Technology and Health Care - Volume 12, issue 4

Authors: Morasso, Pietro G. | Re, Cristina | Casadio, Maura

Article Type: Research Article

Abstract: The purpose of this paper is to describe a system for the rapid spot check of the accuracy of stabilometric platforms used in clinical posturography and, if needed, for estimating a recalibration matrix. It is based on a simple mechanical device which can be applied to any stabilometric platform; it consists of a ballast and a rotating mass which can generate a spiral-shaped training set of posturographic data. A software package has been developed whose purpose is to estimate a calibration matrix and to provide a figure of merit for the calibrated system. The data analysis is organized into two …phases: a preliminary global phase, which uses the covariance matrix of the training set, and a refinement, iterative phase, which exploits the equation of the spiral. The characteristic features of the proposed system are: 1) it uses dynamic, not static loading, 2) loading is not applied manually, 3) it uses distributed, not point loads, 4) there is no need to bolt the system to the platform. Although these features are found, separately, in different prototypes described in the literature, their combination can only be found in the proposed system. Moreover, while most systems in the literature are intended for gait analysis, the proposed one is specifically designed for posturography. Show more

DOI: 10.3233/THC-2004-12401

Citation: Technology and Health Care, vol. 12, no. 4, pp. 293-304, 2004

Authors: Hieber, Simone E. | Walther, Jens H. | Koumoutsakos, Petros

Article Type: Research Article

Abstract: In computer aided surgery the accurate simulation of the mechanical behavior of human organs is essential for the development of surgical simulators. In this paper we introduce particle based simulations of two different human organ materials modeled as linear viscoelastic solids. The constitutive equations for the material behavior are discretized using a particle approach based on the Smoothed Particle Hydrodynamics (SPH) method while the body surface is tracked using level sets. A key aspect of this approach is its flexibility which allows the simulation of complex time varying topologies with large deformations. The accuracy of the original formulation is significantly …enhanced by using a particle reinitialization technique resulting in remeshed Smoothed Particle Hydrodynamics (rSPH). The mechanical parameters of the systems used in the simulations are derived from experimental measurements on human cadaver organs. We compare the mechanical behavior of liver- and kidney-like materials based on the dynamic simulations of a tensile test case. Moreover, we present a particle based reconstruction of the liver topology and its strain distribution under a small local load. Finally, we demonstrate a unified formulation of fluid structure interaction based on particle methods. Show more

DOI: 10.3233/THC-2004-12402

Citation: Technology and Health Care, vol. 12, no. 4, pp. 305-314, 2004

Authors: Marti, Gaëtan | Baur, Charles | Zambelli, Pierre-Yves

Article Type: Research Article

Abstract: We present a new contour segmentation method for femoral head detection in CT images. The principal idea underlying our approach is to represent the contour using active rays. Each ray has internal energy (continuity and smoothness constraints), as well as external energy (image-oriented edges and global a-priori knowledge). The causal nature of this representation allows a globally optimal, non-iterative solution to be found using dynamic programming. Moreover, even pathological bone structures can be automatically segmented. Several clinical situations on pelvis CT scan with hip degenerative change shows that this approach is more efficient than conventional methods. In this paper, we …describe our method and discuss how it can be used to create graphical 3D models of the hip that are suitable for preoperative planning. Show more

DOI: 10.3233/THC-2004-12403

Citation: Technology and Health Care, vol. 12, no. 4, pp. 315-322, 2004

Authors: Hult, P. | Fjällbrant, T. | Wranne, B. | Engdahl, O. | Ask, P.

Article Type: Research Article

Abstract: Reliable monitoring of respiration plays an important role in a broad spectrum of applications. Today, there are several methods for monitoring respiration, but none of them has proved to be satisfactory in all respects. We have recently developed a bioacoustic method that can accurately time respiration from tracheal sounds. The aim of this study is to tailor this bioacoustic method for monitoring purposes by introducing dedicated signal processing. The method was developed on a material of ten patients and then tested in another ten patients treated in an intensive care unit. By studying the differences in the variation of the …spectral content between the different phases of respiration, the described method can distinguish between inspiration and expiration and can extract respiration frequency, and respiration pause periods. The system detected 98% of the inspirations and 99% of the expirations. This method for respiration monitoring has the advantage of being simple, robust and the sensor does not need to be placed closed to the face. A commercial heart microphone was used and we anticipate that further improvement in performance can be achieved trough optimization of sensor design. Show more

Keywords: auscultation, lung sounds, monitoring, bioacoustic

DOI: 10.3233/THC-2004-12404

Citation: Technology and Health Care, vol. 12, no. 4, pp. 323-332, 2004

Authors: Kasra, M. | Parnianpour, M. | Shirazi-Adl, A. | Wang, J.L. | Grynpas, M.D.

Article Type: Research Article

Abstract: We investigated the effect of loading rate on tensile properties of sheep bone-anulus-bone specimens in axial direction. Disc anulus Samples with adjacent bone attachments were prepared from lateral, posterior and anterior regions of sheep lumbar spinal segments. The specimens were then tested at different strain rates under non-destructive cyclic tensile loading followed by destructive tensile loading. Each specimen was prepared by embedding the bony parts in the polymethylmetacrylate (PMMA) exposing the anulus portion to support tension. The results of non-destructive cyclic tests indicated a decrease in the hysteresis energy loss as strain rate increased. In the destructive tests, no significant …differences in ultimate stress, ultimate strain and strain energy density were observed at different strain rates or annulus locations. However, there was a significant increase in the modulus at linear region as strain rate increased. Two major modes of failure were observed; rupture in the anulus mid-substance and at the anulus-endplate junction. The former failure was more frequent with no clear pattern across strain rates and locations, while the latter failure at anulus-endplate junction occurred primarily at slow strain rates. Show more

Keywords: disc anulus, tension, strain rate, stress, failure, modulus

DOI: 10.3233/THC-2004-12405

Citation: Technology and Health Care, vol. 12, no. 4, pp. 333-342, 2004

Authors: Saxena, A.K. | Morcate, J.J. | Schleef, J. | Reich, A. | Willital, G.H.

Article Type: Research Article

Abstract: Rectal atresia is an extremely rare anorectal malformation. A unique case of rectal atresia presenting as an imperforate membrane associated with congenital cardiac malformations and unilateral choanal atresia in a newborn is reported. Ultrasound examination in the newborn infant located the presence of the rectal membrane which was surgically treated successfully.

DOI: 10.3233/THC-2004-12406

Citation: Technology and Health Care, vol. 12, no. 4, pp. 343-345, 2004

Authors: Pambudi, Iwan T. | Hayasaka, Tomoaki | Tsubota, Ken-ichi | Wada, Shigeo | Yamaguchi, Takami

Article Type: Research Article

Abstract: This study explores the Patient Record Information System (PaRIS) for primary health care centers in a developing country such as Indonesia. The specific geography of the thousand islands country Indonesia is the reason for transportation difficulties as well as communication problems. This causes a serious adverse effect on the public healthcare service especially in the rural area within the country. Hence, a sustainable system is required that makes use of appropriate Information and Communication Technology (ICT). We developed a clinical information system with modest communication technology combined with a unique database distribution system. The Internet and its free software are …the main tools for this system. It is a good opportunity for a developing country such as Indonesia to apply open free software in regard to the healthcare sector. This cost effective and sustainable system can enhance the work of physicians in order to provide better and applicable public health care service. Show more

Keywords: information and communication technology, open free software, patient record information system, primary care health center, sustainable system

DOI: 10.3233/THC-2004-12407

Citation: Technology and Health Care, vol. 12, no. 4, pp. 347-357, 2004