Biomedical subjects

Tomoko Yamakawa

Publications and source records attributed to Tomoko Yamakawa.

6 recordsLinked to original sources

PubMed2005

Design and preparation of a novel temperature-responsive ionic gel. 2. Concentration modulation of specific ions in response to temperature changes.

We have designed a novel temperature-responsive dialysis system consisting of mixed electrolyte solutions and an ionic gel whose charge density changes in response to temperature changes. The system can modulate the time-concentration profile of just bivalent ions in arbitrary forms by changing the transport modes of the ions in response to the temperature, as long as the system has a sufficient concentration difference of the driving electrolyte for the modulation. The simulation in a model system consisting of mixed KCl and CaCl(2) solutions and the ionic gel shows that the system modulates the time-concentration profile of Ca(2+) ions as a sawtooth waveform and also keeps the concentration a prearranged value for a certain time period by controlling the transport modes of just Ca(2+) ions in two ways: downhill (transport along their own concentration gradient in a system) and uphill (transport against their own concentration gradient), in response to temperature changes. The simulations agree quantitatively with the experiments using a temperature-responsive ionic gel prepared in the previous paper.

Journal Article↗

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↗

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↗

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↗