Strain rate imaging is known as an effective method for evaluation of the regional heart function. Strain rate can be estimated by the velocity difference and the distance between regional 2 points. In the conventional method, the geometrical centers of correlation windows, which are used for velocity estimation, are referred to determine the distance between two points. However, echo amplitudes in a correlation window are non-uniform, and the contribution of each sampled data needs to be considered. In the present study, the effective position of the correlation window was determined as the gravity center weighted by echo amplitude. In a basic experiment, the strain rate distributions along the depth direction, which were obtained by the conventional and proposed methods, were compared. Using the proposed method, the fluctuation of the strain rate could be decreased to less than 0.1 (m/s)/m compared to that of the conventional method of about 0.3 (m/s)/s.

Flap failure due to impaired blood flow occurs at a certain rate in tissue grafting using free flaps. Early detection of flap failure leads to successful protection of the free flap. The purpose of this study is to develop a flexible optical-sensor-array device that can be attached on the patient's body to detect the flap failure. The device is made up of a Polyimide substrate and sensors consisted of a green LED and a phototransistor embedded on the substrate with a gap for preventing interference. Animal models of ischemia and congestion were used to evaluate the performance. The device monitored blood flow signals in the flaps of each model and its reference counterpart (controlled flaps) and subsequently detected the flap failure. The results demonstrated that blood flow signals were stably obtained from the controlled flaps. The signals from ischemia flaps disappeared immediately after the artery ligation and obtained again after reperfusion. The signals from congestive flaps decreased with time after the vein ligation, several minutes later the signals disappeared and obtained again after reperfusion. Consequently, the device successfully detected the flap failure.

Recently, it has been attracting attention that biological signal can be extracted from the changes in skin color tone of facial video image which obtained by an ordinary camera (e.g. web cam or phone camera). The aim of this study is to investigate the changes in features of pulse wave computed from facial image during cardiovascular regulation. In this study, right and left cheeks and lip sides were selected as regions of interest and video images of the ROIs were recorded at a frame rate of 250fps. Pulse waveform of each ROI was extracted from the changes in green color intensity of the ROI. In result, some indices such as difference of pulse transit time between two positions changed significantly under heating and exercising conditions. This result suggests that not only heart rate but also various indices of cardiovascular regulations can be obtained with non-contact from facial video image.

Power spectral estimation of heart rate variability (HRV) has been widely employed to assess autonomic nervous system function. Among Power spectral-based indices, high-frequency (HF; 0.15 to 0.4 Hz) and low-frequency (LF; 0.04 to 0.15 Hz) band powers have most commonly been used; the physiological significance of these indices has also been extensively studied. However, nonlinear properties of HF and LF components have not been well understood. In this study, we investigated nonlinearity of HF and LF components in 122 healthy subjects and 108 patients with congestive heart failure (CHF). By analyzing bandpass-filtered time series of HRV corresponding to HF and LF components, it is shown that the amplitude modulations display long-range correlation indicating nonlinearity. Compared with the age-matched healthy controls, the CHF patients showed significantly decreased long-range correlation of HF amplitude modulation. Our findings suggest that nonlinearity of HF and LF components provides some complementary information on HRV dynamics.

In late years, biometrics have been used as the robust security. We have focused on high-frequency electrocardiogram (HFECG) as a feature for biometric authentication. In the previous study, sampled HFECG has been applied directly to neural networks for identification, however, provided information was redundant. It have tried the reduction of information amount and the extraction of personal information from HFECG.As the extraction technique, we used matching pursuit (MP) and discrete wavelet transform (DWT) as feature extraction techniques. Identification with extracted features was performed by neural network. In previous study, 200 samples of HFECG waveform gives 100% recognition rate with 15 subjects. In MP evaluation, 95% of recognition rate was obtained with 11 samples. In DWT evaluation, 99% of recognition rate was obtained with 64 samples. MP can largely reduce redundancy and DWT can keep identification rate with reduced number of feature samples.

We compared the b (amplitude of phase II)-to-a (that of phase I) ratio of acceleration-photoplethysmogram (APPG) derived from the photoplethysmogram (PPG) device as a reference with the b/a ratio of APPG derived from smartphone (iPhone 6). In 20 participants (32.1 ± 12.5 S.D. years), simultaneous measurements of near-infrared PPG, green light PPG, and iPhone 6 PPG from the index fingers were made. The results showed that the b/a ratio of APPG derived from the green light PPG device was significantly related to b/a ratio of APPG derived from the iPhone 6 (r = 0.789). In addition, the mean difference in Bland-Altman plots between these b/a ratios was -0.012, and the limit of agreement (2 S.D.) was 0.178. The significant differences were not observed between the b/a ratios of APPGs in each wavelength. In conclusion, these findings suggest that iPhone 6 PPG might be valid measure for estimation of finger-vascular aging.

Hypertension treatment is important to prevent cardiovascular disease. The simulation model has potential to be applied to the treatment. In this study, we evaluated changes in upper limb's blood pressure by increasing lower limb's vascular resistance with simulation model and compared them with human data. We used entire cardiovascular system as a computational model. The arterial system was consisted of 88 vessels coupled with a lumped parameter model, which contains peripheral vessels and capillaries. The brachial blood pressure changes were caused by increasing vascular resistance of the tibial artery. Actual measurements were carried out by cold stimulation to the lower limbs.As results, the simulated data showed the blood pressure increase from 136 / 76 to 143 / 80 mmHg, which were similar to the human data (from 123/66 to 129/73 mmHg) [Conclusion] The entire simulation model recreated pressure change of upper limbs caused by vascular resistance increase of different artery.

Transthoracic electrical admittance cardiography is a practical method for non-invasive and continuous monitoring of stroke volume and cardiac output (CO). The dynamic calibration of a transthoracic electrical admittance cardiograph was needed for CO calibration. Because the cardiography signal includes the time derivative of admittance variation. In this study, we have therefore developed a new cardiac admittance simulator using photoresistor that can be used for dynamic calibration of a transthoracic electrical admittance cardiograph. We proposed the approximate calibration procedure for dynamic calibration using the developed admittance simulator. We have compared the formulae using the approximate calibration procedure and smoothing on time derivative. As a result, the approximate calibration formulae agreed well with the formulae using smoothing on time derivative, which suggests that the approximate calibration is available for the dynamic calibration of transthoracic electrical admittance cardiograph.

Suitable protocols for reproducing active proliferation in culture sufficient for mechanistic examinations are lacking in mammalian fetal cardiomyocytes (fCMs). Because oxygen tension is low (2-3%) in mammalian fetuses before birth, we assume that the exposure of cells to ambient air (21% oxygen) during conventional isolation inhibits the proliferative activity of isolated fCMs. We therefore established an isolation protocol performed under strict low oxygen conditions to mimic the intrauterine environment. This protocol greatly increased mouse fCM division in culture, which was directly observed by time-lapse imaging, to the highest level thus far reported. Even short-term oxygen exposure during isolation markedly inhibited cell division by >70% and repressed cell cycle-promoting gene expression, indicating the absolute requirement of strict low oxygen maintenance in fCMs. Using genome-wide screening, we identified Fam64a as a low oxygen-induced molecule essential for fetal cardiomyocyte proliferation. These data could direct future regenerative therapies using Fam64a in adult hearts.

It is known that blood viscosity has a close relationship with progress of diabetes.A control technique of red blood cell (RBC) aggregation degree is essential to establish an estimation method of the blood viscosity based on ultrasonic or optical approaches.Interface sedimentation velocity, which is known as an index for quantification of particle aggregation degree in suspension, is used to estimate the RBC aggregation degree.In this study the time change in the RBC interface height of porcine blood in test tubes was acquired with three parameters, namely, hematocrit, concentration of dextran as flocculants, and temperature.A relationship between the interface sedimentation velocity and the concentration of dextran was confirmed, and the RBC aggregation degree estimated with the interface sedimentation velocity was reasonably corresponded with results of microscopic observation.

We focused on soft-heating method where high-frequency magnetic field is applied to the FILCT (Ferromagnetic Implant with Low Curie Temperature) implanted near affected part to produce an induction heating of about 43°C. In this study we aim to develop a constant heating system to measure temperature data of FILCT with wireless and automatic controlling intensity of the applied magnetic field. As a result, we confirmed that by using our system we were able to heat 1.0 g of FILCT with a temperature of 30°C that is placed at 1 cm position above the drive coil, to 43°C and maintain constant temperature heating at 42.9±0.3°C.

The objective of the present study was to investigate autonomic nervous system influence on the phase-lag of respiratory sinus arrhythmia (RSA) with respect to the breathing during physical exercise. After 3-min of resting control, eleven young subjects pedaled a stationary cycle ergometer at 50 rpm to exhaustion, with a work rate increase of 20 W/min. Respiratory flow, beat-to-beat R-R intervals, and gas exchange variables were measured. Ventilatory threshold (Tvent) was determined by V-slope method. Analytic signals of breathing and RSA were obtained by Hilbert transform, then mutual information (MI) and the normalized amplitude of RSA (nRSA) were calculated. The nRSA decreased from above 120%Tvent, whereas MI decreased from above 160%Tvent compared to the respective values obtained at rest. There was a significant positive correlation between MI and nRSA. The results indicate that physical exercise exerts an influence on the phase-lag of RSA at different intensity level compared to the nRSA.

The combination treatment system of cryosurgery and hyperthermia treatment was fabricated. This system consists of a surgical probe utilizing Peltier device, the power with temperature control function, Stirling cooler attaching the coolant chamber and a peristaltic pump for circulating liquid ethanol as a coolant. In the fabrication of the system, Peltier device was attached to a hand-piece. The coolant chamber was fixed to Stirling cooler using a thermal conductive adhesive bond. The surgical probe and the coolant chamber was connected with the tube for peristaltic pump, thus the combination system was fabricated. In the evaluation of the system performances, the temperature of the probe reached to -53 degrees C and three temperature cycles of the freezing and the warming could be performed. The result suggests the feasibility of the combination treatment. This work was partly supported by JSPS Grants-in-Aid for Young Scientists (B) number 26820065.

小腸の生体電気インピーダンスがクローン病患者と健常者では、値が異なることが報告されており，生体電気インピーダンスをにより小腸の機能評価ができる可能性がある。Ussing chamber法が広く使われているが，管腔側と漿膜側を電極で挟む形で測定を行うため、小腸を切片にしなくてはならず、in vitroな測定になる。そこで、生体電気インピーダンスの測定により、in vivoで小腸の機能評価を目指し，培養細胞（C2bbe細胞株）実験と，組織切片測定用のUssing Chamberの試作を行った。培養細胞を用いてバリア機能とインピーダンスの関係について薬剤(EGTA)を用いて，低周波数帯での関連を確認した，また周波数特性を見ることで、電解質輸送についても評価ができる可能性が示唆された。

In the condition management of ill patients admitted to an ICU, various kinds of biological signals and its monitoring take an important role. We think that the condition of a patient affects the occurrence frequency of bowel sound, so developed multi-channel measurement over a long time and analysis system of bowel sound. This research aims at establishing a bowel sound measurement as one of the new monitoring technique for ill patients. Accordingly, I suggest a causality analysis method about occurrence tendency of bowel sound and the condition of a patient in the long time using the record of the occurrence frequency change of bowel sound.

Bowel motility abnormalities are observed in patients with functional gastrointestinal disorders. Bowel motility has been generally evaluated by using Magnetic resonance (MR) imaging and X-rays. However these methods may be expensive and inconvenient. In recent years, bowel motility has been evaluated via the analysis of bowel sounds (BSs) recorded using the electronic stethoscopes. BS source localization is considered to be useful in various fields of clinical application. Therefore, we are interested in investigating that BSs is coming from which part of the abdomen. In this study we propose a new method to accurately estimate the BS source using the recorded data of a number of stethoscopes. The proposed method is based on the information of BS power computed by using BSs automatically extracted from the recorded data. The availability of the proposed method is investigated via computer simulations. The estimated BS source position should carry new information on bowel disease.

Slow wave and its propagation play an important role in regulating motility in the small intestine. A simple mathematical model based on the hypothesis about the interaction between autonomous oscillation in Interstitial Cells of Cajal (ICCs) and signal transfer in intestinal longitudinal muscle(LM) cells has already been proposed(Aliev et al.) and widely used. However, the detailed mechanism of pacemaker activity in this model - also in the small intestine - still remains unclear. In this study, a sensitivity analysis for coupling parameters in the ICC/LM network was demonstrated by numerical simulation to elucidate the dynamics of the intestinal pacemaker activity. Aliev's PDE model with two independent variables time t and position x was discretized in the x direction and solved numerically. Synchronicity and stability were evaluated from the periods of each oscillation. The results showed LM cells were essential for ICCs to oscillate synchronously with multiple frequency plateaus.

In order to perform ongoing hemodialysis while minimizing puncture pain and maintaining satisfactory vascular access (VA) function over the long term, an indwelling needle with small diameter should be used. However, as the diameter decreases, differences reportedly occur between the set blood flow rate and the actual rate. We believe that side holes in indwelling needles play a large role in ensuring the set blood flow rate, and have created several prototype 17G indwelling needles with different numbers of side holes and with the side hole apertures in various locations. We then conducted experiments to determine whether these differences affect the ability to ensure the actual blood flow rate.Based on experimental results, we found that the actual blood flow rate that can be ensured increases as the number of holes increases but that the amount of increase may differ depending on the locations of the holes.

We focused on the fact that the color of blood changes from bright red to dark red when coagulation occurs in a circuit, and investigated the possibility of detecting coagulation in circuits from changes in light absorbance before and after coagulation.When the calcium chloride was added, a sharp drop in optical power was seen, and optical power subsequently continued to gradually decrease as coagulation progressed. After blood coagulation had ended and the roller pump was stopped, we saw that optical power gradually recovered. In general, a similar change was seen for the optical sensors at each wavelength. However, if the ratio of optical power before and after coagulation is taken as the change in absorbance, we realized that, because the results differed for different wavelengths, an optimum wavelength exists for detecting changes in absorbance before and after coagulation.

【目的】ダイナミック造影MRIは、対象組織における造影剤の濃度変化を画像化することで、血管新生により増加する腫瘍の循環動態を定量評価することができ、腫瘍の診断能向上や治療効果判定に役立つものと期待される。しかし、従来の薬物動態モデルを用いた解析法は、計算が煩雑な上に定量精度が低い。本研究では、前立腺腫瘍を対象に、シミュレーションおよび実データを用い、簡便かつ精度が高い循環動態の定量評価法を検討した。【方法】血管と組織を独立したコンパートメントとみなし、造影剤の組織移行速度定数（K^trans）、血管外細胞外腔の体積比（V_e）、血管内成分の体積比（V_p）をパラメータとする2コンパートメントモデルを基に、対象部位と参照部位の造影剤濃度の関係から両者のK^trans比を求める参照領域法を導出した。この参照領域法においてシミュレーションを行い、画像中の雑音や時間分解能、V_eやV_pの変動がK^trans比の推定値に与える影響を検討した。次に、本手法を前立腺腫瘍の造影MRI画像に応用し、内閉鎖筋および大臀筋を参照領域に用い、前立腺の正常部位と腫瘍部位のK^trans比を評価した。【結果】シミュレーションでは、参照領域法で算出したK^trans比は真値と良い相関を示し、従来法に比べ推定精度が向上した。臨床データでは、前立腺の腫瘍部位でK^trans比の上昇が見られた。【結論】参照領域法は簡便かつ高精度で、腫瘍の循環動態の評価に有用と考えられる。

Perspiration can be classified into two categories: thermal and mental. We have recently developed a new device for perspiration monitoring, which can capture the perspiration pattern easily with a long-term recording. Here we report the applicability of the developed device in terms of mental perspiration. The developed device, along with the electrodes to monitor the sympathetic skin response (SSR), were attached to the subject's palm, followed by performing the tasks (deep inspiration and mental calculation) that evoke the sympathetic stress. As a result, we could measure the change of palmar perspiration associated with that of SSR. Next, as a simultaneous measurement of thermal and mental perspiration, two devices were attached to the chest and palm followed by the daily activities. As a result, different patterns of perspiration was observed according to the different activities. Therefore, the developed device might be useful for the detailed perspiration analyses.

Purpose: The purpose was to investigate whether the echogenicity of images obtained using different high-frequency ultrasonography devices could be standardized through the use of phantoms. Methods: We imaged a site on the forearms of healthy adults using two high-frequency ultrasonography devices. We calculated the echogenicity ratios by dividing echogenicity in lower dermis by phantom echogenicity. We created silicon pads that included grain for use as phantoms. We calculated the error between the dermal echogenicity of ultrasound A and B as well as the echogenicity ratio error.Results: The values of the dermal echogenicity and echogenicity ratio were respectively significantly different between two devices. The error of the dermal echogenicity between two devices was 25%, whereas that of the echogenicity ratio was 14%. Discussion and Conclusion: Because the error between the echogenicity ratios was lower than the one when using phantoms, it is possible to standardize echogenicity by calculating echogenicity ratio.

There is a high prevalence of lower back pain among care givers of the nursing home in Japan. The use of mechanical lifts has been frequently recommended as an assistive device for lifting or transferring care receivers. However, they increase time for use of the lift compare with manual methods. We think that one of the reasons of the time increase is the time for seating sling. To decrease the seating time, we developed a sling that was seated with a mild posture change of the care receivers. Using a dummy doll, we compared seating time and degree of burden score in the developed sling with the commercially available sling. The seating time in the developed sling was significantly shorter than that of the commercially available sling. The degree of burden score was the same level as the commercially available sling.

The accuracy of targeted center of foot pressure (CoP) movement was evaluated in young and elderly participants to determine whether the phase coupling between the CoP and target is predictive of age-related changes in postural control ability. Young and elderly participants performed CoP movement to a target that moved cyclically in the anteroposterior direction at a period of 6 s with an amplitude of 20% of the height of force-platform. The analytical signals of CoP and target were obtained by Hilbert transform, and the degree of the phase synchronization (λ) and the amplitude of the CoP (A_CoP) were quantified. The mean λ and A_CoP decreased significantly in the elderly as compared to young participants. The elderly had greater coefficients of variations in λ and A_CoP during the 3-min sway task, indicating a reduced ability to adjust their CoP to the target and a narrow safe margin of stability.

A wheelchair is an important transportation device for an elderly and disabled people. A joystick has been used to control the electric wheelchair. However, the joystick is not suitable for every user. A novel input interface using the seat pressure distribution with the posture change of the wheelchair user was developed for the electric wheelchair operation. The seat pressure distributions were measured with a sensor sheet seated on the wheelchair. The correlation coefficients between the seat pressure distributions and 5 templates were calculated to identify the posture change by template matching. 8 directional movements were accomplished in previous study. In this study, we improved to move in any direction. The proposed method was implemented on commercial electric wheelchair. We confirmed that the proposed wheelchair can be easily controlled in any direction.

Wheelchairs are widely used as assistive devices to aid ADL for paraplegic people. However, overuse of upper extremities frequently leads to shoulder pain and carpal tunnel syndrome. The purpose of this study was to evaluate upper limb movements during wheelchair propulsion using an inertial sensor. In this study, coordinate values of the vector defined on the upper arm were calculated from an inertial sensor attached on the upper arm. Methods of detecting stroke motion and for measuring the push cycle by using this vector were examined. Ten able bodied (i.e. non-wheelchair users) propelled the wheelchair on 10m long level and sloped surfaces. Excluding the first stroke and the braking motions, detection rate of the stroke number was more than 97% and mean absolute error of the push cycle was less than 30ms on both surfaces. The results suggest inertial sensors can be used to measure wheelchair activity accurately and reliably.

In this study, we propose a monitoring system for elderly people living alone utilizing the interaction between the elderly and robots. Not only sensors but also small robots are arranged all-around the house. The robots encourage the elderly to speak to them spontaneously by holding a relatively simple conversation. The elderly are informed that their approaches to robots are recorded. When there is no approach from the elderly in spite of a detection of existence, a robot speaks to them. If elderly do not respond, the robot gives the notice to guardians. The slow gradual changes in patterns of living are also detected and reported by analyzing the recordings. The guardians can access to the reports whenever they can. In this presentation, we describe the concept of the proposed system, a part of implementation and a method to detect the abnormality from the recordings.

Recently, Movable prosthesis using biological signal has been reported, however, there are less case focusing movement of only one finger. Therefore, to realize the prosthesis using EEG and enabling them, we aimed to distinguish EEG when subjects move finger in conjunction or not. Thus, we measured EEG on C3, C4 and Cz around motor area when subjects bend fingers specified as the following conditions, (1) only index finger's MP joint,(2) index and middle fingers' MP, (3)index, middle, and ring fingers' MP, (4)index, middle, ring, and little fingers' MP and (5)index, middle, ring, little fingers' PIP and DIP joint. As a result, we found tendency that EEG when bending finger from index to ring in conjunction and when bending only index are difference. Moreover, we confirm the mutually similar peaks of EEG on C3 and C4 in all finger movement tasks.

The number of elderly living alone have increased in Japan. They are often found in the lonely death state because it is difficult to immediately call for help. It is needed to develop the new system to detect subtle changes for the elderly including an accident or illness in order to prevent lonely death. The subtle change might appear with the deteriorating physical condition, accidents and early symptoms of illness. It's necessary to detect subtle changes before the accident or illness occurred. In this study, we measure the body sway during getting out of the bed using the Kinect for one of the subtle changes. We detect the position changes of manubrium and sacrum using the Kinect in order to estimate the changes of subject's posture. We checked the posture changes data using Kinect. And the system determined the abnormal posture when posture changes date exceeds threshold.

The central scotomas, one of the impaired visions, make patients blind at a central visual field which provides superior sight and patients feel difficulty of getting sufficient sight in various scenes. The simulation system of the central scotoma which displays a scotoma following a point of gaze on display has already suggested for sighted people to have an experience of central scotoma and to support patients. However, it is difficult for such the systems to follow the saccades, rapid eye movements, since it is too fast to track by using the conventional eye tracking systems. In this research, we develop a high speed display which can follows saccades in real time, and apply it for a central scotoma simulator system with saccade tracking capability using the display and a high speed camera system we developed. We also evaluate the performance of the simulator.

The patient dosen't want to put it on by reason of metallic appearance. And Varus that planta facing inward isn't handled by orthosis. So the foot slip during a walk form the most suitable position. In this study, I improve the appearance of orthosis for hemiplegia and develop that can handle.It is necessary to make orthosis, I derive a braking moment for handling varus. So I need to measure ankle joint moment of healthy person and hemiplegia patient. But there isn't the moment data about varus. So I need to measure the moment of varus.The conventional AFO(ankle foot orthosis) is handling by a belt for varus tightly. the orthosis named spiral model orthosis, specialized in varus correction. So I suggested to use this orthosis structure.I suggested to develop boot type orthosis for improving metallic appearance. In this section, I review a method of measuring moment of varus power.

Stroke occurs when blood flow to the brain is critically reduced. After the stroke occurred, patients may suffer from paralysis. The key mechanism of recovery after the stroke is involved in neuroplasticity. To induce neuroplasticity, exercise therapy has been conducted. However, it remains unclear how the exercise therapy affects the brain activities. To investigate this, in this study, electroencephalography (EEG) signals during a motor task were recorded and analyzed before and after exercise therapy. In the analysis, event-related desynchronization (ERD) was calculated from EEG signals during the motor task and the strength of ERD was compared between before and after the therapy. As a result, the strength of ERD after the therapy was stronger than that before the therapy. The results suggest that the therapy conducted in this study may be the rehabilitation that facilitates the brain activity related to movement.

Laparoscopic surgery is increasing because it is less invasiveness and faster expectation of postoperative recovery than the traditional open surgery. Also, the benefits of shorter hospitalization, less pain, and better cosmetic results support the increasing use of the laparoscopic surgery. However, the current surgical instruments may cause internal interference with other instruments during the operation and blind spot may occur due to its mechanical structure. To solve these clinical problems, we have been developing a multi-joint manipulator using smart materials called magneto-rheological elastomers (MRE) applicable for laparoscopic-assisted surgery.

In this study, we examined mechanical properties of MRE-ring designed for this manipulator. From the results obtained, it was confirmed that the compression stiffness of the ring increased by increasing the applied magnetic field strength, suggesting availability of this material for controlling the stiffness of the joint of the manipulator.

Nerve-sparing surgery is an essential surgical technique for sustaining the quality of life of patients after surgical treatment. However, frequent disablement of patients after treated with nerve-sparing surgery occurs. At the moment, nerve detection relies on the visual inspection by a surgeon, frequently resulting in undesirable damage of thin peripheral nerve with the diameter of 1 mm or less. Here we present a label-free, non-destructive imaging system that can discriminate such a thin peripheral nerve from adjacent tissues. Raman imaging endoscopic probe with 32 detection points at the sample plane has been developed. Rat ex vivo peripheral nerve with the diameter of 1 mm or less has been successfully discriminated from ex vivo muscle and connective tissues. The accuracy of nerve accuracy was higher than 90%. The measurement time was 5 sec. Our developed probe is a promising basis of a peripheral nerve detection system for nerve sparing surgery.

The number of the people of morbidity of the breast cancer in Japan increases year by year. I work on the development of a device measuring bio-impedance using many electrodes from the skin surface. I confirmed that errors rate less than around 1% was necessary to distinguish the benign malignancy of tumor in the breast tissue by computer simulation. Therefore I produced the bio-impedance measuring equipment which implemented 2 phase locks in amplifier, oscillator, electrode position change in FPGA experimentally to be stable, and to measure. As a result of having measured the living body equivalent circuit to check measurement accuracy, the error rate of measured impedance became around 0.3-0.5%. I evaluate a living body equivalent phantom with the characteristic that is near to the living body in conjunction with circuits in consideration of an electrode position change and contact resistance, and it is necessary to examine it.

睡眠障害の一つである睡眠時無呼吸症候群の確定診断はポリソムノグラフィー検査で行う必要があり，SAS検査のゴールドスタンダードだと言われている．現在，わが国でこの検査を行うには病院に入院し，多数の電極を全身に装着して行う必要がある．電極の装着には，専門の技師，設備，器材などが必要であり装着にも時間を要する．本研究の目的は検査の簡素化のため，少数のセンサで睡眠段階ができることを検討するため心拍数に着目し，心拍変動による心臓自律神経系活動と睡眠段階との関係を検討することとする．まず各睡眠段階の推定のために，若年男性25名を対象に睡眠中の生体信号をポリソムノグラフィー検査にて記録し各睡眠段階を推定した．また，得られた心電図より心拍変動を測定し，トーン-エントロピー法で心臓自律神経系活動解析を行った．結果，深睡眠の割合が多い被験者ではエントロピーは高値になる傾向を示し，深睡眠の割合が少ない被験者ではエンロトピーは低値を示した．つまり，深睡眠が副交感神経系活動の亢進に大きく関与していることを示した．心臓自律神経系活動と睡眠段階との関係が心拍変動より推定できる可能性を示唆しており，将来的に検査の簡素化につなげられる可能性を示唆した．

Electrical stimulation is considered to be a potent method for regulating cell fate determination and differentiation of pluripotent stem cells because of their high temporal controllability. However, little is known about responses of pluripotent stem cells to acute and chronic electrical stimulation. In this study, we aim to evaluate changes in gene expression patterns of human induced pluripotent stem cells (hiPSCs) after applying electrical stimulation. First, intracellular Ca²⁺ concentration was monitored with Ca imaging during electrical stimulation. Second, expression levels of pluripotent and differentiation marker genes were evaluated with real time RT-PCR. As a result, the intracellular Ca²⁺ concentration of hiPSCs elevated after stimulation. Moreover, some differentiation marker genes were upregulated by chronic stimulation. These results suggest that electrical stimulation is capable of modulating cell fate determination and differentiation process of hiPSCs.

Recently, research of the regenerative medicine has attracted much attention and culture techniques of the muscle cell (C2C12) have also been progressed. In this study, effect of Grayanotoxins (GTXs) to the cultured myoblast C2C12 from mouse skeletal muscle is investigated. Grayanotoxins (GTXs) belong to neurotoxins are known to enhance the permeability of a cell membrane for Na⁺ ions. It is famous as a phytotoxin, and is extracted from several kinds of Azalea family of plants such as Asebi and Azalea. As a result of a experiment, a change in a pattern of the muscle contraction, caused by an administration of GTX, has been revealed. We confirmed it depends on GTX's variety and concentration. Also, we confirmed that a high concentration 1.5-seco-GTX caused a sharp decrease of the muscle contraction.

Micro RNAs (miRNAs) control mRNAs. Because only a few analyses treated them simultaneously, we proposed an integrative analysis of expression levels of both miRNAs and mRNAs. This method detected miRNAs and mRNAs whose expression levels changed markedly; miRNAs were detected based on expression ratio while mRNAs were detected by t test. The functions of the mRNAs regulated by a miRNA were investigated. The results of the analysis, however, were influenced by the setting of thresholds on detection. In this study, the thresholds were optimized using two datasets. The results revealed that a ratio of 1.5 (miRNAs) and p = 0.01 (mRNAs) were the optimum for the datasets.

Microneedles (MNs) are transdermal drug delivery systems, making it possible to administer drugs into the dermis without pain. In this study, master male molds of MNs were obtained by moving-mask UV lithography. The MNs female molds were replicated by poly-dimethylsiloxane. Finally, MNs were obtained by casting chondroitin sulfate C sodium salt (CSC) solution to the female molds. The Young's modulus of CSC was evaluated to be 2-4 GPa by tensile test. The CSC was enough stiff to penetrate epidermis. The penetration tests were conducted to characterize various shapes of CSC-MNs.

pH is a parameter used in many fields such as medicine and biology. The pH values of solutions have been measured by glass electrode methods, however present methods have disadvantages, i.e. slow response and unstableness of the electrode to diluted solutions with low buffering capacities. To overcome these problems, we have constructed a measurement system using microfluidic device and ion-sensitive field-effect transistor (ISFET) sensor. The system measured both undiluted and diluted solutions with high-accuracy and within short time, however the device size was not small enough. In this paper, we downsized the device body and verified measurement performances.

Flow rate of fluid in micro channel driven by gravity pump is proportional to the head difference. Regulator for long-term microfluidic cell culture system was needed. The conventional flow regulator systems enabling constant flow rate are not easy to miniaturize to fit on micro channels. In this study, simple passive regulator systems that can be applied to micro channel are presented. The result of FEM analysis predicted the effectiveness of deformable valve structure. The analyzed results were evaluated by experiment using microfluidic system with 4 types deformable passive valves.

We have developed a 3D local high-precision positioning system to be applied to novel medical training models used in medical schools. Twelve units of 1-axis extremely sensitive magnetic sensors, GIGS (nano-Granular In Gap Sensor) and high-speed signal processing circuit on FPGA (Field-programmable gate array) board were used in the system. The system response and the positional accuracy were about 0.1 s and +-0.5 mm respectively. It is expected for medical student to improve the educational effect, since an operator's finger position or surgery tools such as forceps and endoscope position in the medical models can be visualized on a computer's screen.