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Papers - Ogawa, Ami

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Identification of Disease-Specific Turning Movement Hallmarks: A Systematic Review towards Establishment of Disease Screening Algorithm

A Ogawa, T Takeda, K Yoshino, H Iijima

medRxiv, 2022.05. 27.22275714 (Cold Spring Harbor Laboratory) 2022

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非接触変位センサとばねを用いたフォースプレートの開発

川�ア裕太，小川愛実，高橋英俊

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集 2022, B-5-1 2022

ばね構造とセンサ素子を用いた 4 軸フォースプレート

川�ア裕太，小川愛実，高橋英俊

ロボティクス・メカトロニクス講演会講演概要集 2022, 2P1-T02 2022

Force Plate with Simple Mechanical Springs and Separated Noncontact Sensor Elements

Y Kawasaki, A Ogawa, H Takahashi

Sensors 21 (21), 7092 (Sensors) 21 ( 21 ) 2021.11

ISSN 14248220

This paper reports on a force plate (FP) using mechanical springs and noncontact distance sensors. The ground reaction force (GRF) is one of the factors for clarify biomechanics, and FPs are widely used to measure it. The sensor elements of conventional FPs are mainly strain gauges. Thus, the mechanical properties of FP depend on the sensor element performance. If the FP performance must change, we must redesign the FP, including changing the sensor elements. Here, we proposed an FP that uses a measuring principle based on simple springs and noncontact sensors. The shape and performance of the proposed FP are expected to change easily. As a prototype device, we designed and fabricated an FP installed with 12 springs and four sensors for human walking. A planar coil and magnet were used as the sensor elements, and the sensor output was proportional to the vertical and horizontal displacements. The FP resonance frequency was 123 Hz, which was larger than the required specification. The calibration experiments showed that vertical and horizontal forces and moments could be measured independently. The FP’s resolutions were 1.9 N and 1.4 N in the anterior–posterior and vertical directions, respectively. Furthermore, the fabricated FP measured GRF similarly to the commercial FP when a human walked on the plate. These results suggest that the proposed method will be helpful for FPs with custom-made requirements.

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Staircase design for health monitoring in elderly people

A Ogawa, H Iijima, M Takahashi

Journal of Building Engineering 37, 102152 (Elsevier {BV}) 37 102152 - 102152 2021.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 2352-7102

The need for early detection and intervention for age-related health deterioration via home-based health monitoring systems is growing with global population aging. Health deterioration is typically evaluated using questionnaires, but obtaining frequent responses is difficult. Although stair walking involving a high physical load is suitable for assessing health deterioration, uniform assessment using home-based systems is difficult because different stair designs result in different movements. There is currently insufficient research on differences in evaluation performance between different stair designs. The current study aimed to develop an objective index to assess difficulties in activities of daily living (ADLs) as an indicator of health deterioration by observing stair walking, and to investigate the effects of stair dimensions on the relationship between the index and health deterioration. We hypothesized that knee joint positions during stair ascent would be associated with health deterioration, and developed the “Stepping in Level” index, reflecting the knee joint position when stepping in, obtained using a markerless depth information-based system. Seventy elderly people ascended two types of stairs (steep: 33.7°; shallow: 28.2°) and completed a questionnaire regarding ADL difficulty. We used a generalized linear mixed model to investigate the ability of “Stepping in Level” to explain ADL difficulty. The results revealed that “Stepping in Level” was able to explain ADL difficulty, and steep stairs were more suitable than shallow stairs for assessment. Our system enables daily assessment of difficulty in ADLs and detection of subtle changes in daily life. The current findings could inform design guidelines for health monitoring.

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Optimal Waiting Position of a Home Robot for Risk Communication Considering Behavior Patterns of an Occupant

A Mita, K Watanabe, A Ogawa

8th Asia-Pacific Workshop on Structural Health Monitoring, APWSHM 2020, 211-216 (Materials Research Proceedings) 18 ( 2021 ) 211 - 216 2021

Research paper (international conference proceedings), Joint Work, Accepted, ISSN 9781644901304

The risk communication in a home between a home robot and an occupant must be smooth in a way that the home robot does not disturb the occupant lives. In this paper, we propose a new method to determine the optimal waiting position considering the personal space and the obstacles such as furniture and the occupant’s walking patterns. It is shown that the distance to the wall from the occupant in the direction of the home robot and the standing or sitting posture affect most on the personal space. Furthermore, this personal space is dependent on each individual preference. The performance of the proposed method is much more feasible compared with those obtained in our previous approach.

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Extraction of Parameters for 90-degree Turn Prediction Using the IMU-based Motion Capture System

A Ogawa, K Takeda

Materials Research Proceedings 18 (Materials Research Proceedings) 18 ( 2021 ) 241 - 248 2021

Research paper (international conference proceedings), Joint Work, Accepted, ISSN 9781644901304

Against the increasing number of single households, we have been proposing the “Biofied Building” that provides a safe, secure, and comfortable living space for a resident using a small home robot. The robot can be used for real-time sensing of the resident’s position and behavior. On the other hand, for further use of the robot, such as choosing a path that does not disturb the resident, a phase to predict the resident’s behavior is necessary. Walking, which is one of the most basic activities of daily living, is often targeted in studies of motion prediction. However, most of them deal with steady walking, even though walking in daily life includes unsteady walking such as the turning motion. Therefore, the purpose of this study was to extract the prediction parameters to construct a prediction method for the unsteady 90-degree turn. In this study, we explored the effective prediction parameters for 90-degree turns based on the measured data using the inertial measurement unit (IMU) based motion capture system aiming to introduce the prediction of unsteady walking to the “Biofied Building”.

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Changes in Center of Mass during Preliminary Motion for Prediction of Direction Change

N Sugimoto, A Ogawa, A Mita

8th Asia-Pacific Workshop on Structural Health Monitoring, APWSHM 2020, 287-293 (Materials Research Proceedings) 18 ( 2021 ) 287 - 293 2021

Research paper (international conference proceedings), Joint Work, Accepted, ISSN 9781644901304

In recent years, the number of single elderly people has been increasing, and the needs of residents have been diversifying. Towards these backgrounds, we propose the concept of "Biofied bulding". The aim of Biofied Building is to create living spaces where residents can live safely, securely and comfortably. Small robots are used as an interface between residents and living space in Biofied Building. The aim of using robots is to sense the position and movement of residents in real time and providing feedback to them. However, the present control systems of the robot do not have enough functions to estimate the risk of accidents such as falls and choose the pathways which do not disturb residents. Therefore, the purpose of this research is to recognize and predict human behavior in a living space by using a robot to realize Biofied Building. In particular, we focus on the direction change motion, which is an important behavior in a living space, and extract the prediction parameters. In particular, it is reported that the direction change motion account for about 20% of gait during the daily life. Therefore, our research group decided to focus on direction change motion. In this study, we focused on the center of the head to extract parameters for prediction of the direction change motion. There are features in the velocity change of the center of the head compared with straight-line gait. There was a velocity amplification of the opposite direction of the direction change before the start of the motion. It is assumed that the shift of the center of mass make it to easier to step out to the direction of the turn.

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立ち上がり動作の質的評価

小川愛実

生体医工学, 541-541 (Japanese Society for Medical and Biological Engineering) Annual59 ( Abstract ) 541 - 541 2021

ISSN 1347-443X

Assessment systems of people's daily health are getting attention with the global population aging. This study proposes a qualitative evaluation method for the sit-to-stand motions which are frequently performed in daily life but are also highly challenging.Even if the amount of activity, which is easy to be measured, is appropriate, the motion might place an excessive load on a specific part of the body and damage. Thus, it is necessary to design an ideal motion in which the load is distributed to the entire body.Mechanical energy transfer efficiency has been proposed as an index to show the optimality of the motion, but it is limited to a limited evaluation using average or peak values and lacks a temporal element. This study proposes a new index that quantitatively evaluates the continuity of sit-to-stand motions by focusing on the temporal changes of parameters during the motions.

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センサ素子とばねに分離した可搬型フォースプレートの開発

川�ア裕太，小川愛実，高橋英俊

ロボティクス・メカトロニクス講演会講演概要集 2021, 2P2-I01 (The Japan Society of Mechanical Engineers) 2021 2P2-I01 2021

Ground reaction forces (GRF) are one of the important issues to investigate the kinetic characteristics of motion. In general, force plates, which are composed of a plate and force sensors, have been used for measurement of GRF. The measurement method will be useful for various types of walking situation and other animals. However, to specialize the force range for such targets, it is necessary to redesign from the force sensor in each case. Here, this paper presents a two-axis force plate with planar coils as the sensor elements and mechanical springs. By supporting the plate with springs and measuring the displacement of the plate with non-contact sensors, the mechanical performance does not depend on the sensing elements. Therefore, the proposed device realizes it easy to change the force range by replacing the springs. The fabricated device was evaluated in terms of sensitivity and position error.

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ESTIMATION OF THE OPTIMAL WAITING POSITION OF A HOME ROBOT BASED ON THE BEHAVIOR PATTERNS OF RESIDENTS TO FACILITATE HUMAN-ROBOT COMMUNICATION

Keita WATANABE, Ami OGAWA, Akira MITA

Journal of Architecture and Planning (Transactions of AIJ) (Architectural Institute of Japan) 85 ( 778 ) 2529 - 2538 2020.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 1881-8161

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Prediction of 90-degree turn using kinematic parameters for implementation of home robot

K Takeda, A Ogawa, A Mita

Journal of Environmental Engineering (Japan) 85 (778), 1027-1036 (Architectural Institute of Japan) 85 ( 778 ) 1027 - 1036 2020.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 13480685

Presently, social trends are indicating that single elderly households are increasing while lifestyles are diversifying. This paper proposes the Biofied building concept. In Biofied buildings, home robots provide a safe, secure, and comfortable space for residents. The objective of introducing robots is to sense a resident’s position and movement in real-time. However, with the existing system, it is difficult to prevent unexpected accidents and control robots without disturbing the residents. The objective of this study was to incorporate the motion prediction phase into the system and realize more natural spatial control using robots.

Although a simple motion prediction method based on dynamics using system identification has been proposed by a previous study, this cannot be applied to non-steady motion. Hence, it is necessary to extend the system such that it can be applied to various behaviors observed on a daily basis because the nonlinear behavior is not versatile. Particularly, with regard to walking motion, it has been reported that more than 40% of walking motions in daily life are non-steady, and the 90-degree turn accounts for approximately 20% of non-steady motions. Thus, the 90-degree turn was selected as the prediction target, because it is a basic non-steady walking motion and the most essential motion in daily life.

This study investigated the effectiveness of IMU sensors in measuring movements with complicated posture control. Notably, these sensors are inexpensive and not restricted by the measurement environment; therefore, the proposed method was developed based on data obtained using IMU sensors.

The kinematic parameters extracted in the preliminary experiment are useful for predicting the 90-degree turn by comparing steady walking to the 90-degree turn. Through comprehensive observations, the yaw and roll of the head and upper trunk, and the acceleration of shoulders and shanks, were extracted as the prediction parameters.

The 90-degree turn, which was performed at the subject’s own time and according to their free will, was measured to validate the prediction of parameters under the condition wherein the environmental and mental effects are eliminated. The prediction method was developed using the threshold defined by the amplitude during steady walking. The proposed method was evaluated by considering the prediction accuracy and prediction time. The fastest prediction time of 0.85 seconds was that of the yaw angular velocity at the head, and it was possible to predict it at least one step earlier.

Finally, the dependence of parameters on environmental factors was verified by conducting the same experiment at a corner. Compared with the previous experiment, only the response of the yaw angular velocity at the head was significantly faster, which suggests that this parameter depends on environmental factors. The yaw angular velocity at the head was the best predicted parameter with 100% success in each case. Hence, the motion is more likely to be predicted when the prediction time is longer, because the 90-degree turn is often performed at corners.

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Research on Motion Prediction in a House using a Markerless and Non-contact Sensor

Y KIMURA, AMI OGAWA, A MITA

日本建築学会技術報告集 (Web) 26 (63), 793-797 (Architectural Institute of Japan) 26 ( 63 ) 793 - 797 2020.06

Research paper (scientific journal), Single Work, Accepted, ISSN 13419463

Biofied building is a building system that provides safe, secure and comfortable space for residents using a robot. The robot acquires the motions and positions of residents. However, it is difficult to control the robot not to disturb the residents’ activities. The purpose of this research is to incorporate motion prediction in addition to motion recognition. Many of the conventional methods use RNN (Recurrent Neural Networks), which is difficult to implement due to the necessity of big data and large calculation cost. Thus, we aim to propose a simple motion prediction method using a human body model based on dynamics.

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PATH PLANNING IN RESIDENTIAL SPACE OF HOME ROBOT INCORPORATING WAITING BEHAVIOR

Ami Ogawa

AIJ Journal of Technology and Design (AIJ Journal of Technology and Design) 26 ( 62 ) 407 - 411 2020.02

Research paper (scientific journal), Single Work, Accepted, ISSN 13419463

© 2020 Architectural Institute of Japan. All rights reserved. We have been suggesting “Biofied Building” that provides the resident’s healthy life by introducing a small sensor agent robot into the house. The robot acquires the physical information of the resident and also acts as a communication robot. In the conventional motion flow, the robot always keeps following the resident. In this method, there are concerns about the risk of collision accidents with the resident or furniture and discomfort due to the behavior of the robot. Thus, we propose a path planning method incorporating waiting behavior in the motion flow of the robot in this research.