Keywords

1 Introduction

Digital technologies are becoming ubiquitous in everyday life. There is also a trend towards the use of the technology through mobile devices such as smart phones and handheld tablet devices rather than via laptops and personal computers [2]. Access to information and services can be acquired at almost any time and everywhere. However, a large group of people do not engage with these developments. Older adults are now widely understood to be an extremely diverse group and do not uniformly conform to technology averse stereotypes [5]. However, there is reported to be greater fear and anxiety associated with using related technology, 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. Therefore, use of technology for older people can often be more dependent on the availability of training, and also there seems to be a pragmatic assessment of whether the technology will provide specific desired utility and of the relationship between the perception of this and the perceived difficulty of learning [6].

Moreover, older people have been considered high entertainment users after retirement. Older adults spend far more time watching television than reading newspapers, and they watch more television than any other age group. Of all mass entertainment, television series or shows appears to have the highest credibility. Older viewers are major consumers of television shows, preferring entertainment shows to other programming. At the same time, the elderly are increasingly among the most enthusiastic consumers of new media information. The Cole study also suggested that higher percentages of elderly people than teens use the particular technology. Barnard (2013) suggest that the mobile technology is becoming a functional alternative to future society for many [3]. Many interaction techniques exist in virtual reality (VR) to support 3D manipulations (i.e. 3D elements translations and rotations), such as World-in-Miniature, Virtual Hand or Go-Go techniques are popular in current daily lives for multimedia [1]. More advanced forms of interaction include tangible interfaces such as the Hinckley’s puppet and the Cubic Mouse. The above technologies needed not only to find better ways to introduce digital technologies to currently excluded potential users(older adults), but also to improve the design of digital interface in such a way that they are easy to use [4], As information and services are increasingly becoming exclusively accessible via the technology, it is important to understand the reasons why older people have the perception that digital technologies are difficult to use [7, 8], and that some perceive that they are not capable of learning how to use them. In this research, we specifically focus on one of current brand new interaction concept via 3D holography techniques in which involved to manipulate 3D objects for the deeper understanding of entertainment field.

2 Related Works

2.1 3D Holographic Projection

The potential applications of three-dimensional (3D) digital holograms are enormous. In addition to arts and entertainment, various fields including biomedical imaging, scientific visualization, engineering design, and displays could benefit from this technology. For example, creating full-sized organs for 3D analysis by doctors could be helpful, but it remained a challenge owing to the limitation of hologram-generation techniques. 3D holograms, which often appear in science fiction films, are a familiar technology to the public, but holograms in movies are created with computer graphic effects. Methods for creating true 3D holograms are still being studied in the laboratory. For example, due to the difficulty of generating real 3D images, recent virtual reality (VR) and augmented reality (AR) devices project two different two-dimensional (2D) images onto a viewer to induce optical illusions.

2.2 Types of Holography

A hologram is a recording in a two- or three-dimensional medium of the interference pattern formed when a point source of light (the reference beam) of fixed wavelength encounters light of the same fixed wavelength arriving from an object (the object beam). When the hologram is illuminated by the reference beam alone, the diffraction pattern recreates the wave fronts of light from the original object. Thus, the viewer sees an image indistinguishable from the original object. There are many types of holograms, and there are varying ways of classifying them. For our purpose, we can divide them into two types: reflection holograms and transmission holograms.

  1. A.

    The reflection hologram

    The reflection hologram, in which a truly three-dimensional image is seen near its surface, is the most common type shown in galleries. The hologram is illuminated by a “spot” of white incandescent light, held at a specific angle and distance and located on the viewer’s side of the hologram. Thus, the image consists of light reflected by the hologram. Recently, these holograms have been made and displayed in color—their images optically indistinguishable from the original objects. If a mirror is the object, the holographic image of the mirror reflects white light; if a diamond is the object, the holographic image of the diamond is seen to “sparkle.”

  2. B.

    Transmission holograms

    The typical transmission hologram is viewed with laser light, usually of the same type used to make the recording. This light is directed from behind the hologram and the image is transmitted to the observer’s side. The virtual image can be very sharp and deep. For example, through a small hologram, a full-size room with people in it can be seen as if the hologram were a window. If this hologram is broken into small pieces (to be less wasteful, the hologram can be covered by a piece of paper with a hole in it), one can still see the entire scene through each piece. Depending on the location of the piece (hole), a different perspective is observed. Furthermore, if an undiverged laser beam is directed backward (relative to the direction of the reference beam) through the hologram, a real image can be projected onto a screen located at the original position of the object.

  3. C.

    Integral holograms

    A transmission or reflection hologram can be made from a series of photographs (usually transparencies) of an object—which can be a live person, an outdoor scene, a computer graphic, or an X-ray picture. Usually, the object is “scanned” by a camera, thus recording many discrete views. Each view is shown on an LCD screen illuminated with laser light and is used as the object beam to record a hologram on a narrow vertical strip of holographic plate (holoplate). The next view is similarly recorded on an adjacent strip, until all the views are recorded. When viewing the finished composite hologram, the left and right eyes see images from different narrow holograms; thus, a stereoscopic image is observed. Recently, video cameras have been used for the original recording, which allows images to be manipulated through the use of computer software.

2.3 Future of Holography

For now, holograms are static. Recent presentations, such as CNN’s special effect of a reporter appearing live from another location, and the late Tupac Shakur “appearing live” at a music festival, are not “true” holograms. However, new holographic technology is being developed that projects 3D images from another location in real time [1]. The images are also static, but they are refreshed every two seconds, creating a strobe-like effect of movement. The researchers hope to improve the technology over the next few years to bring higher resolution and faster and realistic image streaming.

3 Research Method

3.1 Participants

Forty-one older adults (65 years old) people were recruited from Yilan senior learning community centers, and the final 30 (mean age: 66.8 years; 15 female and 15 males participants) met our inclusion criteria. They were all fluent fluency in Mandarin Chinese or Taiwanese; and attend senior learning community centers for exercise or entertained class at least three times a week. Our therapists evaluated whether their physical health would allow them to participate in our study. We recruited only healthy participants because the goal of this research was to evaluate some of the negative effects of aging. Using participants who were already seriously aging or who had already developed Alzheimer’s disease would have biased our experiments and their results, especially our usability test to manipulate virtual reality objects of the 2 Holographic projection devices and to continue to pay visual attention to transformed and control virtual 3D models.

All participants were fully informed and had signed a consent form. They were paid a nominal fee of NTD 300 as compensation for their time. Some researchers found that repeated exposure to the prior technology experience with would significantly affect participant performance. Therefore, the participants had not been exposed to the related visual displays in the previous test 2 weeks.

3.2 3D Holographic Projection Device and Apparatus

Our goal for this research was to find empirical evidence for age-related effects of different 3d holography devices characteristics on usability, with the overall aim of understanding how to design interface more inclusively. We sought to identify which 3d holography and content characteristics help or hinder usability, and to determine experimentally whether the effects of those characteristics differ across age groups. Little has been reported in the research literature about holography usability issues that seniors experience, and the 3d material and the interaction situation and our work seeks to take steps to fill that gap. With a view on technology adoption, we focused on the initial usability of created 3d holography device, specifically on two types of 3d material manipulated on the platform.

3.2.1 2D HoloAD Device

The main components used for the 2D HoloAD were a monitor and a pyramid-shaped form made of reflective acrylic boards. Images in the monitor were presented, using reflection, in the interior of the pyramid form, which was composed of two right triangles as side boards and one isosceles triangle as a front board. They had a separation angle of 45° with the monitor and the ground so that the augmented images would not be distorted. We feed through software with 2D images, it will be converted to a FLV formatted file waiting to be transferred to the device (Fig. 1).

Fig. 1.
figure 1

2D HoloAD device

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3.2.2 3D Hologram Device

3D hologram were a monitor and a boxed-shaped form made of reflective acrylic boards. Images in the monitor were presented, using reflection, in the interior of the pyramid form, which was composed of two side boards and one isosceles rectangle as a front board. They had a separation vertical angle with the Ipad monitor and the ground so that the virtual images would not be distorted. The 3D hologram was set on a wooden box (Fig. 2).

Fig. 2.
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3D hologram device

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3.2.3 The Leap Motion Device - Operational Characteristics

The leap motion is a kind of operational device. It should first be noted that this device, when capturing hand movement, implements a new way of detecting the human hand and a new means of gesture recognition. Distinguishing it from the Kinect sensor, the producers of Leap Motion claim that this sensor possesses sub-millimeter accuracy. In contrast to devices currently existing in the market, the Leap Motion sensor is under discussion for potential use in interaction applications in virtual interactive environments. We here further outline these features, with greater emphasis than that presented in regarding the usefulness of the Leap Motion device in capturing the configurations of human fingers. Moreover, the Leap Motion device provides a new method that is cost efficient, fast and precise in its capture and digitization of human finger movements.

3.2.4 The 2 Types of Materials

2 sets of 3d objects were used in the study; one set was needed for each of the three dimension-label conditions presented in a floating situation. Objects were selected from the most manipulated of existing basic 3d formation. Figure 3 shows a sample of these 3d objects.

Fig. 3.
figure 3

3D objects as the 2 experiment materials (sphere and cuboid)

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3.2.5 Eye Fatigue

CFF is an effective measure of visual fatigue. It measures the minimal number of flashes of light per second at which an intermittent light stimulus no longer stimulates a continuous sensation. As a highly sensitive and easy-to-use measure, CFF is applied here to evaluate retina functionality. A drop in CFF value reflects a drop in the sensory perception function, attributable to a decrease in alertness.

3.3 Experimental Design and Procedures

A standard experimental desk and chair were provided for experimentation. The experiment environment was standardized. Prior to the experiment each subject was instructed about the purpose and procedure of the study. The sequence of 3d object was randomized for each subject. At the beginning of each manipulated session, the performance was measured as a baseline for comparison. The subject was then asked to control the objects and rotate the star mark to the front side. When the individual found the target, she/he should move the cursor to the object and click the left button of the controller twice to respond ‘hit.’ The sound feedback also shown to indicate the task is complete. Both control speed performance were measured. In addition, a visual fatigue measure was also taken.

4 Results and Discussion

The summarized ANOVA results are shown in Table 1. The Holography type effect was significant on eye fatigue. The 3d object effect was significant both on control speed performance and eye fatigue. Subject effect was significant on both speed performance and eye fatigue.

Table 1. The average performance of both devices for Sphere and Cuboid objects
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4.1 Usability Performance

Control performance was measured by turning and rotating speed. Table 1 shows the average performance of control both Holography types. For the 3D hologram device the average performance time was 17.4(4.6) s. For the 2D HoloAD device the average performance time was 28.6(6.1) s and the control accuracy was 88.2%. On average, controlling the 3D hologram device took 11.2 s less than control the 2D HoloAD device. This may be attributed to the contrast and resolution of the display in a 2D HoloAD device. Also, the subjects were more used to control 3D hologram devices than 2D HoloAD devices. The results also suggest that hand gesture interactions need to be further investigated in terms of their possible advantages over 3D hologram interactions. The study suggests advantages in terms of performance for rotating over traditional tap interactions, in particular for the over 65 age group [7]. However, these differences occurred in tasks where participants had to select one item that did not share the screen with other visual interference items. Given the abundant time of some the participants’ strokes when completing rotating tasks, it is unclear whether the advantages would translate to more realistic situations with multiple possible options to select on the 3d Holography device.

Our participants showed great interest in using our holography interface for testing. Many of them said that 3D holography control methods increased their motivation because they were too unlike formal experience, and that they were little care about their hand movement on the test. However, they did not worry about the real performance because the interaction process seemed more like a game, which increased their interest. They also appreciated that the sound feedback interacted with them and guided them during the experiment.

4.2 Eye Fatigue

Eye fatigue was measured by CFF. 3Dholography type had a significant influence on eye fatigue. After control the 3D hologram device, subjects’ CFF had an average reduction. This reveals that controlling the 3D hologram device caused less eye fatigue than control the 2D HoloAD device. This is due to the viewing range factors, a larger display facilitated control best, bolstering the subjective assumption that larger holography displays led to better operational performance. In fact, the larger holography displays merely resulted in an improved performance for easy tasks. As rotating tasks became more difficult, smaller holography displays could be resulted in better operational performance.

4.3 Discussion and Future Work

We also found that concrete formation helped older adults, more than the sphere types, to identify objects in the outline with direction indicator for intuitive understanding. Furthermore, we found that the prior experience improved initial usability but did not help older adults. We discuss implications of these findings for designing 3d holography device that are better suited to older adults. Our findings constitute a much needed empirical foundation on age-related differences in 3d object usability and for holography design guidelines targeting older users.

Furthermore, tasks containing clue objects (cuboid) with characteristics were easier to complete than those containing obscure objects (Sphere) without characteristics. The turning-in and –rotating out gestures might solve part of the problem. The other geometry objects without obvious characteristics to facilitate guidance may be one plausible solution [8], but this would require further research.

This research presented the fundamental concept to evaluate and design of an integrated interface that displays “holographic” 3D objects for older adults, allows direct hand-based interaction with the visualized objects, while the older user feels virtual feedback from the objects. This concept will furthermore enable other ways of interaction with more different formation type and feedback factors, such as feedbacks sounds or animation effects affecting the real environment, as well as the real workspace being shadowed by the virtual objects. The next phase of the project will involve the implementation of the designed interface including dynamic, interactive and augmented reality operation, software development, as well as its extensive testing by older users and improvement of the entertainment field based on the holographic feedback received.