Developing Concept of Walking Aid for Stroke Survivors ^†

Abstract

This study aims to develop a walking aid model, for stroke survivors. The design of this assistive device focuses on increasing stability and support for correct body posture, as well as ease of use. The concept’s development processes include identifying user needs, generating device concepts, and selecting a final concept. The user-centered design was applied in the concept development, especially in its conformity with the users’ anthropometry and mechanical capacity, as well as the product safety principles. Mechanical load analysis of the design was also carried out to meet the functionality of the device and used as a foundation for prototype development. The developed device is expected to contribute to improving the quality of life of stroke survivors, since they regain their ability to complete many of their daily activities by themselves.

1. Introduction

Stroke is one of the main causes of death and disability throughout the world. In Indonesia, stroke is the primary cause of death, with an incidence rate of 15 per 100,000 population per year [1] That is why stroke is a frightening disease for Indonesian people, not only because it causes disability, but also because it is the second major cause of death after heart disease [2].

Data of Basic Health Research (Riset Kesehatan Dasar) held by the Ministry of Health, Republic of Indonesia, show that the prevalence of stroke in Indonesia has increased drastically from 7 per 1000 population in 2013 to 10.9 per 1000 population in 2018 [2]. This certainly creates a significant burden on health care costs, with a total of 3.23 trillion rupiahs in 2022, making stroke the third most expensive catastrophic disease after heart disease and cancer.

Stroke is a disorder of the cerebrovascular system (blood vessels of the brain) that causes blood flow and oxygen to the brain to be reduced or blocked, which causes death or damage to brain tissue and impaired brain function. When blood arteries in the brain narrow, become blocked, or bleed, blood flow to the brain can be reduced. Ischemic stroke occurs when a cerebral artery is blocked, restricting blood flow to a certain part of the brain. This reduces the amount of oxygen that brain cells need, if not eliminating the oxygen supply altogether. Conversely, hemorrhagic stroke occurs when a blood vessel in the brain bursts, damaging the brain and disrupting nerve function [3].

Stroke symptoms can be physical, psychological, or behavioral. The most common physical symptoms are weakness of the limbs to paralysis, loss of sensation in the face, asymmetrical lips, speech problems (aphasia) or slurred speech, swallowing problems, decreased consciousness, headache, vertigo, nausea, vomiting, and loss of vision in one eye or even blindness [4]. The rapid treatment needed for stroke is greatly influenced by proper pre-hospital detection. Since most (95%) of the initial symptoms of stroke occur outside the home or in the hospital, it is very important to be aware of stroke quickly. Greater permanent disability is associated with medical treatment carried out more than 12 h after a stroke [5].

According to Thilarajah et al. [6], post-stroke is considered one of the most painful periods for stroke patients. They will experience shock when doing activities related to their condition. The first and most important is the ability to take care of themselves (self-care). Apart from the rehabilitation process, stroke patients will be supervised by a physiotherapist to help improve motor functions that have been affected by stroke. As expected, stroke patients must carry out self-care activities independently to prevent similar problems in the future. In order to provide a safe rehabilitation program for mobility and ambulation according to the hemodynamic and neurological stability of stroke patients, it is very important to understand their rehabilitation phase [7].

According to Caro et al. [8], walking or ambulation aids are equipment that help someone to move from one place to another. There are two categories of these aids: the first category includes walking aids that require active participation from the user (such as wheelchairs, walkers, crutches, canes, and sticks). According to the needs and preferences of the patient, walking aids that can be used for post-stroke patients include canes, wheelchairs, parallel bars (for initial walking exercises), and walkers. Canes, also called walking sticks, are walking aids made from a stick with a handle on one side and a rubber tip on the other side. A walker is a walking aid in the form of a frame that requires both legs and hands to move. It is made of lightweight material and can be folded, so it is easy to carry anywhere [8]. Crutches are walking aids in the form of sticks. They are useful for supporting the body of people with leg disorders when walking. Axillary crutches and forearm crutches are the two most common types of crutches (19). In general, most existing assistive devices require a functional hand to operate. They also are not directly connected to the body part they assist. This presents a challenge in designing devices that can be directly attached to the body and used independently, without relying on other body parts, particularly the hand. Nevertheless, such devices are easily obtainable.

Many studies of assistive devices for stroke survivors have been carried out, including on the walking aids [9]. From various studies conducted, the development of walking aids for stroke survivors is considered most crucial for helping them to be able to walk again as before. Research on the improvement of walking aids for stroke survivors is ongoing. The main motivation of this research is to provide an opportunity for stroke survivors to get back on their feet, walk, and to improve the quality of their lives. Various approaches have been used to obtain the expected model of the aid. The ideal walking aid is not just a supporting device but must be able to provide adaptive support and assistance, according to the needs and conditions of the individual [10,11].

This study is a stage in our product development of an assistive mobility device for stroke survivors. This study aims to provide some relevant information and results concerning our stages in developing assistive mobility aids. This paper gives some descriptions of customer needs regarding the design of the assistive devices for stroke survivors. The needs have been transformed into a selected concept by considering ergonomics aspects, namely, comfortable, healthy, effective, efficient, and safe (CHEES).

A comfortable product is pleasant to use and does not cause any discomfort or pain. This includes factors such as ergonomics and overall user experience. A healthy product does not pose any health risks to the user or the environment. This includes considerations of material safety, energy efficiency, and sustainability. An effective product works well and fulfills the user’s needs. This includes factors such as product performance, reliability, and durability. An efficient product minimizes the amount of time and effort required to achieve the desired outcome. This involves user-friendly design and functionality. A safe product does not pose any safety risks to the user or others. This includes considerations such as product design, manufacturing processes, and quality control. By focusing on these five attributes, product developers can create products that are not only functional, but also enjoyable and beneficial to use.

2. Methods

This research concerns the parts of the product development stages which first identify the user (customer) needs. This stage was carried out through interviews involving several potential users and other people who interact with users, starting with stroke survivors. Furthermore, information related to user needs provided a basis for developing concepts of the aid. The concept development process generated a number of alternative designs. Those alternatives were developed based on the users’ needs identified previously. Then, the alternatives were tested and evaluated to obtain the most suitable design. These steps were adopted from the product design and development processes proposed by Ulrich, Eppinger, and Yang [12].

The final concept chosen was developed by considering some relevant anthropometric data. The fit between human anthropometry and related segments of the developed device is an important consideration in the concept selection. Thus, the developed design is ready to be tested using the inventor design application software. The forces acting on the device structure are those caused by the user’s body weight. Most of the user’s body weight will be supported by the device. On the other hand, some parts of the user’s body will also receive loading due to possible deflections that may occur in parts of the device due to the loading experienced.

Overall, the shape and size of each part of the device are developed based on an ergonomic approach, especially the user-centered design principles. Thus, the product concept, namely: comfortable, healthy, effective, efficient, and safe (CHEES) can be fulfilled. Additionally, the design also takes into account the materials and manufacturing processes that are used to produce the device in the next phase of product development.

3. Results and Discussion

The product plan is defined and described in a mission statement which is used as the basis for the first step in formulating user needs. The mission statement contains a description of the product, namely a walking aid with mechanical assistance to improve walking stability for users (stroke survivors). This aid is expected to be a substitute for a stick that can help and be assisted by a mechanical process.

From the results of interviews with users and stakeholders, several aspects that need to be considered have been identified, namely: (1) the assistive device must be equipped with a soft and ergonomic handle for comfort, (2) the assistive device must provide sufficient stability to help balance weak patients, (3) the assistive device must be stable and safe to use, especially when users are just learning to stand alone, (4) the assistive device must have non-slip feet to reduce the risk of slipping on various surfaces, (5) the assistive device must be designed to support safe mobility indoors and outdoors, and (6) the assistive device must be stable and safe to use on uneven surfaces.

The evaluation results of the needs of stroke patients shown in

Table 1. Customer needs for walking aids.

No	Interpretation of Needs Statement (Customer Need)
1	The aid should be equipped with a soft, ergonomic handle for comfort.
2	Assistive devices must provide sufficient stability to aid the balance of a weak patient.
3	Assistive devices must be stable and safe to use, especially when the user is just learning to stand on their own
4	The aid should have non-slip feet to reduce the risk of slipping on various surfaces.
5	Assistive devices should be designed to support safe mobility indoors and outdoors.
6	The aid must be stable and safe to use on uneven surfaces.

represent considerations for developing products, including ergonomics, safety, and comfort in use. This design concept considers the patient’s posture and builds a structure that can regulate the distribution of the load evenly. The concept is used to provide a technical description of how the developed equipment will meet the needs of the user. Sketches are used to express ideas as well as brief text explanations.

The concept selection is the final stage of the concept development process. This concept selection is carried out through internal discussions of the development team, mainly taking into account user needs. Other things to consider include: (1) analysis of the advantages and disadvantages of each proposed concept, (2) availability of materials and their costs, (3) ability to be manufactured with available machines/equipment, and (4) feasibility of the concept from a technical and economic point of view.

From this stage, the selected concept is shown in Figure 1. This selected concept adopts the design principle for adjustable range, so that it can be used by people with various body dimensions within a certain range.

The selected concept is the basis for creating a detailed design. The detailed design is divided into two types. The first is industrial design, which takes into account aspect, especially ergonomics and aesthetics, relevant to the body size (anthropometry) of Indonesian people. The second is mechanical design, which pays attention to the possible loads on the design.

The selected concept design has met the industrial design requirements as it fulfilled customer needs. The concept is also designed for adjustable size. The two main segments, thigh and calf, have length adjusters that are used to adjust to the user’s size.

4. Conclusions

This research has reached the stage of selecting a design concept. The next critical steps include: (1) developing an industrial design that integrates ergonomic principles, utilizing anthropometric measurements specific to the Indonesian population, and (2) creating a mechanical design that addresses potential mechanical loading scenarios using advanced design software. The developed device is expected to contribute to improving the quality of life of stroke survivors, since they regain their ability to complete many daily activities by themselves.