Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Infrared-based quantification of clinical parameters
2014
Abstract Infrared (IR) spectroscopy has become a promising technique for the analysis of clinical samples, and IR-based diagnosis is already a well-established technique in the academic field. This review aims to report the methodologies proposed for IR quantification of different analytes and parameters in a variety of clinical samples; including: liquids, such as whole blood, serum, plasma, urine, human milk, amniotic fluid and cerebrospinal fluid; solids, such as urinary stones, skin, hair and lips; breath; or, microscopic quantifications on tissues. For the application of IR spectroscopy to the clinical field, we also discuss: the benefits, which make IR spectroscopy ideally suited to m…
Simulation Analysis of the Influence of Hemodialysis Control Parameters on Exchange Processes during Therapy
1992
The effect of dialysis control parameters (dialysate composition, ultrafiltration rate, blood flow rate) on the patient's internal milieu were studied using a mathematical model for the description of the dynamic exchange processes during hemodialysis. This model simulates the electrolyte and water distribution, the acid-base and the oxygenation state as well as the ventilation. The dialysate sodium concentration affects mainly the intra-/ extracellular water and the potassium distribution. The dialysate bicarbonate and acetate concentrations control the acid-base state and the electrolyte distribution (sodium and potassium). In addition, the dialysate acetate concentration has a strong ef…
Comparative studies on cytotoxic effects of dental amalgams and alternative alloys according to ISO standards in vitro
1995
Deleterious effects of dental alloys, especially those of dental amalgams, have become an important issue in current discussions on biomaterials. Cytotoxicity and further related risks of amalgams are discussed in a controversial way in the literature without leading to a final conclusion. There is still a need for basic clinical and pre-clinical research, especially with respect to the wide distribution of dental amalgams. Standardized methods of cytotoxicity testing have been established by the ISO. It was the aim of the present study to detect and compare possible cytotoxic effects of dental amalgams and alternative non-amalgam alloys in vitro. According to the ISO standards, direct cont…
Salbutamol Transport and Deposition in the Upper and Lower Airway with Different Devices in Cats: A Computational Fluid Dynamics Approach
2021
Simple Summary Administration of inhaled salbutamol via metered-dose inhalers can effectively treat bronchoconstriction. Different devices are used for the delivery of this drug in cats, either in the hospital or at home, for long-term treatment. Effective drug administration may depend on the drug delivery device as well as patient cooperation. By using non-invasive computational fluid dynamics techniques, the impact of these devices on the deposition and transport of salbutamol particles in the cat airways was simulated and assessed. The results confirm a variable drug distribution depending on the device used. The percentage of particles reaching the lung was reduced when using spacers a…
Manufacturing, characterization and control of cell-based medicinal products: challenging paradigms toward commercial use
2015
During the past decade, a large number of cell-based medicinal products have been tested in clinical trials for the treatment of various diseases and tissue defects. However, licensed products and those approaching marketing authorization are still few. One major area of challenge is the manufacturing and quality development of these complex products, for which significant manipulation of cells might be required. While the paradigms of quality, safety and efficacy must apply also to these innovative products, their demonstration may be demanding. Demonstration of comparability between production processes and batches may be difficult for cell-based medicinal products. Thus, the development …
Realization of administration unit for3He with gas recycling
2011
Hyperpolarized (HP) noble gases (3He,129Xe) are used for MR-imaging of the lung. In the majority of case the HP gas is filled in Tedlarbags and directly inhaled by the patients. Starting from an earlier pilot device, an administration unit was built respectively to the Medical Devices Law to administer patients HP noble gas boli in defined quantities and at a predefined time during inspiration with high reproducibility and reliability without reducing MR-quality. The patient's airflows are monitored and recorded. It is possible to use gas admixtures, measure the polarization on-line and collect the exhaled gas for later recycling. The first images with healthy volunteers were taken with thi…
Optical systems for non-invasive cardiovascular biosensing
2005
Three portable prototype devices for cardiovascular biosensing based on reflection-type photoplethysmography (PPG) principle have been designed and clinically tested. The single-channel PPG finger sensor provides real-time measurements with fast calculation of the mean single-period PPG signal shape ("cardiovascular fingerprint", potentially useful for recognition). The dual-channel PPG system gives additional possibility to monitor on-line the arterial pulse wave transit time and its responses to physical exercises. The four-channel PPG system proved to be applicable for fast detection of cardiovascular pathologies, e.g. arterial occlusions in extremities. Design principles and software al…
<title>Photonic vascular diagnostics by four-channel photoplethysmography</title>
2005
A four-channel photoplethysmography device was designed and built at University of Latvia to detect signals from different body parts and to analyze the signal shapes. The device consists of optical contact probes, interface, and a standard PC. Clinical tests were performed with occlusion patients having vascular problems at arm or leg arteries. Results showed significant difference in the pulse wave transit time in occluded and nonoccluded part of the body.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
End-user Need based Creation of a Medical Device: An Experience of Co-design to Struggle Pathological Scars
2020
International audience; Scar is a common visible mark of human tissue healing. Sometimes pathological phenomena lead to abnormal hypertrophic or keloid scars, with evolutions varying depending on different conditions: origin of the tissue barrier disruption, concerned body area, or ethnic origin. Based on these statements, care procedures have been developed to avoid aesthetical or functional impairments: drugs injection, surgery, cryotherapy or mechanical compression. The story will relate the matching of a multi-disciplinary team that focused on covering an unmet need for ear lobe keloid treatment, providing patients an optimal and holistic care. The benefits researched lied in improving …
Full‐thickness tissue engineered oral mucosa for genitourinary reconstruction: A comparison of different collagen‐based biodegradable membranes
2020
Tissue engineering is a method of growing importance regarding clinical application in the genitourinary region. One of the key factors in successfully development of an artificially tissue engineered mucosa equivalent (TEOM) is the optimal choice of the scaffold. Collagen scaffolds are regarded as gold standard in dermal tissue reconstruction. Four distinct collagen scaffolds were evaluated for the ability to support the development of an organotypical tissue architecture. TEOMs were established by seeding cocultures of primary oral epithelial cells and fibroblasts on four distinct collagen membranes. Cell viability was assessed by MTT-assay. The 3D architecture and functionality of the ti…