DEVELOPMENT OF SUPPORT SYSTEMS FOR THE COLORBLIND: AN APPLICATION OF VISUAL INFORMATION PROCESSING
It is known that the colorblind are unable to discern certain pairs of different color. For example, protanopic persons are unable to tell red from green. In order to help them overcome their difficulties, I develop simple programs in C to understand the false color vision the colorblind experience and in Java to let them realize what the correct color vision should be. To this end, I first study the basic mechanism of color vision operating in the normal persons and the causes that some people suffer from the colorblindness. Next, I write a C code to simulate the color perception experienced by the colorblind. The method and the result of simulations are described in detail. I use a static image with a spectrum of rainbow color to investigate how the dichromats perceive all the colors on the image. Finally, I developed a simple Java program for the colorblind in an attempt to correct their color vision. The major result is as follows: With this software the colorblind persons can remove the confusion between the two seemingly same colors in question. As a result this person can clearly realize that his/her color vision is abnormal. This type of support software is expected to have many practical applications. As an example, I show an application of this support software to the color-coded JR/Subway system map in the metropolitan Tokyo area. This software has been provisionally tested by a few subjects to assess its effectiveness, but more detailed evaluations are necessary to obtain definitive feedback.
The "image surface" is a data collection of spatial vectors that reflect relationship between heart vector and measured electrocardiograms, supposing the heart source is a fixed dipole source. For long, the Frank image surface has been used. However, since the Frank model represents an average model of western population, it may not fit other populations like Japanese, and therefore may affect the accuracy of applications In this study, to improve the accuracy of the derived 12-lead ECG, we developed the digital image surface based on the personalized torso models constructed from MRI images. The boundary element method was used to calculate the values of digital image surface by applying electrical current dipole source on the torso- heart model. Further, the valises of the digital image surface for eight subjects were averaged as a representation of typical models of Japanese population. As an application, derived 12-lead ECG is obtained based on the digital image surface and the results is compared with those based on the Frank image surface. The results show that the digital image surface can get better accuracy than the Frank image surface.
A semi-automatic algorithm is proposed for construction of personalized heart model from Magnetic Resonance Imaging (MRI) images, emphasizing on applications to cardiac electrophysiological simulation. The physiological characterizations of personalized heart models were set in the same way as the Wei-Harumi model. For validation, 12-lead electrocardiograms (ECG) were simulated with a model of normal heart. The results show good agreement with clinical findings. This study suggests a new direction of electrocardiological forward problem and application in whole-heart modeling. 1.
This paper presents an introductory description of a development of virtual reality for computer simulation of catheter-based electrophysiology study (EPS). We first summarize a state-ofthe-art model of the heart and computer simulation of body surface electrocardiograms (ECG), giving a latest example in simulation of Brugada syndrome. We summarize the extension of the whole-heart model in order to compute intracardiac electrograms for simulation of catheter-based EPS. We then introduce a development of virtual reality, called virtual EP Lab, which links the heart model to input device through a computer graphics interface. The virtual EP Lab may be useful for the purposes of medical training in learning catheter operation and clinical EPS