Volume 14 Issue 9 - July 16, 2010 PDF
A new user-centered design approach: A hair washing assistive device design for users with shoulder mobility restriction
Fong-Gong Wu*, Min-Yuan Ma, Ro-Han Chang
Department of Industrial Design, National Cheng-Kung University
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Activity improvement and personal hygiene related issues are the most popular research focuses within assistive technology for people with limited mobility, however, most of the researchers have been paying more attention to the topics of assistive technology than personal hygiene, although the hygiene issue seems to be as important as the assistive devices development.

This study aimed at the investigation into a User Centred Design (UCD) based personal hygienic devices design development. In order to clarify the relationship between the assistive devices and the users, a SWOT (i.e. Strength, Weakness, Opportunity and Threat) analysis theory was applied to analyze the conditions of the participants (users) with the amended name as AD-SWOT, as well as the TOWS (i.e. Threat, Opportunity, Weakness, Strength) strategy, which was proposed by Weihrich in 1982, after the SWOT theory was introduced. Based on the reviewed citation of the TOWS theory, a new concept development method has been developed for assessing the personal hygienic assistive devices named as AD-TOWS. Therefore, this assistive device designing process supported/integrated the AD-SWOT and the AD-TOWS into AD-Design Process model and worked as the framework of this research to complete the practical designing.

The AD-Design Process consists of the understanding and specifying the context of use, which including the requirements of user and organization specification, conceptual designs and prototypes producting and user-based assessment. Within the understanding and specification, there are user-led analysis of general observations and assessments, hierarchical-task analysis and environmental user-mapping/brainstorming analysis. It also provides the following processes, such as the results of previously stated analyses, device properties, and the analyses of strength, weakness, opportunity and threat of the device, AD-TOWS, analytical hierarchical process, concept selection techniques, concept generation/selection and concept embodiments presentation.

As applied practically, understanding of user and environment is the first process. A 65-year-old male participant who was diagnosed with right shoulder joint adhesive capsulitis disorder as been nominated. He experiences his pain at the region of right shoulder joint with disorder under frontal-flexion, abduction and rotation. Activity such as hair washing or brushing (i.e. arms to be required to raise above the ear level), which causes him pain and difficulties. The replacement postures (e.g. result in cervical vertebra reflection and lumbar vertebra flexion), which then develop some degrees of discomfort at the lumbar and cervical regions. His daily-life movements are limited by the ill-side, which might cause his long term sustaining poor posture. The specification of user and organizational requirements are defined as follows: 1. On top of assisting our case in becoming self-reliant, it was also required to improve the poor operating posture. 2. Since the product is in direct contact with the user, the appearance of the product needs to be able to gain the user’s trust. 3. The researchers proceeded with the AD-SWOT analysis onto the participant.

At the initial phase of the concept development, this study has developed a total of 39 sets of design concepts, which was according to the combination of weakness/opportunity, strength/opportunity, and strength/threat. The best-fit concept is selected through the ten items of analysis including both functional and safety factors. Some meetings were held amomg the teams of physio-therapists, occupational therapists and product designers to discuss the importance and degree of each individual factor, as well as to calculate its importance of each factor, based on the Analytical Hierarchical Process(AHP). The points were calculated executively, while the concept scoring the highest points was chosen to be the best-fit concept for our participant. During the last phase, we assessed the process integrity, operating posture, movement opportunity for shoulder joint, subjective pain level of the user, and satisfaction evaluation.

Results of the analyses are shown in table 1. In absence of an assistive device, the case operated steps 1 and 2 using the healthy-side of the body, causing the body to lean onto the right. Steps 3 and 6 were operated with both hands but with the head and neck bending forward. In the presence of an existing assistive device, the participant operated all steps using the healthy-side of the body, with the head and neck bending forward and to the right, while the head and neck rotated during the operation of step 2. In the presence of the assistive device from this study, the participant was able to use both hands simultaneously to complete all steps. The body was able to remain straight in steps 1 and 2, with the head and neck rotating to the left in step 1. During steps 3 to 6, the body was leaning towards the right, with the neck straight throughout the steps except for step 3. On top of that, in absence of an assistive device, the degree of pain was over level 8. In the presence of our assistive device, the degree of pain was lower than that without assistive device supported, with the degree of pain around level 2 during steps 1 to 4. The participant recognizes the composite functions of this product and ensures that this study did successfully assist and simplify the hair-washing process.
Table 1 Results of product evaluation experiment of case study

The “adjustable hair-brushing strip” was developed as a result, which consists of an adjustable strip that users could adjust according to needs. The distinguishing feature is that it guides the user to move the ill-side along with the fit side of the body. The results of this experiment showed that the utilizing of our assistive device was able to assist the participants to enhance the movements of the ill-side, while more easily to keep the head and neck straight. Through the verification of our case, this study reveals that the AD-Design Process provides efficient concept development for assistive device designers. We expect the introduction of the AD-Design Process is able to bring out in the open the concepts of assistive device designs.
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