結合使用性評估與承擔性分析於血糖試片之研究

Combining Usability Evaluation and Affordance Analysis on the Blood Glucose Test Strip

血糖試片是糖尿病患者使用居家血糖量測設備進行自我健康管理重要的部件之一，然而市售的試片仍然有許多設計不良之處，尤其容易因操作簡單不經思考，以直覺方式進行操作而導致錯誤。因此本研究提出先發掘試片的使用性問題再以承擔性探討其原因的方法。第一階段邀請 10 位高齡者針對市佔率較高之 12 款試片進行使用性評估，第二階段邀請 3 位設計專家針對使用性不佳的試片進行承擔性分析。使用性評估的結果發現高齡者無法順利辨識並操作試片主要受限於生理機能退化的影響，此外個人英文程度也影響對試片資訊的解讀。承擔性分析發現，物理承擔性與慣例承擔性均有助於受試者操作試片完成任務，其中物理承擔性對插入試片功能較具影響力。受限於過小的試片尺寸，讓慣例承擔性無法發揮指引採血位置的功用。本研究認為結合使用性評估與承擔性分析除了可有效挖掘高齡者操作試片時所發生的使用性問題，同時更能運用物理（造形）與慣例承擔性（符號或文字）分析問題的原因，可提供設計者進行後續修正之依據。 Blood glucose test strips are one of the most important components of self-health management for diabetes patients. However, the commercial blood glucose meters still have many design deficiencies in that it is easy to operate the test strips in an intuitive way without thinking and may cause operational errors. Therefore, this study proposed a sequential method to investigate the design of its interface: exploring the usability problems of portable blood glucose meters first, followed by affordance analysis to identify the reason of errors. In part 1, we invited 10 elders to evaluate the usability of 12 portable blood glucose meters which are listed on the top of current market share. Then, in part 2, 3 design experts conducted affordance analysis on the inadequate usability items which had been found in phase 1. Usability evaluation showed that the leading causes of poor usability in elders are the subjects' physiological degradation and individual English reading ability related to the interpretation of information of test strips. Affordance analysis disclosed that both physical affordance (product form) and conventional affordance (text and icon) would be helpful for subjects to complete the task, but the former is more effective on the action of insertion strips. Limited by the small size of strips, it was difficult to apply conventional affordance on guiding user the precise site to sample blood. In conclusion, combined usability evaluation and affordance analysis is an effective method to find out the elders' potential problems in using portable blood glucose meters. Furthermore, by applying physical and conventional affordance analysis, researchers could provide designers the basis for subsequent improvement.

Blood glucose test strips are one of the most important components of self-health management for diabetes patients. However, the commercial blood glucose meters still have many design deficiencies in that it is easy to operate the test strips in an intuitive way without thinking and may cause operational errors. Therefore, this study proposed a sequential method to investigate the design of its interface: exploring the usability problems of portable blood glucose meters first, followed by affordance analysis to identify the reason of errors. In part 1, we invited 10 elders to evaluate the usability of 12 portable blood glucose meters which are listed on the top of current market share. Then, in part 2, 3 design experts conducted affordance analysis on the inadequate usability items which had been found in phase 1. Usability evaluation showed that the leading causes of poor usability in elders are the subjects' physiological degradation and individual English reading ability related to the interpretation of information of test strips. Affordance analysis disclosed that both physical affordance (product form) and conventional affordance (text and icon) would be helpful for subjects to complete the task, but the former is more effective on the action of insertion strips. Limited by the small size of strips, it was difficult to apply conventional affordance on guiding user the precise site to sample blood. In conclusion, combined usability evaluation and affordance analysis is an effective method to find out the elders' potential problems in using portable blood glucose meters. Furthermore, by applying physical and conventional affordance analysis, researchers could provide designers the basis for subsequent improvement.