Lossless compression based on inter-frame coding for MDCT.

Many images are generated by medical equipment and the number of images to be stored increases yearly. To cope with the large digital storage and transmission requirements, data compression techniques have been studied. In the present study, grayscale data (2 bytes/pixel) were divided into high bytes and low bytes, and then the original medical images were also divided into high byte (1byte/pixel format) and low byte (1byte/pixel format) images. Inter-frame coding with and without division into high and low byte images was applied to MDCT images. Prediction (inter-frame) coding is a very common method to compress sequence images. The division process can be added to inter-frame coding easily. The compression ratio of the archived file produced by application of Lemple-Ziv compression and prediction coding with the division process was 0.39 at 700 images.

[Online-conference using JGN.].

Telemedicine and online conference systems have some benefits so that equalizing medical level, improving efficiency of medical care and improving service for patients. It is possible to give advice and to support its medical projects stationed in other facility and to provide the same quality treatments for patients. In this paper, we set up an experimental network system to teleconference using JGN (Japan Gigabit Network) and tried to discussion alternatively for case study between Kanazawa university and Fukui red cross hospital, 70 km away. The JGN used in this study is an ultra-high-speed network for the purpose of research and development. Kanazawa university, and Fukui red cross hospital are connected by a 10 Mbps communication link of the JGN. We tried online conference on the experimental network using video chat system. In result, using video chat system, the average transmission rate of MRI images (256 X 256pixel, 16bit) is 0.2 s/frame.

[A study of the security and transmission of medical information using JGN (Japan Gigabit Network)].

The telemedicine and teleconference, for example, make possible that the same qualities information can be accessed from the near facility and from the remote medical facility at 3 - 70 km away. The quality of medical care will be largely improved because high-speed network can be extended to rural areas. We set up an experimental network system to the telemedicine and teleconference using JGN (Japan Gigabit Network). The JGN is an ultra-high-speed network for the purpose of research and development. In this study, A 10 Mbps communication link of the JGN is used to transmission and reception of detailed and large medical information from remote places. Kanazawa University, NTT west kanazawa hospital, toyama city hospital and fukui red cross hospital are connected to the JGN through a router. IPsec system, which is the security protocol, is used for the security of data transmission between each facilities. In result, the date transmission rate using IPsec is 7 Mbps. The average translation rates of CT images (512 x 512, 16bit) and MRI images (256 x 256, 16bit) are 0.8 s/flame and 0.2 s/flame, respectively.

[Influence of electromagnetic waves on portable electronic instruments in medicine].

In this work, we considered the effect of electromagnetic compatibility (EMC) on electronic instruments used in medical facilities. We simulated and measured the intensity distribution of the electromagnetic field around portable phones and examined the influence of electromagnetic field on telemeter-type electrocardiograms (ECG) and computer display cathode ray tubes (CRT) when portable phones were brought close to them. Results showed that the waves observed on ECG are affected up to a distance of 55cm (3.55E+03V/m) from the portable phone, and the grid of the computer display is affected up to a distance of 9cm (7.16E+04V/m) in the front and 14cm (2.97E+04V/m) in the back. Therefore, to reduce electromagnetic intensity (EMI) maintaining a distance far enough from the source is effective.