionality through sensors and electronic circuits. We also examine the advantages, opportunities, and challenges of creating implantable devices that preserve all critical functions. By presenting an in-depth overview of the current state-of-the-art smart implants, we shed light on persistent issues and limitations while discussing potential avenues for future advancements in materials used for these devices

An Implantable Low Pressure, Low Drift, Dual BioPressure Sensor and In-Vivo Calibration Methods Thereof

The human body’s intracranial pressure (ICP) is a critical component in sustaining healthy blood flow to the brain while allowing adequate volume for brain tissue within the rigid structures of the cranium. Disruptions in the body’s autoregulation of intracranial pressure are often caused by hemorrhage, tumors, edema, or excess cerebral spinal fluid resulting in treatments that are estimated to globally cost up to approximately five billion dollars annually. A critical element in the contemporary management of acute head injury, intracranial hemorrhage, stroke, or other conditions resulting in intracranial hypertension, is the real-time monitoring of ICP. Currently, such mainstream clinical monitoring can only take place short-term within an acute care hospital. The monitoring is prone to measurement drift and is comprised of externally tethered pressure sensors that are temporarily implanted into the brain, thus carrying a significant risk of infection. To date, reliable, low drift, completely internalized, long-term ICP monitoring devices remain elusive. The successful development of such a device would not only be safer and more reliable in the short-term but would expand the use of ICP monitoring for the management of chronic intracranial hypertension and enable further clinical research into these disorders. The research herein reviews the current challenges of existing ICP monitoring systems, develops a new novel sensing technology, and evaluates the same for potentially facilitating long-term implantable ICP sensing. Based upon the findings of this research, this dissertation proposes and evaluates a dual matched-die piezo-resistive strain sensing device, with a novel in-vivo calibration system and method thereof, for application to long-term implantable ICP sensing

Wireless body sensor networks for health-monitoring applications

This is an author-created, un-copyedited version of an article accepted for publication in Physiological Measurement. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0967-3334/29/11/R01

Implantoitavat paineanturit

Tämä kandidaatintutkielma on kirjallisuustutkimus implantoitavista paineantureista. Tutkielmassa keskitytään implantoitavien paineantureiden perusrakenteeseen ja kahteen yleiseen sovellukseen: kallonsisäisen paineen ja kardiovaskulaarisen paineen mittaamiseen. Implantoitava paineanturi asetetaan osittain tai kokonaan kehon sisälle. Paineanturi rakentuu painetta mittaavasta elementistä, sekä joko johdoista tai langattomasta toteutuksesta, jolla mitatut painearvot saadaan kuljetettua monitorille, lääkäreille analysoitaviksi. Langattomassa toteutuksessa painearvot yleensä lähetetään monitorille joko radioaalloilla tai induktiivisen linkin avulla. Kallonsisäisen paineen mittaaminen on erityisen tärkeää vakavan päähän kohdistuneen vamman jälkeen. Implantoitavilla paineantureilla saadaan tarkempia ja jatkuvia mittaustuloksia, mitkä ovat tärkeitä ominaisuuksia, sillä lääkäreiden on pystyttävä reagoimaan nopeasti mikäli painearvot alkavat kohota. Kardiovaskulaarista painetta mittaavilla implantoivilla paineantureilla tarkastellaan esimerkiksi sydämen toimintaa sydänkammion tukilaitteen asennuksen jälkeen. Lopuksi tutkielma käsittelee biohajoavia implantoitavia paineantureita, jotka tulevat käyttöön tulevaisuudessa. Tällä hetkellä biohajoavat paineanturit ovat testattavana laboratorioissa ja eläinkokeissa. Monet testien tuloksista ovat lupaavia. Biohajoavat implantoitavat paineanturit tiputtavat tulehdusriskiä, sillä ne eivät tarvitse toista leikkausta kuten ei-hajoavat paineanturit, jotka tarvitsevat poistoleikkauksen