Technology and Health Care - Volume 1, issue 2

Authors: Arnold, Michael

Article Type: Research Article

DOI: 10.3233/THC-1993-1201

Citation: Technology and Health Care, vol. 1, no. 2, pp. 117-125, 1993

Authors: Dequeker, J. | Reeve, J. | Pearson, J. | Bright, J. | Felsenberg, D. | Kalender, W. | Langton, C. | Laval-Jeantet, A.M. | Rüegsegger, P. | Van der Perre, G. | COMAC-BME Quantitative Assessment of Osteoporosis Study Group

Article Type: Research Article

Abstract: 26 European centres participated in a concerted research action Biomedical Engineering: Quantitative Assessment of Osteoporosis. With a newly designed European spine and forearm phantom, the stability, accuracy, precision of dual energy absorption (DXA) and quantitative computer tomography (QCT) densitometry machines have been evaluated. Marked and clinically significant differences were found between brands and between techniques. Cross-calibration formulae have been made and normative data evaluated for different regions (spine, femoral neck, femoral trochanteric and forearm). A general fit for all data obtained from different machines was established. The cross-calibration formulae will allow a sensitivity analysis to assist the choice of …equipment for clinical management of different categories of patients with bone disease. The present results obtained with an internationally accepted European spine and forearm phantom can now serve to stimulate the manufacturers to improve the comparability of bone measurements between machines. Show more

Keywords: Osteoporosis, Bone densitometry, QCT, DXA

DOI: 10.3233/THC-1993-1202

Citation: Technology and Health Care, vol. 1, no. 2, pp. 127-131, 1993

Authors: Skubiszak, L.

Article Type: Research Article

Abstract: This work is the first attempt to propose a complex model of muscle contraction in which different aspects of the sarcomere shortening are collected into a logical entity. Proposed are some suggestions to answer some fundamental questions concerning the molecular mechanism of muscle contraction, such as the following: “of which part of the myosin molecule does the crossbridge consist?”, “how does the crossbridge act?”, “what are two heads of the myosin molecule needed for?”, “in what way is the metabolic energy of ATP converted into the mechanical work of muscle contraction?”, “does the actin filament influence have a passive or …active role in the process of muscle contraction?”, “what is the role of the third filament – a connecting one?”, “in what way is muscle relaxation generated?”. Show more

Keywords: Muscle contraction, Myosin filament, Actin filament, Connecting filament

DOI: 10.3233/THC-1993-1203

Citation: Technology and Health Care, vol. 1, no. 2, pp. 133-142, 1993

Authors: Majurin, Marja-Leena | Kiuru, Aaro | Svedström, Erkki | Kurki, Timo | Helenius, Hans

Article Type: Research Article

Abstract: Fifty-five patients undergoing routine chest CT were examined with four additional high resolution computed tomography (HRCT) slices to determine the proper milliampere-second settings for clinical HRCT of the lungs. The following technical factors were used: 1-mm collimation, 2-s scan time, 120 kVp and different milliampere settings (160 mA, 100 mA, 60 mA, 30 mA). On 47 out of 54 patients all the four HRCT cuts were at exactly the same level. These images were independently reviewed and assessed by three radiologists. The body mass index was calculated in order to determine the effect of the size of the patient on …the milliamperage setting needed. The standard deviation of CT values of 1 mm and 10 mm slice was measured in a Plexiglas phantom with different mA settings. The slice thickness was measured with thermoluminescence dosimeter. In the phantom study the change of milliamperage from 160 mA to 30 mA at 120 kVp and 2 s increased standard deviation in CT units from about 4.6 to 8.9 in 1 mm slice and from about 2.9 to 4.3 in 10 mm slice. The Computed Tomography Dose Index (CTDI) values of both 1 mm and 10 mm slices at 160 mA–30 mA were approximately from 9 to 2 cGy (rad). In the patient study 1 mm HRCT scans with 120 kVp/100 mA/2 s showed the same diagnostic information as 120 kVp/160 mA/2 s scans for all patients regardless of size. If only the normal weight patients are considered, all the details were also well seen with 120 kVp/60 mA/2 s settings. In our study contrary to earlier reports 30 mA/2s was inadequate for diagnosis. We conclude that at 120 kVp medium-dose settings 60–100 mA/2 s or 120–200 mA s are in clinical practice appropriate for HRCT studies of the lungs in most patients. Show more

Keywords: Lung, High resolution computed tomography, Imaging parameter, Absorbed dose, Computed Tomography Dose Index

DOI: 10.3233/THC-1993-1204

Citation: Technology and Health Care, vol. 1, no. 2, pp. 143-153, 1993

Authors: Rosinski, S. | Sentek, J. | Lewinska, D.

Article Type: Research Article

Abstract: A special carbon adsorbent (CA), designed for use in extracorporeal detoxification by hemoperfusion, was produced from a spherical synthetic polymer by our own technolique and tested at a preclinical level. Comparison of mechanical properties, sorption and biocompatibility between CA and medical hemosorbents was made. The carbon adsorbent is hard, has a smooth surface, shows good sorption properties and has acceptable biocompatibility. These features qualify the carbon adsorbent for use in clinical hemoperfusion without any additional membrane coating.

Keywords: Hemoperfusion, Hemosorbent, Carbon adsorbent

DOI: 10.3233/THC-1993-1205

Citation: Technology and Health Care, vol. 1, no. 2, pp. 155-158, 1993

Authors: Kleber, Bernd-Michael

Article Type: Research Article

DOI: 10.3233/THC-1993-1206

Citation: Technology and Health Care, vol. 1, no. 2, pp. 159-163, 1993

Authors: de Muinck, E.D. | Meeder, J.G. | Magielse, C.P.E. | Bom, V.J.J. | Verkerke, G.J. | Lie, K.I.

Article Type: Research Article

Abstract: A new, 5 ml, piston type hemoperfusion pump, designed to prevent myocardial ischemia during coronary angioplasty, was evaluated in vitro at different flow rates. The driving pressures necessary to achieve the different flow rates and biochemical indicators of hemolysis, were assessed. Fresh human blood was perfused through 2 angioplasty catheter types, one with distal side holes and another catheter type without side holes but with a tapered distal segment. Despite high driving pressures, shear stress > 200 Pa, turbulent flow and the presence of occlusive valves in the pump, hemolysis proved to be minimal. This is most readily explained by …the short period of time during which the blood was subjected to mechanical factors that cause hemolysis. Additionally, the volume of the pump, and hence the amount of blood subjected to mechanical hemolysis, was small. The side holes in the catheter caused obstruction by promoting the formation of clots. Show more

Keywords: Coronary perfusion pump, Coronary angioplasty, Hemolysis

DOI: 10.3233/THC-1993-1207

Citation: Technology and Health Care, vol. 1, no. 2, pp. 165-170, 1993

Authors: Ramstein, G. | Bernadet, M.

Article Type: Research Article

Abstract: Chromosome, a knowledge-based analysis system has been designed for the classification of human chromosomes. Its aim is to perform an optimal classification by driving a tool box containing the procedures of image processing, pattern recognition and classification. This paper presents the general architecture of Chromosome, based on a multiagent system generator. The image processing tool box is described from the met aphasic enhancement to the fine classification. Emphasis is then put on the knowledge base intended for the chromosome recognition. The global classification process is also presented, showing how Chromosome proceeds to classify a given chromosome. Finally, we discuss further …extensions of the system for the karyotype building. Show more

Keywords: Chromosome analysis, Knowledge-based system, Image analysis

DOI: 10.3233/THC-1993-1208

Citation: Technology and Health Care, vol. 1, no. 2, pp. 171-180, 1993

Authors: Reuzé, P. | Coatrieux, J.L. | Luo, L.M. | Dillenseger, J.L.

Article Type: Research Article

Abstract: This paper describes a new method for the three-dimensional (3-D) tracking and the quantification of blood vessels from magnetic resonance angiography (MRA). The approach is based on 3-D geometrical moments and consists of the following steps: (1) interactive selection of 3-D seed points; (2) automatic tracking of the vessels; (3) local computation of both diameter and orientation; (4) rendering of the vessels. This detection and estimation scheme has been validated on simulated and real data.

Keywords: Magnetic resonance angiography, Detection, Quantification, Tracking, Rendering

DOI: 10.3233/THC-1993-1209

Citation: Technology and Health Care, vol. 1, no. 2, pp. 181-188, 1993

Article Type: Calendar

DOI: 10.3233/THC-1993-1210

Citation: Technology and Health Care, vol. 1, no. 2, pp. 189-189, 1993