Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering最新文献

{"title":"Measurements of the quantities of particles accumulated in the lungs of workers.","authors":"M Muluaka,&nbsp;Y Zheng,&nbsp;M Kotani,&nbsp;Y Uchikawa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The human body is enveloped in weak (10-9 T) magnetic fields generated by magnetic particles accumulated in the lungs and other organs. We studied magnetic fields from the lungs (magnetopneumogram) in order to determine how they may be utilized in the early diagnosis of pneumonoconiosis and other diseases. The effects of these diseases have been positively correlated with the size of the magnetic particle deposits in the lungs. When we measured the relaxation effect and the secondary magnetization for smokers and non-smokers, we found there was a large difference in these characteristics between these groups.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 4","pages":"287-94"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20713856","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}

{"title":"Closed-loop subcutaneous insulin infusion algorithm with a short-acting insulin analog for long-term clinical application of a wearable artificial endocrine pancreas.","authors":"S Shimoda,&nbsp;K Nishida,&nbsp;M Sakakida,&nbsp;Y Konno,&nbsp;K Ichinose,&nbsp;M Uehara,&nbsp;T Nowak,&nbsp;M Shichiri","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Considering the management and safety of the insulin delivery route when a wearable artificial endocrine pancreas is applied to ambulatory diabetic patients on a long-term basis, we developed a s.c. insulin infusion algorithm by analyzing the dynamics of a s.c. injected short-acting insulin analog (Insulin Lispro) by a three-compartment model. Principally the insulin infusion algorithm was developed as a transfer function with the first-order delay in both proportional and derivative actions to blood glucose concentrations. The parameters for this algorithm were calculated to simulate a physiological plasma insulin profile as closely as possible. By applying this algorithm with regular insulin, diabetic patients showed a 2 h postprandial hyperglycemia and a delayed hyperinsulinemia, followed by hypoglycemic episodes 4-5 h after oral glucose load, just as observed in the computer simulation study. However, using Insulin Lispro, a near-physiological glycemic control (postprandial blood glucose of 153.1 +/- 8.3 mg/100 ml at 60 min and 90.3 +/- 7.1 mg/100 ml at 180 min, respectively) could be achieved without showing any delayed hyperinsulinemia or hypoglycemia. Daily glycemic excursions were also controlled near-physiologically and although the daily insulin requirement (731.7 +/- 160.5 mU/kg/day) was slightly higher, it was not significantly different from that with i.v. insulin infusion (622.3 +/- 142.6 mU/kg/day). These results indicate that the application of s.c. insulin infusion algorithm with Insulin Lispro is feasible for long-term glycemic control with a wearable artificial endocrine pancreas in ambulatory diabetic patients.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 3","pages":"197-211"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20370982","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}

{"title":"ECG recording by a microdot thermal printer.","authors":"I A Dotsinsky","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Recently high quality ECG records have been obtained by means of microdot thermal printers, because of their numerous advantages. Usually they contain a shift register in the thermal head and the fast control of the dot locations to be heated is an important software problem. We implemented the TLP 480Z-N Gotemba thermal printer (made in Japan) in our ECG instruments, and elaborated two algorithms for lengthwise and crosswise printing on the paper. They use 'black and white' strips loaded into the shift register by 1-byte parallel data organization. The lengthwise mode can operate in real time, while the crosswise one is intended for memorized signals.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 3","pages":"213-20"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20372185","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}

{"title":"Physical characteristics of a new synthetic fiber mattress in relation to pressure sores.","authors":"K Mita,&nbsp;K Akataki,&nbsp;K Itoh,&nbsp;M Yoshida,&nbsp;T Shinoda,&nbsp;Y Ishida","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The purpose of the present investigation was to develop a mattress which was made of the new synthetic fibers called 'Shin-Gosen', and to determine its physical characteristics associated with pressure sores such as pressure distribution, temperature and humidity. The Shin-Gosen mattress consisted of three layers of elastic fibers made of polyester multifilaments, which were mediated by four layers of wave-like fabrics made of nylon monofilaments. The physical characteristics of the mattress were compared with (a) the conventional cotton hospital mattress and (b) the SORELESS MAT made of vacuole gel which effectively eliminated compression forces. The Shin-Gosen mattress was found to provide pressure relief effects similar to that of the SORELESS MAT the desired thermal insulation as well as that of the cotton mattress and a higher level of moisture vapor permeability. These excellent features will not only contribute to preventing pressure sores, but will also enable comfortable resting and sleeping.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 3","pages":"221-30"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20372186","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}

{"title":"Controllability of temporomandibular joint loading by coordinative activities of masticatory muscles: a two-dimensional static analysis.","authors":"K Itoh,&nbsp;T Hayashi,&nbsp;M Miyakawa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Masticatory and bite forces, when applied to the teeth, generate tremendous compressive energy in the temporomandibular joint (TMJ). Excessive 'TMJ loading', if left untreated, deteriorates articular functions. Normally, it is controlled, to a certain extent, by stomatognathic means. In an attempt to clarify this control mechanism, we analyzed the relationship between TMJ loading and the activities of the masticatory muscles, by employing a static two-dimensional jaw model. This comprises two rigid bodies, the upper and lower jaws, including three dominant muscles, i.e. the masseter, the anterior portion of the temporalis and the lateral pterygoid. Static equilibrium analyses determined that TMJ loading can be minimized, under controlled bite conditions, by pointing the loading vector in a direction solely indicated by individual morphological factors, such as the position and orientation of the masseter and the temporalis. This theoretically optimum direction of TMJ loading was also anatomically acceptable, because the load is applied exactly to those portions of the articular disk and mandibular head that can most easily sustain it. Interestingly, this factor was absolutely independent of both the activities of the lateral pterygoid and the direction of bite force. Consequently. TMI loading can be minimized, by coordinating the activities of the masseter and the anterior portion of the temporalis.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 2","pages":"123-38"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20200146","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}

{"title":"High speed detection of R-R intervals for universal Holter recordings.","authors":"K Sekioka,&nbsp;H Takaba,&nbsp;T Nakano","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Heart rate variability (HRV) has been gaining popularity for its potential to estimate the autonomic nerve function and prognosis of patients with cardiovascular diseases. Holter recordings have been used for the measurement of R-R intervals in out-patients and for the estimation of circadian variations of HRV. However, when the manufacturer of the Holter tape recorder is not the same as that of the Holter analyzer a correction of the tape speed error for the accurate measurement of the R-R intervals is abandoned. The simultaneous assessment of additional physical parameters recorded on the Holter recorder and R-R interval is not possible with commercial software. To overcome these problems, we developed a system to detect R-R intervals at the playback speed of a Holter analyzer 500 times real-time with the correction of tape speed error from a system clock recorded on the Holter tape. High- and low-pass filter processed ECG signals and a comparator provided digital signals representing the R-R intervals. The R-R intervals and system clock intervals (tape speed) were measured simultaneously by interrupt-driven software, using timer-counters in a personal computer. The measured R-R intervals were corrected with the system clock intervals. The power spectra of the tape speed error showed that tape speed error significantly affects the power spectra of HRV, if not corrected. This method is applicable to Holter tape recorders of any manufacturer. This system also enables the simultaneous measurement of HRV and other physical parameters to evaluate their relations.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 2","pages":"139-56"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20200147","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}

{"title":"Complexity and frequency hierarchies in the catfish retina.","authors":"M J Korenberg,&nbsp;H M Sakai,&nbsp;K I Naka","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The intricate connectivity and interactions between neurons in the vertebrate retina have made their individual roles in signal processing very difficult to elucidate. We have used a recently developed mathematical tool, fast orthogonal search (FOS), to probe the catfish outer (distal) and inner (proximal) retina, and study the signal processing within. Through FOS, a given waveform can be decomposed into a parsimonious sinusoidal series containing the most significant constituent frequencies. In particular, we examined the light-evoked first-order Wiener kernels of horizontal cells and on-bipolar cells, and on-off, off- and on-amacrine and ganglion cells. Here we report a hierarchy (correlation coefficient up to 0.86) in preferred frequency and complexity of response corresponding to the retina's structural hierarchy. In addition, clear differences between on-, on-off and off-cell functional characteristics were detected. For example, the kernel waveform for the on-amacrine cell was found to be more complex and to have a higher preferred frequency than that for the off-amacrine cell. Indeed FOS analysis revealed that both off- (sustained) amacrine and off-ganglion cells exhibit significantly less complexity in their waveforms for signal processing of light input than do the corresponding on- and on-off cells. This shows a clear breakdown in symmetry between on- and off-pathways, and suggests that connections to off-cells may provide fewer or a smaller variety of inputs than those to on- and on-off cells. Many of our new findings can be appreciated by assuming an underlying cascade structure for the retinal information processing. The FOS findings in particular support the following previously advanced hypothesis: the transition in nonlinear processing from on-off amacrine to on- off-amacrine cells is due to high-pass linear filtering. Furthermore, our results indicate that the high-pass filtering is more sharply differentiating for the on-amacrine than for the off-amacrine cell.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 2","pages":"87-107"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20200144","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}

{"title":"Experimental study of the discrimination of two signal sources in the brain by three-dimensional vector magnetic field measurement of a magnetoencephalogram.","authors":"M Muluaka,&nbsp;Y Uchikawa,&nbsp;M Kotani,&nbsp;Y Yamashita","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>To determine the possibility of discriminating multi-sources in the brain by 3D vector magnetic field measurement of a magnetoencephalogram (MEG), measurements were made of magnetic fields produced by two current dipoles implanted in a spherical head model. The 3D vector magnetic field measurements were made by using a 3D second-order gradiometer connected to three rf-SQUIDs, which can detect magnetic field components perpendicular to and tangential to the scalp. The MEG distribution measuring the magnetic field perpendicular to the scalp was not helpful in estimating the location and number of sources because of the lack of a dipole pattern. By referring to the MEG distribution measuring the magnetic field distribution tangential to the scalp, however, two current sources could be clearly discriminated in a spherical head model. It was found that this MEG distribution measuring tangential to the scalp could provide information on new constraint conditions for the calculation of inverse problems with multi-sources. These results were also confirmed by measurement of the mixed somatosensory evoked fields elicited by simultaneous electric stimulation to the median nerve and the thumb.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"8 1","pages":"35-45"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20036193","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}

{"title":"A compartmental brain model for chemical transport and CO2 controlled blood flow.","authors":"S Sorek,&nbsp;A Yakirevich,&nbsp;M Feinsod","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>A compartmental transport model is developed, capable of predicting the evolution of CO2, HCO-3 and H+ in the cerebrovascular system. In the model, the transport of these components is simulated at a subset of three compartments: cerebrospinal fluid (CSF), capillary-choroid plexus and brain tissue, belonging to a seven compartmental assembly representing the entire brain. The remaining ones are; artery, vein, venous sinus and jugular bulb. The model accounts for advection associated with non-steady perfusion fluxes across semi-previous boundaries. Pressures, associated with perfusion, are solved in the seven-compartment model. The three-compartment transport model also takes into account changes in compartmental volume due to displacement of its boundaries, diffusion through boundaries and rate of generation of substances by chemical reactions. A first-order reaction rate is assumed in the CSF compartment. A parameter estimation method is then developed to assess boundary diffusivities from time-averaged observed values of perfusion pressure, tension of carbon dioxide, pH values, and concentration of free hydrogen and bicarbonate ions. An equation of state describing the regulation of flow from arteries to capillaries, as a function of CO2 tension in the CSF, is then suggested. Upon solving all coupled mass balance equations, and for a pre-evaluated perfusion pressure in the artery and capillary compartments, one can estimate the change in arteries to capillaries conductance at every time step. Boundary diffusivities between the capillary, cerebrospinal fluid and brain tissue compartments, were estimated. A sensitivity analysis proves the consistency between model predictions and available clinical observations, this, in terms of the influence of the parameter associated with CO2 metabolic rate on CO2 tension. It was shown that decrease of this tension caused an abrupt pressure fall at the first instant which later increased to an asymptotic value. This, however, was not evident in the capillaries at which pressure slightly falls and then remains constant.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"7 1","pages":"45-70"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19654418","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}

{"title":"Assessment and comparison of algorithms for in vivo ESR-CT imaging of bioradicals with L-band microwaves.","authors":"T Yuasa,&nbsp;A Tamura,&nbsp;T Ogata,&nbsp;T Akatsuka,&nbsp;H Kamada","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In ESR-CT imaging, it is much more difficult to obtain satisfactory images than in imaging with other modalities, since two inverse problems, i.e. deconvolution of observed data and reconstruction from projections, must be solved. In this work, suitable algorithms for ESR-CT are examined using simulations and experiments. The algorithms were applied to actual data from a rat's head and a satisfactory reconstructed image was obtained from the viewpoint of morphological imaging. Several properties of the algorithms are discussed: (1) which combination of deconvolution and reconstruction method is favorable, (2) whether or not a raw differential signal should be integrated before deconvolution and reconstruction procedures, and (3) how SIRT, which offers good performance in ESR-CT, depends on an initial value and a noise type.</p>","PeriodicalId":77139,"journal":{"name":"Frontiers of medical and biological engineering : the international journal of the Japan Society of Medical Electronics and Biological Engineering","volume":"7 4","pages":"311-30"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19919604","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}