Eric Abel

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Open Access Design of SMA Actuator Based Access Device for Transanal Endoscopic

Abstract: An access device using a combination of a compression coil spring made of NiTi shape me... more Abstract: An access device using a combination of a compression coil spring made of NiTi shape memory alloy (SMA) and NiTi superelastic strips has been developed. Particular consideration is given to the application of the concept in tran-sanal endocopic microsurgery (TEM), but it could be used in other procedures where tissue expansion is required. In TEM, it could realize the gasless dilation of the rectum with safety and reliability, and facilitate surgeons to perform TEM. The theoretical design procedure to determine the specifications of the NiTi SMA spring and superelastic compo-nents is established. The feasibility and the possible problems associated with this application are discussed generally.

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Hearing aid: B1 patent specification

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An impulse response flow cytometric technique for blood cell characterisation-instrumentation and preliminary evaluation

A new technique for studying the properties of blood and other cells has been developed. It is ba... more A new technique for studying the properties of blood and other cells has been developed. It is based on measurement of the continuous electrical impedance spectrum of individual cells. The cellular impedance is obtained by applyng an impulse and recording the impulse response while a stream of cells suspended in an electrolyte pass through a measurement aperture in a single file. Preliminary evaluation has demonstrated that the instrument prototype is capable of detecting characteristic spectra of different cell populations. This paper presents some theoretical aspects of the technique, an outline of the instrumentation design and preliminary experimental reSUltS.

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Electromechanical behaviour of Nafion-based soft actuators

Journal of Materials Chemistry B, 2013

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$Research paper thumbnail of Bone mineral density of the radius in patients with Colles' fracture$

Bone mineral density of the radius in patients with Colles' fracture

The Journal of Bone and Joint Surgery, 2000

T o ascertain whether patients with Colles' fracture should be investigated for osteoporosis and ... more T o ascertain whether patients with Colles' fracture should be investigated for osteoporosis and the risk of future fractures, we measured the bone mineral density of the distal radius of the other arm in 31 women patients and compared the results with those of a control group of 289 normal women. We divided the patients into two groups, those younger than 66 years and those older. In 25 patients we found values for bone mineral density which were lower than one standard deviation below the mean value for their age. Younger patients had a deficit greater than that expected for their ages. We believe that women with Colles' fracture should be evaluated routinely for osteoporosis, particularly if they are under 66 years of age.

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Singularity Characteristics of Needle EMG IP Signals

IEEE Transactions on Biomedical Engineering, 2006

Clinical electromyography (EMG) interference pattern (IP) signals can reveal more diagnostic info... more Clinical electromyography (EMG) interference pattern (IP) signals can reveal more diagnostic information than their constituents, the motor unit action potentials (MUAPs). Singularities and irregular structures typically characterize the mathematically defined content of information in signals. In this paper, a wavelet transform method is used to detect and quantify the singularity characteristics of EMG IP signals using the Lipschitz Exponent (LE) and measures derived from it. The performance of the method is assessed in terms of its ability to discriminate healthy, myopathic and neuropathic subjects and how it compares with traditionally used Turns Analysis (TA) methods and a method recently developed by the authors, Inter-Scale Wavelet Maximum (ISWM). Highly significant intergroup differences were found using the LE method. Most of the singularity measures have a performance similar to that of ISWM and considerably better than that of TA. Some measures such as the ratio of the mean LE value to the number of singular points in the signal have considerably superior performance to both TA methods. These findings add weight to the view that wavelet analysis methods offer an effective way forward in the quantitative analysis of EMG IP signal to assist the clinician in the diagnosis of neuromuscular disorders.

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Design of SMA Actuator Based Access Device for Transanal Endoscopic Microsurgery

The Open Medical Devices Journal, 2010

An access device using a combination of a compression coil spring made of NiTi shape memory alloy... more An access device using a combination of a compression coil spring made of NiTi shape memory alloy (SMA) and NiTi superelastic strips has been developed. Particular consideration is given to the application of the concept in transanal endocopic microsurgery (TEM), but it could be used in other procedures where tissue expansion is required. In TEM, it could realize the gasless dilation of the rectum with safety and reliability, and facilitate surgeons to perform TEM. The theoretical design procedure to determine the specifications of the NiTi SMA spring and superelastic components is established. The feasibility and the possible problems associated with this application are discussed generally.

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Hysteresis Behaviour and Modeling of SMA Actuators

Shape Memory Alloys, 2010

format_quoteExperimental work with a NiTi tension spring under 6N showed both major and minor hysteresis loops during actuation cycles.format_quote

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Defining optical distortion in rigid endoscopes

The Laryngoscope, Jan 24, 2014

To describe lens and perspective distortion using new measures that have practical meaning to the... more To describe lens and perspective distortion using new measures that have practical meaning to the surgeon, and to apply these measures to show the extent of optical distortion in rigid endoscopes used in endoscopic sinus surgery. Laboratory measurements on rigid endoscopes. Barrel and perspective distortion were measured in 4-mm diameter 0°, 30°, 45°, and 70° rigid sinus endoscopes. Images of square grids were obtained with the endoscopes aligned in a specially constructed test rig. The terms relative size (RS) and relative distance (RD) were introduced to describe size and distance errors; and the term relative angle (RA) was used for assessing perspective errors. All the endoscopes exhibited similar barrel distortion. RS of the image at the periphery was 52%; RD was 80%. For RA values of 30°, 45°, and 70°, RS values were 77%, 58%, and 32%, respectively. Objects at the edge of the surgical field appear significantly more distant than suggested by their screen position. Perspective ...

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Methods for removing glare in digital endoscope images

Surgical Endoscopy, 2011

Images produced by rod-lens telescopes used in minimally invasive surgery are brightest in the ce... more Images produced by rod-lens telescopes used in minimally invasive surgery are brightest in the central region and darker at the periphery. To enable a clear view of the darker regions of the image, the intensity of light from the source usually is set to a high level. This often causes substantial reflection and glare from surgical tools and some tissue surfaces, which can be disturbing for the surgeon. This study investigated digital image processing methods in an attempt to reduce glare without introducing other adverse qualities into the images. Two methods of reducing glare in local high-brightness regions of the image were evaluated. The first method reduced intensity by a fixed amount while also optionally introducing a slight color. The second method combined a proportion of the original intensity value with a proportion of a lower intensity value, again with an optional color bias. Two surgical video clips were modified with each of 13 different glare-reduction variants using these methods. These and the original sequence were played to a group of 10 experienced surgeons for subjective assessment. The pixel-based methods both showed statistically significant improvements over the original version. The incorporation of a slight yellow bias was preferred to a straightforward gray-level reduction. The simple approach of using a lower level of brightness alone was found to be unacceptable. Both new methods work in real time at normal video speeds. Antiglare methods have been found that reduce the perception of glare and are otherwise unobtrusive. This encourages further work to refine the preferred methods and to test them with a larger group over a wider range of video sequences. Clinical trials then will follow.

A New Hospital Wheelchair

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society Volume 13: 1991

A new attendant operated wheelchair has been designed for use in hospitals, for both ward and tra... more A new attendant operated wheelchair has been designed for use in hospitals, for both ward and transit use. Its design is based on findings of a survey into the use of hospital wheelchairs and questionnaires given to 29 nurses, porters and therapists, who operate them. The new chair seeks to solve the major problems with existing models and has been designed to assist patient transfer and to improve propulsion and braking. The chair has new designs of pushing handle and braking system and a loweringlraising footrest to ease patient transfer. Extensive user trials in local hospitals have shown the chair to be very successful.

Distance learning courses in orthopaedic and rehabilitation technology

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1992

Distance Learning courses have been introduced for medical, paramedical and industrial employees ... more Distance Learning courses have been introduced for medical, paramedical and industrial employees working in the fields of orthopaedics and physical rehabilitation. These courses provide an introduction to orthopaedic and rehabilitation engineering and technology. The courses are modular and cater for a wide range of academic backgrounds. Certificate and diploma qualifications can be awarded by credit accumulation on the course modules.

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