The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, we present a tethered soft assist experimental system for the hip, incorporating virtual compliant actuator model into the control system. We adjust the parameters of the virtual compliant actuator to generate assistance torques around the hip during walking. Experimental tests for level walking at 1.25 m/s shows that variable stiffness assist is capable of reducing the energy cost...
In this study, we propose a method of prediction of sit-to-stand movement for an assist system. The proposed method enables the prediction of sit-to-stand movement before the buttocks leave the seat. To verify the accuracy of the proposed method, we conducted evaluation experiments on five subjects to determine whether the movement is sit-to-stand or another movement. The evaluation results showed...
A method of monitoring a driver's heart rate using a microwave sensor on a seat backrest is proposed. The heartbeat signal was learned as a template while the car engine idled. This template was used to calculate correlation between observed signals. The proposed method amplifies a weak heartbeat signal and reduces road noise. A basic experiment was conducted on an actual road at low speed. The proposed...
A new method to estimate muscle fatigue quantitatively from surface electromyography (EMG) is proposed. The ratio of mean frequency (MNF) to average rectified value (ARV) is used as the index of muscle fatigue, and muscle fatigue is detected when MNF/ARV falls below a pre-determined or pre-calculated baseline. MNF/ARV gives larger distinction between fatigued muscle and non-fatigued muscle. Experiment...
Since the development of wearable sensor, operating a device can be done by hand gesture based on EMG. However, some operations are not easily assigned by a single gesture, such as gradual volumes. To enable those operation types, we propose an estimation method that exploits the hysteresis loop between the joint angle and measured EMG. We confirm the effectiveness of the proposed method using EMG...
This paper proposes a method to estimate temporally accurate human pulse peaks for noncontact pulse transit time (PTT) measurements. The PTT is considered as a significant diagnostic index for conditions such as blood pressure and arterial stiffness; however, millisecond-order accuracy is required in the determination of each pulse peak. In this study, human pulse waveforms are obtained from wrist...
This study reports pulse transit time (PTT) measurements of two areas of the human body (wrist and ankle) by a single imaging camera. The pulse peaks at both areas were extracted by finite impulse response (FIR) low-pass filtering and phase delay compensation. The interbeat intervals (IBIs) obtained by the camera and a photoplethysmogram sensor were almost identical, confirming the temporal accuracy...
In this study, we discuss a layout of electrodes on a wrist for EMG measurements to recognize hand gestures. Experimental results show that the proposed layout uses only half of the electrodes, but suffers only about 3% drop in recognition rate compared with the conventional layout. Furthermore, we developed a television operating system based on hand gestures, using a wristband-type EMG device with...
Visual color information is thought to affect human perception. This study proposes a master-slave system that performs force feedback compensation control based on the color of the target object. In this system, the ratio between forces exerted during tasks performed on dark and bright objects is used as a compensatory gain in the feedback force. The system is designed to maintain task consistency...
This paper proposes a method for vascular load reduction control that operates in regard to the load on contact points of catheter and blood vessels in catheter insertion. We make an extracorporeal estimation of the load on the contact points, and perform control with a robot arm to reduce the estimated load. We aim to reduce the vascular load through extracting and vibrating action as actually applied...
In this study, we propose a method for estimating fixation distance on the basis of measurements of vergence eye movements. The aim of this approach is to control the lens focus of automatic focusing glasses. To reduce user effort at the time of calibration, the calibration was performed at infinite distance gazing, and the parameters were determined from the premeasured pupillary distance at infinity...
A new method to estimate respiratory signal from thoracic impedance is proposed. To realize battery powered, wearable respiratory monitoring devices, low current impedance measurement techniques are desired. However, under low current conditions, conventional methods to separate cardiac and respiratory signals do not work well as the cardiac signal is much larger than the respiratory signal. In the...
A novel algorithm of collision avoidance path planning, especially for hospital robot, is proposed. The algorithm puts into consideration the movement characteristic of various kinds of disabled person, which are represented by wheelchair user and crutch user here. A model which implies the energy to move to a certain point from present location is introduced for each kind of disabled person. The...
In this study, we discuss indexes that can be used to quantify users' visual fatigue when they watch three-dimensional (3D) visual contents with consumer displays. We discuss two indexes with values that can be calculated by biological signal processing without disturbing the viewing of 3D contents. One is a video-oculography (VOG) index, and the other is an electro-oculography (EOG) index. To clarify...
This paper proposes a help system that would simplify the use of search functions on audio visual (AV) appliances. The proposed help system is equipped with an interface for user interaction that employs a frame-driven dialog model. The frames are designed using common structures extracted by analyzing device functions based on interaction primitives. In addition, the proposed help system estimates...
In this paper, a robot with a dual-shell structure is proposed to improve operability using direct teaching. The dual-shell structure separates the robot arm actuator from the gripper for the operator. Hence, during the teaching process, the robot arm is able to track the motion of the operator and the operability within the arm's movable range can be improved. Furthermore, by inserting an elastic...
Determining the loudest sound level that a person can comfortably tolerate (uncomfortable loudness level: UCL) imposes a strain on people suffering from hearing loss. In the present study, we propose a method of estimating UCL based on auditory evoked potentials (AEPs). Adults with normal hearing (18 men aged 25–56 years) participated in the study. Three tone bursts (S1, S2 and S3; a triplet) of the...
In this paper, we present near infrared spectroscopy (NIRS) signal patterns of subjects when they are focused on specific tasks. We determined that oxygenated hemoglobin in the frontal cortex decreased when the subjects were engrossed in tasks, and we propose an evaluation method for TV commercials based on the results. TV commercials are produced to be as attractive as possible and can increase consumer...
This paper proposes a target estimation method based on users' operation history in which the operation history is assumed to be based on the label-following strategy. The proposed method is applied for AV appliances, and the effectiveness of the method is assessed. A target function is estimated from the semantic similarity between the collection of words of the menu items and labels of remote controller...
A scheme of direction-of-arrival (DoA) estimation is proposed based on 2D-ESPRIT algorithm with multiple combinations of subarrays. The pairs of elevation and azimuth angles are obtained by applying the standard 2D-ESPRIT algorithm to three combinations of two set-of-subarrays in a 7-element hexagonal array. The pairs obtained from one of three combinations are permuted according to the descending...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.