Koredianto Usman

Medical Image Encryption Based on Pixel Arrangement and Random Permutation for Transmission Security

This paper describes the result of our investigation on the utilization pixels arrangement and random permutation to encrypt medical image for transmission security. The objective of this scheme is to obtain a high speed computation process and high security. Among other algorithms such as transform method and traditional method, pixels arrangement and permutation provide simple and quick processes; it particularly does not need any mathematical manipulation. This feature is especially very useful for medical image where the image can be very big. We tested the algorithm using gray-scale images. The scheme shows a good randomness and quick computation process. We closed the paper by discussing the strength and limitation of this for practical for example in telemedicine.

A study of increasing the speed of the independent component analysis (IA) using wavelet technique

Independent component analysis (ICA) is a multivariate data analysis tool. The basic principle of ICA is the assumption of independency of the source data. On the separation of the data source, ICA algorithm searches for a demixing matrix that will maximize the independency. This searching process is mostly done in iterative way and involving high order statistics. This process is time consuming. For a certain application, such as speech, where the source signal has its power at the lower frequency, we can reduce the data length by removing the high frequency component. Wavelet decomposition is a popular method for this purpose. In this paper, we propose the data reduction using wavelet as a preprocessing of ICA to speed up the ICA computation. We investigate Haar, Daubechies 2, Daubechies 3, and Daubechies 4 wavelet as the wavelet analysis. We further investigate the computation time as the function of level of decomposition of the wavelet. In this study, we found that Haar wavelet at third level of decomposition gave the biggest advantage of computation speed, which is about 40-50%.

A study of heartbeat sound separation using independent component analysis technique

Physician often infers the patients heart problem by listening to heartbeat sound. Such technique is well known as auscultation. The doctors auscultation skill was gain after he or she experiencing a lot of cases of heart diseases and heartbeat sounds. There is a need of computer-aided equipment to analyze heartbeat sound especially for young doctors to gain a quick learning process. For this purpose, we need accurate and dependable equipment for heartbeat analysis. To improve the heartbeat analysis, we investigate the possibility of the heartbeat sound analysis, especially the separation and localization of heartbeat signal, using independent component analysis technique. The separation or localization of heartbeat signal using independent component analysis is made possible by putting several probe at appropriate places in body. Our aim is to separate two major beat sequences, which are referred as S1 and S2. The S1 beat is due to the closure of mitral-tricuspid valve and the S2 beat is due to the closure of aortic-pulmonary valve. Since the pairs of mitral-tricuspid and aortic-pulmonary valves are physically separated and can be viewed as independent sources, we can treat the beats produced by them as independent components. The FastICA algorithm was used in this study, and we do experience with a healthy 29 year-old man. The experiment showed a promising result. A refinement in the scheme of experiment, especially technique to reduce signal saturation and noise during data acquisition, will lead us to scheme for the real application.

A study on nationwide emergency medical network for ambulances via HEOs

We have studied specifications for satellite transponder to perform nationwide emergency medical network for ambulance over Japan. If it is possible to send in real-time a large volume of biological data (such as when a thrombolytic dose is administered to a patient suffering acute cardiac infarction being conveyed in an ambulance, based on his or her 12 leads electrocardiogram data and cardio-echogram with compressed motion picture, for early treatment for removal of a coronary occlusion) and color video images (such as light reflex images and video images of the airway) from an ambulance to a triage center to receive instructions from a doctor, more patients will be saved and medical expenditures for emergency medicine will ultimately be reduced. We investigate required specifications as follows; 1) channels, 2) bandwidth, 3) frequency, 4)footprints, 5) technical limitations of the transponder others.

A visibility study in Japanese urban area to collect environment profile for HEOs

This paper presents the methodology and result of our visibility experiment on mobile satellite communication. The main aim of this research is to find the optimal distance of space diversity for mobile satellite communication using Quasi Zenith Satellite. This experiment based on the assumption that microwave signal propagation from satellite to the mobile terminal (in this case a moving vehicle) is the same to the visible ray propagation, if this ray were transmitted from the satellite to the mobile terminal. Using this assumption, we developed an experiment scheme based on the optical visibility of the satellite. This experiment scheme consists of a fish eye camera that capture image in the range of 0-90 elevation and 0-360 azimuth. GPS was used to indicate the direction of satellite. The experiment was done at the Takaoka City in Takaoka Prefecture at the northwestern part of Japan. The area involved the urban and suburban area of the city. From the statistical value of the result, we found that the optimum distance for antenna diversity for this area to be 23 meters. We hope that this result will be useful to design mobile ambulance for real-time telemedical communication using satellite especially in Japan.

Telemedicine in remote areas of Bhutan via PSTN

ECG and echocardiography are important tools for the diagnosis and management of cardiovascular patients. The transmission of medical images from remote understaffed centers to any big hospital through the use of internet protocol (IP) is now a possibility and would enhance diagnosis and management and thereby eliminating unnecessary referral would reduce health care costs. By using laptop computers and multipurpose ECG equipment, the two hospitals in remote areas of Bhutan were connected with the Asia Pacific Telecommunication (APT) supported second opinion center at Tokai University, Japan, through dial-up type workstation linking with Public Switched Telephone Network (PSTN) and internet. The second opinion center interpreted ECGs and echocardiograms and made recommendations to the physicians of both hospitals in Bhutan. The system was started in March 2003 and since than 60 studies was transmitted over IP protocol. The results of ECG and echocardiographic images transmitted to the APT supported second opinion center at Tokai University, showed promising results. This practical experience has shown the most appropriate use of dynamic information technology, using PSTN, to improve the diagnosis, management and quality of life of patients with cardiovascular diseases in remote and difficult in access areas of Bhutan.

Wavelet Technology in Wearable Terminals For ETS-VIII Satellite

In cooperation with Communication Research Laboratory of Japan, Tokai University has developed wearable satellite terminals for jogger via ETS-VIII to monitor ECG (electrocardiogram). The ECG signals provided from three skin electrodes attached to a runners chest wall are passed onto a CR frequency filter to remove loop-back noise generated during sampling. Following A/D conversion (250/sec, voltage/10 bit) with an A/D converter, noise is removed from the digital data obtained, using Wavelet algorithm. A filter relying on this algorithm is more effective than standard averaging FIR filters for processing ECG signals that include noise involving a number of different frequency elements. We also evaluate transmission protocol for ETS-VIII.