A Multielectrode Nerve Cuff for Chronic Velocity Selective Recording in a sheep model.

Supra-sacral spinal cord injury (SCI) causes loss of bladder fullness sensation and bladder over-activity, leading to retention and incontinence respectively. Velocity selective recording (VSR) of nerve roots innervating the bladder might enable identification of bladder activity. A 10-electrode nerve cuff for sacral nerve root VSR was developed and tested in a sheep model during acute surgeries and chronic implantation for 6 months. The cuff performed well, with 5.90±1.90 kΩ electrode, and <~800 Ω tissue impedance after 189 days implantation with a stable device and tissues. This is important information for assessing the feasibility of chronic VSR.Clinical Relevance-This demonstrates the manufacturing and performance of a neural interface for chronic monitoring of bladder nerve afferents with applications in urinary incontinence and retention management following SCI.

Wastewater-based epidemiology in hazard forecasting and early-warning systems for global health risks.

With the advent of the SARS-CoV-2 pandemic, Wastewater-Based Epidemiology (WBE) has been applied to track community infection in cities worldwide and has proven succesful as an early warning system for identification of hotspots and changingprevalence of infections (both symptomatic and asymptomatic) at a city or sub-city level. Wastewater is only one of environmental compartments that requires consideration. In this manuscript, we have critically evaluated the knowledge-base and preparedness for building early warning systems in a rapidly urbanising world, with particular attention to Africa, which experiences rapid population growth and urbanisation. We have proposed a Digital Urban Environment Fingerprinting Platform (DUEF) - a new approach in hazard forecasting and early-warning systems for global health risks and an extension to the existing concept of smart cities. The urban environment (especially wastewater) contains a complex mixture of substances including toxic chemicals, infectious biological agents and human excretion products. DUEF assumes that these specific endo- and exogenous residues, anonymously pooled by communities' wastewater, are indicative of community-wide exposure and the resulting effects. DUEF postulates that the measurement of the substances continuously and anonymously pooled by the receiving environment (sewage, surface water, soils and air), can provide near real-time dynamic information about the quantity and type of physical, biological or chemical stressors to which the surveyed systems are exposed, and can create a risk profile on the potential effects of these exposures. Successful development and utilisation of a DUEF globally requires a tiered approach including: Stage I: network building, capacity building, stakeholder engagement as well as a conceptual model, followed by Stage II: DUEF development, Stage III: implementation, and Stage IV: management and utilization. We have identified four key pillars required for the establishment of a DUEF framework: (1) Environmental fingerprints, (2) Socioeconomic fingerprints, (3) Statistics and modelling and (4) Information systems. This manuscript critically evaluates the current knowledge base within each pillar and provides recommendations for further developments with an aim of laying grounds for successful development of global DUEF platforms.

The Effects of the Presence of Multiple Conduction Velocities in the Analysis of Electrically-Evoked Compound Action Potentials (eCAPs).

New methods for the analysis of electrically-evoked compound action potentials (eCAPs) are described. Mammalian nerves tend to have broad multi-modal distributions of fibre diameters, which translates into a spread of conduction velocities. The method of velocity selective recording (VSR) is unable to distinguish between this spectral spread and the transfer function of the system. The concept of the velocity impulse function (VIF) is introduced as a tool to differentiate between these signal and system attributes. The new methods enable separate estimates of velocity spectral broadening and signal-to-noise ratio (SNR) to be obtained.

Selective Recording of Urinary Bladder Fullness from the Extradural Sacral Roots.

Managing the urinary bladder is of primary importance to clinicians and patients after trauma to the spinal cord. Sacral Anterior Root Stimulators that control the bladder have been available as clinical technology for many years, however these devices cannot measure the fullness of the urinary bladder or detect the onset of reflex voiding. In order to address this fundamental limitation, it is necessary to develop a method for recording the neural signals that encode bladder fullness. This paper presents a proof of concept technique for recording bladder afferents from the extradural sacral roots using a multiple electrode cuff. Results are provided from acute in-vivo experiments performed in sheep.

Pressure Sensitive Skin for Prosthetic Hands: 2D Contact Location Determination Using Output Connections from a Single Side.

The human hand is a vital component of our interaction with the environment, containing a large number of sensory receptors. The loss of a hand is, therefore, a serious and debilitating injury. Surveys have shown that 98% of users of upper limb prostheses desire to feel the level of force they apply through their prosthetic hands. Developments in tactile sensors have yielded many functional electronic skins. However, their complexity remains a barrier to their use in commercial prosthetic hands. This paper introduces a new design of a simple, flexible pressure sensor using carbon fibre tows as both the sensor and the electrodes. The design results in a dynamic pressure range of 0.35 to 280 kPa in a 25-by-25 mm prototype.

First demonstration of velocity selective recording from the pig vagus using a nerve cuff shows respiration afferents.

Neural interfaces have great potential to treat disease and disability by modulating the electrical signals within the nervous system. However, whilst neural stimulation is a well-established technique, current neural interfaces are limited by poor recording ability. Low signal amplitudes necessitate the use of highly invasive techniques that divide or penetrate the nerve, and as such are unsuitable for chronic implantation. In this paper, we present the first application of the velocity selective recording technique to the detection of respiration activity in the vagus nerve, which is involved with treatments for epilepsy, depression, and rheumatoid arthritis. Further, we show this using a chronically implantable interface that does not divide the nerve. We also validate our recording setup using electrical stimulation and we present an analysis of the recorded signal amplitudes. The recording interface was formed from a cuff containing ten electrodes implanted around the intact right vagus nerve of a Danish Landrace pig. Nine differential amplifiers were connected to adjacent electrodes, and the resulting signals were processed to discriminate neural activity based on conduction velocity. Despite the average single channel signal-to-noise ratio of - 5.8 dB, it was possible to observe distinct action potentials travelling in both directions along the nerve. Further, contrary to expectation given the low signal-to-noise ratio, we have shown that it was possible to identify afferent neural activity that encoded respiration. The significance of this is the demonstration of a chronically implantable method for neural recording, a result that will transform the capabilities of future neuroprostheses.

A new method for spike extraction using velocity selective recording demonstrated with physiological ENG in Rat.

BACKGROUND: This paper describes a series of experiments designed to verify a new method of electroneurogram (ENG) recording that enables the rate of neural firing within prescribed bands of propagation velocity to be determined in real time. Velocity selective recording (VSR) has been proposed as a solution to the problem of increasing the information available from an implantable neural interface (typically with electrodes in circumferential nerve cuffs) and has been successful in transforming compound action potentials into the velocity domain. NEW METHOD: The new method extends VSR to naturally-evoked (physiological) ENG in which the rate of neural firing at particular velocities is required in addition to a knowledge of the velocities present in the recording. RESULTS: The experiments, carried out in rats required individual spikes to be distinct and non-overlapping, which could be achieved by a microchannel or small-bore cuff. In these experiments, strands of rat nerve were laid on ten hook electrodes in oil to demonstrate the principle. COMPARISON WITH EXISTING METHOD: The new method generates a detailed overview of the firing rates of neurons based on their conduction velocity and direction of propagation. In addition it allows real time working in contrast to existing spike sorting methods using statistical pattern processing techniques. CONCLUSIONS: Results show that by isolating neural activity based purely on conduction velocity it was possible to determine the onset of direct cutaneous stimulation of the L5 dermatome.

How do directors of public health perceive leadership?

This study examines how directors of public health (DsPH) perceive effective leadership. Kelly's repertory grid technique is used. A total of 13 out of a possible 14 DsPH in one NHS region of England were interviewed. Qualitative and quantitative analysis were carried out. The findings show that male DsPH (n = 8) rate their leadership ability more highly than do female DsPH (n = 5). Qualitative analysis produced a number of categories of constructs, some of which are perceived to be indicative of effective leadership, these being "working for others", "personal attributes", "vision and innovation" and "courage and integrity" Some categories appear to be applicable only to the UK (or to public health) and not to the existing dominant US models of leadership. In general, DsPH perceptions of effective leadership converge with current theories; most specifically the UK-based theories. This study therefore refutes any simple extrapolation of US theories of leadership to UK health organisations.

Leadership development in UK companies at the beginning of the twenty-first century: lessons for the NHS?

States that the development of leadership in the NHS is currently high on the agenda of the Department of Health, the government and local health sector organisations. Reports the findings of a study of public and private sector organisations, exploring the development of their in-house leadership skills. Outlines the findings in depth and discusses the implications for health organisations.

Gene therapy for cardiovascular disorders: is there a future?

Incidence of cardiovascular disease has reached epidemic proportions in spite of recent advances in improving the efficacy of pharmacotherapeutics. This has led many to conclude that drug therapy has reached a plateau in its effectiveness. As a result, our efforts have been diverted to explore the use of gene transfer approaches for long-term control of these pathophysiological conditions. The purpose of this review is to present various approaches that are being undertaken to provide "proof of principle" for gene therapy for cardiovascular diseases. Finally, we will discuss the future of gene therapy and other new technologies that may further advance this field of therapeutics.

Leadership. Heaven can wait.

A major survey of some 2,000 NHS managers revealed a clear profile of the leadership qualities seen as important. The most important characteristic emerged as concern for others, followed by the ability to communicate and inspire. The picture which emerges is of the leader as servant, rather than hero. Developing leaders along these lines will require support from the centre.