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It has been theorized that the neutral zone (NZ) may be a more sensitive parameter of spinal instability than the range of motion (ROM). An anatomic detailed, nonlinear finite element (FE) model of the occipito-atlanto-axial (C0-C1–C2) complex based on Visible Human Male dataset was developed in this study, which can improve the previous upper cervical spine FE models by its increased geometric modeling accuracy and more precise material assignment. According to the analysis of the motions of each vertebral level under physiological static loadings to simulate the movements of upper cervical spine under axial rotation, flexion, extension, and lateral bending, the ROMs and NZs agreed well with published experimental data. The moment-rotation relationship predicted by this model was apparently nonlinear, and the largest rotation was predicted in horizontal plane, followed by median plane and coronal plane. The complex exhibited large ROMs and high proportions of NZ to ROM. According to our knowledge, there are no published results of FE models of upper cervical spine by far that have already undergone validations for both ROM and NZ under physiologic loads and are in good agreement with experimental data. The findings of the validation of this newly-developed model also coincide with the experimental studies. Therefore, it can be concluded that the current FE model validated for NZ is useful in the investigation of abnormal NZ in disease and trauma.

In this report, we present feasibility of our newly developed laser device for prospective human fetoplacental surgery. Fetuses having congenital fetoplacental anomalies, if untreated before birth, occasionally deteriorate in utero with high perinatal mortality and/or morbidity. If this is the case, outcomes of conventional postnatal care might be quite unrewarding medically as well as economically. Although the advent of minimally invasive fetal endoscopic laser treatment (fetoscopic laser photocoagulation, FLPC) has strikingly improved the natural history of fetuses with twin-twin transfusion syndrome (TTTS), this underwater unique surgery is still technically demanding depending on placental location, position of floating twins, gestational age, and fetomaternal obstetrical conditions. In an attempt to resolve most of these difficulties associated with FLPC, we developed a composite-type optical fiber scope that enables transmission of laser light and endoscopic images concurrently. This technology is a spin-off of our research works on the International Thermonuclear Experimental Reactor (ITER) at Japan Atomic Energy Agency and the device is an integrated system consisting of a composite-type optical fiber scope (2 mm in OD), a coupling device for transmission/distribution of laser light along with object images, a laser light source and a magnified image monitoring system. A lens made by quartz is installed on the tip of composite-type optical fiber scope. It has the resolution of about 9,000 pixels and the angle of view of 54 degrees. In addition, it can transmit the 40W laser energy with a focal length of 10 mm. Clinically, the composite-type optical fiber scope, if mounted on our multi-DOF robotic manipulator, is supposed feasible for much more accurate identification and coagulation of the target placental vessels responsible for TTTS pathophysiology. Our current state of the art will be presented in detail along with basic test results.

In robot-assisted surgery projects researchers should be able to make fast 3D reconstruction. Usually 2D images acquired with common diagnostic equipments such as UT, CT and MRI are not enough and complete for an accurate 3D reconstruction. There are some interpolation methods for approximating non value voxels which consume large execution time. we introduce a novel algorithm based on generalized regression neural network (GRNN) which can interpolate unknown voxles fast and reliable. It is shown that composition of GRNN with image distance transformation can produce higher quality 3D shapes. The results of this method are compared with other interpolation methods practically.

In this paper, the models for predicting the thrombus formation with simple estimation method in the orifice flow are proposed by conventional CFD and Lattice Boltzmann method. It is concluded that the thrombus formation (thickness) was estimated using (1) shear rate and adhesion force to the wall independently, and (2) shear rate function with adhesion force.

Currently used knee prostheses are broadly classified into the CR type and the PS type. We are planning to develop a new type of knee prosthesis which could make a complete deep knee flexion. Although the new prosthesis should be developed on the basis of the PS rather than the CR, we should further consider about weather we could cut the PCL so readily, and weather high stress concentration might not arise on the articulation surfaces whose conformity is usually so high. Thus we performed simulation analyses subject to the CR instead of the PS, thereby introducing the relationship between the PCL function and the joint articulation conformity. Then making most of the simulation results, we designed a complete flexionable knee prosthesis designated CFK prosthesis .

Recently, Artificial Heart (AH) is recognized as the alternate method of the heart graft. Though there are many problems and defect on AH, long term durability, miniaturization and weight saving interfaced with flow rate performance, efficiency of device. Considering rehabilitation into the society and advancement of QOL (Quality of Life), the construction of power source which supplies electric power to the device is important and has many problems. Especially, the electric feeder line restricts behavior of the transplant recipient and disturbs rehabilitation into the society. For solving these problems, Transcutaneous Energy Transmission System (TETS) is noticed and studied. This study proposes core-type TETS. It achieves high magnetic coupling compared with aircore- type TETS which is carried out on clinical study. Because core-type TETS has high magnetic coupling, it is possible to reduce the input current and to miniaturize trans size. This paper mentions the characteristic of core-type TETS.

We investigated the measurement of low molecular weight substances in dialysate by visible ultraviolet spectroscopy. The absorbance spectrum of creatinine and uric acid in dialyzate were clearly detected, however, that of urea was almost undetected. And also, there was significantly correlation between actual creatinine concentration in blood and predicted creatinine concentration in blood by the absorbance spectrum of effluent dialysate. Visible ultraviolet spectroscopy may be a useful method for noninvasive and real-time measurement of creatinine during hemodialysis treatment.

In the emergency medicine, icing has been used as first aid treatment to the patient of head injury. By reducing cerebral temperature, prevent the generation of secondary brain damage such as discharge of neurotransmitter, and the reaction of free radical. The average boarding time is 15 minutes in an ambulance, however by icing treatment quantitative temperature control is very difficult as it always occur insufficient cooling or excessive cooling. Icing for 30 minutes or more has the danger of frostbite. As an other problem homeostasis, which happens when icing is stopped is suggested. Therefore, the issue is how and quickly cools an injured head without generating any secondary damage. In this study, we have developed a cooling unit using Peltier device. A Peltier is a thermo-electric semiconductor device that generates heat surface on one side and cool surface on the other, when passes electrical current. By adjusting passing current, heat controlling can be made easily. Other advantages are small size, light weight, vibration and noise free. A Peltier device is also harmless to the environment as it does not use any material like Freon. We have fabricated a helmet type unit that can cool a head from the surface. As a fundamental evaluation we have investigated electrical properties as well as cooling ability, and response time. The result of our investigation showed a uniform electrical properties without getting any interference of ambient temperature while use water as heat radiation coolant. An 80 watt device (39.6mm X 39.6mm X 3.94mm) is found sufficient to cool a helmet around 15 degree C. Only 30 second is necessary to reach the expected temperature when direct-current stabilization power supply of 11V-15V was used.

Macrophages are considered as a source of important mediators to release growth factors that stimulate fibroblast proliferation during wound repair. The goal of the study was to evaluate the potential of stimulation on fibroblast proliferation cultured in the supernatant from low level light irradiated U-937 cells, a macrophage-like lymophoma cell line. The U-937 supernatant was removed twenty-four hours after Light Emitting Diodes (LEDs) exposure and was added to human foreskin fibroblast culture media. The proliferation of fibroblasts was measured by trypan blue stain. The concentration of total collagen and non-collagenous protein of fibroblasts was estimated by Fast green-Sirius red staining assay. The result showed that LEDs irradiation under the setting of 630 nm, 15 mw/cm^2, and 4J/cm^2 might encourage U-937 cells to release growth factors to stimulate fibroblast proliferation compared to the control group. The rate of fibroblast proliferation increased 1.1 fold compared to the control group which received supernatant from U-937 culture without light irradiation. The ratio of the concentration of collagen to non-collagenous protein of fibroblasts increased from 38.46±0.25 to 42.50±0.92 µg/mg (p<0.01) at forty-eight hours after fibroblast culture media replaced by light irradiated U-937 culture supernatant. The result suggests that in vitro irradiation of U-937 cells by LEDs at specific parameter could modify their ability, therefore, affect the proliferation of fibroblasts.

This study was motivated, in part, by the well-known presence of fibrocartilage in regions of tendon that wrap around bone. These regions experience compressive as well as tensile stresses. We investigated the influence of cyclic hydrostatic pressure on the induction of fibrocartilaginous metaplasia in a non-cartilaginous cell source. Eight Achilles tendons were harvested from Wistar male rats and digested in collagenase solution to recover the cells, which were seeded into standard polystyrene flasks for pellet culture. Hydrostatic compression was employed as a mechanical stimulus to induce the changes in gene expression indicated by alteration of the phenotype of tendon to fibrocartilage. RT-PCR was carried out using GAPDH as a housekeeping gene. The results demonstrates that loading for 2 h caused initial 50% and 65% increases in the mean expression of aggrecan and type II collagen, respectively. This upregulation persisted for 24 h, by which time mean aggrecan and type II collagen expression were increased approximately 2 and 3-fold, respectively, relative to non-loaded controls. Expression of type I collagen in loaded samples was initially suppressed by 46% but had rebounded to 3-fold that of controls by 24 h. Expression trends in the long-duration experiment paralleled the initial response to 2 h loading, but differences were not statistically significant. Transmission electron micrographs from long-duration experiment reveal no obvious apparent differences in nuclei and cell organelles of each loaded and control tenocyte. Taken together, rat tendon fibroblasts subjected to cyclic hydrostatic compression displayed transient changes in gene expression associated with development of cartilaginous matrix, including increases in aggrecan and collagen type II mRNA and a suppression of collagen type I mRNA. Interestingly, collagen type II and aggrecan mRNA expression remained elevated 24 h later, while collagen type I expression had rebounded to exceed that of controls. Tenocytes pressurized for 7 days exhibited stable changes in gene expression that paralleled the initial transient change, suggesting possible transdifferentiation to a more cartilaginous phenotype.