A5102834669- Electrical and Bioimpedance Tomography
- Ophthalmology and Visual Impairment Studies
- Visual perception and processing mechanisms
- Retinal Development and Disorders
- Retinal Diseases and Treatments
- Body Composition Measurement Techniques
- Glaucoma and retinal disorders
- Hemodynamic Monitoring and Therapy
- Retinal Imaging and Analysis
- Microfluidic and Bio-sensing Technologies
- Flow Measurement and Analysis
- Ergonomics and Musculoskeletal Disorders
- Photoreceptor and optogenetics research
- Geophysical and Geoelectrical Methods
- Corneal surgery and disorders
- Ocular and Laser Science Research
- Neuroscience and Neural Engineering
- Tactile and Sensory Interactions
- Non-Invasive Vital Sign Monitoring
- Ocular Surface and Contact Lens
- Microwave Imaging and Scattering Analysis
- Muscle activation and electromyography studies
- Non-Destructive Testing Techniques
- Neural dynamics and brain function
- Retinal and Optic Conditions
University of California, Irvine
2024
Spartanburg Regional Healthcare System
2023
University of Sheffield
2011-2022
Applied Materials (United States)
2022
The University of Texas at Arlington
2017
De Montfort University
2007-2015
Children's of Alabama
2015
Queensland University of Technology
2003-2014
Sheffield Teaching Hospitals NHS Foundation Trust
2006-2014
Royal Hallamshire Hospital
2003-2013
A review of attempts which have been made to produce in vivo images the spatial distribution tissue resistivity is given. The collection systems for and methods reconstruction such are discussed. Some problems that remain be solved applied tomography identified.
Electrical impedance tomography (EIT) is an attractive method for clinically monitoring patients during mechanical ventilation, because it can provide a non-invasive continuous image of pulmonary which indicates the distribution ventilation. However, most clinical and physiological research in lung EIT done using older proprietary algorithms; this obstacle to interpretation images reconstructed are not well characterized. To address issue, we develop consensus linear reconstruction algorithm...
Because of the intrinsically low sensitivity any surface potential measurement to resistivity changes within a volume conductor, data collection system for impedance imaging must be sensitive in peripheral profile order 0.1%. For example, whilst associated with lung ventilation and movement blood during cardiac cycle range from 3 100% recorded at are very much less than this. The Sheffield uses 16 electrodes which addressed through 4 multiplexers. Overall accuracy is largely determined by...
Applied potential tomography (APT) or electrical impedance imaging has received considerable attention during the past few years and some in vivo images have been produced. This paper reviews current situation terms of what results are likely to be obtained near future. Both static dynamic possible these two areas dealt with separately. Features existing system good tissue contrast, high-speed data collection, sensitivity resistivity changes, low spatial resolution, cost no known hazard. It...
A method of obtaining images electrical resistivity is described. It uses measurements voltage differences on the periphery region to be imaged, and a reconstruction using backprojection. An image human forearm presented.
In an investigation of the functional impact amblyopia in children, fine motor skills amblyopes and age-matched control subjects were compared. The influence visual factors that might predict any decrement was also explored.Vision tested a group children (n = 82; mean age, 8.2 +/- 1.7 [SD] years) with different causes (infantile esotropia, n 17; acquired strabismus, 28; anisometropia, 15; mixed, 13; deprivation 9), 37; age 8.3 1.3 years). Visual (VMC) upper limb speed dexterity (ULSD) items...
Purpose. In Chinese societies, primary and secondary schoolchildren perform large amounts of reading homework thus spend long periods performing near work during their growth years. Progressive lenses, which can permit a focused retinal image at distance, intermediate, near, without accommodation, may slow the development myopia. This paper reports results 2-year longitudinal study to examine effects progressive lenses on myopia progression in myopic children; these children were aged...
This paper describes the Sheffield Mk3.5 EIT/EIS system which measures both real and imaginary part of impedance at 30 frequencies between 2 kHz 1.6 MHz. The uses eight electrodes with an adjacent drive/receive electrode data acquisition protocol. is modular, containing identical boards, contain DSPs to generate drive perform FFT used for demodulation. current in three sequentially applied packets, where each packet contains ten summed sine waves. interfaced a host PC through optically...
Impedance pneumography, electrical impedance measurements of the lung, is a technique which has been widely used to monitor respiration non-invasively and more recently, onset pulmonary oedema. Attempts have made try localise changes in using electrode arrays guarding. These techniques allow localisation particular hemithorax, but resolution majority systems remains poor. To assess performance possible clinical applications APT, following increases lung volume blood volume. During...
Electrical impedance measurements have been made from the human trunk over frequency range 9.6 kHz to 614 kHz. Measurements 12 normal subjects and amplitude of changes associated with cardiac respiratory cycles recorded. It was found that real part fell 64.0% its low value measured frequencies respiration in a similar manner. However, related more rapidly increasing 28.2% value. The origin is discussed view understanding why fall rapidly. not possible relate any simple way dispersion single...
In an investigation of the psychosocial impact amblyopia on children, perceived self-esteem children who had been treated for was compared with that age-matched controls. The influence condition or treatment factors may self-perception scores also explored.Children a history (n = 47; age 9.2 +/- 1.3 years) and controls 52; 9.4 0.5 completed standardized age-appropriate questionnaire based evaluation (Harter Self Perception Profile Children). Their vision characteristics regimen were...
Electrical activity in the region of anal canal man has been previously recorded on many occasions from voluntary muscle external sphincter.We have attempted addition to delineate electrical arising smooth surrounding with aim assessing relative roles two components preserving continence.A preliminary report some data was made Surgical
Multi-frequency electrical impedance tomography (EIT) systems require stable voltage controlled current generators that will work over a wide frequency range and with large variation in load impedance. In this paper we compare the performance of two commonly used designs: first is modified Howland circuit whilst second based on mirror. The output both circuits were determined through PSPICE simulation measurement. Both ranges 1 kHz to MHz. maximum for was 2.0% mirror 1.6%. greater than 100...
Purpose We assessed repeatability and intercorrelations of five standard vision tests in subjects with normal vision. Methods Seventy-eight (aged 21 to 68 years) completed measurements each high- low-contrast visual acuity, near acuity contrast sensitivity (Pelli-Robson chart). Results Except for correlations between (r = 0.78), were low moderate < 0.5). For measure, variability the group was about one line on chart (one triplet Pelli-Robson chart) minimum an individual subject third this....
An instrument is described which produces images of the electrical impedance distribution within body at a rate 25 frames per second, allowing lung ventilation and perfusion to be observed in real time. The makes measurements using an array 16 electrodes on surface body, reconstructs weighted backprojection technique. design data acquisition electronics reconstruction display processor are described. Some preliminary vitro vivo results from system presented.< <ETX...