In healthcare data radio system, it is essential to avoid the communication disconnection when the transmission signal bit error rate (BER) exceeds a specific value. When the BAN antenna is attached at wrist, the polarization characteristics will be varied significantly according to the antenna rotation angle caused by the arm-swing motion. In this paper, the BER characteristic of a weighted-polarization BAN antenna considering human walking motion is measured while the validity of the proposed antenna is verified. At first, a method of BER Over-The-Air (OTA) Testing is proposed, where a fading emulator is utilized for realizing the actual propagation environment. Then, the BER measurement is carried out in considerations of the arm-swing motion using a human phantom. Compared with the conventional antenna, less SNR is required when the weighted-polarization BAN antenna is used to obtain the desired BER, indicating the effectiveness of proposed weighted-polarization antenna for BAN wireless applications.
We have proposed a method for estimating the flow volume and flow rates from the streakline images based on the multi-cylindrical model. This approach provides the flow volume by integrating the flow rates calculated from liquid trajectories in images taken liquid immediately after urination in the air. Thus, the subject can measure the urine volume with high accuracy under a normal urination behavior. Our method can be applied to both the male urinal and the western-style toilet stool. The measurement accuracy of our method compared to other sensors has been raised to a feasible level depending on the ingenuity. In this manner, life log data to be recorded in the toilet have potential for one of the important indicators in healthcare. Here, we show remaining problems to be solved by introducing advantages and disadvantages of our method when it was applied to urine volume estimation.
In healthy longevity society, prevention of lifestyle-related diseases and enhancement of home healthcare are required for improvement of QOL (quality of life). It is well known that blood pressure estimation is useful for prevention of hypertension and patient monitoring. It is the key technology for improvement of QOL, but the measurement by using a cuff all the time is a heavy burden. Therefore, we co-developed “the continuous health monitoring system with the cuffless sphygmomanometer using the pulse wave” to facilitate health care and home care patient monitoring. In particular, we constructed a cloud system to collect and manage blood pressure data using the internet and a wristwatch type photoplethysmograph sensor. Thus we applied the cuffless blood pressure estimation by a single photoplethysmograph sensor to the continuous health monitoring system.
A high intensity focused ultrasound (HIFU) field of a transducer for ultrasound therapy was visualized using an image subtraction Schlieren technique. The transducer of 110 mm in diameter and 100 mm in focal length was driven by a burst pulse of 1.58 MHz in center frequency and of 10 W or 100 W in input electric power. 10 instantaneous HIFU fields were visualized at 10 different phases, and a beam profile was determined by superimposing the fields. FWHMs of the beam were 5.8 mm in a visualized field but was 7.3 mm in a field determined by hydrophone measurement.
The scattering effect in light propagation through random media can be suppressed with the phase-conjugate optics. We have applied this technique to the transillumination imaging of animal body using a digital phase-conjugate system. In the experiment, we attempted to restore various incident light patterns through a scattering medium. As a result, the feasibility of scattering suppression using digital phase-conjugate light was verified.
Reduction in Dorsolateral Prefrontal Cortex (DLPFC) blood flow is reported to be seen during the wakefulness to the early stage of sleep, and is often the cause of car accidents. Near-infrared spectroscopy is necessary for measuring DLPFC blood flow, but is not suitable for the daily use due to cost and complexity. To prevent traffic accidents, we proposed a non-restricting and low-cost method for estimating DLPFC blood flow. We made up a formula by applying a multivariate analysis for heart rate and heart rate variability measured by Doppler radars. The correlation between DLPFC blood flow and the estimated value was high in the cases of subjects with decreased DLPFC blood flow.
The low attenuation areas (LAA) in lung are understood one of the important factor for promoting Chronic Obstructive Pulmonary Disease (COPD). Mortality of COPD has been increasing, and World Health Organization (WHO) expects it to become the third leading cause of death in the world by 2030, up from its current tenth place. In this present report, we studied the estimating procedure for confirm the primary changes of LAA using Computed tomography (CT) images. Under-950 HU CT areas were scored in CT image, and estimated using Goddard's method. No relationships were confirmed in age and smoking history. The data might be indicated that the other factors of promoting LAA have been existed.
When two flat ring coils are layed on a plane in free space, overlapping about 20%, there can be found a null-coupling point where mutual flux coupling is cancelled to make zero transmission to each other. On such setup we can detect nearby interrupting magnetic material and/or LC-resonant tank circuit which causes extra transmission via cross-coupling to the interrupter. Such detection capabikity would depend on accuracy of null-point setup, driving signal design, gain and bandwidth of detecting amplifier and the size of the interrupter to be detected. Adequate design can detect a similar size tank circuit having Q0=70 or more at several times distance of interlogating coil pair diameter. In this study we aimed to use this for extrra corporeal sensing of intra corporeal passive sensing device. In our model experiment 5cm interlogating coil pair can steadily sense 1cm dia. x 1cm length ferrite cored LC tank circut, at 1 to 2 MHz frequency band.
We have been developing a computer-controlled infusion system of cardiovascular drugs (vasodilator, inotropes, diuretics, volume-expander) to automatically optimize arterial pressure (AP), cardiac output (CO), and pulmonary wedge pressure (PCWP) in heart failure (HF). In our previous developments, however, CO and PCWP were measured through thoracotomy, and inotropes were inevitably infused, which were clinically impractical or not in line with HF guidelines. We have made the system less invasive and clinically feasible. CO and PCWP were estimated and monitored less-invasively utilizing transthoracic-echocardiography. Control algorithm was revised in accordance with the guidelines. We applied the system to 9 HF dogs. Once activated, our system immediately started infusions of vasodilator/diuretics in all animals. Inotropes was not used in 3, and used at minimal doses in 6 animals that were intolerant of vasodilators. Hemodynamic variables were controlled to their targets accurately. In conclusion, the advanced system may be useful in managing patients with HF.
Although the dynamic mechanical properties such as arterial compliance (C) have been shown to predict increased mortality in patients with pulmonary arterial hypertension (PAH), a simple static index, i.e., pulmonary arterial resistance (R) has been exclusively used in clinical settings. We examined how a Rho-kinase inhibitor, fasudil, that is known to suppress vasoconstriction, affects pulmonary artery input impedance (Z) in Sugen/Hypoxia (SuHx) PAH in rats. We measured Z before PAH induction (Normal), and re-measured before/after fasudil injection (10 mg/kg) (PAH/Fasudil). PAH increased R while Fasudil decreased R (Normal: 16.3±2.6, PAH: 56.5±6.9, Fasudil: 39.9±5.2 mmHg/ml/sec, p<0.01). In contrast, PAH decreased C while Fasudil increased C (Normal: 3.6±0.6, PAH: 1.8±0.4, Fasudil: 2.5±0.8×103 ml/mmHg, p<0.01). We conclude that the pulmonary arterial impedance may serve as a new tool in analyzing vascular mechanics to assess the severity or the drug efficacy in PAH patients.
In this paper, simultaneous measurement of electromyogram (EMG), Mechanomyogram (MMG), and oxygen dynamics at the forearm is presented by the proposed sensor. The proposed sensor is a layered structure of a transparent thin electrode, a transparent piezo film and near-infrared sensor. EMG, MMG and oxygen dynamics are respectively measured by the electrodes, piezo film and near-infrared sensors. The three types of data are obtained by a pair of proposed sensors. In an experiment, simultaneous measurement of EMG, MMG and oxygen dynamics at the forearm was demonstrated using the proposed sensors. As a result, it was shown that simultaneous measurement of EMG, MMG and oxygen dynamics at the forearm was possible although measurement accuracy was insufficient. In addition, it is suggested that the proposed sensor has the potential for analysis of the muscular activity.
It is important to consider the thigh-calf contact force to analyze the kinetics of a lower limb during deep knee flexion, however, the measured forces have varied very much and difficult to understand systematically. In this study, we considered that the thigh-calf contact force might be estimated by considering not only the individual difference but also the joint angles or the posture of an upper body, and measured the forces and introduced the estimating equation. The test subjects were 6 healthy male, and measured the joint angles and thigh-calf contact force, and performed a multiple regression analysis. As a result, equations to estimate thigh-calf contact force using joint angles and the individual parameter were introduced. The average error of estimation was 0.11BW and the maximum was 0.33BW. It was clearly indicated that the postures of the upper body effected to the thigh-calf contact force.
Facial paralysis is the loss of voluntary muscle movement on one or both sides of the face inhibits the movement of orbicularis oculus. People with facial paralysis cannot blink which triggers dry eye and it affects the lives of many people. We propose a novel approach for supporting blinking with facial wearable robotic technology. This robot has a novel eyelid gating support mechanism using deformation of elastomer for recreating eye blink, triggered by blink detection on healthy side. We evaluated this system witha healthy participantand indicated the feasibility of eye blink support for people with facial paralysis.
We investigated the effect of low frequency pulse wave stimulation (LFPWS) on transcription levels of Na/K pump in skeletal muscle cells. Bilateral anterior tibial muscles of an F344 rat were pierced by two needles respectively under anesthesia with isoflurane. LFPWS (5 V, 0.7 msec) was given only to the right-side muscle for 1 hour at 30 ppm or 400 ppm. Those muscles were collected followed by total RNA extraction. The mRNA levels of both α1 and β1 subunits of Na/K pump were measured by reverse transcription-quantitative polymerase chain reaction. The mRNA level of α1 subunit did not change significantly between LFPWS-treated and untreated muscles either at 30 ppm (n=7) or 400 ppm (n=7). The level of β1 subunit did not change by LFPWS at 30 ppm (n=7), while that increased 1.5-fold at 400 ppm significantly (P<0.05, n=6). Our study demonstrated relatively selective upregulation of β1 subunit transcription induced by LFPWS on the skeletal muscles.
The eye fixation time distribution was obtained from the fixation data in the subjective evaluation test with paired food pictures by the stimulus-comparison method, and the diffusive and specific searches were discussed. Results showed no significant difference between the reference and the evaluated pictures in the specific search, which indicates to differ from the case of the selection test.
Although the most of the modern medical instruments has been computerized, they are not connected to hospital information systems. As a result, clinical recording still heavily relied on manpower. In this research, we attempt to connect medical instruments to a hospital information system. Once it is connected, detailed medical record can be obtained without increasing the workloads of clinicians. We selected infusion pump and syringe drivers as the examples of such medical devices. Connecting such devices enables the hospital information systems to watch detailed settings and statuses of the devices and to inform errors to clinicians. In this paper, we discuss preferable way to inform collected errors through interview with nurses.
Age-related or disorder-induced changes of the central nervous system and the musculoskeletal system lead an impairment of postural stability. While considerable effort has been provided to archive better recovery from postural disorders, current therapeutic approaches in the rehabilitation field are still insufficient to accomplish this. Our group has been recently developed a real-time postural feedback system in order to establish a novel rehabilitation strategy for the adjustment of the postural control. The developed system can implicitly modulate subject's body sway decreasing (in-phase) or increasing (anti-phase). In this perspective paper, we firstly explain the concept of our newly developed system and its potential effectiveness for the improvement of postural control, and will then, secondly introduce some examples of the clinical attempt to use our system for various type of postural disorders.
There are a lot of patients with movement impairment who are paralyzed by brain stroke. Sufficient rehabilitative training is necessary for these patients. Rehabilitation support systems using force display devices are also expected to quantify the effects of rehabilitative training and enhance the motivation of patients and rehabilitation effects. Development of Upper Limb Rehabilitation System PLEMO-BAT for Stroke Patients Using Bilateral Limb Motion is presented in this paper.
Split-belt treadmill walking has been recently used as a tool not only to investigate the process of adaptation during walking but also to improve gait asymmetry in patients post stroke. Previous study used remarkably larger speed ratio more than 1:2, we here use very mild extent of speed ratio about 1:1.2. The purpose of this study was therefore to investigate the effect of split-belt walking on gait asymmetry in stroke patients. In order to determine the extent of speed ratio, we firstly determined the detection threshold when the subject can perceive the changed speed ratio during gradual increment/decrement of each belt speed. Subjects were administrated on two split-belt treadmill walking; (1) affected leg fast and (2) affected leg slow. Results show that the detection threshold is approximately 1:1.2. Stance time symmetry gradually changed to symmetry in affected leg fast. Step length symmetry gradually changed to symmetry in affected leg fast.
The f-NIRS is becoming widespread by progress in cost reduction, downsizing, and portability of the measuring equipment. On the other hand, in several research reports, we can easily find a lack of uniformity in using and the fact that each of the experimenter proceeded in one's own way. Thus, we verified how those differences affect to results in the sense of reconfirmation about various measurement conditions and methods that are common-sense in the f-NIRS measurement; for example, a time length of a rest for a task, a presence or absence of binding the cables of probes, and so on. And we conducted comparative evaluation of the results due to formal or informal analysis methods. With reporting their results, we felt about necessity of a certain rules and proficiency skills in the use of f-NIRS.
The advance in semiconductor manufacturing technology has been promoting lower prices and higher performance for microprocessors and sensors. Herewith, it is possible to develop low cost bio-measurement equipment and these applications are expanding. Thus, we started to develop the compact electroencephalograph that is easier to use. The downsizing of the electroencephalograph was possible at a low cost by build-up type hardware structure consists of main module, amplifier module and filter function using software. The brain wave signal that is measured at the amplifier board is converted to data at main module. The processed data is sent to the PC or tablet via Wi-Fi. In this paper, we discuss the technology of the developed electroencephalograph and its applications.
There is an important cohort study indicating that frequent performance of music instrument has the significant effect of reducing the risk of dementia in the elderly. We have been developing a novel electronic musical instrument Cymis (Cyber Musical Instrument with Score), showing that persons with neural or motor impairments such as cerebral palsy can play the piece easily. The aim of the present study is to develop a network system enabling the ensemble of the Cymis. Firstly we found that the elderly can play the Cymis easily under support of a music therapist. Secondly, four university students including two female majoring music and two beginners of music were able to perform ensemble with the Cymis, where two beginners watched guide of performance on the monitor. By measuring time differences in performances of four people, it was indicated that beginners also could perform ensemble with slight time differences against others.
In laparoscopic liver surgery, laparoscopic ultrasound (LUS) is indispensable to understand inner structure such as vessels and tumors. However, LUS is not convenient due to poor operability, and does not provide positional information in the endoscopic view. To address the issue, we have developed both a robotic hand for LUS and a 3D visualization software. In this study, we describe the software which provide 3D ultrasound by scanning LUS. To confirm the system feasibility, an experiment using a polyurethane liver phantom was conducted. Figure shows the reconstructed volume with vessels. The computational time was approximately 50 msec less than typical imaging period of ultrasound.
We proposed a technique of variable window-width of Moving-Average Method to extract only the pulse wave signals from the output signals of radars installed underneath the mattress, which enabled to calculate the heartbeat intervals. We applied a canonical discriminant analysis to classify the four sleep stages using the heart rate variability (HRV) derived from 10 students. LF/HF had a high degree of contribution to discriminate between LIGHT and DEEP sleep, and it was showed that the sleep cycle could be estimated (Figure). For the further improvement, we attempted to introduce a new decision tree analysis using not only HRV but also body movement index and respiratory interval indices.
To prevent heat stroke, we will develop a system to determine presence or absence of a rise in deep body temperature using physiological indices, i.e., heart rate, respiratory rate and body surface temperature. Prior to development, we conducted tests using ergometer for 15 min. with nine male students. We measured three physiological indices and deep body temperature for 15 min. with one-minute intervals after the exercise and conducted linear discriminant analysis by leave-one-out cross-validation. 37.5 degrees of deep body temperature was set as boundary and we classified heat stroke preliminary group from normal one. The sensitivity was 90.5% and the positive predictive value was 47.5%.
In the study of biological effects of ELF electric field, we found that the blood flow changes when the field is exposed to our body. The aggregability of red blood cells (RBC's) in vivo increases right after the field exposure. To elucidate this phenomenon, an experimental study was conducted. Electric field was applied to the blood sample on a slide glass using insulated metal electrodes to make the current density 100 mA/m2 which simulates the current induced inside an adult body with a therapeutic instrument of electric field exposure. As a result, the ratio of the aggregated RBC's increased about 25% in the field exposure. Through this study, the change in the RBC aggregability was confirmed in the well-controlled in vitro measurement. This suggests the possibility that the blood property change is caused not by the physiological change but by the physical change that is observable in the in vitro condition.
An infant-friendly earphone using the cartilage conduction for non-invasive functional brain imaging was developed. The earphone was composed of a piezoelectric vibrator that is firmly glued to a flat round brass panel, with a diameter of 35 mm, to amplify the vibration. The earphone can be attached to the baby head cap, and just mildly touched to baby's pinna. Since sounds are conveyed via both air- and bone-conduction (mainly osseotympanic emission) pathways by the earphone, the enhancement of low frequency component is expected by the occlusion of the ear canal. Clear auditory evoked MEG responses were obtained from awake babies (6-month-old and 8-month-old) as well as adults, using our first prototype flat-panel earphone. Also, the babies did not dislike to wear the developed earphone at all. The earphone enables an experiment of dichotic listening that was quite difficult for awake babies.
Tactile presentation of various hardness/softness feeling of complicated multilayered anatomical structures has been required for the medical robots, because the relationship between psychological and physical multilayer hardness/softness has not been clarified. In this study, the threshold of psychological and physical multilayer hardness/softness was investigated by validating the prediction from the previous study using the psychological engineering approaches and the physical Young's modulus of multilayer. Eleven subjects' fingers touched to both 3.75%(softer) and 5.0%(harder) concentration single-layer gelatin jellies and touched to 5 double layer gelatin jellies of which upper layer was 3.75% and 5.0% jelly, and lower layer were 10.0%, 12.5%, 15%, 20%, and 25% jellies, respectively. After that, subjects were answered whether the specimen had multilayer tactile. The results showed that the threshold of multilayer hardness/softness was consistent with the prediction of the previous research.
Finger manipulation is a basic action of human in our daily lives. The measurement of finger manipulation is important to know person's behavior and support the work. When the finger touches the object, the vibration from contact point occurs. We defined the contact position as the load center in the finger contact area, and estimated finger manipulation by measuring the different speed of the transverse and longitudinal waves. When the direction of the force applied to the finger is different, load center changes between in finger's contact area. In this paper, we investigated relationship between the load center and stroking direction using the pressure measurement sheet. The result of ANOVA and multiple comparison showed a significant difference in the average load center positions.
Electromyogram (EMG) is recorded electrical muscle contraction, mechanomyogram (MMG) indicates cross-sectional area change of muscle, reflect mechanical muscle contraction. By simultaneously measuring both signals, it is possible to multifaceted evaluation of muscle contraction. However, MMG measurement at voluntary movement was difficult. Therefore, the authors developed MMG / EMG hybrid transducer capable of simultaneous measurement of MMG and EMG. This study evaluated MMG and EMG of rectus femoris (RF) and hamstrings using recumbent bicycle of easy load regulation. As result, dMMGbase (baseline of displacement MMG) indicated cross-sectional area change of muscle at pushing down and pulling up of pedal. In addition, EMG and dMMGbase increased with pushing down of pedal in RF, dMMGacc (acceleration dMMGbase) showing muscle contraction force was output simultaneously. Each signal of hamstrings had output that antagonize RF. By simultaneously measuring MMG and EMG at recumbent bicycle pedaling, it was possible to evaluate muscle contraction of voluntary movement.
The aim of this study was to evaluate muscle stiffness during one cycle of pedaling exercises. Electrical stimulation was applied to the vastus lateralis muscle at various clank angles in a resting state and during pedaling exercises. The angles were -30°, +30°, and +90°. The angle of 0° corresponds to top center of the pedal, and the clockwise direction is positive. A mechanomyogram (MMG) was measured with a capacitor microphone. The MMG system was identified using a singular value decomposition method and the poles of the transfer function were calculated. The poles and mass of the vastus lateralis muscle were used to estimate the muscle stiffness. The muscle stiffness increased as the muscle activity increased. In conclusion, it was suggested that muscle stiffness during pedaling exercises changes depending on muscle activity.
Hyperthermia is a cancer therapy using heat and drug to accelerate the death of cancer cells by exploiting its high thermosensitivity characteristics. 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℃. Through application of this method, we developed a wireless temperature measurement system using the change in the magnetic permeability near Curie temperature of FILCT. 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℃ that is placed at 1 cm position above the drive coil, to 43℃ and maintain constant temperature heating at 42.9±0.3℃.
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.
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.
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.
The purpose of this study was to clarify the influence of footwear on the stiffness of the tibialis anterior muscle during walking. Three males participated in this experiment. Electrical stimulation was applied to the common peroneal nerve every two toe-offs while walking in sports shoes, slippers, and socks. Mechanomyograms (MMGs) were measured. The evoked MMG in walking was extracted using a Kalman filter and subtraction of the walking acceleration. The evoked MMG system was identified using a singular value decomposition method, and the natural frequency of the system was calculated from the transfer function. In conclusion, the natural frequency increased in the order of walking in sports shoes, slippers, and socks. It was concluded that the muscle stiffness in walking at toe-off increased in the order of walking in sports shoes, slippers, and socks.
The purpose of this study is to establish a method for identifying the transfer function between the electromyogram (EMG) and mechanomyogram (MMG) in voluntary contraction of the abductor digiti minimi muscle using a system identification method. An MMG and EMG in twitch-like contraction were measured. The measurements were repeated ten times. The EMG was full-wave rectified and then smoothed with a low-pass filter (fc=100 Hz). The smoothed EMG and the MMG were regarded as an input and an output of the system, respectively. The transfer function was identified with the subspace state space system identification method. The transfer function could be approximated with a third-order model for all subjects in five measurements or more. It was suggested that the MMG system was identified in voluntary contraction.
We propose a novel method of recognizing a noise. In recent years, the electrocardiogram (ECG) is widely used not only in the hospital but also in home care and health management situation. However, the measurement of ECG is susceptible to motion noise or other external factors. The noise can cause easily degrade the performance of automatic analyzers and can cause false alarms. In this study, we quantify an irregular disorganized pattern of the noises using attractor analysis. The ECG signal is converted to the two-dimensional time-delay coordinates, and the internal area of the attractor is split up into equal intervals. The irregularity index is defined as the products of the correlation coefficient and the entropy of each area. This index is evaluated using the MIT-BIH arrhythmia database. The result suggests the proposed method is able to classify the ECG or noises.
In indwelling needles, use of thinner needles leads to a greater discrepancy between set blood flow rate and actual blood flow rate. Providing side holes in the indwelling needle is an effective means for increasing the actual blood flow rate without changing the diameter of the indwelling needle. Given this situation, we are seeking theoretical optimization of side holes using computational fluid dynamics (CFD) analysis. The blood removal pressure obtained at each prescribed blood flow rate was determined at the blood removal end. In addition, I defined fluid resistance in order to reconcile the results of the analysis with the experimental results. The results showed that the blood removal flow rate obtained from the CFD analysis conducted on indwelling needles with side holes was largely consistent with the actual blood flow rate obtained from the experiment. Thus, we were able to explore the optimization of side holes from a theoretical standpoint using CFD analysis.
The stress is classified roughly into the eustress and distress. We have developed stress evaluation system using onomatopoeia for stress reduction. We focused on Image conversation used by LINE. Creating an image of onomatopoeia was introduced it into the system. The first purpose of this study was to develop of simple evaluation system using image conversation. The second was to evaluate the system and usefulness of production image. Fourteen male subjects were participated in the experiment using the system for 3 days. After that, they answered the system evaluation test of 17 items in 5-stages. As the result, the system has obtained a high average 3.58 rating however the average of two evaluation items was less than 3. This means that the system needs a more clear feedback and further development.