Technology and Health Care - Volume 8, issue 5

Authors: Mihaylov, D. | Verkerke, G.J. | Rakhorst, G.

Article Type: Research Article

Abstract: Congestive Heart Failure (CHF) is a major health problem with a high mortality rate. Its ultimate therapy, heart transplantation, is limited by the shortage of donor hearts. Since decades researchers have been working to solve this problem by developing Mechanical Circulatory Support Systems (MCSS) that can replace or assist the failing heart. Short-term and intermediate-term ventricular assist devices are used nowadays frequently to bridge patients with severe heart failure to recovery. Long-term ventricular assist devices (VADs) and Total Artificial Hearts (TAHs) are used increasingly as a bridge to heart transplantations or as permanent circulatory support in patients with end-stage heart …failure that are contraindicated for heart transplantation. The early TAHs and VADs were mainly driven from an external pneumatic drive unit. The latest generation TAHs and long-term assist devices are electrically powered, ultracompact, totally implantable, and have small wearable drive/control consoles, allowing patients to return to their daily activities. The article categorizes and reviews the development of MCSS, highlights the medical indications and contraindications of pump implantation, advantages and disadvantages of the various systems, and results of animal and clinical studies. Show more

Keywords: heart failure, circulatory support, artificial heart

DOI: 10.3233/THC-2000-8501

Citation: Technology and Health Care, vol. 8, no. 5, pp. 251-266, 2000

Authors: Cindik, E.D. | Maurer, M. | Hannan, M.K. | Müller, R. | Hayes, W.C. | Hovy, L. | Kurth, A.A.

Article Type: Research Article

Abstract: Objective: Pathological processes in bone can lead to fatal health consequences. Therefore, it is important to study factors that possibly influence the activity of bone cells. The mast cell is a normal component of bone, storing and producing many potent bioactive substances. One of the most important factors to influence mast cell number, function, and phenotype is the c-kit ligand. A defect of the c-kit receptor leads to mast cell deficiency. In literature oversight, evidence for the importance of mast cells in skeletal homeostasis is compiled. Methods: To investigate the influence of c-kit receptor deficiency on bone mass, …geometry, microstructure, and strength, 30 femora of profoundly c-kit receptor deficient mouse mutants and 30 control group animals aged 8–20 weeks were phenotypically characterized using peripheral quantitative computed tomography (pQCT), micro-computed tomography (μ CT) and 3-point-bending. Results: The femora of the c-kit receptor and therefore mast cell deficient animals were significantly altered in bone mass and geometry but not in bone density and microstructure. The mutants had a lighter femur with a thinner shape. The lower load bearing capacity of the femora of mast cell deficient mouse mutants is more likely explained by the smaller amount of bone material than due to a change in intrinsic material properties. Technical considerations: With the little dimensions of mouse bones, it is of prime importance to have precise methods to phenotypically characterize the bone. The pQCT allows the separate assessment and analysis of trabecular and cortical bone density, as well as a statement about bone geometry. Beyond it, the μ CT-technique delivers a 3-D analysis of bone microstructure, which so far was only achieved with 2-D histomorphometry. μ CT is an efficient alternative to destructive histological preparations allowing further biomechanical testing of the same specimens to also deliver measures for bone strength. Show more

Keywords: bone microstructure, peripheral quantitative computed tomography, micro computed tomography, biomechanical testing, c-kit receptor deficiency, mast cell deficiency, mouse femur

DOI: 10.3233/THC-2000-8502

Citation: Technology and Health Care, vol. 8, no. 5, pp. 267-275, 2000

Authors: Sim, M.F. Victor | Stone, Mike | Johansen, Antony | Evans, Wil

Article Type: Research Article

Abstract: Measurements of bone density (BMD) are central to the World Health Organisation (WHO) approach to the definition of osteoporosis. Dual energy X- ray absorptiometry (DXA) remains the gold standard technique for measuring the bone mineral density (BMD) but Quantitative Ultrasound (QUS) is an attractive alternative method of bone assessment because it is easy to use and relatively inexpensive. It has been suggested that QUS could be used as a selective population pre-screen, to maximise the cost effectiveness of referral for DXA assessment of BMD. We set out to examine how such an approach might perform in the assessment of women …with low trauma Colles’ fracture. In 46 women aged 50–80 (mean 67) years we used DXA to measure BMD at lumbar spine and hip, and heel bone ultrasound to measure Broad Band Attenuation (BUA) and Velocity of Sound (VOS). We calculated local costs of £45 for DXA and £15 for QUS. We identified a BUA threshold of 60 dB/MHz as most cost effective as pre-screen, and calculated a sensitivity of 93% and specificity of 84% in identifying those subjects who were subsequently identified ashaving osteoporosis by DXA. DXA assessment of all patients had a cost of £77 per osteoporotic subject identified. We examined the cost-effectiveness of using QUS as a pre-screen, only referring subjects for more expensive DXA assessment if BUA was less than 60 dB/MHz. However this approach had no advantage, still costing £78 per osteoporotic subject identified. QUS assessment does not appear cost-effective as a pre-screen for DXA, even in this high risk group of women with low trauma Colles’ fracture. A QUS pre-screen would only be cost-effective if the scan could be performed at a substantially lower cost. Show more

DOI: 10.3233/THC-2000-8503

Citation: Technology and Health Care, vol. 8, no. 5, pp. 277-284, 2000

Authors: Stores, Gregory | Crawford, Christina

Article Type: Research Article

Abstract: Fragmentation of sleep by brief arousals has become an acknowledged aspect of poor quality sleep but there is a shortage of normative data on such arousals, especially for children. Norms for arousals (defined according to American Sleep Disorders Association criteria) were compiled for 61 children age 5–16 years using the Oxford Medilog system for a single night of home polysomnography. No significant differences were seen between the five age subgroups considered in average number of arousals per hour of sleep although individual differences were apparent at each age level and arousal duration was somewhat longer at younger ages. The low …arousal rates in the children studied are in keeping with other evidence that arousal rates increase throughout life. Boys were no different from girls in either arousal frequency or duration. Arousal frequency was correlated with PSG awakenings but only to a modest extent. These new normative values should be useful in clinical practice and research for the assessment of the quality of children's sleep. Show more

DOI: 10.3233/THC-2000-8504

Citation: Technology and Health Care, vol. 8, no. 5, pp. 285-290, 2000

Authors: Schnorrenberg, F. | Pattichis, C.S. | Schizas, C.N. | Kyriacou, K.

Article Type: Research Article

Abstract: The Biopsy Analysis Support System (BASS), previously used for image analysis of immunohistochemically stained sections of breast carcinoma, has been extended to include indexing and content-based retrieval of biopsy slide images from a database of 57 captured cases. Images from histopathological biopsy slides are described and these are accessed in terms of the properties of either individual nuclei or groups of cell nuclei present in the slide. Visual similarity of cases is specified in terms of a diagnostic index, commonly known as the H-score, which incorporates the heterogeneity of nuclear staining intensity, as well as the percentage of nuclei staining …at specific intensities. The system provides a platform that can be exploited in telepathology and teleconsultation, but further research is needed to explore its full potential and accuracy in a diagnostic clinical environment. Show more

Keywords: breast cancer biopsy, content-based retrieval of biopsy slide images, digital medical libraries, optical imaging

DOI: 10.3233/THC-2000-8505

Citation: Technology and Health Care, vol. 8, no. 5, pp. 291-297, 2000

Authors: Larios, Yannis G. | Matsopoulos, George K. | Askounis, Dimitris Th. | Nikita, Konstantina S.

Article Type: Research Article

Abstract: The design of each new hospital site is typically preceded by decisions on the most appropriate level of biomedical equipment which significantly influences the layout of the hospital departments which are under construction. The most appropriate biomedical equipment should ideally be decided upon considering a series of demographic and social parameters of the hospital and international regulations and standards. This information should ultimately be distilled to proper technical specifications. This paper proposes a streamlined management process related to the procurement of biomedical equipment for new hospital sites or for those under expansion. The new management process aims to increase the …efficiency of the experts involved in the definition of the most appropriate level of equipment and its technical specifications. It also addresses all aspects of the biomedical equipment-selection cycle, including the evaluation of the bids submitted by the equipment suppliers. The proposed process is assisted by a management information system, which integrates all related data-handling operations. It provides extensive decision-support facilities to the expert and a platform for the support of knowledge re-use in the field of biomedical-equipment selection. Show more

Keywords: management information systems, business process reengineering, biomedical equipment procurement

DOI: 10.3233/THC-2000-8506

Citation: Technology and Health Care, vol. 8, no. 5, pp. 299-313, 2000