Model-based design of a pneumatic actuator for a dynamically reconfigurable socket for transtibial amputees.

In this work, a cost-effective, scalable pneumatic silicone actuator array is introduced, designed to dynamically conform to the user's skin and thereby alleviate localised pressure within a prosthetic socket. The appropriate constitutive models for developing a finite element representation of these actuators are systematically identified, parametrised, and validated. Employing this computational framework, the surface deformation fields induced by 270 variations in soft actuator array design parameters under realistic load conditions are examined, achieving predictive accuracies within 70 µm.

Pulmonary Veins Function as Echo Chambers in Persistent Atrial Fibrillation: Circuitous Re-Entry Generates Outgoing Wavefronts.

Background: Although the substrate in persistent atrial fibrillation (PeAF) is not limited to the pulmonary veins (PVs), PV isolation (PVI) remains the cornerstone ablation strategy.

Objectives: The aim of this study was to describe the mechanism of outgoing wavefronts (WFs) originating in the PV sleeves during PeAF.

Methods: Eleven patients presenting for first-time PeAF ablation were recruited (mean age 63.

A pneumatic reconfigurable socket for transtibial amputees.

Many transtibial amputees rate the fit between their residual limb and prosthetic socket as the most critical factor in satisfaction with using their prosthesis. This study aims to address the issue of prosthetic socket fit by reconfiguring the socket shape at the interface of the residual limb and socket. The proposed reconfigurable socket shifts pressure from sensitive areas and compensates for residual limb volume fluctuations, the most important factors in determining a good socket fit.

A pilot study to evaluate changes in pelvic floor muscle tone following pelvic organ prolapse surgery using a novel intra-vaginal pressure sensor device.

Introduction And Hypothesis: Pelvic floor muscle weakness is a common cause of pelvic organ prolapse and urinary incontinence. Surgical repair of prolapse is commonly undertaken; however, the impact on pelvic floor muscle tone is unknown. The aim of this study was to compare the effect of anterior and posterior colporrhaphy on pelvic floor activation.

Non-Contact Intracardiac Potential Mapping Using Mesh-Based and Meshless Inverse Solvers.

Atrial fibrillation (AF) is the most common cardiac dysrhythmia and percutaneous catheter ablation is widely used to treat it. Panoramic mapping with multi-electrode catheters has been used to identify ablation targets in persistent AF but is limited by poor contact and inadequate coverage of the left atrial cavity. In this paper, we investigate the accuracy with which atrial endocardial surface potentials can be reconstructed from electrograms recorded with non-contact catheters.

Intracardiac Inverse Potential Mapping Using the Method of Fundamental Solutions.

Atrial fibrillation (AF) is the most prevalent cardiac dysrhythmia and percutaneous catheter ablation is widely used to treat it. Panoramic mapping with multi-electrode catheters can identify ablation targets in persistent AF, but is limited by poor contact and inadequate coverage. To investigate the accuracy of inverse mapping of endocardial surface potentials from electrograms sampled with noncontact basket catheters.

The Safety of Micro-Implants for the Brain.

Technological advancements in electronics and micromachining now allow the development of discrete wireless brain implantable micro-devices. Applications of such devices include stimulation or sensing and could enable direct placement near regions of interest within the brain without the need for electrode leads or separate battery compartments that are at increased risk of breakage and infection. Clinical use of leadless brain implants is accompanied by novel risks, such as migration of the implant.

Using codesign to develop a mobile application for pelvic floor muscle training with an intravaginal device (femfit®).

Aims: The aim of this project was to use codesign to develop a mobile application (app) for pelvic floor muscle training, with an intravaginal device (femfit®). The objective was to obtain user feedback to guide the design and development of a mobile app, consistent with the Mobile Application Rating Scale (MARS) framework.

Methods: Twenty-six women (22-62 years) provided mobile app feedback using a Design Thinking framework and grounded theory approach.

Assessing vaginal pressure profiles before and after prolapse surgery using an intravaginal pressure sensor (femfit®).

Introduction And Hypothesis: The impact of surgery on pelvic floor muscle (PFM) function remains uncertain. There is a pressure differential along the length of the vagina, influenced by surrounding active and passive tissue structures, giving rise to a pressure profile. The aim of this study is to determine if an intravaginal pressure sensor, femfit®, can measure differences in pressure profiles before and after surgery for pelvic organ prolapse (POP).

A Capacitive Pressure Sensor Interface IC with Wireless Power and Data Transfer.

This paper presents a capacitive pressure sensor interface circuit design in 180 nm XH018 CMOS technology for an implantable capacitive pressure sensor, which has a wireless power supply and wireless data transfer function. It integrates full-bridge rectifiers, shorting control switches, low-dropout regulators, bandgap references, analog front end, single slope analog to digital converter (ADC), I2C, and an RC oscillator. The low-dropout regulators regulate the wireless power supply coming from the rectifier and provide a stable and accurate 1.

Thermal evaluation of a hermetic transcutaneous energy transfer system to power mechanical circulatory support devices in destination therapy.

Current generation left ventricular assist devices (LVADs) are powered by a percutaneous driveline. The high prevalence of driveline infections has motivated the development of transcutaneous energy transfer (TET) systems which eliminate driveline associated complications by wirelessly delivering power across the skin. Destination therapy (DT) requires long-term reliable operation of the TET electronics suggesting the use of hermetic packaging techniques as used in all other chronically implanted devices.

Reliability and validity of intravaginal pressure measurements with a new intravaginal pressure device: The FemFit®.

Aims: To test the reliability and validity of intravaginal pressure measurements acquired during pelvic floor muscle (PFM) tasks in different body positions using the FemFit®, a new intravaginal pressure device.

Methods: Twenty healthy adult women participated in this study. Two assessment sessions were conducted.

Injection Molded Liquid Crystal Polymer Package for Chronic Active Implantable Devices With Application to an Optogenetic Stimulator.

Implanted electronics require protection from the body's fluids to avoid moisture induced failure. This study presents an injection molded liquid crystal polymer (LCP) package to protect active implantable devices for chronic applications, such as in optogenetic research. The technology is applied and assessed through a custom package for a fully implantable optogenetic stimulation system, built on a versatile telemetry system that can incorporate additional stimulating and recording channels.

Can you train the pelvic floor muscles by contracting other related muscles?

Aims: The aim of this study is to assess whether contraction of muscles other than the pelvic floor muscles (PFM) would be of sufficient magnitude to provide a "training" effect for the pelvic floor.

Methods: Women were recruited via advertisement from a convenience sample of pelvic floor physiotherapists. A thin flexible array of pressure sensors (FemFit) was self-inserted into the vagina.

Pulse-Width Modulation of Optogenetic Photo-Stimulation Intensity for Application to Full-Implantable Light Sources.

Optogenetics allows control of neuronal activity with unprecedented spatiotemporal precision, and has enabled both significant advances in neuroscience and promising clinical prospects for some neurological, cardiac, and sensory disorders. The ability to chronically stimulate light-sensitive excitable cells is crucial for developing useful research tools and viable long-term treatment strategies. Popular optogenetic stimulation devices often rely on bench-top light-sources tethered via an optical fibre to the research animal, or significant componentry protruding externally from animal.

New multimodal data obtained in-vivo from a single ultra-miniature transducer.

Recent advances in multimodal sensing technology and sensor miniaturization technologies are paving the way for a new era in physiological measurement. Traditional approaches have integrated several transducers on a single silicon chip or packaged several sensing elements within a biocompatible catheter. Thermal and electrical cross-talk between sensors, time-lag between parallel measurements, lower yields associated with the increased complexity, and restrictions on the minimum size are challenges presented by these approaches.

MRI interactions of a fully implantable pressure monitoring device.

Purpose: To investigate the potential patient risk and interactions between a prototype implantable pressure monitoring device and a 3T clinical magnetic resonance imaging (MRI) machine to guide device design towards MR Conditional safety approval.

Materials And Methods: The pressure monitor device contained a catheter-mounted piezo-resistive pressure sensor, rechargeable battery, wireless communication system, and inductive pickup coil. Standard testing methods were used to guide experiments to investigate static field induced force and torque, radiofrequency (RF)-induced heating, image artifacts, and the MR's effect on device function.

Clinical evaluation of a high-fidelity wireless intravaginal pressure sensor.

Introduction And Hypothesis: A wireless intravaginal pressure sensor (IVPS) has been developed to quantify abdominal pressure (P(abd)) changes during exercise and activities of daily living to guide post-operative advice given to women. In this pilot study, we aimed to compare IVPS performance, comfort, retention, and acceptability to a standard fluid-filled intrarectal pressure catheter currently used to measure P(abd) during routine urodynamics.

Methods: A Life-Tech 3-mm urodynamic intrarectal catheter and IVPS were inserted concurrently in volunteers attending a urodynamics clinic.

Chronic measurement of left ventricular pressure in freely moving rats.

Measurements of left ventricular pressure (LVP) in conscious freely moving animals are uncommon, yet could offer considerable opportunity for understanding cardiovascular disease progression and treatment. The aim of this study was to develop surgical methods and validate the measurements of a new high-fidelity, solid-state pressure-sensor telemetry device for chronically measuring LVP and dP/dt in rats. The pressure-sensor catheter tip (2-Fr) was inserted into the left ventricular chamber through the apex of the heart, and the telemeter body was implanted in the abdomen.

Intracranial temperature and pressure measurement: in vitro temperature sensing characteristics of the dual sensing element.

A pressure sensor has been used to measure temperature concurrently. We have designed, and characterized the measurement of temperature from the same sensor to allow simultaneous monitoring of intracranial temperature and pressure. The temperature measurement has a sensitivity of 85.

Power flow control based solely on slow feedback loop for heart pump applications.

This paper proposes a new control method for regulating power flow via transcutaneous energy transfer (TET) for implantable heart pumps. Previous work on power flow controller requires a fast feedback loop that needs additional switching devices and resonant capacitors to be added to the primary converter. The proposed power flow controller eliminates these additional components, and it relies solely on a slow feedback loop to directly drive the primary converter to meet the heart pump power demand and ensure zero voltage switching.

Implantable ICP monitor for improved hydrocephalus management.

Background: Hydrocephalus patients are commonly treated by insertion of ventriculoperitoneal shunts, but these have high complication rates. Monitoring of shunt and patient condition can be achieved through measuring intracranial pressure (ICP). Significant zero drift has limited previous developments towards a long-term implantable ICP monitor.

A high bandwidth fully implantable mouse telemetry system for chronic ECG measurement.

We report on the development of a novel system that enables the wireless transmission of high-bandwidth physiological data from a freely moving mouse. The system employs inductive power transfer (IPT) to continuously power a battery-less transmitter using an array of overlapping planar coils placed under the animal. This arrangement provides a minimum of 20 mW at all locations and orientations across the mouse cage by selecting a coil which will sufficiently power the transmitter.

Reactive component selection for TET powered medical devices.

Transcutaneous energy transfer (TET) is capable of supplying power across the skin to implantable devices and avoids the risk of infection associated with wires passing through the skin. These systems rely on a high frequency magnetic field to overcome the relatively low coupling between a coil located outside the body, and a coil implanted within the body. This paper introduces a new optimisation procedure to choose tuning capacitors that minimises the amount of power dissipated in the power transfer coils of an implantable TET system.

A fully implantable telemetry system for the chronic monitoring of brain tissue oxygen in freely moving rats.

The ability to monitor tissue oxygen concentration in a specific region of the brain in a freely moving animal could provide a new paradigm in neuroscience research. We have developed a fully implantable telemetry system for the continuous and chronic recording of brain tissue oxygen (PO(2,BR)) in conscious animals. A telemetry system with a sampling rate of 2kHz was combined with a miniaturized potentiostat to amperiometrically detect oxygen concentration with carbon paste electrodes.