Journal of biomedical engineering最新文献_第3页

Neural network segmentation of magnetic resonance spin echo images of the brain 脑磁共振自旋回波图像的神经网络分割

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90071-6

S. Cagnoni , G. Coppini , M. Rucci , D. Caramella , G. Valli

{"title":"Neural network segmentation of magnetic resonance spin echo images of the brain","authors":"S. Cagnoni , G. Coppini , M. Rucci , D. Caramella , G. Valli","doi":"10.1016/0141-5425(93)90071-6","DOIUrl":"10.1016/0141-5425(93)90071-6","url":null,"abstract":"<div><p>This paper describes a neural network system to segment magnetic resonance (MR) spin echo images of the brain. Our approach relies on the analysis of MR signal decay and on anatomical knowledge; the system processes two early echoes of a standard multislice sequence. Three main subsystems can be distinguished. The first implements a model of MR signal decay; it synthesizes a four-echo multiecho sequence, in order to add images characterized by long echo-times to the input sequence. The second subsystem exploits <em>a priori</em> anatomical knowledge by producing an image, in which pixels belonging to brain parenchyma are highlighted. Such anatomical information allows the following submodule to distinguish biologically different tissues with similar water content, and hence similar appearance, which might produce misclassifications. The grey levels of the reconstructed sequence and the output of the second module are processed by the third subsystem, which performs the segmentation of the sequence. Each pixel is assigned to one of five different tissue classes that can be revealed with brain MR spin echo imaging. With a suitable encoding, a five-level segmented image can then be produced. The system is based on feed-forward networks trained with the back-propagation algorithm; experiments to assess its performance have been carried out on both simulated and clinical images.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 5","pages":"Pages 355-362"},"PeriodicalIF":0.0,"publicationDate":"1993-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90071-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19219703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 35

An integrated procedure to assess knee-joint kinematics and kinetics during gait using an optoelectric system and standardized X-rays 使用光电系统和标准化x射线评估步态期间膝关节运动学和动力学的综合程序

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90076-B

J. Li, U.P. Wyss , P.A. Costigan , K.J. Deluzio

引用次数: 45

PC-based system for an objective quantification of manual movement disability for clinical and scientific purposes 基于pc的系统，用于临床和科学目的的手动运动障碍的客观量化

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90072-7

J. Machetanz, J. Forster, C. Bischoff, B.-U. Meyer, C. Isenberg, B. Conrad

{"title":"PC-based system for an objective quantification of manual movement disability for clinical and scientific purposes","authors":"J. Machetanz, J. Forster, C. Bischoff, B.-U. Meyer, C. Isenberg, B. Conrad","doi":"10.1016/0141-5425(93)90072-7","DOIUrl":"10.1016/0141-5425(93)90072-7","url":null,"abstract":"<div><p>In clinical management and research of movement disorders exact knowledge about the extent of motor impairment is essential. This paper presents a computer program which allows for an objective measurement of manual movement disability. The program was developed for standard hardware and can easily be used in a variety of clinical and research environments. The program runs on MS-DOS computers and uses a Microsoft computer mouse as the only input device. The temporal resolution is 100 Hz, the spatial resolution 400 dots per inch. The user may choose between standard test sets or he may design sets according to his individual needs from a pool of available protocols which includes tracking tasks, ballistic tasks, complex sequential tasks, and finger tapping. All tasks are implemented in a similar way in order to keep the test environment as consistent as possible for the patient. The patient must usually carry out movements which correspond to the movements of a target symbol on the computer screen. This entails the manipulation of a follower symbol, also visible on the computer screen, via the computer mouse. The program itself and the theoretical background of the protocols are described in the paper. Additionally, preliminary results from pilot experiments are presented.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 5","pages":"Pages 363-370"},"PeriodicalIF":0.0,"publicationDate":"1993-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90072-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19219704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

A new geometric description of the right ventricle 一种新的右心室几何描述

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90075-A

F.P. Czegledy, J. Katz

引用次数: 18

Quantitative analysis of four EMG amplifiers 四个肌电放大器的定量分析

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90079-E

E.J. Perreault, I.W. Hunter, R.E. Kearney

引用次数: 13

Development of a concentric water-displacement model lung 同心水驱替肺模型的研制

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90080-I

E.M. Williams, L.B. Gale, P.A. Oakley, M.C. Sainsbury, C.E.W. Hahn

引用次数: 16

New method for estimating explosive anaerobic leg power 一种估算爆炸性无氧腿力的新方法

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90082-A

H.A.M. Al-Nashash , Z.D.M. Al-Kurdi

引用次数: 0

Precision and accuracy of bone landmarks in characterizing hand and wrist position 精确和准确的骨标记表征手和手腕的位置

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90073-8

C.F. Small, D.R. Pichora, J.T. Bryant, P.M. Griffiths

引用次数: 25

An adaptive finite-element approach for the analysis of dental restorations 牙体修复体自适应有限元分析方法

Journal of biomedical engineering Pub Date : 1993-09-01 DOI: 10.1016/0141-5425(93)90077-C

P.F. Hübsch , J. Middleton , J.S. Rees , P.H. Jacobsen

引用次数: 13

Computer-controlled portable stimulator for paraplegic patients 截瘫病人用电脑控制的便携式刺激器

Journal of biomedical engineering Pub Date : 1993-07-01 DOI: 10.1016/0141-5425(93)90012-N

J. Minzly , J. Mizrahi , E. Isakov , Z. Susak , M. Verbeke

{"title":"Computer-controlled portable stimulator for paraplegic patients","authors":"J. Minzly , J. Mizrahi , E. Isakov , Z. Susak , M. Verbeke","doi":"10.1016/0141-5425(93)90012-N","DOIUrl":"10.1016/0141-5425(93)90012-N","url":null,"abstract":"<div><p>A six-channel lightweight, portable and computer-controlled stimulator for the functional activation of paraplegic patients is described. To enable programming of the various functions, the stimulator was designed to work in a remote-control mode hosted by an IBM PC or compatible computer, in addition to its normally used local mode. The stimulus parameters, including current intensity, stimulus frequency and pulse width, are individually adjustable and programmable for each channel. The power source is 12 V 500 mAh<sup>−1</sup>, from 10 rechargeable nickel cadmium batteries, with a run time of 1.5 h for a load of 200 mA in four channels. Various training programmes for the activation of paraplegics in the sitting, standing and walking positions are described. The final design of the stimulator is based on experience gained from 25 patients, treated and evaluated during the course of development. Ongoing work including clinical, biomechanical and physiological studies is carried out to evaluate performance of the activated patients and to optimize stimulation.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 4","pages":"Pages 333-338"},"PeriodicalIF":0.0,"publicationDate":"1993-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90012-N","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19347536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25