We performed Laser angioplasty for 3 ASO cases, with a ceramic contact delivery system of Nd-YAG laser energy (Surgical Laser Technologies, Inc., Japan). Case 1 and 2 were successful. Power of laser irradiation was 280J for case 1; a 2cm stenotic region of a left superficial femoral artery, and 360J for case 2; a 2cm stenotic region of a right external iliac artery. PTA was performed for both cases, additionally. But, case 3 failed, because the dissection of the right superficial femoral artery by the laser fiber had been occured. In conclusion, laser angioplasty was useful for ASO with short stenotic regions of arteries. We think that a contact delivery system is more suitable for angioplasty and more safe that another systems. And, the efficiency of energy is better that that of another systems, too. As several points to be improved, we think the diameter of a contact probe, the flexibility of laser fiber, and surgical technique.

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In optical measurement of action potential in the intact cerebral cortex and the heart, the optical signal concerned with the membrane potential is weak and is affected by motion artifact arisen from movement of the measuring area which leads to light scattering, and has not direct dependency on the membrane potential. In this paper, we present an experimental study of the optical discrimination of the optical signal dependent on the membrane potential from the motion artifact by comparing with different wave-length optical intensities. The heart muscle has the Excitation-Contraction coupling. The action potential of the heart was measured by the optical method which gives important information on the relation between action potential and motion artifact caused by contraction. The heart was removed from the carp and was stained with solution of voltage-sensitive dye (Nile Blue A). The dye was pumped by a low power He-Ne laser (0.5mW). Fluorescence emission of the dye is increased by depolarization of the membrane potential. We recored simultaneously the temporal changes of the fluorescence emission intensity from the dye and the reflected light intensity from the surface of the heart. The fluorescence emission was increased about 4% by the action potential of the heart. When the motion artifact is occured, the time variation of the fluorescence emission intensity has similar characteristics to the time variation of the reflected light intensity.

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Recent advance of various optical techniques such as laser, high sensitive detector, and optical fiber, has proved the usefulness of optical measurements into medical field. The living tissues have several unique optical properties which make the uncertainty and confusion as to the quantitative treatemt of tissue spectroscopy including absorption, fluoresence and phophorescence. The linear-relationship between the absorption and concentration, Beer-Lambert law, does not stand for the turbid system by scattering. The present paper describes the funda mental properties of tissue using various optical techniques. The quantitation of absorption in the tissue is presented.

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In this paper, we report for the first known time the feasible and realible method for the laser absorption tomographic imaging based on the optical heterodyne technique that has very high sensitivity and excellent directivity to distinguish one specific direction from another. This new method is named the Coherent Detection Imaging(CDI). For the establishment of laser absorption tomography for biomedical applications on the basis of the projection slice theorem, the following four fundamental conditions should be satisfied basically ; 1) detectable optical transmittance through living tissues and systems, 2) excellent detectivity to distinguish a directly transmitted beam component from widely dispersive multiple scattering of light, 3) establishment of the Lambert-Beer's law for the directly transmitted beam component, and 4) existence of straightly propagated beam component even in the presence of complex distributions and boundaries of refractive index in the medium.
We have experimentally demonstrated the fullfillment of these fundamental conditions to establish the CDI method in highly scattering absorptive media. Thus the first successful tomographic image reconstruction was achieved using actual in vitro biological objects.

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The highly reactive oxygen-derived free radicals are suspected to play an important role for progress of edema and cell membrane perturbation in ischemic lesion in the central nervous systern (CNS). These free radicals in vivo pathophysiology following ischemic lesions are not confirmed directory in the tissue. We have developed a new mapping technique for superoxide free radicals, energy metabolism and vascular permeability in the brain tissue, simultaneously.
The theory of mapping of superoxide free radicals in the frozen tissue section is based on the photochemical reaction; 2-Methyl-6-phenyl-3, 7-dihydroimi dazode- [1, 2-a] pirazie-3-one (CLA-phenyl) produce the 380nm chemiluminescence with superoxide anion free radicals.
The mapping of superoxide fee radicals, vascular permeability and energy metabolism, using milipore filter paper technique opened an opportunities for identifying the localizing effect of free radicals in the evolving pathophysiology in injured tissue.

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A new diagnostic angioscope-fluorescence analyzer system consisting of an excimer pumped dye laser, fluorescence spectrum analyzer system, a dual time imaging system and 2.1mm diameter of angioscopical catheter is presented.
The system was possible to display a fine image patern' of intravascular structure and the fluorescence spectra patern from those tissue at same time on the monitor screen.
The analyzer system was inserted into the aorta under sterile codition.
Photosensitizer was administrated intravenously into the ear vein of cholesteremial rabbits and they were sacrificed 24 hours later.
Fluorescence of photosensitizer could be emited in a progressive atheroscllerotic lesion, but the normal lesion had not a emission peake at 405nm excitation.
Thus, this system is useful for early detection of atheroscleotic lesion in an aorta.

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Photodynamic therapy (PDT) has been recognized as a new expected procedure in treatment of early stage cancer for this decade. We have already treated more than 170 cases of lung cancer with PDT. And also Photodynamic diagnosis for endoscopical occult cancer has been paid attention in the world. We developed excimer dye laser cancer detection and treatment system in cooperation with Hamamatsu Photonics Corporation. The excimer dye laser is puls laser and has a better penetrating ability to the tissue than argon dye laser which is continuous wave. In this system, fluorescence from lung cancer can be observed in 15 cases of 16. And immediately PDT could be performed for these patients, switching two different wave length laser light.
We supposed that there is a possible application for the detection of early stage lung cancer with this system.

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[in Japanese]

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