Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Therapeutic laser guidelines: On the effects of laser radiation on human skin-fibroblast metabolism in culture
1989
A promising field of laser utilization is the modification of cell behaviour. Acting on cell biological functions it might be possible to use them to improve medical therapies. This possibility suggests investigation of dosimetry guidelines employing different wavelenghts, power and exposure durations for future potential use of lasers in medicine.
Respiratory snorkel and valve system for breath-by-breath gas analysis in swimming
2003
The present study aimed to compare a standard facemask (CM) and a newly modified swimming snorkel and valve system (SV) for breath-by-breath (BxB) gas analysis (K4 b2, Cosmed, Rome, Italy), and to validate the system under controlled laboratory conditions before being used in swimming. Nine healthy males performed two bouts of a stepwise exercise on an electrically braked stationary bicycle on separate days. Ventilatory and gas exchange parameters were analyzed using the same BxB portable system, with subjects breathing alternatively through the two different valves. Agreement between both methods was evaluated by Passing-Bablok regression analysis. The gas exchange values measured using th…
TRANS-FUSIMO - clinical translation of patient specific planning and conduction of FUS treatment in moving organs
2015
The movement of the target challenges the application of high intensive focused ultrasound (HiFU/MRgFUS) for the treatment of malignancies in moving abdominal organs such as liver and kidney. Moreover, the anatomical location of the lesion is often behind the rib cage. The physiology of the organs, the dynamic and complex blood perfusion impairs the energy disposition in the tissue due to the heat transfer within the organ. To explore the full potential of extracorporeal FUS to safely and precisely destroy tissue in the depth of a moving organ requires sophisticated software and advanced hardware. In the EU project FUSIMO (http://www.fusimo.eu) a software demonstrator for the patient specif…
<title>Potential of advanced photoplethysmography sensing for noninvasive vascular diagnostics and early screening</title>
2002
Advanced sensor device for shape analysis of the tissue- reflected mean single period photoplethysmography (SPPPG) signals has been designed and clinically tested. The SPPPG signal shape reveals individual features of the patient's cardio-vascular state. Clinical studies of several patient groups (e.g. diabetes mellitus, atherosclerosis obliterans, Raynaud's syndrome) made possible to specify components of the SPPPG signal that are sensitive to the corresponding organic or functional pathologies. Comparison of the right and left arm finger SPPPG signal shapes, for instance, appears to be efficient tool for early screening of unilateral atherosclerosis obliterans.© (2002) COPYRIGHT SPIE--The…
Die Röntgendigitalanlage als Instrument zur kinematischen Untersuchung der Schulter — Eine Untersuchung zur Strahlenbelastung - Digital Radiography a…
1991
The radiation exposure during biomechanical investigation of the shoulder joint done with a digital radiography system (Polytron 1000 VR - Siemens) was measured experimentally. Total radiation dose and surface dose were determined by phantom measurements. The radiation exposure per image is about 1/6 to 1/7 of that of a conventional study. The digital radiography system used is thus suitable for kinesiologic studies of large joints in healthy volunteers.
Correlation between clinical and radiographic classification of osteoarthritis and SNPs linked to osteoarthritis susceptibility
2013
Media-fill simulation tests in manual and robotic aseptic preparation of injection solutions in syringes
2014
Objective The purpose of this study was to evaluate the contamination rate of media-fill products either prepared automated with a robotic system (APOTECAchemo™) or prepared manually at cytotoxic workbenches in the same cleanroom environment and by experienced operators. Media fills were completed by microbiological environmental control in the critical zones and used to validate the cleaning and disinfection procedures of the robotic system. Methods The aseptic preparation of patient individual ready-to-use injection solutions was simulated by using double concentrated tryptic soy broth as growth medium, water for injection and plastic syringes as primary packaging materials. Media fills w…
The anatomy of the heart in the sonogram. A comparison between anatomic and ultrasonic cross-section.
1977
Cardiac sonography has only recently been introduced as a diagnostic procedure. In order to facilitate the interpretation and evaluation of the ultrasonic cardiac cross-section displayed by this two-dimensional technique, we performed anatomic cross-sections corresponding to ultrasonic cross-sections. The ultrasonic cross-sectional images were taken from children with a real-time-motion scanner. The anatomic cross-sections were taken from adult hearts. Two ultrasonic transverse cross-sections are compared with the two corresponding anatomic cross-sections and three ultrasonic longitudinal cross-sections with one corresponding anatomic cross-section. The direct comparison between anatomic an…
Tissue classification by texture and spectral analysis of intracoronary ultrasound radio-frequency data
2002
Imaging of vascular structures by intracoronary ultrasound allows in principal the recognition of different lesion types due to the echomorphology in the B-mode image. The subjective visual diagnosis is often difficult, especially the differentiation between thrombi and non-calcified plaque. The aim of this study was the extraction of features from the ultrasound radio-frequency signal for an objective characterization of coronary tissue. Methods of texture analysis and frequency analysis were used to differentiate red and white thrombi in vitro. Eight texture parameters of first and second order significantly differentiated red and white thrombi. The backscatter transfer function of red th…
Usability of photoplethysmography method in estimation of conduit artery stiffness
2011
Three channel photoplethysmography (PPG) signal waveform studies of leg conduit arteries during a provocative occlusion test were performed. PPG waveform second derivative amplitude ratio and arterial pulse wave velocity values showed significant correlations with ultrasound (US) reference method of local and regional arterial stiffness (AS), showing the ability to use PPG for AS change quantitative assessment.