By simultaneously measuring Mechanomyoram (MMG) and Electromyogram (EMG), it is possible to accurate assessment of skeletal muscle contraction. However, MMG measurement has been rarely used for reasons such as having to fix body. Therefore, the authors developed MMG/EMG hybrid transducer system. The device was small and light (47x34x24 mm, 34 g). It was capable of MMG/EMG measurement without requiring any accessory, because sensor section, transducer and storage were integrated. Attachment to the skin was used a dedicated belt conforming to device shape. In addition, hybrid transducer was communicated with operation terminal via Bluetooth(R), and measurement control software collectively controlled five hybrid transducers and could set measurement parameters such as sampling time. MMG/EMG waveforms were monitored in real-time, and data were output in CSV format. By MMG/EMG hybrid transducer system, everyone could simply measure regardless of any field. ACKNOWLEDGEMENT: This research was partially supported by Okayama Prefecture.

An ensemble averaging of frequency spectrum of biosignal corresponds to a smoothing of frequency spectrum obtained by Fourier transform of entire signal. As a general rule, a variation of frequency spectrum obtained by an ensemble averaging of signals becomes small, therefore, a spectrum becomes smooth by an increasing of segment number. On the other hand, a decrease of number of data per segment under dividing signals into a plurality of segments decreases a frequency resolution. Therefore, an ensemble averaging which is balanced between spectrum smoothness and frequency resolution is desirable. However, there is no definite method to determine both a segment number and a segment overlap ratio, which are parameters in ensemble averaging of frequency spectrum. In this study, we propose a method to determine these two parameters in surface electromyogram using breakpoint. Also, we present experimental results that were applied our method to surface electromyogram.

The natural frequencies of the longitudinal and radial directions of the biceps brachii muscle were estimated by measuring evoked torque and muscle oscillation, respectively. The purpose of this study is to reveal the relation between the natural frequencies of longitudinal and radial directions to the biceps brachii muscle. An evoked torque and mechanically stimulated evoked muscle oscillation were measured with a strain gauge load cell and myotonometer, respectively. The measurement was carried out during a resting state and an isometric contraction. The systems of the evoked torque and the muscle oscillation were identified. The natural frequency of the systems was calculated from the poles of the transfer function. In conclusion, the frequency of evoked torque and muscle oscillation increased as the muscle contraction level increased. It is suggested that the natural frequency of the axial direction might be estimated from the natural frequency of the radial direction of the muscle.

The purpose of this study is to clarify the relationship between gastrocnemius muscle stiffness and gait speed. Eight males participated in this experiment and walked at 2, 3, 4, and 5 km/h on a treadmill. Electrical stimulation was percutaneously applied to the medial gastrocnemius muscle once every two push offs, and the mechanomyogram was measured. The evoked mechanomyogram was extracted by subtracting the walking vibration from the measured mechanomyogram. The evoked mechanomyogram system was identified using a singular value decomposition method, and the natural frequency was calculated from the transfer function. The natural frequency was used as an index of stiffness. Two natural frequencies increased as gait speed increased; however, one natural frequency did not. The increased natural frequencies might be related to the muscle contraction, and the unchanged frequency might be related to the skin and subcutaneous tissue. In conclusion, medial gastrocnemius muscle stiffness increased as gait speed increased.

Neurologists evaluate the severity (5 states: 0~4) of the muscle rigidity by their perception of resistance to passive movement based on UPDRS part III. Endo developed the measurement system to evaluate muscle rigidity quantitatively based on the mathematical model explaining the resistance torque by the elastic component of the antagonistic muscle. The value of the elastic coefficient in the model was estimated that best fits the measured elbow joint angle data. In this study, we extend the model to take viscous and contraction components into accounts. We analyzed the data from 80 Parkinson's disease patients, and showed that AIC of the presented model was lower than the previous model in most cases. The elastic coefficients estimated using the presented model significantly increased as the severity increased. The discrimination ratio between severity 1 and 3 or more was 90% using logistic discrimination.

When the lesion progresses in living tissue, the hardness of the tissue changes. Therefore, quantitative measurement of tissue hardness is required. In this study, the object is vibrated by dual acoustic radiation pressure. We aim to estimate viscoelastic properties by examining the frequency response of the tissue. In this report, we observed the change in the displacement amplitude of the object by changing the oscillating frequency. As a result, it was found that the displacement amplitude becomes smaller as the frequency is set higher. It was confirmed that it decreases with a slope of -40dB/decade between 10 Hz and 200 Hz. This phenomenon is thought to be due to stress relaxation. We will clarify frequency characteristics from stress relaxation function.

Total hip arthroplasty (THA) is a surgical procedure that replaces a painful osteoarthritic hip joint with artificial components. Although the THA is an efficient treatment for osteoarthritic patients, there have been some problems to be resolved. Dislocation is one of the most common deuteropathy associated with the THA. Canine THA has been recently performed for dogs with the joint pain. The dislocation is a more serious problem for dogs than humans, because it is difficult to control the movement of dogs after the THA. We have newly proposed the artificial hip joint with a preventing structure from dislocation. In this study, the pull-out forces of the joint were calculated using a three dimensional finite element analysis. The relationships between the pull-out forces and the joint structures were obtained from the analysis. We gain insights into a principle to optimally design the artificial joint that does not easily occur the dislocation.

The purpose of this symposium is to discuss the significance and the strategy to found the department of bio-medical engineering in Japan. The symposium is the 2nd one after the last 55th conference of JSMBE which was held at Toyama. The department of bio-medical engineering has been already established in most of the leading universities in Europe and the United States of America since 1950, while there are a few institutes of the bio-medical engineering in Japan. Until now, There is an agreement at the last meeting toward a positive direction on the foundation of the department of bio-medical engineering by discussing the current problems and learning the history and the strategy from the founders. It is the mandatory issue to be solved in order to grow the young generation up to the international level in the field of biomedical engineering and to strengthen the international competition in medical industry.

[Introduction] We have studied ME research from a practical aspect. We want to shorten the distance between hospitals and universities, companies.[Purpose] We are trying practical and primary education for medical staffs and high school students, we consider that the problems of the needs and the seed for establishing the department of ME from this practice. So we want to discuss to establish ME department with our approaches. [Results] From the practical study of electrocardiogram and ultrasound for the medical stuffs and engineering, mainly in Osaka University School of Medicine and Osaka Electro-Communication University, the students are satisfied. In addition, our experiences of lectures on graduate school of engineering at Nagoya University and Tokyo Institute of Technology, the students' interests are quite large. [Conclusion] By our practice, there are large number of needs in engineering students. But, it is necessary to show the route and goal and an evaluation system.

Background: We conducted an investigator initiated trial to evaluate the efficacy and safety of Laserphyrin-based PDT as a salvage treatment after chemoradiotherapy (CRT) or radiotherapy (RT) for EC. Methods: Patients with histologically proven local failure limited to the T2 after definitive CRT or RT (≥50 Gy) for EC were enrolled. PDT began with intravenous administration of 20 mg/kg of Laserphyrin followed 4-6 hrs later by a diode laser irradiation with a fluence of 100 J/cm2. The primary endpoint was a complete response (CR) of the primary site, and the secondary endpoints were PDT related toxicities. Results: 26 patients were enrolled. 18 cases were estimated as T1b and 8 cases were T2 by EUS. 23 cases achieved CR at primary site (CR rate: 88. 5%). Toxicity was acceptable. Conclusions: Laserphyrin-based PDT is a safe and potentially curative salvage treatment for local failure after CRT or RT for EC.

Photodynamic technology using light-sensitive and fluorescent substances has attracted attention as an auxiliary diagnostic tool in cancer. Light-sensitive and fluorescent substances injected into the body accumulate specifically in tumor cell, and by light irradiation and excitation at specific wavelengths, fluorescence is emitted. This application of photodynamic reactions as medical technology is called photodynamic diagnosis (PDD). PDD for bladder cancer was clinically introduced in 2004. PDD is very useful for the detection of tiny lesion and flat lesions such as carcinoma in situ (CIS). Transurethral resection of bladder cancer (TURBT) with PDD improved treatment outcome of bladder cancer in clinical practice. In our attempt of ALA-PDT for prostate cancer, we conducted therapy effect in human prostate cancer cells. We tried to improve the effectiveness of ALA-PDT by mechanism analysis of porphyrin metabolism in human prostate cancer cells. The control of porphyrin metabolism can make PDT system with high efficiency and safety.

We examined the anti-tumor effects by photothermal action derived from near-infrared (NIR) irradiation combined with DDS type photoabsorbing agent, ICG lactosome (ICGm). A subcutaneous tumor (Colon26) mice model was intravenously administered with ICGm, The tumor was then irradiated by a laser (808 nm) under several conditions while measuring tumor surface temperature (TST) by non-contact thermometer. A positive correlation was confirmed between the maximum TST (℃) and the power density (mW/cm2) of irradiation. In addition, under a constant power density (750 mW/cm2) anti-tumor effects depended on the maximum TST regardless of the duration of irradiation time (s). When TST reached at > 43℃ during irradiation, tumors were shrank with the possibility of 100%, while almost all of the tumors were not shrank when TST did not reach at 43℃. These results suggest that a temperature dosimetry during NIR irradiation combined with ICGm admistration provides definite anti-tumor effects.

Hemodynamic resuscitation in septic shock requires aggressive fluid replacements and appropriate use of vasopressors to optimize arterial pressure (AP) and cardiac output (CO). This is time/labor consuming task, because strict hemodynamic monitoring and repetitive adjustment of drug dose are required. To overcome this, we have developed a closed-loop drug infusion system for automated hemodynamic resuscitation in septic shock, and validated performance of the system in 8 dogs with endotoxin shock. Our system computes arterial resistance (R) and stressed blood volume (V) from AP and CO. Our system controls R with noradrenaline, and V with Ringer's solution, thereby controlling AP and CO. Once activated in dogs with shock (AP=42±5 mmHg, CO=60±17 ml/min/kg), our system automatically restored AP to 70±2 mmHg and CO to 130±10 ml/min/kg within 40 min, and maintained them over 4 hours. We conclude that our system could be an attractive clinical tool in rescuing patients with septic shock.

A synchronized control of left ventricular assist devices has some advantages in comparison with constant rotational speed control. However, because a risk of occurrence of abnormal situation such as suction and regurgitation increase, the controller should adapt such abnormal situations. The aim of this study is to simulate the abnormal condition using hybrid-mock circulatory system combining computer simulator and mock circulatory system.Suction, regurgitation and deterioration of heart function were simulated in hybrid-mock circulatory system and the each behavior were compared with the results of animal experiments.As a result, it was confirmed that the abnormal situation simulated using the hybrid-mock circulatory system and each behavior was similar as the result of the animal experiment. Therefore, it is possible to investigate and evaluate the control algorithm using actual pump and controller.

An implantable type ventricular assist device becomes mainstream, but an extracorporeal type pump has advantage in case of short term assistance. However, in the case of extracorporeal type device, it is expected that the assist flow is affected by cannula diameter and length. In this study, the influence of diameter and length of the cannula on assist flow was investigated and compensation method by pump control was proposed.The HQ curves combining cannula with pump was obtained. The model expressing HQ curve was identified from measured data and the slope of HQ curve at any drive point was evaluated. In result, although the same assist flow was actualized in small diameter by high pump speed, the slope of HQ curve around driving point became steep. Besides, the result indicated that the steepness was compensated by dynamic rotational speed control such as co-pulse mode control.

This investigation describes the hybrid method to combine concentration transport process of species by FDM and platelet aggregation by DPD. Computational objects are 5 types of pipe flows through an orifice, which were same geometries in our previous observation experiments of thrombus formation. Using the velocities and pressures in case of turbulent flow by N.S. Equations, the concentrations of species with chemical reaction are computed by FDM. In our newly proposed hybrid model, DPD is applied to express the aggregation process of platelet on the wall. By adding the DPD model with aggregation, number of aggregated and activated platelets was evaluated. By using probability of deposed platelets on the wall, the total number history of activated and aggregated platelets was obtained. The rate of aggregated platelets was compared with our previous experiments of thrombus formation rate.

We have proposed novel short-term thermal angioplasty named Photo-thermo Dynamic Balloon (PTDB) for the treatment of arteriosclerosis. In our previous study, we found that smooth muscle cells (SMCs) were stretch-fixed after this treatment. To estimate the influences on stretch-fixing and heating of SMCs, we studied the activity evaluation method in the growth arrest state. SMCs were set the growth arrest state cultivated by 0.5 % low serum medium for 96 hours. To evaluate the SMCs' activity, we measured the quantity of NADH, the indispensable enzyme for aerobic respiration of cells using by WST-8 assay. SMCs were continuously stretched with 0-50 %. We found that the activity of the stretch-fixed smooth muscle cells increased compared to that of the non-stretched smooth muscle cells. We think that we might be investigated about smooth muscle cells' activity in the growth arrest state.

[Purpose] Models of the diseased heart produced by 3D printers are expected to provide useful information for surgical procedures. However, the precision of commercially available machines is uncertain. Therefore, we assessed the 3D models by two different methods. [Method] Using DICOM data derived from x-ray CT images of a heart, 3D models were produced by a fused deposition modeling method (FDM) and an ink-jet method. Polylactic resin (PLA) and silicone rubber (AR-G1L) were used as materials for the FDM and ink-jet methods, respectively. [Result] The model created using the FDM was produced at a reduced size due to limitations of the machine, which caused the coronary artery to collapse. It was also difficult to cut. The model created using the ink-jet method was produced at full scale and quite flexible. [Conclusion] The heart model created using the ink-jet method with silicone rubber provides excellent information for surgical treatment.

This study proposes a method of cardiac risk assessment based on the long term Holter ECG recordings. Conventional risk assessment indices are obtained by short term ECG record recorded at the clinical laboratory in the hospital. Recently, characterization of the long term ECG record draw a considerable attention. This research adopted several such indices based on the long term ECG record for the cardiac risk assessment. Namely, Indices based on QT and RR intervals, such as cRRI-QT, RRI-Amplitude, ARP are introduced and examined. Logistic regression analysis is applied to those indices obtained from 11 cardiac high risk (SCD-H), 14 low-risk (SCD-L) patients and 25 control subjects (Control). It has been shown that the combination of RRI-amplitude, ARP and cRRI-QT yielded the best classification accuracy. Sensitivity and specificity were larger than 0.8 except for SCD-L sensitivity being 0.7. The number of cases should be increased to validate the result.

The conventional configuration of cryoprobe systems uses triple coaxial tubes. Moreover, in order to measure the temperature shift at the outer wall of the probe tip, a wired thermocouple was externally attached using an adhesive. However, as the adhesive works as thermal resistance, the temperature measurement accuracy deteriorates. To cope with the problem, in the proposed system, the outer and middle tubes of the triple coaxial tube were designed using two different metals, which are the materials used to build the thermocouple, and these tubes were welded only at the probe tip. As a result, the proposed system achieves a built-in thermocouple that does not need the adhesive. To evaluate and verify the effectiveness of the proposed system, the measuring accuracy was investigated. Through the experiments, we verified that the proposed system could more accurately measure the temperature shift at the probe tip as compared to conventional systems.

Transcranial Magnetic Stimulation is effective for treatment of brain dysfunctions. We have developed a new coil, a double-D coil. The coil was designed with simulations to be able to maintain steady stimulation at target when it is displaced from the optimal spot. In this study, five healthy subjects participated voluntarily, and the double-D coil was assessed experimentally. For comparison, a figure-8 coil was also used. A subject was stimulated at 200 points around the left primary motor cortex by each coil. Motor evoked potential was recorded at the first dorsal interosseous and its amplitude was mapped on the coordinate axes. The distributions of them were arranged with a Gaussian function. The half-value width of the short axis improved 1.6 times, whereas that of the long axis increased 1.5 times. The results showed the double-D coil is less affected by the coil displacement than the figure-8 coil.

Magnetic stimulation to a base of brain may become effective therapy for the treatment of Alzheimer's disease. In this study as basic experiment, we designed and made an intraoral coil to stimulate a base of brain from the oral cavity which is near to a base of brain. In the design, the size of the coil was optimized so that magnetic flux density was as large as possible. We measured magnetic flux density of various coil angle at the position that is assumed to be a base of brain. As a result, the magnetic flux density at the base of brain showed a maximum when the coil angle was about 35-40 deg. Additionally, we conducted a numerical analysis of the head model. The magnetic flux density showed a maximum when the coil angle was about 35-40 deg. We evaluated the induced current density at the base of brain.

Since malignant brain tumor infiltrate the tissue and the boundary between normal and tumor tissue is unclear, it is difficult to remove completely by surgical operation. On the other hand, as there is a possibility of recurrence or malignancy, the improvement of tumor resection rate is strongly required. The purpose of the study is to construct a system that can gather many pathological specimens by resecting tumor continuously and decide extraction range in real time based on the biopsy results.Porcine brain used as an alternative of tumor was resected and collected using the continuous resection forceps developed in the study. Since the specimens was swept away in the column with a large amount of cleaning water, dehydration mechanism is necessary for diagnosis. Using the developed dehydration mechanism, most specimens can be collected with 70.24% dehydration rate, but some remained in the mechanism 4 times out of 10 trials.

In this study , we estimated the connectivity configuration of epileptiform discharges in the ictal earlystage from electrocorticography of intractable epilepsy . In this time , we propose estimation methodusing partial correlation function(PCF) and conpared the estimated result used PCF and used cross-correlation function(CCF) because it is considered that more correct connectivity is estimated . Boththe estimated result used PCF and CCF is seen connectivity which is temporal lobe inside to frontal lobe and temporal lobe inside to temporal lobe outside . Only proposal method is seen connectivity which is temporal lobe outside to frontal lobe . Guessable that ECoG of intractable epilepsy is propagated frontal lobe and one part of temporal lobe outside from temporal lobe inside and else temporal lobe outside fromfrontal lobe because there is the epileptic focus on the hippocampus .

In Alzheimer's disease (AD) amyloid-β (Aβ) depositions disturbs neurons irreversibly, and early treatment before occurrence of dementia is important for AD treatments. This study aims at proposing an automated delineation algorithm for reference regions (AutoRef) for Aβ accumulation quantification. This presentation focuses on merits of a limited temporal information and the increased number clusters. As a result, for 86 clinical data (43 cases of AD, 33 cases of normal and 10 cases of equivocal deposition of Aβ), AutoRef succeeded in delineating the reference region for all the data. There was no significant difference (p < 0.05) between AutoRef and manually delineated reference region by a physician. The standard deviation of the difference between them was smaller than the discrimination threshold of AD used in actual clinical practice. In conclusions, the effectiveness of this study was suggested.

Akinetic mutism has a lack of intention to act.Therefore, we set the region of interest as anterior cingulate cortex(ACC), which is related to the intention of behavior in DMN and has a connection to motor cortex(MC) and somatosensory cortex(SC). We performed ROI-based functional connectivity analysis on 5 epileptic patients who underwent callosotomy. As a result, 1 out of 2 who developed acute transection syndrome(ATS) had a correlation with MC and SC for ACC before surgery, but the correlation disappeared after surgery. To examine this result, we performed a similar analysis on the brain fMRI data of healthy subjects and compared it with this result. As a result, healthy subjects have correlation with MC and SC for ACC, and the above findings are considered to occur when ATS develops due to callosotomy. ATS is thought to be due to the disappearance of connection to MC and SC for ACC.

The damage to health by the smoking is thought to be a severe problem. So the messages or images that show the risk with the smoking are printed on the packages of cigarette all over the world. The package design called plain package was defined by the law in order to reduce the consumption of the cigarette in Australia in 2012. Making the image for quitting smoking which has a certain effect is important to promoting healthy society. In this study, we investigated the effect of quitting smoking of plain package and conventional package based on brain activity. Results showed conventional package activated the orbitofrontal cortex which relate to the smoking desire. On the other hand, plain package activated the primary somatic sensation field related the sense of pain recognition. This result shows the possibility that plain package strongly reminded subjects of a risk of continuing smoking.

It is well known that the carbon emits far infrared rays (FIR). FIR has a thermal effect and it is widely used for heater and widely applied in medicine, including the treatment of chronic fatigue syndrome, chronic pain, and wound healing. Sericite, which emits FIR, has been used in the medical field to promote health and there are numerous reports that show beds made from sericite ceramics help relieve dysmenorrheic pain. So the carbonaceous personal ornaments may have good effect to improve the human physiological and psychological state. In this study, we investigated the physiological and psychological effect of the carbonaceous personal ornaments, glasses and watch (made by OHGI TECHNOLOGICAL CREATION CO.,LTD.) by comparing them with conventional ones, based on EEG, visual analog scale (VAS) questioner, etc. As a result, it was shown that the carbonaceous personal ornaments has significant effect of decreasing stress level and decreasing tension-anxiety level.

Intravascular surgery, such as coil embolization and stent placement, has been widely performed for treatment of cerebral aneurysms. Doctors must be skillful and sufficiently experienced to successfully manipulate and insert a guidewire and a catheter into the aneurysm via carotid and cerebral artery. Though blood vessel model is useful for training of the doctors in the field of the intravascular surgery, evaluation of doctor's skill and efficacy of training is insufficient. In this study, an ultrasound sensor was fabricated and equipped in the cerebral blood vessel model to measure the displacement of the vessel wall that is contacted and pushed by a guidewire or a catheter. It is confirmed that the fabricated ultrasound sensor could measure the displacement of blood vessel wall by the inserted catheter.

Recently, with the increased popularity of endovascular therapy, blood vessel model become more important owing to its practicality in skill training and new device evaluation. To develop the appropriate model, it's necessary to understand how doctors evaluate the model. In this research, a doctor in NeuroEndovascular therapy was interviewed to analyze his evaluation structure of blood vessel. During the test, the doctor was asked to evaluate three different blood vessel models made based on a same realistic geometry of cerebral artery by using catheter. A sensory test methodology called evaluation grid method was used to analyze the evaluation structure of the doctor. Our results suggest that, the evaluation of a blood vessel model by a doctor is made based on the sensation given by the model through the catheter, including the friction of the inner wall, the similarity of the shape, and the confidence obtained by using the model.

In recent years, coil embolization of cerebral aneurysm has been widely performed as a method of endovascular treatment. Therapeutic effect tends to be insufficient when coils are placed in biased position in the aneurysm or blood flow in neck area is insufficiently reduced. It is considered that quantitative evaluation of therapeutic effect of coil embolization is important. Pressure changes before and after coil placement were measured by multipoint pressure measurement locally at the inside of the aneurysmal part and the vessel part near the aneurysm in the blood vessel model fabricated using PVA-H (Poly (Vinyl Alcohol) Hydrogel). Two ultra-miniature fiber-optic pressure sensors were inserted and located into the aneurysm from the outside of the model. Two commercially available pressure sensors were also connected to both upstream and downstream sides of the model, respectively. Pressure change in the aneurysm in accordance with the number of the coils could be measured. (137words)

Intravascular treatment is recognized as one of the most difficult skills to acquire for medical doctors and realistic in vitro training systems for endovascular treatment are increasingly demanded these days. Vessel model is a major part to construct the system with strong requirements of the reproducibility of both mechanical properties and haptic sense during catheter operation. In this study, the condition to fabricate realistic models and the training system imitating the environment of intravascular treatment were established and 4-coil occlusion in the aneurysmal model was performed by a skilled medical doctor. The coils are successfully inserted into the aneurysm and the doctor evaluates haptic sense during the operation is similar to realistic situations. The experimental result and the doctor's evaluation indicate the new developed system is beneficial to the training of intravascular treatment.

Nowadays, a variety of vital sensing devices have been able to be easily and inexpensively connected to any smart phones by means of wireless technologies. Typical examples of such wireless tools are Bluetooth, WiFi and WiSUN, which are all based on the IEEE 802 standard families. This paper presents the current status of the IEEE 802 standardization activities related to the support of everyday healthcare, such as the IEEE 802.15.1, 802.11, and 802.15.4g. In addition, this paper introduces the detail of the IEEE 802.15 6 standards for supporting highly reliable wireless communications, which is required for providing medical and healthcare services.

Healthcare IoT is a new trend in the field of the next generation medical/healthcare services. A daily healthcare checking by seamless vital data collections using vital sensors combining with high level data analysis is one of the key services that the healthcare IoT can provide with users. In order to realize this service, a seamless and unconscious data collection method is an important technology.SmartBAN technology that has been standardizing in ETSI is suitable for a low-power and seamless vital data collection method. In this presentation, we present the latest update of SmartBAN and its challenges for the next generation medical/healthcare services.

In this talk, we discuss challenges in wireless networking technologies for realizing real-time and reliable vital data collection from a large number of exercisers. Especially, we focus on vital data collection for sports-day events in schools. We propose a wireless communications system where vital data obtained by a vital sensor attached to the back-waist position of each exerciser are collected by employing wireless networking technologies. In this scenario, wireless transmissions suffer from attenuations due to shadowing caused by human bodies, which requires multi-hop transmissions of sensing data. Furthermore, we need to alleviate the impact of congestion resulting from simultaneous transmissions of a large number of sensor nodes. Therefore, we apply multi-hop communications protocols with multi-channel settings to our system. With computer simulation results, we discuss challenges to improve the reliability of data communications in our proposed system.

Recently, wearable biomedical sensor networks which sense bio-information such as electrocardiogram and brain wave have attracted high attention. However, biomedical sensors have to be equipped with battery, which replacement gets into mess. Furthermore, the wireless signals from sensor modules may interfere to biomedical signals or other communication devices. To conquest the above problems, in this paper we introduce a wearable biosensing system via sheet medium communication, which performs both data and power transmissions for the real time unrestrained measurement of biomedical signal in our daily life.

Spiral wave (SW) is recognized as a cause of lethal ventricular arrhythmia. Previously, it was reported that SW moved around the regional cooling (RC) region. However, the mechanism of SW in RC was not elucidated. On the other hand, phase variance analysis was suggested for quantitative and accurate SW's core detection. In this study, we simulated the RC experiment in computer simulation model and analyzed the behavior of SW by phase variance to elucidate the mechanism of SW in RC. As a result, we found that SW's core moved around the RC region in the same direction irrespective of RC position. Wave tail delayed by the RC blocks the propagation of wave front and SW drifts toward the periphery of the RC region.

We constructed a 3-compartment pharmacokinetic model for canine consisted of three compartments including plasma, interstitial space, and cell to estimate talaporfin sodium concentration change in interstitial space. Photosensitization reaction is performed when talaporfin sodium distributes in the interstitial space employing a short drug-light interval in our arrhythmia ablation. We studied interstitial concentration constructing the 3-compartment numerical model using talaporfin sodium concentration in canine plasma, and in addition, other measured relative concentrations of canine tissue, including plasma, interstitial space and cell information. We represented differential rate equation of the drug concentration in each compartment. Fitting the measured data set to the calculated concentration in each compartment, the rate constants in the constructed 3-compartment model were determined with R2=0.98. Using the 3-compartment model, the interstitial talaporfin sodium concentration and the available condition in our arrhythmia ablation could be estimated.

The importance of the skeletal muscle pump in reducing the accumulation of blood in the veins during orthostatic stress is well recognized. We hypothesized that the increase in venous return elicited by the muscle pump requires coupling of heartbeats to muscle contraction. To address this, we simulated the mechanical muscle pump effect using rhythmic lower-leg cuff inflation (RCI) with 120 mmHg cuff pressure at three different cycles. Time series of R-R interval (RRI) and beat-to-beat blood pressure (BP) were acquired in 13 healthy subjects without or with RCI during quiet standing. The coupling strength was quantified by phase coherence (&lambda) between cuff-pressure induced heart rate variability (HRV) and cuff-pressure rhythm. Shortening of RRI during standing was suppressed by RCI and increase in &lambda was associated with the increase in parasympathetic activity estimated from HRV analysis, suggesting that coupling may play a role in an increase in venous return.

Previous study revealed that phase coherence (&lambda) of respiratory sinus arrhythmia (RSA) correlated with parasympathetic nerve activity. The aim of the present study was to examine how &lambda is altered depending on the sleep status and to evaluate the temporal relationship to the brain activity during sleep. Overnight EEG and ECG of 17-healthy volunteers were recorded. The EEG was band-pass filtered to extract the activity in the &delta-range. RSA was determined by applying a band-pass filter to the R-R intervals. From the oscillatory signals of RSA and respiration, time-dependent &lambda was obtained. Using auto- and cross-correlation analyses, we found that the periodicity of &lambda was quite similar to that of &delta-wave and that the variation of &lambda preceded changes in &delta-wave in the order of few minutes. These results suggest that &lambda is coupled with EEG &delta-activity and that &lambda could be used as a measure of sleep status.

Sleep quality is important for maintaining good health. However, many people are not satisfied with their quality of sleep. As a decline in sleep quality leads to a deterioration in attention and concentration during the day, the evaluation of sleep quality in daily life is necessary to improve sleep quality. In our previous works, smart-wear that could measure the electrocardiogram (ECG) in daily life was developed. The purpose of the present study is to measure the ECG during overnight sleep by using the smart-wear in order to evaluate sleep quality. The ECG of 15 healthy males was measured for 8 h during overnight sleep and stored on their smartphone. After the experiment, the measured ECG was evaluated by visual confirmation of R peaks at intervals of 60 s. The results show that the R peaks can be observed at 79.9 ± 10.5 % during overnight sleep.