Development of Learning System to Support

for Passing Steps of Wheelchair

Kotone Sakiyama

, Yukie Majima

and Seiko Masuda

Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, Osaka, Japan

Graduate School of Informatics, Osaka Metropolitan University, Osaka, Japan

Keywords: Learning Support, System Development, Wheelchair.

Abstract: Recent aging of the population has led to an increased number of persons requiring assistance and a shortage

of caregivers. Wheelchairs are often used for transportation by people who require assistance, but they must

use appropriate operating techniques because they can easily impose burdens on caregivers when climbing

over steps. Therefore, for this study, an educational system was developed based on issues elucidated by

conventional educational methods and earlier research. Assistive technology evaluation in this system is

performed from the perspective of a passenger's riding comfort by measuring and analyzing the wheelchair’s

degree of tilt and vibration level using a sensor. The system provides a learner with feedback for adopting an

appropriate operating posture based on the evaluation results. This system can engender efficient learning by

quantitatively measuring and presenting the learner's level of proficiency and by providing immediate

feedback according to the user’s proficiency level.

1 INTRODUCTION

In recent years, the population in Japan has been

aging rapidly: as of October 2018, the population

aged 65 and over numbered 35.58 million. The ratio

of aged persons, as a percentage of the total

population, was 28.1% (Cabinet Office, 2018),

representing an increase of 6.0% from 22.1% during

the prior decade (Cabinet Office, 2008). That increase

in the number of persons requiring assistance

(Cabinet Office, 2017) and the shortage of caregivers

(Ministry of Health, Labour and Welfare, 2021)

accompanying the aging population have come to

pose major difficulties for Japan.

Wheelchairs are extremely common assistive

devices for people who need caregivers. Of course,

wheelchair mobility requires appropriate caregiving

techniques so that caregivers do not feel burdened

even if they are elderly or female. Particularly,

climbing over steps in a wheelchair requires lifting of

the front and rear wheels, which can impose heavy

burdens on a caregiver. Accidents such as falling

down and loss of riding comfort can also occur

because of inappropriate wheelchair assistance.

Therefore, caregiver education for appropriate

wheelchair assistance skills must be provided.

In recent years, asynchronous caregiver education

including e-learning and video materials has become

possible because of the rapid spread of online

education. Nevertheless, many caregiving skills

involve tacit knowledge such as how to apply force

and how to move the body. Therefore, quantitative

evaluation of improvement in the skills of unskilled

caregivers (unskilled caregivers) in asynchronous

education is difficult.

For this study, we developed a system that uses

sensors to evaluate wheelchair assistance skills

quantitatively, especially when climbing over steep

steps. The system educates non-skilled users about

the appropriate operation of wheelchairs.

2 WHEELCHAIR ASSISTANCE

EDUCATION SYSTEM

What should be done to help non-skilled workers

acquire appropriate operation skills through

asynchronous education? We can review some

challenges of conventional asynchronous education

in the course of education.

Sakiyama, K., Majima, Y. and Masuda, S.

Development of Learning System to Support for Passing Steps of Wheelchair.

DOI: 10.5220/0011772500003414

In Proceedings of the 16th International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2023) - Volume 5: HEALTHINF, pages 497-501

ISBN: 978-989-758-631-6; ISSN: 2184-4305

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

497

2.1 Functional Requirements

During current nursing and caregiving education,

most teaching materials that particularly address

wheelchairs are based on videos and texts. Evaluation

of learning is based on the number of times the

material is viewed or a test to confirm knowledge

retention. Nevertheless, the degree of actual

improvement of skills is not evaluated quantitatively.

It therefore remains unclear whether students have

acquired the appropriate operating techniques, or not.

To resolve this difficulty, Huang et al. (2014)

proposed a self-study support system that extracts the

wheelchair transfer techniques and skills of skilled

nurses, teaches them to learners, and evaluates them

using a Kinect™ motion sensor (Microsoft Corp.).

Later, Nakagawa et al. (2015) proposed a skill

teaching system that emphasizes skill teaching and

which evaluates skills using a similar sensor. They

reported that this system enables learners to

understand their proficiency level quantitatively and

to learn more efficiently than the conventional

teaching by video, voice, or text. Based on those

earlier studies, we believe that an effective

educational system that is more effective than

conventional teaching methods requires a teaching

function, a sensor-based measurement function, and

an evaluation function that evaluates wheelchair

assistance skills quantitatively.

Compared to conventional video-based or text-

based teaching methods, the sensor-based technology

teaching system provides immediate feedback to the

learner, which helps the learner to visualize the skill.

However, previously described systems (Huang et al.,

2014; Nakagawa et al., 2015) require special

equipment and personnel with specialized knowledge

to operate the equipment, which makes learning

difficult. By contrast, this system will enable

unskilled users to learn proper wheelchair operation

using a smartphone (iPhone; Apple Corp.), a common

device, for skill measurement and using an interface

designed to require no complicated operations.

2.2 Technical Evaluation

Preventing a decrease in wheelchair users’ comfort

and reducing burdens on caregivers when operating

wheelchairs are necessary. Factors reported as

reducing riding comfort include increased wheelchair

movement speed (Tanaka et al., 2006), large

gradients when ascending or descending a ramp

(Yamada et al., 2004), and strong bumping when

passing over a step (Narisawa et al., 2001).

Particularly, the lifting angle of the wheelchair

and the vibration felt by the user are regarded as

affecting the ride quality, especially when the

wheelchair is lifted up and down, because the

operator stops near a step and starts the operation

when climbing over a step. Noto and Muraki (2016)

analyzed the relation between the caregiver's posture

during the operation, the wheelchair trajectory, and

the caregiver's subjective evaluation. Results clarified

that increased leaning of the wheelchair when the

front wheels are lifted when climbing over a step can

decrease the user’s riding comfort. Sawada et al.

(2007) specifically examined the vibration level,

which is an index of vibration felt by the human body,

and analyzed the vibration level of a wheelchair when

climbing over a step. Results clarified that the

vibration at frequencies of 20–30 Hz generated in the

vertical direction affect the user’s riding comfort.

For this study, based on methods used for earlier

studies, we use the tilt of the wheelchair body when

the front wheels are lifted and the vibration level

during wheelchair operation as technical evaluation

indices for surmounting a step.

2.2.1 Tilt of Wheelchair when Lifting Front

Wheels

When climbing over a step, the tilt angle of the

wheelchair relative to the ground (the shaded area in

Figure 1) reaches its maximum when the front wheels

are lifted. This angle is measured by a level sensor

attached to the side of the wheelchair.

Figure 1: Wheelchair tilt and sensor.

2.2.2 Vibration Level during Wheelchair

Operation

The vibration level is an index to evaluate the effects

of vibration on the human body. The vibration level

is calculated by obtaining the frequency-weighted

acceleration run-time value of the measured

acceleration with vibration sensory correction (Figure

HEALTHINF 2023 - 16th International Conference on Health Informatics

498

2), as defined in JIS C 1510 (Japanese Standards

Association, 1997).

The frequency-weighted acceleration run-time

value (a

) is obtained using the following equation,

where the vibration acceleration run for the frequency

i Hz component is a(i) and the relative response at

frequency i Hz is C

(i).

𝑎







𝛴



𝑎



𝑖





















⁄

(1)

The vibration acceleration running value a(i) is

obtained using the following equation, where G(i) is

the power spectrum G(i) of the components of the

fundamental frequency Δf and frequency i Hz of the

frequency analysis of the vibration acceleration

response.

𝑎



𝑖





𝛥𝑓𝑥𝐺



𝑖



(2)

By substituting equation (2) into equation (1), we

obtain equation (3).

𝑎







𝛴



𝛥𝑓𝑥𝐺



𝑖



















⁄

(3)

As a result, vibration level (4) is obtainable using

the following equation.

𝐿



20𝑙𝑜𝑔



𝑎



𝑎



⁄

(4)

 10log 



𝛴



𝛥𝑓𝑥𝐺



𝑖

















/𝑎







Figure 2: Human body vibration sensory compensation.

2.3 Technical Instruction

Teaching is performed by providing the learner with

information (challenging points and advice) inferred

from values of the evaluation indices. The teaching

information for the wheelchair step climbing

operation is based on the appropriate operating

posture (Figure 3) as identified by Noto et al. (2016).

Figure 3: Operating posture when wheelchair climbs over

steps.

(1) Apply force to the grip in a perpendicular

direction to the line connecting the tipping lever

and the grip.

(2) Do not apply force only to the legs, but press

down the grip obliquely downward and

backward simultaneously.

(3) Maintain a moderate elbow angle.

(4) Maintain an appropriate distance between the

caregiver's trunk and the wheelchair.

Failure to maintain the operating posture above will

impose a physical burden on the caregiver and also

affect the comfort level of the wheelchair user.

3 EDUCATION SYSTEM

We configured the system based on the requirements

of the functions necessary for teaching wheelchair

technology described in the previous section. From

the viewpoint of ease of learning, we use the sensor

built into the iPhone, which does not require any

special equipment. Although the technical

specifications of the iPhone sensor are not disclosed,

some previous studies (Noto et al., 2016; Sawada et

al., 2007) have used the iPhone sensor as a substitute

for existing sensors. Table 1 lists technologies used in

the development of the proposed system, and Figure

4 provides an overview. The proposed system has

three functions.

Table 1: Technologies used for system development.

Item Technology

Frontend Vue.js

Backend Node.js, Python

DB MySQL

PaaS Heroku

Development of Learning System to Support for Passing Steps of Wheelchair

499

Figure 4: System overview.

3.1 Measurement Functions

After placing the device on the wheelchair, the

measurement starts by clicking the start button.

During the measurement, triaxial acceleration and

angle data are recorded every 0.1s. This process

continues until the button is clicked again. The data

are sent to the server after measurement completion.

Figure 5: Measurement function interface.

3.2 Evaluation Functions

The vibration level and maximum angle are

calculated from the data sent in 3.1.1 according to the

technical evaluation method described in 2.2. Results

are stored in the database and are displayed on the

client side. Difference between data of the learner and

data of skilled persons of similar physique are also

displayed to assist learners in quantitatively

understanding their own techniques.

Figure 6: Evaluation function interface.

3.3 Teaching Functions

Return feedback to the learner based on 3.1.2&2.3.

Feedback information is provided to the learner based

on the assumed technical tasks according to

differences between the learner's data and the expert's

data. Table 2 presents examples of the assumed tasks

and the feedback information for the learner to take

appropriate operating postures.

Figure 7: Teaching function interface.

4 CONCLUSIONS

When learning how to assist a patient without a

nearby instructor, learners were forced to learn by

themselves through video and text-based materials.

Therefore, learners had to judge their proficiency

level subjectively. It was difficult for them to assess

HEALTHINF 2023 - 16th International Conference on Health Informatics

500

Table 2: Examples of Feedback Information.

Assumed issue

Feedback for proper

operating posture

Lifting the front wheel

too much.

• Gently pull the grip.

• Reduce elbow angle.

Insufficient height to lift

the front wheels, hitting

a step.

• Increase elbow angle.

• When lifting the front

wheel, pull the grip

ackward at an an

le.

Distance between the

body and the wheelchair

is too much.

• Approach and operate

the wheelchair.

their own skills quantitatively. By contrast, the

educational system proposed in this study measures

and presents the learner's proficiency level

quantitatively. Moreover, it enables immediate

feedback according to their level of proficiency,

which can be expected to engender more efficient

learning. In future studies, we would like to verify the

usefulness of our system by comparing the learning

effects of the proposed educational system with those

of conventional video-based and text-based teaching

methods.

ACKNOWLEDGEMENTS

This work was supported by JSPS KAKENHI Grant

Number 20H03971.

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