Technology and Health Care - Volume 5, issue 4

Authors: Duyck, J. | Naert, I.E. | Van Oosterwyck, H. | Van der Sloten, J. | De Cooman, M. | Lievens, S. | Puers, B.

Article Type: Research Article

Abstract: Considering biomechanics of oral implants, both loading on the implant itself and the transferred load to the bone need our attention. Mastication induces vertical and transverse forces, which induce axial forces and bending moments and exert stress gradients in the implant as well as in the bone. By the use of strain gauges or piezo-electric force transducers, one succeeds in precise intra-oral force measurements which make it possible to study a wide range of varying conditions in implant dentistry. A key determinant of the success or failure of an oral implant is the way mechanical stresses are transferred to the …surrounding bone. The load transfer from implants to surrounding bone depends on the type of loading, the bone-implant interface, the length and diameter of the implants, the implant shape, structure of the implant surface, the superstructure and the quality and quantity of the surrounding bone. Finite element analyses indicate maximum stress concentrations in the contact area of the implants with the cortical bone and around the apex of the implants in the trabecular bone. Although the precise mechanisms are not fully understood, it is clear that there is an adaptive remodelling response of the surrounding bone to the current situation. Show more

Keywords: Biomechanics, oral implants, oral prosthesis, loading

DOI: 10.3233/THC-1997-5401

Citation: Technology and Health Care, vol. 5, no. 4, pp. 253-273, 1997

Authors: Mayer, Isabella V. | Koerner, Roland J.

Article Type: Research Article

DOI: 10.3233/THC-1997-5402

Citation: Technology and Health Care, vol. 5, no. 4, pp. 275-283, 1997

Authors: Bloch, Konrad E.

Article Type: Research Article

Abstract: Polysomnography refers to the continuous monitoring of multiple neurophysilogical and cardiorespiratory variables, usually over the course of a night, to study normal and disturbed sleep. Electroencephalographic, electrooculographic and electromyographic channels provide the basis for staging the recording into successive epochs of wakefulness and various non-Rapid-Eye-Movement (REM) and REM sleep. Detection of airflow at the nose and mouth by means of thermistors, and analysis of breathing patterns recorded from sensors placed around the ribcage and abdomen, sound recordings, the electrocardiogram and the combined application of several other measurement techniques allow the assessment of normal and abnormal physiological events in relation to …sleep structure. Polysomnography has an important role in the diagnosis of disorders of sleep and wakefulness as well as in the assessment of treatment effects and in scientific investigations. Developments in digital signal processing have contributed to its widespread application in clinical practice and research. Show more

Keywords: Polysomnography, sleep, physiological monitoring, sleep apnea, computer assisted signal processing, sleep disorders diagnosis

DOI: 10.3233/THC-1997-5403

Citation: Technology and Health Care, vol. 5, no. 4, pp. 285-305, 1997

Authors: Kiani, K. | Snijders, C.J. | Gelsema, E.S.

Article Type: Research Article

Abstract: The primary goal of an ambulatory monitoring of motor activities (AMMA) system is to document the occurrence of random and spontaneous motor activities (e.g., sitting, lying, standing, walking, running, etc.) of the ambulatory subject in natural environmental circumstances. Much progress has been made in recording fidelity, reduction in energy requirement, fixation of the accelerometers, equipment size and weight, memory capacity and data acquisition. At present, our laboratory is interested in developing an automated off-line AMMA-signal analysis system. The system has to take care of activity (wave) detection, recognition of onsets and endpoints of the various activities (waves), and computation of …a set of relevant clinical parameters (e.g., total walking time, number of times rising from a chair, etc.) from long-term recorded data. Two methods are currently being used for computerizing the off-line analysis system: using an artificial neural network and using a set of selected features extracted from the input data. The present paper is aimed at the latter method. The method was successfully applied to long-term recorded data sets of eight male amputees and three other subjects. The primary results indicate that the method is a potentially useful tool to computerize the off-line analysis system. Show more

Keywords: Daily-life activity, ambulatory monitoring, rehabilitation, pattern recognition, feature extraction

DOI: 10.3233/THC-1997-5404

Citation: Technology and Health Care, vol. 5, no. 4, pp. 307-318, 1997

Authors: Friesdorf, Wolfgang | Classen, Bernd | Konichezky, Sergio | Schwilk, Bernhard

Article Type: Research Article

Abstract: Objective: To find out and analyse the events which are expected to influence the future of Intensive Care Units (ICU). Design: Three round Delphi study. Setting: In a first preparation round 9 events were defined. In the two rating rounds an international panel of 60 experts (heads of ICUs) estimated the time when the events may come true and whether they are desired or not. Results: Computer tools are desired and expected in the near future (before the year 2000) for audit, quality assurance, record keeping and telecommunication; complex closed loops and nursing robots …will not be used in clinical routine before 2005, they are not desired. Show more

Keywords: Forecast, Delphi, Intensive Care Unit, development, technology

DOI: 10.3233/THC-1997-5405

Citation: Technology and Health Care, vol. 5, no. 4, pp. 319-330, 1997

Authors: Mhic Iomhair, Maura | Lavelle, S.M.

Article Type: Research Article

Abstract: Sarcoma may arise on unabsorbable foreign bodies in rodents and more rarely in man. Perforations of the implant reduce its carcinogenicity so that nitrocellulose filters of pore size 0.45 microns have failed to induce tumour. We examined whether increase of surface area would restore carcinogenesis to film with such pore size. Nitrocellulose filters of 25 mm diameter and pore size 0.45 microns were implanted singly, in pairs and in trios subcutaneously in 3 respective groups of BALB/c mice (total 97) and observed for sarcomagenesis for 100 weeks. No tumour arose on the singles (surface area 0.98 mm2 ), while 7 …arose on the paired (1.96 mm2 ) at a mean of 54 weeks and 16 on the trios (2.95 mm2 ) at a mean of 46 weeks (differences significant at p > 0.01). A sufficiency of surface area restores carcinogenicity to perforated foreign surfaces in mice. Surface area is dominant over film perforation size in film sarcomagenesis. Show more

Keywords: Foreign body, sarcoma, man, mouse, surface area, pore size

DOI: 10.3233/THC-1997-5406

Citation: Technology and Health Care, vol. 5, no. 4, pp. 331-334, 1997