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Biomedical subjects

Kouhei Akazawa

Publications and source records attributed to Kouhei Akazawa.

12 recordsLinked to original sources
PubMed2005

Impact of sociocultural factors on hospital length of stay in children with nephrotic syndrome in Japan.

Hospital length of stay (LOS) of Japanese inpatients is extraordinarily long, partly because of the nature of the health insurance system in Japan. We investigated factors that affect the LOS in Japan, taking pediatric nephrosis as an example. The characteristics of 78 hospitalized children with steroid-sensitive nephrotic syndrome were studied. The median LOS of the patients was 47 days. Most of the patients' mothers (92.3%) stayed in hospital during admission to care for their children. Using multivariate Cox's regression analysis with time-dependent covariates, non-working mother and smaller number of siblings were found to be factors significantly associated with prolonged LOS. These factors are presumed to allow the mothers to care for their hospitalized children for a long period. No medical or clinical factors played a significant role in the prolonged LOS. These results suggest that sociocultural factors have a greater influence on the LOS in Japan than do medical factors such as disease course, coexisting illness, complications, and treatment response.

Child↗
PubMed2005

Circannual variation in the onset and relapse of steroid-sensitive nephrotic syndrome.

Idiopathic nephrotic syndrome is the most common form of nephrotic syndrome in children, but little is known about the etiology of the disease. To obtain new insights into the etiology of the disease, we studied circannual patterns of initial episodes and relapses of steroid-sensitive nephrotic syndrome (SSNS). From 1986 to 2003, there were 45 children with SSNS in our hospital, and they experienced 43 relapses during that period. Initial episodes of SSNS were found to show significant circannual variation with an autumn peak both by Roger's test and Freedman's test, and the circannual pattern was more obvious in patients with high serum IgE levels. Chronological evaluation by means of Fourier analysis showed a clear circannual pattern. In contrast, relapses of SSNS showed circannual variation with a spring peak, which was a result of a high frequency of relapses after upper respiratory infections in January. These results suggest that circannual variation in initial episodes of SSNS might be associated with allergic predisposition, whereas circannual variation in relapses might be associated with preceding upper respiratory infections.

Adolescent↗
PubMed2004

Actual and estimated costs of disposable materials used during surgical procedures.

It is difficult to estimate precisely the costs of disposable materials used during surgical operations. To evaluate the actual costs of disposable materials, we calculated the actual costs of disposable materials used in 59 operations by taking account of costs of all disposable materials used for each operation. The costs of the disposable materials varied significantly from operation to operation (US$ 38-4230 per operation), and the median [25-percentile and 75-percentile] of the sum total of disposable material costs of a single operation was found to be US$ 686 [205 and 993]. Multiple regression analysis with a stepwise regression method showed that costs of disposable materials significantly correlated only with operation time (p<0.001). Based on the results, we propose a simple method for estimating costs of disposable materials by measuring operation time, and we found that the method gives reliable results. Since costs of disposable materials used during surgical operations are considerable, precise estimation of the costs is essential for hospital cost accounting. Our method should be useful for planning hospital administration strategies.

Cost Allocation↗
PubMed2004

Web-based delivery of medical multimedia contents using an MPEG-4 system.

Moving picture expert group compression standard version 4 (MPEG-4) is a standard for video coding aimed at multimedia applications. MPEG-4 was developed to enable high compression rate in a low bitrate transmission via the Internet or mobile telecommunications. Although these characteristics of MPEG-4 are suitable for telemedicine, little is known about the possibility of using this technology in the field of telemedicine. We evaluated the quality of MPEG-4-encoded medical video streams and compared them with original analogue videos and audio-video-interleave (AVI) files. Although MPEG-4 video streams have the advantage of small file size, they were found to be inferior to original videos and AVI files in terms of smoothness of motion pictures, sharpness of images and clearness of sound. Illegibility of characters was a major problem in MPEG-4 files. The score for total impression of MPEG-4 files was significantly lower than those for AVI files. The results of this study suggest that the quality of MPEG-4-encoded video streams is not adequate for telemedicine.

Humans↗
PubMed2004

A method for displaying two images on a screen in distance medical education.

This article describes a method for simultaneously displaying several images on a screen during an online multimedia presentation. Users with 'REALPLAYER' software and Web browsers can view images with synchronous audio on their personal computers via the Internet. Medical researchers and physicians often find it useful to compare images after treatment with those before treatment, by displaying several arranged images simultaneously. Medical care providers can browse this type of multimedia content in their offices and universities at their convenience. There presently exist two methods for creating multimedia content with voice and images using RealSystem technology. Electronic lectures of otorhinolaryngology explaining new surgical procedures for patients with chronic otitis media were created with this method and made available to otorhinolaryngologists through the Internet.

Computer Terminals↗
PubMed2004

MPEG digital compression and analogue videotape: a comparison of moving images and electroencephalogram data in epileptic patients.

PRIMARY OBJECTIVES: The objective of this study was to compare the clinical usefulness, in the field of epileptology, of digital moving images and electroencephalogram (EEG) waveforms by Motion Pictures Expert Group compression algorithms (MPEG-1 and MPEG-2) to that of conventional analogue recording. RESEARCH DESIGN AND METHODS: Three epileptic seizure scenes consisting of moving images and the corresponding EEG waveforms in an epileptic patient were selected as the images to be evaluated. Each scene was recorded using MPEG-1, MPEG-2 and videotape. Ten doctors used six criteria to evaluate the quality of moving images, EEG data and audio. MAIN OUTCOMES: Analysis of variance and Bonferroni tests indicated that the image quality of MPEG-2 was superior to that of MPEG-1 or videotape for all criteria. Furthermore, MPEG-2 obtained much higher scores in EEG waveform quality than did the other modalities. CONCLUSIONS: Our findings suggested that data from MPEG-2 images will lead to more precise diagnosis and treatment decision-making than data from analogue videotape recordings.

Data Compression↗
PubMed2004

Development and evaluation of a teleradiology and videoconferencing system.

We developed a teleradiology system linking a general hospital on Sado Island to tertiary care hospitals in Niigata City. The island is 40 km from Niigata City on the mainland and has only one diagnostic radiologist (for 72,000 islanders). Fibre optic cables between Sado Island and Niigata City were used for transmission. The introduction of the teleradiology system facilitated diagnostic and therapeutic consultation with specialists in Niigata City. The performance of the system was evaluated (on a scale of 0-6, with higher scores indicating better performance) by five diagnostic radiologists, who rated 32 features of the system twice, once in April 2002 and once in September 2003. The performance ratings improved from 1.38 to 2.86. While many of the initial problems with the software had been resolved, many still remained.

Adult↗
PubMed2003

Delivery of medical multimedia contents through the TCP/IP network using RealSystem.

We developed a low cost, user-friendly multimedia delivery system, to provide medical lectures saved as multimedia contents to persons engaged in medicine. This system was created using the RealSystem package with the TCP/IP network. Users can review lectures and medical meeting presentations with video and audio through the Internet, whenever convenient. Each medical source of video and slide has been clearly displayed on a screen. Members of medical associations or medical students can easily review the most interesting parts of these files. This system is being used efficiently in distance learning and aids the diffusion of the latest information and technology to busy physicians and medical students.

Computer-Assisted Instruction↗
PubMed2003

An integrated medical image database and retrieval system using a web application server.

We developed an Integrated Medical Image Database and Retrieval System (INIS) for easy access by medical staff. The INIS mainly consisted of four parts: specific servers to save medical images from multi-vendor modalities of CT, MRI, CR, ECG and endoscopy; an integrated image database (DB) server to save various kinds of images in a DICOM format; a Web application server to connect clients to the integrated image DB and the Web browser terminals connected to an HIS system. The INIS provided a common screen design to retrieve CT, MRI, CR, endoscopic and ECG images, and radiological reports, which would allow doctors to retrieve radiological images and corresponding reports, or ECG images of a patient simultaneously on a screen. Doctors working in internal medicine on average accessed information 492 times a month. Doctors working in cardiological and gastroenterological accessed information 308 times a month. Using the INIS, medical staff could browse all or parts of a patient's medical images and reports.

Databases, Factual↗
PubMed2003

The efficacy of tonsillectomy on long-term renal survival in patients with IgA nephropathy.

BACKGROUND: Little information has been available until now about the clinical efficacy of tonsillectomy on long-term renal survival of patients with idiopathic immunoglobulin A nephropathy (IgAN). METHODS: To investigate the effect of tonsillectomy on long-term renal survival, we reviewed the clinical course of 118 patients with idiopathic biopsy-diagnosed IgAN from 1973 to 1980. Of those, 48 patients received tonsillectomy and 70 patients did not. The starting point of observation was defined as the time of the diagnostic renal biopsy, and the end point as when requiring the first dialysis. Up to 2001, the mean observation time was 192.9 +/- 74.8 months (48-326 months). Renal survival and impact of covariates were evaluated by Kaplan-Meier analysis and Cox proportional hazards regression model. RESULTS: Age, gender, amount of urinary protein excretion, serum creatinine, serum IgA, blood pressure, and histopathologic findings at the time of renal biopsy and treatments during the observation period were not significantly different between patients with and without tonsillectomy. Five (10.4%) of the patients with tonsillectomy and 18 (25.7%) of the patients without tonsillectomy finally required dialysis therapy (chi-square test, P = 0.0393). By Kaplan-Meier analysis, renal survival rates were 89.6% and 63.7% at 240 months in the patients with and without tonsillectomy, respectively, and were significantly different (log-rank test, P = 0.0329). In the multivariate Cox regression model, tonsillectomy (hazard ratio, 0.22; 95% CI, 0.06 to 0.76; P = 0.0164) had a significant effect on renal outcome. CONCLUSION: These results indicate that tonsillectomy has a favorable effect on long-term renal survival in patients with IgAN.

Adult↗
PubMed2002

A method to convert HDTV videos of broadcast satellite to RealSystem multimedia contents.

Recently, the Internet is widely used in the field of medicine. Daily use of e-mail for medical communication is very common. Also various information regarding hospitals can be accessed via the network. Apart from this practical use of the computer network, the mediums of telemedicine, tele-education, and telecare are also available. The Medical Information Network via Communications Satellite for University Hospital (MINCS-UH; http://www.umin.ac.jp/mincs/) was constructed by the Ministry of Education, Culture, Sports, Science and Technology. These programs feature high quality images viewed on High Definition Television (HDTV) through the Broadcast Satellite (BS). We have compiled a video library of MINCS-UH program contents with W-VHS tapes for HDTV and VHS or S-VHS tapesfor NTSC, available to medical staff in our university hospital through the Hospital local area network (Hospital intranet). We have also constructed a web-based streaming system that is a low cost, user-friendly multimedia delivery system capable of providing medical lectures. This system was constructed using the RealSystem package with the Internet Protocol (IP) network. Although the image quality of RealSystem is inferior to that of the original video, users can review lectures and medical congress presentations with video and audio through Hospital intranet, at any time that is convenient to them. This system can also be an efficient tool for distance learning and supports the diffusion of up-to-date information and technology to busy physicians via the Internet.

Education, Distance↗