Journal of biomedical engineering最新文献_第6页

Validation and reproducibility of pressure-corrected aortic distensibility measurements using pulse-wave-velocity Doppler ultrasound 使用脉冲波速度多普勒超声测量压力校正主动脉扩张率的验证和可重复性

Journal of biomedical engineering Pub Date : 1993-05-01 DOI: 10.1016/0141-5425(93)90118-I

E.D. Lehmann , J.R. Parker , K.D. Hopkins , M.G. Taylor , R.G. Gosling

{"title":"Validation and reproducibility of pressure-corrected aortic distensibility measurements using pulse-wave-velocity Doppler ultrasound","authors":"E.D. Lehmann , J.R. Parker , K.D. Hopkins , M.G. Taylor , R.G. Gosling","doi":"10.1016/0141-5425(93)90118-I","DOIUrl":"10.1016/0141-5425(93)90118-I","url":null,"abstract":"<div><p>A non-invasive Doppler ultrasound technique is described for the assessment of aortic compliance based on the <em>in vivo</em> measurement of pulse wave velocity along the thoraco-abdominal aortic pathway. A structured protocol, which has been developed to improve the reproducibility of the technique, is validated. A method of correcting for the effect of non-chronic changes in blood pressure on arterial elasticity is considered and applied to compliance measurements performed on 66 normal, healthy volunteers. The results of a study to ascertain the overall reproducibility of the method are provided and problems associated with the technique are discussed. Medical disorders such as atherosclerosis, diabetes mellitus, familial hypercholesterolaemia and growth hormone deficiency have all been shown to affect arterial wall compliance. It is suggested that the <em>in vivo</em> measurement of pressure-corrected aortic distensibility may be a useful, non-invasive tool for assessing such patients' susceptibility to atheromatous arterial disease and for monitoring their response to therapy. Measurements in the aorta may be especially pertinent since the natural history of fatty streaks there tends to parallel that in coronary arteries thereby potentially affording a convenient surrogate estimate of coronary heart disease.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 3","pages":"Pages 221-228"},"PeriodicalIF":0.0,"publicationDate":"1993-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90118-I","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19308558","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: 91

A method for continuous monitoring of meconium in the amniotic fluid during labour 一种连续监测分娩过程中羊水中胎粪的方法

Journal of biomedical engineering Pub Date : 1993-05-01 DOI: 10.1016/0141-5425(93)90119-J

E.S.G. Genevier , P.J. Danielian , N.J. Randall , R. Smith , P.J. Steer

{"title":"A method for continuous monitoring of meconium in the amniotic fluid during labour","authors":"E.S.G. Genevier , P.J. Danielian , N.J. Randall , R. Smith , P.J. Steer","doi":"10.1016/0141-5425(93)90119-J","DOIUrl":"10.1016/0141-5425(93)90119-J","url":null,"abstract":"<div><p>In about 10% of pregnancies overall, the fetus discharges meconium (its bowel contents) into the amniotic fluid during labour. In about 10% of cases where meconium is passed, the fetus gasps, inhaling the sticky meconium into the upper respiratory tract. After birth, the meconium blocks the air passages in the lungs, impairing gas exchange — meconium aspiration syndrome (MAS). Up to 20% of infants suffering from MAS die and recently published studies have shown a long-term effect of MAS in causing cough and wheeze. The risk of meconium aspiration is thought to be increased by intrauterine hypoxia. At present, meconium is only noticed at birth or occasionally when amniotic fluid leaks past the presenting part of the fetus. A method has been developed which measures absolute meconium concentration with a 99% prediction interval of ± 30 gl<sup>−1</sup>; allows monitoring of the rate of appearance of meconium linearly with a nonlinearity of 5%, and differentiates between meconium and blood. The method uses the ratio of the intensity of back-scattered light from the amniotic fluid at 700 and 415 nm, the latter being near the peak of light absorption by meconium and the former a reference value. The ratio is also affected by the presence of blood. However, blood has specific absorption peaks at 540 and 575 nm from which it can be detected (the presence of blood is also a significant abnormality, and is relatively uncommon). The measurement method could easily be integrated into an optical sensor mounted onto an intrauterine probe. The measurement of back-scattered light at 415, 540 and 700 nm would allow continuous monitoring of meconium which could provide valuable information for the study of the pathophysiology of meconium passage <em>in utero</em> during labour and allow preventative measures to be developed.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 3","pages":"Pages 229-234"},"PeriodicalIF":0.0,"publicationDate":"1993-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90119-J","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19308559","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: 13

Development of an accurate portable recording peak-flow meter for the diagnosis of asthma 一种用于哮喘诊断的精确便携式记录峰流量计的研制

Journal of biomedical engineering Pub Date : 1993-05-01 DOI: 10.1016/0141-5425(93)90114-E

D.J. Hitchings , S.A. Dickinson , M.R. Miller , A.J. Fairfax

{"title":"Development of an accurate portable recording peak-flow meter for the diagnosis of asthma","authors":"D.J. Hitchings , S.A. Dickinson , M.R. Miller , A.J. Fairfax","doi":"10.1016/0141-5425(93)90114-E","DOIUrl":"10.1016/0141-5425(93)90114-E","url":null,"abstract":"<div><p>This article describes the systematic design of an electronic recording peak expiratory flow (PEF) meter to provide accurate data for the diagnosis of occupational asthma. Traditional diagnosis of asthma relies on accurate data of PEF tests performed by the patients in their own homes and places of work. Unfortunately there are high error rates in data produced and recorded by the patient, most of these are transcription errors and some patients falsify their records. The PEF measurement itself is not effort independent, the data produced depending on the way in which the patient performs the test. Patients are taught how to perform the test giving maximal effort to the expiration being measured. If the measurement is performed incorrectly then errors will occur. Accurate data can be produced if an electronically recording PEF instrument is developed, thus freeing the patient from the task of recording the test data. It should also be capable of determining whether the PEF measurement has been correctly performed. A requirement specification for a recording PEF meter was produced. A commercially available electronic PEF meter was modified to provide the functions required for accurate serial recording of the measurements produced by the patients. This is now being used in three hospitals in the West Midlands for investigations into the diagnosis of occupational asthma. In investigating current methods of measuring PEF and other pulmonary quantities a greater understanding was obtained of the limitations of current methods of measurement, and quantities being measured. It is now possible to define the quantities that need to be measured for accurate pulmonary diagnosis and the requirements of future instrumentation to make these necessary measurements. We are now in the process of developing this new instrumentation.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 3","pages":"Pages 188-192"},"PeriodicalIF":0.0,"publicationDate":"1993-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90114-E","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19308554","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: 1

The mechanical behaviour of bony endplate and annulus in prolapsed disc configuration 椎间盘脱垂状态下骨终板和椎环的力学行为

Journal of biomedical engineering Pub Date : 1993-05-01 DOI: 10.1016/0141-5425(93)90120-N

A.N. Natali, E.A. Meroi

引用次数: 12

AIDA2: A Mk. II automated insulin dosage advisor AIDA2: Mk. II型自动胰岛素剂量顾问

Journal of biomedical engineering Pub Date : 1993-05-01 DOI: 10.1016/0141-5425(93)90116-G

E.D. Lehmann , T. Deutsch

{"title":"AIDA2: A Mk. II automated insulin dosage advisor","authors":"E.D. Lehmann , T. Deutsch","doi":"10.1016/0141-5425(93)90116-G","DOIUrl":"10.1016/0141-5425(93)90116-G","url":null,"abstract":"<div><p>A prototype computer system has been developed to provide advice on the day-to-day adjustment of insulin dosage in the insulin-dependent (type 1) diabetic patient. The system also allows the patient's daily steady-state blood glucose profile to be generated based on these adjustments using a clinical model of glucose-insulin interaction. The prototype is intended to be used as a decision support system by clinical personnel. It is designed for use during consultations, as a simulator of patient response following changes in the insulin and/or dietary regimen, and as a system to provide education on planning insulin therapy. Advice is generated by a qualitative therapeutic advisor which suggests what the next step in improving glycaemic control might be for a given patient.</p><p>The clinical model attempts to reflect the underlying (patho)physiology of insulin action and carbohydrate absorption in quantitative terms. It consists of a one-compartment glucose model linked to a model with plasma and ‘active’ insulin compartments. An overview of the integrated prototype is provided along with a detailed description of the new time-point-orientated logical reasoning methodology adopted by the therapeutic advisor. The operation of the system is illustrated by a clinical case study from a 70 kg, male, insulin-dependent diabetic patient.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 3","pages":"Pages 201-211"},"PeriodicalIF":0.0,"publicationDate":"1993-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90116-G","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19308556","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: 46

The effect of surgical floor mats in prolonged standing: an EMG study of the lumbar paraspinal and anterior tibialis muscles 手术脚垫对长时间站立的影响:腰椎棘旁肌和胫骨前肌的肌电图研究

Journal of biomedical engineering Pub Date : 1993-05-01 DOI: 10.1016/0141-5425(93)90122-F

J. Cook , T.P. Branch , T.J. Baranowski , W.C. Hutton

引用次数: 43

Quantitative photoplethysmography: Lambert-Beer law or inverse function incorporating light scatter 定量光容积脉搏波:兰伯特-比尔定律或包含光散射的逆函数

Journal of biomedical engineering Pub Date : 1993-03-01 DOI: 10.1016/0141-5425(93)90047-3

M. Cejnar, H. Kobler, S.N. Hunyor

{"title":"Quantitative photoplethysmography: Lambert-Beer law or inverse function incorporating light scatter","authors":"M. Cejnar, H. Kobler, S.N. Hunyor","doi":"10.1016/0141-5425(93)90047-3","DOIUrl":"10.1016/0141-5425(93)90047-3","url":null,"abstract":"<div><p>Finger blood volume is commonly determined from measurement of infra-red (IR) light transmittance using the Lambert-Beer law of light absorption derived for use in non-scattering media, even when such transmission involves light scatter around the phalangeal bone. Simultaneous IR transmittance and finger volume were measured over the full dynamic range of vascular volumes in seven subjects and outcomes compared with data fitted according to the Lambert-Beer exponential function and an inverse function derived for light atternuation by scattering materials. Curves were fitted by the least-squares method and goodness of fit was compared using standard errors of estimate (SEE). The inverse function gave a better data fit in six of the subjects: mean SEE 1.9 (<span>sd</span> 0.7, range 0.7–2.8) and 4.6 (2.2, 2.0–8.0) respectively (<em>p<0.02</em>, paired <em>t</em>-test). Thus, when relating IR transmittance to blood volume, as occurs in the finger during measurements of arterial compliance, an inverse function derived from a model of light attenuation by scattering media gives more accurate results than the traditional exponential fit.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 2","pages":"Pages 151-154"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90047-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19441771","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: 23

Control of hyperglycaemia in diabetic rabbits by a combination of implants 联合植入物对糖尿病家兔高血糖的控制

Journal of biomedical engineering Pub Date : 1993-03-01 DOI: 10.1016/0141-5425(93)90038-Z

P.Y. Wang

{"title":"Control of hyperglycaemia in diabetic rabbits by a combination of implants","authors":"P.Y. Wang","doi":"10.1016/0141-5425(93)90038-Z","DOIUrl":"10.1016/0141-5425(93)90038-Z","url":null,"abstract":"<div><p>Insulin demand varies with meal intake and physical activity. In this study the feasibility of using two implants to meet varying insulin demands was tested in rabbits with alloxan-induced diabetes. One group of severely diabetic rabbits was maintained on a basal dose released by a 50-mg implant made of a compressed admixture of 15% insulin in palmitic acid. The other group of mildly diabetic rabbits required no basal dose implant, but displayed a transient hyperglycaemia as well upon challenge. The supplemental dose was provided by another silicone implant with reservoirs containing 6 mg of compressed insulin. Serous fluid entered the 100μ l internal volume of the silicone implant slowly through an orifice, and dissolved some of the solid insulin. When required, sideways compression of this second implant over the abdominal skin fold of the rabbit delivered the supplemental dose. Typically, a severely diabetic rabbit on a basal dose implant exhibited a transient hyperglycaemia after drinking sweetened water, which raised the blood glucose from 5.4 ± 1.3 mmol l<sup>−1</sup> to 14.0 ± 0.5 mmol l<sup>−1</sup> for 3 to 4.5 h. In the three test runs, the supplemental bolus of insulin from the silicone implant interrupted the expected rise in blood glucose at 6.1 ± 2.2 mmol l<sup>−1</sup> within 1 to 2 h, which then decreased to 3.0 ± 0.2 mmol l<sup>−1</sup> for 4 to 5 h before returning to the basal level. A mildly diabetic rabbit showed a blood glucose level of 10.5 ± 1.9 mmol l<sup>−1</sup> without the basal dose implant. Its expected transient hyperglycaemia rise to 13.1 ± 0.3 mmol l<sup>−1</sup> could also be prevented by the supplemental insulin dose from the silicone implant, and kept at 2.5 ± 0.3 mmol l<sup>−1</sup> for 1 to 1.5 h, before returning to the mildly diabetic level in 8 to 9 h. The results demonstrated the feasibility of using an erodible implant to provide a basal insulin dose which could be supplemented by a second implant for better control of transient hyperglycaemia episodes.</p></div>","PeriodicalId":75992,"journal":{"name":"Journal of biomedical engineering","volume":"15 2","pages":"Pages 106-112"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0141-5425(93)90038-Z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19443260","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: 4

Effects of pH and temperature on the scanning Soret oximeter pH值和温度对扫描式索氏血氧计的影响

Journal of biomedical engineering Pub Date : 1993-03-01 DOI: 10.1016/0141-5425(93)90052-Z

D.J. Clark, P.O. Byrne

引用次数: 1

Comment on: Qualitative holographic study of hemi-pelvic deformation caused by loading different hip prostheses 点评:装载不同髋关节假体引起的半骨盆变形的定性全息研究

Journal of biomedical engineering Pub Date : 1993-03-01 DOI: 10.1016/0141-5425(93)90053-2

Patricio AA Laura PhD

引用次数: 0