Technology and Health Care - Volume 6, issue 4

Authors: Jämsä, Kaisa | Jämsä, Timo

Article Type: Research Article

Abstract: A comprehensive health technology assessment is needed to meet the demands of holistic health care. We performed a qualitative study to describe the parents’ experiences of the nursing care of sick newborn infants. The parents of seven full-term infants in a neonatal intensive care unit were interviewed. The parents found the intensive care unit shocking. The equipment with wiring, tubing and blinking lights looked frightening. The parents felt very unpleasant because of the audible signals. The technological environment was oppressive, which caused the parents to feel as outsiders in their parental role and delayed the development of their ability to …participate in the care of the child. To relieve the anxiety of the parents and to promote their ability to take care of their newborn child, parental experiences should be taken into account when developing devices. Special attention should be given to designing the outside appearance and the audible signals and alarms of the equipment. Show more

Keywords: Technology assessment, design, medical devices, neonatal intensive care, NICU, parents, infant

DOI: 10.3233/THC-1998-6401

Citation: Technology and Health Care, vol. 6, no. 4, pp. 225-230, 1998

Authors: Stores, Gregory | Crawford, Christina | Selman, Jessica | Wiggs, Luci

Article Type: Research Article

Abstract: Home polysomnography (PSG) by means of ambulatory monitoring systems has distinct advantages over sleep laboratory recordings, especially for children. However, normative data have been lacking. Norms for conventional PSG variables were compiled for 60 children age 5–16 years using the Oxford Medilog ambulatory monitoring system. Recordings were confined to a single night in view of previous demonstrations that the sleep on the first night is not significantly affected by the recording procedure. The results are presented in 5 age subgroups. Broad comparisons with published laboratory PSG norms for children of the same ages suggest that in home recordings …sleep duration is longer, and slow wave sleep is much more pronounced with a commensurate reduction in stage 2 NREM sleep. That is, sleep quality and quantity appears better at home even when adaptation to the laboratory situation has been promoted. These new normative data are considered valuable for both clinical and research purposes where physiological sleep studies in children are required. Show more

DOI: 10.3233/THC-1998-6402

Citation: Technology and Health Care, vol. 6, no. 4, pp. 231-236, 1998

Authors: Le Dour, Olivier | Norstedt, Iréne

Article Type: Research Article

Abstract: To validate clinically a new stereotactic device for real-time monitored minimally-invasive brain surgery; to perform the first European phase I clinical trials of Boron Neutron Capture Therapy (BNCT) for treatment of glioblastoma, using the facility of the Community Joint Research Centre (JRC) in Petten, on forty patients from six different European centres. These are typical objectives of the current EC BIOMED 2 demonstration projects. The number of supported projects under BIOMED is now 16 in 1998, and will be in total around 80 for the three Life Sciences and Technologies Programmes. Demonstration is expected to play a major role in …the Fifth Framework Programme, particularly in its so-called “Key Actions”. This article addresses three of the main issues for potential applicants: the readiness for demonstration, the content of the consortium, and the dissemination strategy. Show more

Keywords: Demonstration Project, Life Sciences, Biomedical Engineering, European Commission funding

DOI: 10.3233/THC-1998-6403

Citation: Technology and Health Care, vol. 6, no. 4, pp. 237-243, 1998

Authors: Reisch, S. | Schneider, M. | Timmer, J. | Geiger, K. | Guttmann, J.

Article Type: Research Article

Abstract: The forced oscillation technique (FOT) is a non-invasive method which may be suitable for assessing upper airway obstruction in obstructive sleep apnea/hypopnea syndrome (OSAS) patients. The aim of this study was to determine in vitro if FOT can provide an early detection index of total or partial upper airway occlusion. A respiratory system analog was developed which includes an upper airway analog that allows simulation of upper airway collapse (thus mimicking the situation in patients with OSAS). We simulated different degrees of upper airway obstructions ranging from 0 (unobstructed airways) to 1 (total occlusion). Furthermore, we imitated the collapsible upper …airway wall by means of elastic membranes with ten different wall compliances ranging from 3.3 × 10 − 4 to 1 l/mbar. For the two stiffest rubber membranes (C wall = 0.01 and 3.3 × 10 − 4 l/mbar) the absolute value of the impedance (| Z | ) showed a marked increase for obstructions greater than 0.6. For the two membranes with the highest wall compliances (C wall = 0.03 and 1 l/mbar) obstructions with an increase in | Z | could not be detected before the obstruction reached 0.8. For degrees of obstruction less than 0.6 the phase angle of collapsible membranes with low compliance (stiff airway wall) were about 1.5 π which significantly differed from phase angles of 1.7 π measured in membranes with high compliance (elastic airway wall); p < 0.01 . We hypothesized that stiffness of upper airway walls corresponds with their muscle tone, i.e., stiff airway walls are related with high muscle tone and vice versa. Thus, a decrease in upper airway muscle activity would cause an increase of upper airway wall elasticity that enables upper airway collapse. As a consequence the phase angle ϕ could be expected to change from values characterizing stiff membranes to values characterizing more elastic membranes which could be used as early indicator for obstructive respiratory events. We have frequently observed such changes in morphology of ϕ ( t ) data obtained from patients with OSAS. Show more

Keywords: Obstructive sleep apnea syndrome, obstructive apnea prediction, forced oscillation technique, upper airway wall compliance, muscle tone

DOI: 10.3233/THC-1998-6404

Citation: Technology and Health Care, vol. 6, no. 4, pp. 245-257, 1998

Authors: Barbaro, V. | Grigioni, M. | Daniele, C. | D’Avenio, G.

Article Type: Research Article

Abstract: Heart valve replacement has become, since many years, a common surgical practice. Along with the improvement that the patients’ health has derived from it, however, a certain amount of risk could not be avoided, bound to the inevitable hemodynamic disturbances that an artificial device generates. A major shortcoming, often reported, is the formation of thrombus on the edge of the prosthetic valve, with a possible obstruction of the orifices through which blood should normally flow undisturbed. Hemolysis is another possible consequence of the implantation of a mechanical heart valve, generally correlated to turbulence downstream of prosthetic heart valves (PHV). …As it is agreed upon by many researchers, the risk of thrombogenicity or hemolysis is higher in those valves that are more subject to promote turbulence and flow separation in the flow through them. In the following paper, we present a study of the turbulence-related shear stress downstream of a bileaflet valve of minimum size (19 mm external diameter) Sorin Bicarbon. This size was chosen, accordingly to the Food & Drug Administration (FDA) draft guidance suggestion to investigate the worst case in turbulence promoted by PHVs, in order to have the highest velocity gradients and shear stresses for the FDA-stated cardiac output (6 l/min), related to maximum Reynolds number conditions. Velocity data were collected with the two-dimensional laser Doppler anemometry (LDA) technique; whereas this approach does not investigate directly all three components of the flow field, in the present case (bileaflet valves) it is not a limitation to the assessment of the maximum turbulence shear stress (TSS), thanks to the two-dimensional flow nature downstream of bileaflet models. Data taken in coincident mode were elaborated in order to determine the maximum shear stress in the measured points in the flow field, using the 2D Principal Stress Analysis (PSA). The consequences of a variable principal normal stress direction all along the measured profile will be illustrated in terms of differences between measured and maximum shear stresses. Results show the need to estimate the maximum values for the TSS and the direction along which it is obtained to correctly define the turbulent flow field downstream of PHVs. Show more

Keywords: Flow visualization, laser Doppler anemometry, principal stress analysis, cardiac valve prostheses, in vitro testing, velocity profiles

DOI: 10.3233/THC-1998-6405

Citation: Technology and Health Care, vol. 6, no. 4, pp. 259-270, 1998

Authors: Schoenmakers, Coen

Article Type: Research Article

DOI: 10.3233/THC-1998-6406

Citation: Technology and Health Care, vol. 6, no. 4, pp. 271-274, 1998

Authors: Sun, X.Q. | Cheetham, B.M.G. | Evans, K.G. | Earis, J.E.

Article Type: Research Article

Abstract: This paper is concerned with devising a standard procedure for determining the gain and phase responses of the analogue filters used to pre-process pulmonary signals prior to their digitisation. The customary high-pass filtering, in particular, will strongly affect the time-domain wave-shapes of digitised signals and this must be taken into account when analysing the signals. Several means of determining the effect of the high-pass filtering are investigated and a measurement procedure is proposed which may be easily carried out using simple laboratory equipment.

DOI: 10.3233/THC-1998-6407

Citation: Technology and Health Care, vol. 6, no. 4, pp. 275-283, 1998