Keywords

1 Introduction

1.1 The Problem of Using New Products for the Elderly

The aging of the population has become an extremely serious social problem in China, and its population aging is accelerating. Because the incidence of chronic diseases such as cardiovascular and cerebrovascular diseases is significantly increased, the use of medical auxiliary products can greatly prevent the diseases of the elderly, such as electronic sphygmomanometers (ES) and other medical devices that can measure physical and physiological indicators. As McCann et al. pointed out, medical devices that measure the physical indicators of the elderly are used at home to provide continuous health care for the elderly, reducing the cost of physical examination and the risk of life [1]. Because there are a large number of elderly people in the country of China, it is very expensive to go to the hospital frequently. As such, elderly people can significantly promote their health services by using home medical equipment. The elderly can quickly understand the physical condition. The equipment even can transmit information to the medical staff through the network to achieve the telemedicine guidance. Health assessment and decision support was conducted, which plays an important role in the early prevention and timely medical treatment of the elderly.

Since home medical testing equipment has such an important role, the elderly should use the equipment frequently. However, due to the gradual decline of the physiology of the elderly and their ability to process information is also declining, their learning and memory skills are also significantly less than young people’s [2]. Therefore, the elderly often shy away in the face of new products and new technologies. Previous studies have also found that elderly people have low acceptance of home medical equipment [3,4,5,6]. There is reported to be greater fear and anxiety associated with using computers, and in addition, their assessment of their own skills and abilities, with both using and learning to use them, is generally lower than for other age groups. New productions’ interfaces and interaction styles are continually evolving. There are many reasons for being digitally excluded including those related to financial constraints, lack of training and prior experience.

Through a survey of Chinese elderly, it has been found that one key obstacle is always difficult for them to learn to operate new equipment [7]. They are concerned about the negative consequences of erroneous operations, avoiding the use of new devices, and the perceived ease of use (PEU) of medical devices has an important role in promoting the intended use of older people. They avoid the use of new devices because of the negative consequences of erroneous operations. Thereby, the PEU of medical devices has an important role in promoting the intended use of older people.

1.2 Purpose of the Study

PEU requires designers to promote the use of new technology products from the perspective of mental models and visual guidance. PEU is important for the use and acceptance of the product, and affordance has a strong positive correlation with PEU [8]. Elderly people often afraid to use the product for the first time because of the obstruction caused by visual perception. Previous studies indicate that usability is one of the important determinants of technology used by older people [9], and the research models commonly used in this field are Technology Acceptance Model (TAM) and UTAUT Model [10, 11], which provide a solution to the problem of perceived usability. Norman’s affordance to extended HCI is also well applied in the user perception of usability [12].

Affordance and PEU have many applications in product and technology, but few studies have focused on the PEU of home medical devices by older people. This study provides guidance for older people to more easily use medical products, combining the above models to discuss the main influencing factors of the perceived availability of ES design from the perspective of affordance.

2 Literature Review

2.1 Previous Frameworks and Models

TAM was early framework that effectively explain adoption of technology innovations [10, 13]. The susceptibility or difficulty of understanding and use has been identified as a key determinant of TAM adoption. TAM identified two factors that determine the user’s decision to use the new technology: perceived usability and ease of use. In the past, safety and functional factors were watched for older products. However the usability of products was neglected. The actual expectations and needs of older.

The Diffusion of Innovations Model has also confirmed the importance of usability for older products [14]. While it is important to meet older adults’ needs by providing practical benefits, it is critical to make technology easy to use so that such benefits are realized. The combined effects of these age-related changes may affect older people, making it easy to use technology to achieve these benefits [15].

Pan studied the factors affecting the adoption of the Internet by Chinese elderly by applying the Extended Technology Acceptance Model (TAM) [16]. The results show that perceived use richness (PU) and perceived ease of use (PEU) Subjective norms (SN) and facilitate conditions (FC) are four key predictors, while gender and age play an important role in two key TAM components (PU and PEU).

Lee et al. through a literature review of the Technology Acceptance Model (TAM) research field, concludes with 10 final and most important influencing factors, namely value, usability, affordability, accessibility, Technical support, social support, emotion, independence, experience and confidence, among which availability is identified as an important determinant of the adoption of technology by older people [9]. The study demonstrates two important characteristics of older users’ anxiety about technology and resistance to change. Cao integrates context-aware and unified theory of acceptance and use of technology (UTAUT) models to explain the use of Alipay users from both the perspective of technology perception and context awareness. Researchers believe that users’ behavior depends not only on their perceptions and attitudes toward technology, but also on good contextual perception [17].

Affordance theory is based on user contextual awareness and has been successfully applied in the field of perceived usability. Hsiao et al. used an online availability assessment model to measure the degree of availability to evaluate products. Availability [12]. Designers can gain PEU and easily identify the look and feel of products that need to be modified and optimized by using this model.

2.2 Summary

The above studies as shown in Table 1 show that, the PEU of medical products is critical for older people are willing and able to use them such as ES. This study will obtain the key influencing factors of the PEU of ES through Affordance theory, based on the research models such as TAM and UTAUT. The design of an ES that is more attractive, practical and usable for the elderly, to interact safely, healthily, independently, with mobility and happiness between the elderly and technical products.

Table 1. Summary of technology acceptance and use models.
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3 Method

3.1 Experimental Sample

An Electronic Sphygmomanometer (ES) is a medical device that uses modern electronic technology and indirect measurement of blood pressure to measure blood pressure. The ES is divided into an arm type, a wrist type, and a watch type. Older people choose the upper arm type ES because the pulse is weaker and the wrist ES is not suitable for patients with blood circulation disorder. Therefore, we mainly chose the upper arm type ES in this study.

Samples of Electronic Sphygmomanometer.

First of all, 56 types of ES were found out from the mall and e-commerce website. In this study, considering the factors affecting the use of new products by the elderly (60-70 years) and feedback of markets, combining with experts’ opinions and the purpose of this experiment, 10 samples were selected. The final choice is shown in Table 2. Ten types of upper arm ES are shown.

Table 2. 10 samples
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Perceptual Usability Evaluation Questionnaire.

According to the relevant research methods of the literature [10, 18], choose 9 dimensions of the Use of Comfortable, Function Clear, First Step Operation Clear, Reading Clear, the Role of Each Button Clear, Operation Ideas Clear, Easy to Get Started, Operation No Risk, Willing to Use and 1 overall evaluation of Feel Easy to Use, select the above 10 kinds of upper arm ES pictures. In order to avoid the influence of factors such as brand and view, use Photoshop cc to delete all the logo information on the image, and modify all the images to 577 * 577 pixels, all of which use the view that reflects the product information as much as possible, except 8 uses 3D view. All of them use the front view, and finally t a perceptual usability evaluation questionnaire (Fig. 1 shows one sample) is generated through WJX.cn (a website for making a questionnaire).

Fig. 1.
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Expert’s questionnaire and elderly’s

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3.2 Participants

20 elderly participants aged between 58 and 72 are selected from Wuxi, China. The 10 experts have experience of design more than 10 years. 1 expert works in the enterprise. The other 9 are lecturers and associate professors of university.

3.3 Experimental Procedure

First experiment.

The first experiment was conducted to allow 10 experts to score the PEU (1–7 points) of the above 10 ES from the perspective of affordance. The total average score of the different dimensions and was calculated. The scores of experts are shown in Table 3.

Table 3. Expert score.
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In addition, 10 elderly people were found (mean = 64, SD = 3.5) to subjects. The above 10 types of ES were scored (1–7 points) from the perspective of PEU. Because the elderly did not understand the survey questionnaire clearly, the experimenter guided elderly when they scored the sample. The average score of PEU of each ES was obtained. The elderly scores are shown in Table 4.

Table 4. Elderly score.
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Experts scored the total average score, and the elderly chose to feel easy to use the average score, sorted by comprehensive evaluation. The top 5 experts’ evaluations are No. 1, No. 9, No. 7, No. 8 and No. 10, and the top five results of the evaluation of the elderly group are No. 1, No. 9, No. 7, No. 3 and No. 8, respectively. It was found that the four products in the top 5 scores were No. 1, No. 9, No. 7, No. 3 and No. 8, respectively, and the lowest scores of the experts and the elderly group was No. 6.

Second Experiment.

In the second experiment, the test group was elderly. The order was sorted according to the overall evaluation of the elderly scores, sorted as 1, 9, 7, 3, 2, 8, 5, 4, 10, and 6. The other 10 elderly people (mean = 64, SD = 3.3) as subjects were found, and divided into 2 groups. Each group was randomly selected, and each of them used these ES in turn. The first group (mean = 63.6, SD = 3.6) was used for the forward exercise in the order obtained in the first experiment, and the other group (mean = 64.4, SD = 3.6) was used in the reverse exercise (see Fig. 2). The perceptual usability ranking of the test product was not told before the experiment. After the task was completed, the two groups of participants evaluated the usability of 10 products separately. Finally, the two sets of data were analyzed.

Fig. 2.
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Using ES of OMRON U30

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4 Result and Discussions

4.1 Relationship Between Appearance Characteristics and PEU

From the first experiment, it can be found that the products with the top 5 scores in the top 5 are No. 1, No. 9, No. 7, No. 8. By summarizing the appearance characteristics of the four products, we can find that the above-mentioned products have important effects on the PEU in terms of text affordance, color affordance, and form affordance (See Fig. 3).

Fig. 3.
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Key Feature Affordance.

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Key Feature Affordance.

In addition, we will revisit the appearance of the product based on the previous score. From the perspective of product complexity, the top four products do not have many function buttons, and not seem complicated. However, No. 6 with the lowest score needs to rely on the mobile APP to connect and use, which may be an important reason for the perception that the score of product’s PEU is low. From this experiment we can summarize, the appearance of the product has a certain impact on the PEU of the product. Therefore, the design of ES for the elderly should focus on Key Feature Affordance.

4.2 Relationship Between Accepted to Use (AU) and PEU

From the second experiment, it was found that the average total score of the forward exercise used in the first group was 47.80, and the average total score used in the reverse exercise of the second group was 44.08, as shown in Table 5.

Table 5. Forward and reverse score.
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The total score for forward order use is greater than the total score for reverse order use indicating that perceived usability can also help the performance of older people. Due to the learning effect, the products used later have higher scores than the previous products. The scores of the forward order group No. 1 ES and the reverse group No. 1 ES may not be objective. Therefore, we chose to compare the scores of the 5 (experimental NO. 2) and 6 (experimental NO. 8) products in the middle of the sequence. Data obtained in the second experiment were input to SPSS 19.0, and the data of samples 2 and 8 were subjected to mean T test. We found that the forward order use group scores of the samples 2 and 8 were significantly higher than the reverse group scores. As can be seen, PEU of product has a significant effect on the use of new products by older people. See Tables 6 and 7.

Table 6. NO. 2 score T test
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Table 7. NO. 8 score T test
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5 Conclusions and Shortages

Conclusions.

This study shows that older people are more willing to use an ES with good PEU. The ES showed affordance characteristics through features such as text affordance, color affordance, and form affordance, making it easy for the elderly to perceive the product use to ease, which in turn makes older people more willing to use ES products and learn to use them faster. The products designed for the elderly should not seem too complicated. The buttons and colors of the product interface should not be too much, and the function of the product should be practical and easy to operate.

Shortages.

The main Shortages of this study are that the number of samples is small, and it is not possible to comprehensively and objectively respond to the scores of the samples in the experiment. In addition, the Affordance characteristics of the product itself may be related to many factors, which cannot be completely attributed to the points mentioned in the conclusion.

Future study.

The next step the Affordance characteristics of the product will be further refined, and the perceived ease of use of the product from the product characteristics will be analyzed. And it is hoped to improve the medical level and quality of life of the elderly through increasing the usability of home-based medical care products.