Design of walking aids for the elderly based on the Kano-AHP-FEC method (2025)

Abstract

As global populations age, ensuring the mobility safety of elderly individuals has become a prominent concern, highlighting the need for innovative designs in assistive products for seniors. This study aims to offer a scientific and practical design methodology for mobility aid designers, validated through the design of a walker for elderly users. To begin, potential user needs for walkers were identified using User Journey Mapping, with these needs categorized through the Kano model to establish a structured hierarchy of design requirements. Then, the Analytic Hierarchy Process was applied to weight these requirements, pinpointing the most critical design needs for walkers to guide practical design decisions. Finally, the Fuzzy Comprehensive Evaluation method was used to systematically assess walker design proposals, helping to identify the optimal solution and specifying areas for improvement. The findings demonstrate that the combined KANO-AHP-FCE framework effectively guides the design of walker products, enhancing their ability to meet user needs. This approach not only provides a valuable reference for future assistive product innovation but also contributes to solutions for enhancing elderly mobility safety in an aging society.

Keywords: Product innovation design, User journey mapping, Kano, AHP, FCE, Population aging

Subject terms: Health care, Engineering

Introduction

In recent decades, the global elderly population has surged, and it is expected to exceed 2 billion by 20501. This rapid aging of the population will put significant pressure on healthcare and social services2. According to China’s National Bureau of Statistics, by the end of 2023, people aged 60 and above made up 21.1% of the population, with those aged 65 and above accounting for 15.5%3. The 14th National People’s Congress of China has emphasized the need for a national strategy to actively address aging4. This strategy includes increasing the supply of products and services for the elderly to improve their quality of life. Elderly individuals face physical challenges such as muscle atrophy, weakened joint function, and reduced cardiac function. These issues significantly limit their mobility and endurance. When seniors lose their ability to care for themselves, they are much more likely to develop depression compared to the general population5. This dual impact on their mental and physical health gradually marginalizes them from society. Elderly walking aids, which serve as vital links connecting seniors to social life, have increasingly attracted research attention in recent years.

Existing research on walker design primarily focuses on the following aspects: (1) Ergonomic Design. Many researchers focus on the ergonomic characteristics of walkers to enhance comfort and usability. For example, Shi et al. studied a new power-assisted walker for the elderly, emphasizing ergonomics while improving functionality6. Jinhee Park adjusted the structural components of walkers to match appropriate body dimensions, reducing fatigue and discomfort for elderly female users7. However, this research often focuses on single physical attributes and lacks consideration of users’ emotional needs. Walkers for the elderly should meet functional and social needs, addressing emotional requirements during use8. (2) Safety Design. Some studies focus on improving the safety of walkers, particularly fall prevention and stability. Shu et al. researched a four-wheel laser walker for elderly Parkinson’s patients based on safety design principles9. Miao et al. explored design principles for fitness aids for elderly stroke patients, aiding their recovery10. Guo et al. integrated shopping cart functions with walkers, incorporating emergency calls, location tracking, and heart rate monitoring to expand the scope of elderly walker research11. These studies improve walker structure, materials, and technology to reduce the risk of accidents. Despite advancements in ensuring safety, there is a lack of comprehensive consideration for the physiological, psychological, and social needs of different elderly groups. This limitation restricts the usability of walkers, affecting user experience. (3) Intelligent Design. With technological advancements, more studies attempt to integrate smart sensors and IoT technologies into walkers to enhance functionality. Jiwon Shin et al. researched the application of sensors and actuators in walkers12. Dadaso D. Mohite used obstacle sensors, GPS, and load sensors to improve walker design13. Yeon-Kyun Lee studied tracked walkers to meet various terrain needs14. Francesco Ferrari designed an intelligent walker that leaves mobility responsibilities to the user, increasing their mobility and control over the device15. Although these studies excel in technological innovation, highly intelligent products often have high learning costs and complex operations, making them difficult for the elderly to use effectively.

It is of great significance to study elderly walking aids from the perspective of user-centeredness and the elderly’s usage process and satisfaction. As the elderly consumer demand for quality assistive products increases, enhancing user satisfaction through design becomes an urgent issue. For elderly walker products that include multiple design elements, an integrated method that encompasses user needs acquisition, multi-attribute needs analysis, and comprehensive evaluation is essential. In terms of user needs acquisition, the user journey map is effective in uncovering implicit needs. This method, often used in service design, helps summarize user workflows, uncover potential needs and product characteristics, and identify pain points and design opportunities16. Therefore, this study uses the user journey map to analyze the problems in the current use of elderly walkers, extracting key design points from a user-centered perspective based on user needs. The Kano model helps understand how customers evaluate products17,18, guiding designers in resource allocation to focus on the most impactful needs for user satisfaction. The Analytic Hierarchy Process (AHP) systematically analyzes the relative importance of various needs19, while Fuzzy Comprehensive Evaluation (FCE) allows a thorough evaluation of multiple design schemes to select the optimal design20. The integrated application of the Kano, AHP, and FCE methods combines qualitative evaluation with quantitative calculation, transforming subjective assessments into precise values to address issues objectively and accurately. This method has been applied in many fields21,22. In the field of product design, Avikal et al. used the Kano model to help product designers easily classify customer needs and integrate these needs into the final product design23. Wang et al. conducted innovative research on lighting for the 2022 World Cup using AHP-FCE24. Yu et al. quantified ambulance user requirements with AHP, resulting in improved community ambulance designs25. Zhao et al. applied GT-AHP-FCE to teaware design, considering both qualitative and quantitative factors, reducing subjective biases and making design and evaluation more comprehensive, accurate, and reasonable26. Despite the feasibility of these methods in various contexts, the Kano-AHP-FCE approach has not yet been applied to elderly walker design. There is a research gap in applying this method to decision-making and evaluation systems for elderly walker design that addresses diverse user needs.

In summary, current research on similar product designs primarily focuses on technological innovations or functional improvements, often overlooking the emotional needs of the elderly. Additionally, there is a lack of systematic methods for design decision-making and evaluation. To address these gaps, this study explores user-centered approaches for innovating and evaluating elderly walkers. It aims to provide effective guidance for design decisions and evaluations, helping future designers create walkers that cater to the diverse needs of elderly users.

Methods

This study has received ethical approval from the Ethics Committee of Anyang Institute of Technology. All experiments were conducted in accordance with relevant guidelines and regulations. The primary focus of this paper is on methodological research, and it does not involve studies on human organs, animal tissues, or other living organisms. The recruitment period for this study is from January 10, 2024, to January 20, 2024. All participants are non-minors who have signed informed consent forms and have voluntarily agreed to participate in this study. Furthermore, all data and information collected from the participants are anonymous and will not disclose any personal information. Based on this information, all research methods and procedures outlined in this paper comply with ethical principles and regulations.

Kano model

The Kano model was developed by Japanese scholar Noriaki Kano27. Berger and colleagues further explored the model’s importance in quality management and customer satisfaction28. The Kano model is a flexible and versatile tool with wide-ranging applications across various fields and industries. From airline travel agencies to situational leadership theory2931, as well as in radical innovation and political elections, the Kano model provides valuable insights. The Kano model is widely used in current research for product design and service optimization to enhance user satisfaction3235. In this study, we use the Kano model to identify essential user needs for designing walkers for the elderly.

Analytic hierarchy process

Analytic Hierarchy Process (AHP) is a multi-criteria decision-making method introduced by Thomas L. Saaty in the 1970s36. This method combines both qualitative and quantitative analysis in a systematic way19. AHP helps solve complex decision problems and enables decision makers to make more informed choices under multiple criteria3739. Existing research has demonstrated AHP’s significant achievements in policymaking, project evaluation, business management, and strategic planning3941. In this study, AHP is used to derive and rank weights after establishing user requirement indicators, thereby avoiding design biases that may arise from subjective designer intentions.

Fuzzy comprehensive evaluation

The concept of fuzzy sets was introduced by Professor L.A. Zadeh in 196542. The application of FCE in decision making and evaluation is detailed by Chen et al.43. The Fuzzy Comprehensive Evaluation (FCE) method is suitable for evaluating multi-level criteria. This method not only provides an overall evaluation result but also evaluates each criterion individually, making it easier to identify weaknesses and suggest improvements44. Existing research shows that FCE is widely used to handle fuzzy and uncertain information, particularly in multi-criteria evaluation and decision-making, helping to enhance the accuracy and rationality of decisions24,26. In this study, the application of the Fuzzy Comprehensive Evaluation (FCE) method assists designers in systematically identifying the optimal design solution. Additionally, it offers valuable insights that can guide future improvements and upgrades of the design. Combining the Kano model and AHP method with FCE enhances the scientific and rational aspects of design decisions. This approach ensures that walker designs comprehensively and accurately meet the diverse needs of elderly users, thereby improving user satisfaction.

QUEST test

The QUEST test (Quebec User Evaluation of Satisfaction with Assistive Technology) was developed by L. Demers and his team in 199645. This tool is designed to assist healthcare and rehabilitation professionals, as well as researchers, in gathering user feedback on assistive technology to better understand and improve the design and service of these technologies46,47. In this study, the QUEST questionnaire is used to gather direct feedback from users on the characteristics and service quality of assistive devices, which helps identify and quantify specific issues and needs encountered during use. The analysis not only provides an objective evaluation of the products but also offers guidance for designers to further refine existing assistive medical product designs, enhancing their functionality and comfort.

Design process framework

The research process is divided into three parts. First, the user demand attributes are obtained by constructing the Kano model. Next, the hierarchical analysis method is used to construct the hierarchical analysis model and obtain the design element priority, so as to design the product according to the obtained element requirements. Finally, the schemes are scored and evaluated through fuzzy comprehensive evaluation to obtain the best scheme. See Fig.1 for the flow chart.

Fig. 1.

Design of walking aids for the elderly based on the Kano-AHP-FEC method (1)

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Analysis and results

User needs acquisition

To gain a deeper understanding of the latent needs of elderly users, this study conducted behavioral observations of 16 individuals over the age of 60 who require walking aids. The analysis focused on identifying problems encountered and potential needs during their outings, as illustrated in Fig.2.

Fig. 2.

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By examining the behavioral journey diagram of elderly users, we can identify pain points and opportunities in walker design. During the use process, we can determine the functional needs (Z1) of the elderly by analyzing these pain points. Additionally, their psychological needs (Z2) can be identified through the observation of 16 elderly individuals. A detailed analysis of the appearance requirements (Z3) is provided in Table 1.

Table 1.

Categories of user needs analysis.

Target demandDemand categorySubordinate demand
Assistant user needsFunctional requirements Z1A1 structure stability
A2 Easy to operate
A3 Adjustable
A4 Safety
Psychological needs Z2A5 Material environmental protection
A6 In line with man–machine
A7 Rich functions
A8 Intelligent design
Appearance needs Z3A9 Comfort
A10 Streamlined shape
A11 Eye-catching colors
A12 Portable

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Design of Kano questionnaire for elderly walking aids

In this study, the KANO model is applied to classify and assess various user needs related to walker design, clarifying how specific functions and features impact user satisfaction. The KANO model categorizes user needs into five types: Must-be Requirements (M), One-dimensional Requirements (O), Attractive Requirements (A), Indifferent Requirements (I), and Reverse Requirements (R)48. This process establishes a clear prioritization of design features, providing a solid foundation for subsequent AHP-based design analysis. Detailed user requirements for elderly walker design are presented in Table 2.

Table 2.

Detailed explanation of users’ needs for walkers.

Requirements attributesExplanation details
Basic Type MThe basic requirements provided by the basic M-walker must be met, and if they are not met, the degree of satisfaction will decrease
Charming Type AMeets this need in the design of walker, the satisfaction will be improved, and vice versa
Undifferentiated Type IThe influence is not considered in the design of the walker
Reverse Type RIn the design of the walker, if it is insufficient, it will be reduced
The expected value OMeets the hidden needs of users. If it is not met, it will not affect, but if it is met, it will be greatly improved

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When designing the Kano questionnaire, responses are recorded from both positive and negative perspectives. Satisfied needs are addressed with positive questions, while unmet needs are addressed with negative questions. Each question has five response options: Like, Must-be, Neutral, Live with, and Dislike, corresponding to scores of 5, 4, 3, 2, and 1, respectively. Based on the results of the Kano questionnaire, the demand attributes of each element are determined according to the evaluation criteria in Table 3.

Table 3.

Comparison table of Kano model evaluation results classification.

Function/serviceNegative problem
Dislike
(1 point)
Live with
(2 points)
Neutral
(3 points)
Must-be
(4 points)
Like
(5 points)
Forward problem

Dislike

(1 point)

QRRRR

Live

(2 points)

MIIIR

Neutral

(3 points)

MIIIR

Must-be

(4 points)

MIIIR

Like

(5 points)

OAAAQ

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Attractive (A), One-dimensional (O), Must-be (M), Indifferent (I), Reverse (R), and Questionable (Q).

In a provincial capital city in central China, two nursing homes with a capacity of more than 100 people were selected for questionnaire analysis. Through the questionnaire survey, the design elements with high priority in the design requirements of walkers were obtained. The preliminary questionnaire design is shown in Table 4. The complete questionnaire can be found in Appendix S1. A total of 100 questionnaires were distributed and 93 valid questionnaires were collected. 63% of the questionnaires were returned by males and 37% by females, with an age range of 60–75years old.

Table 4.

Excerpts from Kano Questionnaire.

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Reliability Analysis: After collecting data from the questionnaire, a reliability analysis is necessary to ensure the data’s dependability for further calculations. As shown in Table 5, the Cronbach’s α values for both the positive and negative items in the questionnaire are greater than 0.8. This indicates that the data from the questionnaire are highly reliable and suitable for subsequent analysis.

Table 5.

Reliability test results of Kano model questionnaire.

Sample sizeNumber of sample itemsCronbach α coefficient
Forward problem93120.826
Inverse problem93120.801

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Validity Analysis: Validity analysis is performed to determine whether the questionnaire design and the data collected are reasonable. Using SPSS software for data analysis, the KMO value was found to be 0.764, and the Bartlett’s test of sphericity yielded an approximate chi-square value of 540.43, as shown in Table 6. These results indicate high validity of the questionnaire. Therefore, detailed user data obtained can be used to calculate user satisfaction based on the functional requirements of the walking aid.

Table 6.

validity test results of Kano model questionnaire.

KMO value0.764
Bartlett sphericity test
Approximate chi-square540.43
df190
Sig0.000

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Satisfaction Index, SI) and Dissatisfaction Index, DSI), where SI is usually positive and DSI is usually negative. See formulas (1) and (2).

SI=A+OA+O+M+I1
DSI=-1·O+MA+O+M+I2

Better-Worse coefficient indicates the selection ratio of each demand, where SI tends to 1, then satisfying the demand can improve the user’s satisfaction, and DSI tends to −1, then not satisfying the demand can improve the satisfaction. See Table 7 for the analysis results of Kano questionnaire user needs.

Table 7.

Summary of analysis results of Kano model.

Function/serviceA (%)O (%)M (%)I (%)R (%)Q (%)Classification resultSI (%)DSI (%)
A121.5123.6625.8124.732.152.15M47.19−51.69
A227.9632.2612.9022.583.231.08O62.92−47.19
A39.688.6022.5859.140.000.00I18.28−31.18
A411.8320.4337.6327.962.150.00M32.97−59.34
A523.6635.4816.1319.354.301.08O62.50−54.55
A611.8323.6636.5627.960.000.00M35.48−60.22
A734.4123.6618.2820.431.082.15A60.00−43.33
A817.2010.7525.8145.161.080.00I28.26−36.96
A935.4853.762.158.600.000.00O89.25−55.91
A1029.0325.8124.7316.132.152.15A57.30−52.81
A1140.8627.9618.289.683.230.00A71.11−47.78
A1220.4329.0321.5127.961.080.00O50.00−42.39

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Attractive (A), One-dimensional (O), Must-be (M), Indifferent (I), Reverse (R), and Questionable (Q).

Take the better value as the Y-axis coordinate and the worse value as the X-axis coordinate, and establish the image limit diagram. It can be seen from Fig.3 that the expected demand of A2, A9, A5 and A12 should be met first, and the expected demand of A11 and A7 should be met preferentially.

Fig. 3.

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User needs analysis based on hierarchical analysis

Based on the Kano questionnaire results, Basic Needs (M), Performance Needs (O), and Excitement Needs (A) significantly impact user satisfaction. In contrast, Indifferent Needs (I) have a minimal effect on user satisfaction according to the walker requirements analysis. Consequently, 10 out of 12 design elements were selected as evaluation criteria. Next, a hierarchical structure model was developed using the Analytic Hierarchy Process (AHP). The model includes three layers: the Goal Layer, the Criteria Layer, and the Indicator Layer. Details are presented in Table 8.

Table 8.

Walker demand analysis model.

Target layerCriterion layerIndicator layer
The walker design (U)

Must-be Quality

(M)

Structural stabilization M1
In line with man–machine M2
High safety M3

One-dimensional Quality

(O)

Portability O1
Comfort: O2
Easy to operation O3
Material environmental protection O4

Attractive Quality

(A)

Rich functions A1
Streamlined shape A2
Eye-catching colors A3

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To determine the priority ranking of elements in the indicator layer, this study enlisted five experts in the field of medical rehabilitation for scoring and evaluation. Their profiles are as follows: Three Senior Physical Therapists: Each therapist has over five years of experience in elderly rehabilitation and physical recovery. Their extensive industry knowledge provides a deep understanding of the needs and preferences of elderly users, which helps accurately identify user requirements for walker products. One Chief Rehabilitation Physician: This physician has significant experience in elderly rehabilitation and chronic disease management. They have led multiple rehabilitation research projects and published numerous academic papers. Their expertise offers valuable medical insights into the physiological changes and rehabilitation needs of the elderly. One Rehabilitation Psychotherapy Counselor: With over five years of experience, this counselor specializes in elderly mental health and emotional support. Their comprehensive understanding of elderly psychological needs, emotional support, and rehabilitation therapy provides critical information for addressing the psychological and emotional aspects of walker design. The scoring criteria are detailed in Table 9. The weights of the criterion-level attributes are presented in Table 10, and the weights for secondary needs are shown in Tables 11, 12 and 13.

Table 9.

Saaty Scale.

Scale valueImportance levelImplication
1coordinate withBoth are equally important
3A little more importantThe former demand is slightly more important than the latter
5Obviously more importantThe former demand is obviously longer than the latter
7Especially more importantThe former demand is particularly more important than the latter
9Extremely more importantThe former demand is more important than the latter
2 4 6 8Between the importance of the above median value

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Table 10.

Demand weight analysis.

MetricEssential attributesExpect attributesCharm attributesWeighted value
Must-be Quality1320.54545
One-dimensional Quality0.33310.6670.18182
Attractive Quality0.51.510.27273

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Table 11.

Matrix A the layer weight of the essential subcriterion.

Must-be QualityM1M2M3Weighted value
M110.3330.50.17169
M2310.6670.38688
M321.510.44143

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Table 12.

Expected expected subcriterion layer weights.

One-dimensional QualityO1O2O3O4Weighted value
O1110.250.3330.11181
O2110.250.3330.11181
O344110.41597
O433110.36042

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Table 13.

Charm attribute subcriteria weight.

Attractive QualityMetric 1Metric 2Metric 3Weight
A111.6672.50.50077
A20.611.4290.29563
A30.40.710.20361

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To verify the consistency of the weights for the criterion level and sub-criterion level, we conducted consistency checks using Formula (3). The results of the consistency checks are shown in Table 14. All consistency ratios (CR) are below 0.1, indicating that the consistency requirements have been met.

CR=λmax-nn-1×RI3

Table 14.

Summary of consistency test results.

Consistency checkThe standard layerMOA
CI00.0370.0030
RI0.5250.5250.8820.882
CR00.070.0040

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Combine the weight of criterion layer with the weight of sub-criterion layer, and the final result of comprehensive weight calculation is as follows in Table 15.

Table 15.

Comprehensive weight ranking.

Demand typeDemand weightLower demandLower demand weightComprehensive weight valueSort of weight values
Essential attributes0.5454Structural stabilization M10.1710.09184
In line with man–machine M20.3860.20522
Safety M30.4410.23761
Expect attributes0.1818Portability O10.1110.01989
Comfort: O20.1110.01989
Easy to operation O30.4150.07386
Material environmental protection O40.3600.06487
Charm attributes0.2727Rich function A10.5000.13533
Streamlined shape A20.2950.07835
Eye-catching colors A30.2030.05408

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The use of the hierarchical model and judgment matrix ensures the scientific and rational selection of design elements. Designers can prioritize these elements based on their importance as shown in Table 15 when developing walkers for the elderly.

Design practice

It can be seen from the above that according to the extracted design elements as the key design elements of the walker design, the preliminary design of the scheme is carried out, and the sketch is shown in Fig.4.

Fig. 4.

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The designer outputs the scheme according to the creative sketch and produces the experimental prototype, as shown in Fig.5.

Fig. 5.

Design of walking aids for the elderly based on the Kano-AHP-FEC method (6)

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Scheme 1: This design features a robust all-metal frame to ensure stability on various surfaces. The handles are made of wood to enhance grip comfort and include a non-slip feature. The bottom of the walker is equipped with a storage compartment for convenient storage of personal items.

Scheme 2: This design utilizes lightweight aluminum alloy for easy portability. The minimalist Scandinavian style adds to its visual appeal. To accommodate different terrains, the walker has wide wheels. The rear wheels are designed to rotate 360 degrees, facilitating maneuverability in tight spaces.

Scheme 3: This design incorporates a modular approach, allowing the walker to be assembled and adjusted according to user needs. The handles, seat, and support legs are detachable for easy cleaning and replacement. The extended front-to-back axle provides enhanced stability. Additionally, the design includes an adjustable seat for resting and a braking system on all wheels for added safety. This proposal is ideal for users who require personalized adjustments and frequent outings.

Design scheme evaluation

The Fuzzy Comprehensive Evaluation (FCE) method is highly suitable for quantifying and analyzing abstract and ambiguous data. In this study, the primary reason for using the Fuzzy Comprehensive Evaluation (FCE) method is to scientifically select the optimal design solution, minimizing the influence of individual subjective factors. To ensure the scientific nature of the research, we assembled a review panel of 10 experts and users. The panel consists of 2 full-time senior caregivers with over 10years of experience in elderly care, 3 elderly individuals with over 5years of experience using walking aids, 2 engineers specializing in medical assistive devices, and 2 rehabilitation therapists with more than 5years of clinical experience.

Based on the weight vectors obtained from the indicator layer, a fuzzy comprehensive evaluation matrix was constructed. The review panel was invited to score and rank the three proposed solutions. By comparing these scores, the optimal solution was selected. For instance, to illustrate the process using Scheme 1:

1. According to the factors selected by the experts, establish the factor set and establish the evaluation factor index set U, U = {UM,UO,UA}.

2. Establish the comment set and evaluation criteria: V = {V1,V2,V3,V4}, representing {very satisfied, satisfied, average, dissatisfied} respectively, and the corresponding scoring format is V = (90, 75, 60, 50).

3. Establish the fuzzy matrix R. Use the percentage method to calculate the membership degree and determine the fuzzy matrix R, as shown in formula (4).

R=r11r12r1nr21r22r2nrm1rm2rmn4

Taking Scheme 1 as an example, the necessary attribute evaluation matrix in the sub-criteria layer is represented by RM, the desired attribute is represented by RO, and the attractive attribute is represented by RA. The results are as follows:

RM=0.70.20.10.00.60.20.20.00.70.30.00.0

RO=0.70.20.10.00.60.20.20.00.70.30.00.00.70.20.10.0

RA=0.80.20.00.00.60.20.20.00.60.30.10.0

4. Determine the weight vector of the evaluation factor, W = {a1,a2,...,ap}. According to Tables 10, 11 and 12 above, the weight vector of the criterion layer is WU={0.54545,0.18182,0.27273}, and the weight vectors of the sub-criterion layer are WM={0.17169,0.38688,0.44143};

WO={0.11181,0.11181,0.41597,0.36042}; WA={0.50077,0.29563,0.20361}.

5. According to the determined weight vector W and matrix R, calculate the fuzzy evaluation vector X, as shown in formula (5).

X=WR5

Calculate the evaluation weight vector X of the criterion layer indicators of Scheme 1:

XM=WMRM=0.6610.2440.0950.000

XO=WORO=0.6890.2310.0800.000

XA=WARA=0.7000.2210.0790.000

The final comprehensive evaluation vector for Scheme 1 is:

P=WUXU=WUXMXOXA=0.6770.2350.0880.000

6. Calculate the comprehensive percentage score of Scheme 1:

Y1=PV6

Through the weighted calculation of the comprehensive evaluation vector P and the score corresponding to the comment set levels, the percentage score of Scheme 1 is 83.835. According to the above method, the score of solution 2 is 85.515, and the score of solution 3 is 87.045. The specific calculation process and data of Scheme 2 and Scheme 3 can be found in Appendix S2. From the scores, we can see that Scheme 3 is the best option.

Feasibility evaluation and verification

To ensure the accuracy and reasonableness of the evaluation results and the feasibility of the evaluation methods, researchers often employ standardized questionnaires to assess user experience. These questionnaires help validate the evaluation results and determine whether the product effectively meets the needs of elderly users based on their feedback. The commonly used standardized questionnaires include the Questionnaire for User Interaction Satisfaction (QUIS)49, the Post-Study System Usability Questionnaire (PSSUQ)50, the System Usability Scale (SUS)51, and the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST)52. The QUEST questionnaire, in particular, is designed to provide a systematic way for users of assistive technology to evaluate their satisfaction53.

Figure5 displays the functional prototypes of the three proposed solutions. To validate these prototypes, 100 elderly individuals with experience using relevant products from a nursing home in Zhengzhou City were selected for the study. The participants consisted of 63 males and 37 females, with ages distributed as follows: 33 people aged 60–65, 45 people aged 66–70, and 22 people over 70years old. The duration of use of the walking aid products among participants was categorized as 23 individuals using them for 1–3years, 38 for 3–5years, and 39 for over 5years. All participants were volunteers, and the study was classified as a social investigation. No human research was conducted, and data collection was anonymous, ensuring compliance with ethical standards.

Each of the 100 elderly users tested the three product prototypes and completed the QUEST questionnaire based on their experience. As shown in Table 16. The questionnaire used a 9-point Likert scale, with 1 indicating strong disagreement and 9 indicating strong agreement. According to the QUEST standards, the products were evaluated across six indexes: comfort, safety, durability, ease of use, practicality, and appearance design. Each index was derived from the average value of its corresponding items. Higher scores reflect greater satisfaction, while lower scores indicate less satisfaction. A total of 100 questionnaires were distributed, and 92 valid responses were obtained after screening. The αcoefficient of the questionnaire calculated using SPSS software was 0.982, indicating that the reliability was high and met the requirements.

Table 16.

Product use questionnaire.

NoQuestionnaire questionsStrongly disagree → Strongly agree
123456789
1Feel very comfortable using a walker
2Walkers are very stable and safe during use
3I am satisfied with the material and build quality of the walker
4The adjustment and folding function of the walker is easy to operate
5Walkers are easy to use in different environment
6I am pleased with the exterior design of the walker

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The six indexes of comfort, safety, durability, ease of use, practicality and appearance design of the three schemes are compared and analyzed. Figure6 shows that the score of Scheme 3 is significantly higher than that of the other two schemes. The user evaluation results are consistent with the comprehensive assessment obtained through the Fuzzy Comprehensive Evaluation (FCE) method used in this study, indicating that FCE is both applicable and feasible for evaluating and selecting design options for elderly walkers.

Fig. 6.

Design of walking aids for the elderly based on the Kano-AHP-FEC method (7)

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Discussion

The development of walking aids for the elderly requires considering multiple factors, making the process highly complex. The findings indicate that by thoroughly identifying the latent needs of elderly users and integrating both qualitative and quantitative factors in walking aid design, the decision-making process becomes more scientific and balanced. Reducing subjective elements in design decisions significantly enhances the accuracy of user needs analysis, enabling the development of products that align more closely with user expectations. Furthermore, incorporating multi-objective attributes into the decision-making process substantially improves solution feasibility, supporting findings from previous studies. For instance, Zhao et al. demonstrated the effectiveness of reducing subjective factors to improve accuracy by analyzing user needs using a combination of the Kano and AHP methods54. Similarly, Liu et al. applied multi-objective decision-making in chair design, meeting both functional and emotional needs for outdoor leisure chairs, which resulted in more feasible solutions55. The combined application of multidimensional methods is considered effective. Wang et al. successfully developed a greenhouse drone design by combining grounded theory, AHP and QFD methods56.

Compared to previous studies, this research presents a more systematic design evaluation process and a more comprehensive method of analyzing user needs. By thoroughly exploring potential user needs through user journey mapping and integrating the Kano-AHP-FEC methods, this study not only made breakthroughs in identifying user needs but also enhanced the scientific rigor and rationality of design decisions through quantitative analysis and priority evaluation. Additionally, this study also emphasizes on multi-dimensional user experience in design evaluation, ensuring that design solutions are more aligned with actual needs. Hence, improving the practicality and user satisfaction of walking aids.

However, this study presents several limitations despite the significant progress in reducing subjective influences and enhancing decision feasibility. For example, the scope of field observation was limited during the user needs acquisition stage. This study could not provide provide detailed age segmentation or regional differentiation of the research subjects. Differences in body sizes and environmental factors across different age groups and regions may also affect the user needs for walking aids. Therefore, future research could focus on more specific studies targeting elderly groups from various age segments and regions. Furthermore, the number of experts involved in the needs assessment was limited, which may have an effect on the results. Future studies could expand the sample size of evaluation experts to make the assessment more comprehensive.

Conclusion

This study proposes a novel approach for designing walking aid products tailored to elderly users. First, user journey mapping was employed to identify key latent needs effectively. The Kano model was then applied for quantitative analysis to categorize these requirements, and in combination with the Analytic Hierarchy Process (AHP), it enabled prioritization of design criteria for walking aids. Based on these priorities, design solutions were generated and subsequently evaluated and validated through the Fuzzy Comprehensive Evaluation (FCE) method. This process resulted in a comprehensive design and evaluation framework. Prototype testing results indicated that this approach significantly increased user satisfaction with walking aids. This framework offers designers a structured tool to develop age-friendly products. It provides meaningful insights that may help in addressing the challenges of an aging population. The main conclusions are as follows:

  1. The use of user journey mapping effectively identified diverse latent needs.

  2. Combining the Kano model and AHP allowed for both qualitative and quantitative analysis of user needs and technical elements, clarifying design priorities and increasing satisfaction with technical solutions.

  3. The application of FCE provided a comprehensive evaluation of walking aid design schemes, aiding in their selection and optimization.

  4. Despite these advantages, this study has limitations, including sample variability and a limited number of experts involved in the needs assessment. In large, aging populations spread over vast geographic areas, such factors could influence the generalizability of the results. Additionally, this study did not delve into the specific processes for translating user needs into product form. Future research could explore detailed methods for form design to further refine the product optimization model. This would contribute to establishing a more systematic approach to product design and decision-making.

Supplementary Information

Supplementary Information. (24.1KB, docx)

Acknowledgements

This research is especially grateful to Henan Jinliu Intelligent Robot Co., Ltd. for providing the experimental site. We would like to thank Anyang Institute of Technology for providing the necessary prototype production tools for this study. Thanks to all authors for their selfless contributions. Thanks to all the researchers who provided advice and support during the writing process of this article. We would like to acknowledge the Innovation and Entrepreneurship Training Project for College Students in Henan Province (202311330040); Innovation and Entrepreneurship Training Project for College Students in Henan Province (202411330031); Innovation and Entrepreneurship Training Project for College Students in Henan Province (202411330032); Innovation and Entrepreneurship Training Project for College Students in Henan Province (202411330035) and Henan Provincial Education Science Planning Project (2024YB0265) for funding this work. We also extend heartfelt thanks to the proof-readers, editors and reviewers who have helped us.

Author contributions

Conceptualization: T.W.; methodology: T.W. and Y.Z.; software: T.W.; validation: T.W., Y.Z., X.Z., Y.X. and L.L.L.P.; formal analysis: T.W. and Y.Z.; investigation: T.W., Y.Z. and X.Z.; resources: T.W.; data curation: T.W. and X.Z.; Writing—original draft: T.W.; Writing—review and editing: T.W. and Y.Z.; visualization: T.W. and Y.X.; supervision: T.W.; project administration: T.W.; funding acquisition: T.W. All authors have read and agreed to the published version of the manuscript.

Data availability

All relevant data that supports the findings of this study are available within the manuscript.

Competing interests

The authors declare no competing interests.

Footnotes

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

The online version contains supplementary material available at 10.1038/s41598-025-85540-y.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary Information. (24.1KB, docx)

Data Availability Statement

All relevant data that supports the findings of this study are available within the manuscript.

Design of walking aids for the elderly based on the Kano-AHP-FEC method (2025)
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