Technology and Health Care - Volume 16, issue 6

Authors: Asti, Annalia | Visai, Livia | Dorati, Rossella | Conti, Bice | Saino, Enrica | Sbarra, Sonia | Gastaldi, Giulia | Benazzo, Francesco

Article Type: Research Article

Abstract: The objective of this study was to investigate the surface modification of a natural bone substitute, Bio-Oss, coated with a synthetic polymer poly-D,L-lactide (PLA), in order to improve cell growth. Bio-Oss is a natural bone substitute made of the mineralized portion of bovine bone. The material is used mainly to fill bone defects in periodontal and maxillofacial surgery and permit reossification. Poly-α-hydroxyacids such as polylactic acid are receiving an increasing attention due to their ability to retain a great quantity of water, good biocompatibility, low interfacial tension, and minimal mechanical and frictional irritation. All of these features are appealing from …the perspective of bioenvironmental mimicking. The human osteosarcoma cell line SAOS-2 was added to the top of scaffolds uncoated or coated with PLA and incubated at 37° in 5% CO2 for 15 days. PLA-coated scaffolds improved cell growth. Polymer degradation behaviour, extraction and measurement of the extracellular matrix proteins of the cultured scaffolds (such as decorin, fibronectin osteocalcin, osteonectin, osteopontin and type-I and type-III collagen), immunolocalization of bone proteins and morphological analysis of the scaffolds confirmed the bioactive properties of Bio-Oss/PLA4M suggesting that it could be a valuable grafting material. Show more

DOI: 10.3233/THC-2008-16601

Citation: Technology and Health Care, vol. 16, no. 6, pp. 401-413, 2008

Authors: Coupaud, S. | Gollee, H. | Hunt, K.J. | Fraser, M.H. | Allan, D.B. | McLean, A.N.

Article Type: Research Article

Abstract: Tetraplegic volunteers undertook progressive exercise training, using novel systems for arm-cranking exercise assisted by Functional Electrical Stimulation (FES). The main aim was to determine potential training effects of FES-assisted arm-crank ergometry (FES-ACE) on upper limb strength and cardiopulmonary {fitness} in tetraplegia. Surface FES was applied to the biceps and triceps during exercise on an instrumented ergometer. Two tetraplegic volunteers with C6 Spinal Cord Injury (SCI) went through muscle strengthening, baseline exercise testing and three months of progressive FES-ACE training. Repeat exercise tests were carried out every four weeks during training, and post-training, to monitor upper-limb strength and cardiopulmonary fitness. At …each test point, an incremental test was carried out to determine peak work rate, peak oxygen uptake, gas exchange threshold and oxygen uptake-work rate relationship during FES-ACE. Peak oxygen uptake for Subject A increased from 0.7 l/min to 1.1 l/min, and peak power output increased from 7 W to 38 W after FES-ACE training. For Subject B, peak oxygen uptake was unchanged, but peak power output increased from 3 W to 8 W. These case studies illustrate potential benefits of FES-ACE in tetraplegia, but also the differences in exercise responses between individuals. Show more

Keywords: Electrical stimulation, spinal cord injury, cardiopulmonary fitness, rehabilitation, tetraplegia

DOI: 10.3233/THC-2008-16602

Citation: Technology and Health Care, vol. 16, no. 6, pp. 415-427, 2008

Authors: Gabay, Michael | von Martius, Konstantin

Article Type: Research Article

Abstract: Introduction: Comparative information related to the properties of intravenous containers is lacking. Information is important as healthcare providers weigh the strengths and weaknesses of various competing products. The aim of this study is to evaluate and compare three different intravenous containers: two closed-system fully collapsible bags that do not require external venting to empty (containers A and B) and one semi-rigid “bottle pack” that partially collapses unvented (container C). Methods: Through an observational study design, these containers were subjected to the following tests in order to evaluate their performance: determination of total and residual volume, air volume, …admixture volume, presence of particulate matter, and a drop test. Results: The mean residual volume of container C was higher compared to containers A and B: between 0.6% and 11.7% with a closed administration set and between 0.7% and 10.8% with an open administration set. The mean air volume measured was increased relative to the nominal volume for container C. In addition, containers A and B exhibited no visible particulate matter after puncture, satisfied the drop test more frequently, and had relatively higher admixture volumes in comparison to container C. Conclusion: The results of these examinations reveal that containers A and B outperformed container C; however, caution must be used when interpreting these observational results in the clinical setting. Show more

Keywords: Intravenous container, admixture, closed-system, open-system

DOI: 10.3233/THC-2008-16603

Citation: Technology and Health Care, vol. 16, no. 6, pp. 429-435, 2008

Authors: Ionescu, Clara | Chirita, Mihai

Article Type: Research Article

Abstract: The biomimetic formed solution of collagen reconstituted films into native fibers proved to be of high interest because of its regenerative medical applications. A variety of tests to characterize the mechanical properties of biomimetic engineered films are illustrated in this paper. Based on our previous results, the modulus of elasticity and the ultimate strain of reconstituted collagen films were compared to the reported stress-strain data in the literature on various tissues (animal material), correlating the achieved properties with possible use for artificial tissue implants. The results presented in this study, with great potential to provide reference data for future work, …show that the mechanical properties of the biomimetically formed collagen films is close to that of several native collagen fibers, a fact which suggests their use in medical applications. Show more

Keywords: Eucollagen, biomaterials, biomimetics, tissue mechanics, collagen, elastin, stress strain, power law, pressure-volume curves

DOI: 10.3233/THC-2008-16604

Citation: Technology and Health Care, vol. 16, no. 6, pp. 437-444, 2008

Authors: Giger, Hans | Fankhauser, Franz

Article Type: Research Article

Abstract: An analysis and mathematical comparison of models underlying the phenomena of brightness and contrast are presented. The concept of self-excitation which has not so far been considered is introduced into the structure of the models. Mach Bands can be described by two essentially different but formally identical mechanisms. The phenomenon allows neither a functional explanation in terms of models presented heretofore nor an answer to the question whether data processing is based in the human visual system on integrating of differentiating of on both.

Keywords: Brightness sensation, Mach Bands, coupling of retinal elements, lateral inhibition

DOI: 10.3233/THC-2008-16605

Citation: Technology and Health Care, vol. 16, no. 6, pp. 445-459, 2008

Authors: Niederer, Peter

Article Type: Editorial

DOI: 10.3233/THC-2008-16606

Citation: Technology and Health Care, vol. 16, no. 6, pp. 463-463, 2008

Authors: Jossinet, Jacques

Article Type: Research Article

Abstract: The paper describes the physical phenomena involved in the conduction of electricity, with particular reference to living tissue. The conduction of electricity depends on the flow of charge carriers in the material, while the dielectric properties are due to the rotation of dipoles that can align along an applied electric field. The relation between the electric variables in a conducting medium and their physical meanings are explained. The phenomena responsible for the electric and dielectric properties of living tissues are described. The presence of cells limits the flow of charge carriers, in particular at low frequency, and the membranes are …responsible for dielectric relaxation. The passive response of cell membranes to weak applied signals enables bioelectrical tissue characterisation. Practical tools for electrical impedance spectroscopy are given with an overview of the most recent applications. Show more

Keywords: Electric conduction, dielectric permittivity, bioimpedance, tissue characterisation

DOI: 10.3233/THC-2008-16607

Citation: Technology and Health Care, vol. 16, no. 6, pp. 465-474, 2008