医療の効率化・最適化を図るために,健康を自己管理して医療費を抑制する方向に進んできている。このパラダイムシフトには患者側と医療側に信頼できる有益なデータをタイムリーに提供することが必要であるが,技術革新によりスマートなパーソナル・ヘルスケア・システムが実現可
Genomic/Biological information has been measured over a wide range of spatial resolution: 1) micro-size level (e.g. gene expression, DNA methylation, chromosomal territory), 2) single cellar level (e.g. intracellular transmission, signal processing between protein and membrane), 3) small cell population level (e.g signal processing in cells), 4) tissue-size level (e.g. development or metastasis of tumor), 5) whole-body level (e.g drug delivery system).
Data acquiring technique using fluorescence imaging has been intensively studied. The fluorescent probe binds specific DNA sequence in nucleus or specific protein in a cell, and the probe labels target location specifically. Furthermore, improved fluorescent light of longer wavelength provides imaging information on deeper parts of the whole body.
This paper focuses on the fluorescence imaging methods such as super resolution fluorescence microscopy, fluorescence in situ hybridization, and deep imaging. Both of the microscopic imaging and the macroscopic imaging are discussed in detail.
Mid-infrared lasers having the wavelength of the vicinity of 3µm are considered as effective for treatment of biomedical tissue because of the strong absorption to water. The drawback of 3µm laser is the difficulty to propagate the silica optical fiber. We have reported the optical fiber tip oscillation laser that has a Er,Cr:YAGG laser crystal and coupling lenses on the tip of a silica fiber outputs 2.8µm laser pumped by laser diode (LD). In this paper, we demonstrated a lens-less laser head for the optical fiber tip oscillation. By using the silica optical fiber having a core diameter of 105µm and a numerical aperture (NA) of 0.12, the average output power of 1.0W was achieved from the lens-less laser head during a squire wave modulation for suppressing heat generation.
In hemodialysis, blood is removed from the body through a vascular access (VA) and the filtered blood is returned to the body through the VA. The VA is made by joining an artery and a vein. This connection increases the amount of blood flow into the vein. A dialysis needle, which punctures into the VA, causes endothelial injury. This injury triggers leukocyte adhesion and the proliferation. This phenomenon promotes a thickening of the VA that leads to stenosis. In the clinical field, there are reports that the rapid blood removal vibrates the VA which has the stenosis. There is the possibility that self-excited oscillation has occurred. If the stenosis induces the oscillation, it is possible to estimate the stenosis by detecting the oscillation. In this study, we performed the experiment using a simulated VA circuit made of thin silicon tube (collapsible tube). The stenosis was set the lower end of the collapsible tube in the circuit, and the external pressure of the collapsible tube was controlled to vary the transmural pressure. Experimental results demonstrated that when the stenosis ratio was high, the oscillation of the tube occurred. Also, higher stenosis ratio decreased the frequency of the oscillation and increased the peak power of that. These results suggested that the stenosis could be estimated by analyzing the power spectrum of the oscillation frequency.
Several speckle tracking methods have been proposed for noninvasive and quantitative evaluation of tissue motion. Since the low temporal resolution causes a large myocardial motion in the elevational direction and a large deformation, two-dimensional (2D) speckle tracking at a high frame rate is desirable for accurate estimation of myocardial contraction and relaxation. 2D speckle tracking at a high frame rate requires a high computational load, and the large suppression of calculation time is, therefore, essential for clinical use. In the present study, we investigate the minimum frame rate required for the estimation of myocardial contraction and relaxation. Furthermore, we employ a parallel computing principle using a graphical processing unit (GPU) system with 2,496 streaming processors to decrease the calculation time effectively. The employment of a parallel computing principle with a GPU system successfully decreased the calculation time to 1/50 of that using a desktop PC with a CPU. When the number of tracking points is 64, the calculation time was decreased to 28.7 s for the estimation during 1 s at a frame rate of 287 Hz, indicating that the proposed method with a GPU system has a potential to realize a near real-time estimation of myocardial contraction and relaxation.
Previous studies have reported that gaze influences on body sway direction induced by neck dorsal muscle stimulation (NS) and that the strength of the gaze influence differs from a subject to another. In the present study, to investigate the reason for the difference, we analyzed a relationship between the strength of the gaze influence and the stability of subjective straight ahead. Seventeen subjects participated in the following two sets of measurements. First, the direction of body sway induced by NS was measured at different gaze orientations. Then, subjective straight ahead was measured. Depending on the strength of the influence, the subjects were classified into two groups. Five subjects were deemed to have strong gaze influence while the other twelve showed weak influence. A comparison between the two groups revealed a significant difference in the stability of the measured subjective straight ahead, suggesting a relationship between the strength of the gaze influence and the stability of the subjective straight ahead.
Eye-gaze input interfaces have been proposed. A main purpose of these systems is communication aid for the severely disabled. We have previously developed a text input system using eye-gaze based on an image analysis under natural light. This input system is employed dwell time based method to select indicators. By employing voluntary (conscious) blink based method rather than dwell time as indicator selection, it is expected to increase the efficiency of text input. We propose a new text input system based on eye-gaze and voluntary blink method. The newly added eye blink measurement function is necessary to realize high time resolution. Furthermore, each of the eye-gaze and eye blink measurements is very time consuming. If these measurements are performed sequentially, it is difficult to finish calculation within required time for real-time processing. To cope with this problem, we realize the concurrent processing of these measurements by multi-thread structure. We conducted an examination of nine subjects to input Japanese text using our new input system. All of nine subjects could complete the task of Japanese text input. Based on a result of this experiment, we evaluated our new system.
Techniques using electroencephalography (EEG) based brain computer interfaces (BCIs) have been developed and are eagerly anticipated as novel interfaces for controlling some electric devices including power wheelchair. In addition, smart glass technology also has been developed and anticipated as new wearable interfaces. In this study, we proposed an intuitive control system for a power wheelchair which is composed of a simple EEG recorder, a smart glass and a microcontroller. In this system, the power wheelchair moves straight ahead when a user concentrates, stops when the user blinks, and turns left or right tilt his/her neck to the left or right, respectively. A β/α ratio as an indicator of the concentration and a blinking are detected from a raw EEG signal, and the tilting neck is detected by an acceleration sensor in the smart glass. Furthermore, the β/α ratio is induced by a visual feedback which is displayed on the smart glass. Our results show that the system successfully worked for twelve subjects, and the visual feedback have the effect to induce the β/α ratio in specific concentrating states.
Magnetic resonance imaging (MRI) has been used in clinical as major tomographic inspection with CT scans. Compared with CT, MRI has a number of advantages for example no radiation exposure. However, MRI has also disadvantages e.g. large size, high cost and never use to patients who have implant devices or metals because have to use strong field. Therefore, ultra-low-field MRI (ULF-MRI) has attracted attention because of usage of ultra-low fields such as earth field about 40∼50 μT. But there is a fatal weakness of ULF-MRI which SN ratio decreases. In this paper we show that spin-exchange optical pumping (SEOP) can increase 131Xe nuclear magnetic resonance (NMR) signals. We also show that SEOP is possible at very low power LASER with field in pulse sequence of NMR measurement.
Electrocardiogram (ECG) provides useful information for the diagnosis of cardiovascular disease. In capacitive-coupled ECG sensing, electrostatic artifact and movement artifact become serious problems. In particular, low frequency components such as T wave of ECG are susceptible to the artifacts. To obtain clear ECG, high stability is required for the electrocardiograph using capacitive-coupled electrode. In this study, tolerance of capacitive wearable chest-belt electrocardiograph was tested for the electrostatic and movement artifacts. A constant electrostatic artifact was discharged repeatedly on three types of electrode having different shielding configurations, and their transient responses were compared in terms of deviation area, transient slope and recovery time. The results revealed the best tolerance of doubly-shielded five-layered electrode. The best performed five-layered electrode was used for exercise tolerance test. Then, detection rates of R-wave and T-wave of ECG, and standard deviation of base line of the recordings were calculated as tolerance indices and compared to those obtained by commercial disposable electrode. Although R-wave detection rate of the five-layered electrode decreased by 2.0%, the rate of T-wave was comparable to those of the disposable electrode. Furthermore, the standard deviation of the base line was significantly smaller than that of the disposable electrode (p<0.01).
Brain-Computer interfaces (BCIs) have been studied by using transient visual evoked potential (VEP) with various blinking stimuli. We examined to change the phase and the frequency of the blinking light with variable onset interval and changing luminance in order to realize multiple choices in the BCI using transient VEP. However, the number of the multiple choices was limited to four choices. Therefore, we examined to change the luminance of the blinking stimulus in order to increase the number of multiple choices. In this study, we try obtained VEPs based on synchronous addition method, and verified effects of changing luminance and lighting interval of indicators. In addition, we develop multiple choices interface by using blinking light with variable onset interval and changing luminance. In this paper, we report the possibility of multiple choices by experiment of estimate for proposed methods.
The eye gaze input is attracting attention as a method for operating an information device with hands-free. However, it is difficult to use gaze input system over a small screen such as a smart device because eye gaze input method must accurately measure gaze positions. In order to solve this problem, we have proposed the eye-glance input method to use operating a small information device like smart phone. The eye-glance input method is able to input multiple-choice using oblique direction reciprocating movement. Accordingly, enabling an input operation that is independent of the screen size. In this paper, we report result of evaluation experiment of numbers inputting of using our developed a Multiple-choice eye-glance input system that utilized electrooculography that amplified via an AC coupling. As the result of experiments, it was found that the average of the input success rate and the average of the input character number per a minute in real-time eye-glance input at the experimental display design was 91.5% and about 15.2 character for 10 subjects.
Our previous studies have proposed Eye Glance input system that is used to only combination of contrary directional eye movements instead of eye gaze input. It was measured by EOG, but constraint and dedicated apparatus are brought into question. So we proposed non-contact measuring method using camera to measure eye movement. We enabled the eyes movement measurement with internal camera and USB camera by using optical follow in Open CV. In this study, we improve algorithm to measure and give visual feedback to subjects in real time. Then we researched the algorithmic effectiveness and influence by feedback.
In the elderly, various physical functions decline with aging. Therefore, quantitative assessments of ambulatory function play a very important role in rehabilitation for the elderly. However, special equipment such as a three-dimensional position analyzer is necessary for accurate measurement of gait. Because these equipment is complex and expensive, they are unavailable for routine gait assessments of the elderly. In this study, we developed a posture analysis system based on a small information terminal to provide a tool that can be used for elderly gait assessment in research and clinical practice. There is another problem that pedometers designed for healthy people cannot count the number of steps accurately when the elderly walk slowly. We devised a new pedometer algorithm for smartphones that detects the number of steps during slow walking.
A diet is possible by various methods now. Recently, the system which enables a partial thin figure by using ultrasonic wave and laser is developed. However, these methods are at risk of a burn or the internal hemorrhage. Therefore, the establishment of the safe method not to destroy a fat tissue is expected. In this study, warm and cold stimulus and vibration stimulus were given in the thigh posterior surface, we examined subcutaneous fat changes over time. We aimed at the establishment of the possible method of the simple and safe diet and fat movement using these external stimulus.
In this paper, we propose an eyeblink feature parameter for automatically classifying conscious and unconscious eyeblinks. For the feature parameter, we focus on eyeblink waveform integral values, which are defined as a measurement record of the progression of eyeblinks. Previous studies have used duration time and waveform amplitude as the feature parameters. The integral values, on the other hand, have characteristics of both of those feature parameters. We obtain these parameters using a National Television System Committee format video camera by splitting a single interlaced image into two fields. We use frame-splitting methods to obtain and analyze the integral value of the eyeblink waveform. We experimentally compared the feature parameters to automatically classify conscious and unconscious eyeblinks. Duration time and amplitude did not significantly differ in some subject cases; however, we confirmed a significant difference when using the integral value. Our results suggest that eyeblink waveform integral values are effective for discriminating conscious eyeblinks. We believe that the integral value of the eyeblink waveform is applicable to an eyeblink input interface.
This paper proposes a contour-line-based feature and analyzes its relationship with blood pressures. The proposed method extracts an existence and a variation property from the contour lines drawn on the waveform. The existence property is the total length of the contour line in the waveform. The variation property is the number of intersection points of the waveform and contour lines. The proposed feature is a quite different from the conventional feature, which is extracted from peak wave height. We made a comparative experiment whose participants are 71 females with ages ranging between 18 and 94 years. The result showed that the proposed feature was obtained highly correlation with the blood pressure than the conventional peak feature.
We propose a novel road monitoring system named YKOB (Your Kinetic Observation Bike) based on participatory sensing. YKOB collects acceleration signals using smartphones worn by cyclists, and analyzes the collected signals to investigate road surface condition. When a bicycle passes on a bump or a dimple, its wheels vibrate. The vibrations are transmitted to the smartphone via the bicycle frame or the cyclist body, and registered as acceleration signals. Conversely, by analyzing the acceleration signals we can estimate the road surface condition. There are mainly two research issues in this system. The first issue is that the acceleration registered at the smartphone includes cyclist motion signal as well as road surface signal. The second issue is that it is necessary to distinguish abnormality of road surface from artificial differences in level, such as a difference between streets and sidewalks. We developed a signal separation algorithm based on Independent Component Analysis (ICA) to solve the first issue. We also developed a bump classification algorithm using Real Mother Wavelet (RMW). These two proposed algorithms were evaluated with 640 trials in total of experimental data conducted by eight cyclists. The classification accuracy of 0.68 validates the simultaneous utilization of our proposed algorithms.
Ensemble inverse reinforcement learning from semi-experts' behavior is proposed. In many inverse reinforcement learning (IRL) problem, the expert agent which has ideal rewards for achieving the goal is supposed to be existing. However, in real world problem, the expert is not always observed. Moreover, the estimated reward function includes the bias depending on its inherent behavior if the reward for achieving the goal task is estimated from one agent. In order to overcome the limitation of IRL, we apply Adaboost, one of ensemble and boosting approach, to IRL and integrate estimated reward functions from semi-expert agents. To confirm the effectiveness of the proposed method in the grid world including incomplete areas, we compared the results of reinforcement learning using estimated reward functions and integrated reward function by simulation. The simulation result shows the proposed method can estimate the reward adaptively.
In this paper, we discuss estimation accuracy of a nano-satellite(HIT-SAT) spin rate using received power strength data at about 830 km away two locations. The estimation method of received data at a single location was announced. It was difficult to collect a long-term data of a low orbit nano-satellite. Therefore, short-term data at two locations is proposed based on estimation accuracy of satellite spin rate. It is found that the proposed method by using estimating spin rate is highly accurate in spite of Additive White Gaussian Noise.
This letter proposes an accurate association method in multiple target tracking for a single pulse Doppler radar interferometer. The proposed method is an extension of a conventional nearest-neighbor association method by use of radial velocity information acquired in interferometric positioning processes. Numerical simulations clarifies that the proposed method achieves better accuracy and noise tolerance than conventional methods.