121 Figure 7.3 Effects of gender and device thickness on perceived comfort of the upper arm associated with preferred pull (SE range. 121 Figure 7.4 Effects of gender and pull duration on %MVC of ECR (Full name) associated with preferred (ForceP) and acceptable ( ForceA) draw (SE series.
Introduction
- Background
- Objective and Specific Aims
- Scope
- Dissertation Outline
In previous studies on handheld devices, including mobile devices, hand length has been commonly considered (Kong & Lowe, 2005; Otten, Karn, & Parsons, 2013). Although there are many other dimensions related to handedness, such as hand width and finger length, because hand length is significantly related to hand width and finger length (Dey & Kapoor, 2015; Xiong & Muraki, 2016), hand length was chosen to differentiate between different hands.
Study 1] Non-flexible Smartphones: Rear Interactions
Introduction
Smartphones with interaction methods on the back (e.g. Pantech VegaTM series, LG G2TM and G3TM, Samsung Galaxy S6TM) redistribute or duplicate the functions of the home and/or side buttons on the back of the device. To increase the screen size without increasing the overall smartphone size, the home button on the front, the volume button(s) on the side and/or the power buttons have been moved to the back of the smartphone (Lee et al., 2016 ).
Material and Methods
- Participants
- Design of experiment
- Data collection and processing
- Data analysis
The FDI muscle, between the first and second metacarpal bones of the index finger, engages in index finger abduction. The first electrode for the FDI was attached to the center of the muscle belly (Kleim, Kleim, and Cramer 2007; Zijdewind and Kernell 1994; Zipp 1982).
Results
- Grasp
- Index finger reach zone
- Subjective discomfort
- Muscle Activation (Electromyogram)
The bottom center of each device was defined as the origin (0, 0) of the XY coordinates. The index finger touch areas (cm2) were wider in PW in all tasks, and the size of the index finger reach zone varied by hand size.
Discussions
- Grasp classification
- Index finger reach zone and comparison with the rear interactions of
- Subjective discomfort
- Muscle Activation (Electromyogram)
- Limitations
As the position of the last interaction zone rises, abduction of the index finger increases. Overall, the highest % MVE of the index observed in the current study was 32.6 (% MVE FDS in the TCHS condition), and other cases required muscle activation <20% MVE.
Conclusions
Therefore, index finger reach zones of the older population are likely to be similar to those of teenagers. Second, various hand sizes may not have been reflected in the results of the field study, as it used a random sampling method, and hand size was not evaluated.
Study 2] Non-flexible Smartphones: Smartphone
Introduction
Increasing the size of smartphones and screens can reduce grip comfort and portability of the device (Chowdhury & Kanetkar, 2017): Models with mm screens allow one-handed interaction, while widescreen phablet phones (phone + tablet) sometimes need two hands for use. Therefore, both grip comfort and design attractiveness should be taken into consideration when determining smartphone sizes.
Material and Methods
- Participants
- Experimental design
- Data collection and processing
- Data analysis
In Phase III, participants rated grip comfort on a seven-point scale, similar to that described for Phase II, but based solely on mass (GCMS). For the grip comfort data obtained in phase I, a two-way mixed-factor analysis of variance (ANOVA) (hand length and each dimension) was performed.
Results
- Determining the range of each smartphone dimension suitable for grip
- Device width and thickness, and their interaction effect on three types of
- Associations between dependent variables
- Determination of phone mass for one-handed grip comfort (Stage III)
The low fit ratios to the overall range shown in Table 3.2 indicate that only a narrow range of dimensions provide grip comfort. Device width and thickness and their interaction effect on three types of grip comfort (Phase II) comfort (Phase II). Overall, the highest and second highest grip comfort in terms of GCWD and GCOV were typically observed at PWD = 65 mm and 70 mm, respectively.
Discussion
- Comparison between the experimental results and existing smartphones
- Effects of smartphone shape and task on grip posture
- The best specifications of smartphone for high grip comfort
- Limitations
As described above, interior width-optimizing grip comfort (where haptic information is of relatively greater importance) coincided with width-maximizing design attractiveness (where visual information is of greater relative importance). This study determined the smartphone dimensions and mass that provide the greatest one-handed grip comfort. Finally, the results of this study were based on subjective grip comfort and design attractiveness ratings.
Conclusion
Sixth, smartphone dimensions that provide high grip comfort for touch interaction tasks should be explored. Width had the greatest impact on grip comfort and design appeal among the four smartphone dimensions studied. In this study, a horizontal circumference of 146 mm was associated with high grip comfort and design attractiveness.
Study 3] Future Mobile Display Devices: Foldable Display
- Introduction
- Material and methods
- Participants
- Experimental design
- Data collection and processing
- Data analysis
- Results
- Determining suitable foldable screen sizes for each task (Stage I)
- Determining most preferred folding method and device concept (Stage II)
- Discussions
- Conclusions
Regarding the preference rankings (related to Qs 3 – .5), the percentage ratios [(number of votes received / total votes) × 100] were compared between the prototypes. Two other benefits of VOUT were 'you can quickly get a visual notification of an alarm, even if the screen is locked' (21 participants (70%)), and 'the side screen (the folded screen part) and the rear screen of VOUT can potentially be used for both input and output' (eight participants (26.7%)). A frequently mentioned disadvantage of RIN and ROUT was 'I can easily fold this incorrectly, and then I have to unfold and refold it' (four participants (13.3%)), and for RIN it was noted 'the RIN screen cannot are used when folded, similar to VIN' (six participants (20.0%)).
Study 4] Future Mobile Display Devices: Rollable Display
Introduction
It is therefore necessary to investigate the effects of the different types of grip used when rolling the screen on grip comfort. However, the effects of hand length on the grip comfort of rollable displays have not been investigated. Finally, measures of the effects of grip type, device thickness, and hand length on grip comfort were compared.
Material and methods
- Participants
- Experimental setting
- Experimental design
- Experimental procedure and data processing
- Statistical analysis
The objective of the current study was to determine the ergonomic shape of the rotary display by investigating the main and interactive effects of grip type, device thickness, and hand length on the grip area of each side bezel and the grip comfort of each hand. Device thickness (DeviceThin/Medium/Thick; within-subjects factor), i.e., the thickness of the right side of the device, was a three-level factor that could be scored as DeviceThin (2 mm thick), DeviceMedium (6 mm thick), or DeviceThick (10 mm thick). A 3 × 3 × 3 mixed-factor analysis of variance (ANOVA) was performed to examine the main and interaction effects of grip type, device thickness, and hand length on horizontal and vertical grip width and grip comfort for each hand.
Results
- Interaction effects
- Grip type effects
- Device thickness effects
- Hand length effects
- Gripped regions and percentile values for grip widths
- Bimanual coupling with respect to grip widths and comfort
Regarding the vertical grip width for the left hand, the grip type levels were statistically divided into two groups (GripFF-GripFP and GripMM). For left-hand grip comfort, the grip type levels were statistically divided into two groups (GripFF-GripFP and GripMM). For right hand grip comfort, the grip type levels were statistically divided into two groups (GripFF and GripMM-GripFP).
Discussions
- Overview of grip type, device thickness, and hand length effects
- Grip type effects
- Device thickness effects
- Bimanual coupling
- Limitations and future studies
The comfort of the right hand increased with the increase in device thickness from 51.7 (for DeviceThin), 56.5 (for DeviceMedium) to 57.3 (for DeviceThick). Although roughly a fraction of the right-handed population (Llaurens, Raymond & Faurie, 2009), the effects of handedness on bimanual coupling need to be investigated in terms of grip areas and grip comfort. Therefore, the effects of screen unfolding direction on grip areas and grip comfort need to be investigated.
Conclusions
Finally, this study only investigated bimanual display unfolding in the transverse plane (using the device in landscape mode), but not in the sagittal plane (using the device in upright mode). Despite these limitations, the fundamental findings of this study will be useful for the design of ergonomic scroll display devices.
Study 5] Future Mobile Display Devices: Rollable Display
Introduction
A scrollable screen has the advantage of changing the screen's aspect ratio by increasing or decreasing the screen length. Small screen size was preferred for calls, due to one-handed grip, and a 2-3 times larger screen was preferred for tasks that require information on the screen. In the case of the scrollable display device, it has the advantage that users can adjust the screen size as they prefer according to the task at hand.
Material and Methods
- Participants
- Experimental setting and design
- Experimental procedure
- Statistical analysis
- Device Height × Task effects
- Device Height × Hand effects
- Device Height effects
- Task type effects
- Hand length effects
- Gripping methods
Two mock-ups (HeightS × TaskMail and HeightS × TaskVideo) were placed in the same group as HeightS × TaskSearch, which showed the narrowest mean (SE) preferred screen width of 66.9 (3.7). Four treatments (HeightS×TaskVideo, HeightM×TaskVideo, HeightM×TaskVideo, and HeightS×TaskSearch) were placed in the same group as HeightS×TaskMail, which showed the highest mean (SE) preferred screen aspect ratio of 1.5 (0.07). The effect of device height on desired screen aspect ratio was also significant (p-value <.0001).
Discussion
- Overview of effects of device height, task type, and hand length
- Device height × Task type effects
- Device height × Hand length effects
- Device height effects
- Task type effects
- Hand length effects
- Gripping method
- Limitations and future studies
TaskVideo was associated with the widest preferred screen width as well as the highest preferred aspect ratio. Therefore, it is expected that the preferred screen width is smaller for TaskVideo, which does not have this limitation. Although preferred screen width was wider as hand size increased, preferred screen aspect ratio showed no significant difference between hand length groups.
Conclusion
Therefore, the effect of different ethnic groups on the desired screen size of scrollable display devices needs to be investigated. Although the average palm length of men is longer than that of women (Tilley, 2002), it is worth examining gender differences in preferred screen size, preferred screen aspect ratio, user satisfaction, grip comfort, portability, and design appeal for display devices. roll devices using two gender groups with comparable hand sizes.
Study 6] Future Mobile Display Devices: Rollable Display
Introduction
In Study 4 (Chapter 5), the effects of grip condition, device thickness and hand length on bimanual grip comfort when using mobile devices with a scrollable screen were investigated. The results found that grip comfort increased with increasing device thickness, and rollable display devices should have more than 20 mm side edge widths and 10 mm thicknesses to ensure high grip comfort for bilateral screen pulling. The aim of this study was to investigate the main and interactive effects of gender, device thickness and pull duration on pulling forces, muscle activities and perceived discomfort to determine user preference and acceptable screen pulling forces for scrollable display devices.
Materials and methods
- Participants
- Experimental setting
- Experimental design
- Experimental procedure and data processing
- Statistical analysis
Withdrawal duration (within-subjects factor) was the model's withdrawal duration, which was a three-level factor containing 0.5, 1, and 1.5 s. As soon as the second sound is heard, the participant begins to pull the pattern in the correct direction until the third sound is heard. The participant then places the model down on the table and verbalizes the perceived comfort of each part of the arm (right shoulder, upper arm, elbow, lower arm, wrist, and hand).
Results
- Interaction effects
- Gender effects
- Device thickness effects
- Pulling duration effects
Post-hoc analysis of ForceP showed that the pull duration levels were statistically divided into two groups (1 s-1.5 s and 1.5 s-0.5 s; Figure 7.10). Post-hoc analysis of the perceived ease of shoulder with ForceP showed that the pull duration levels were statistically divided into two groups (0.5 s-1 s and 1 s-1.5 s; Figure 7.12). Post-hoc analysis of the perceived ease of forearm with ForceP showed that the pull duration levels were statistically divided into two groups (0.5 s-1 s, and 1.5 s; Figure 7.13).
Discussion
- Overview of effects of gender, device thickness, and pulling duration
- Gender × device thickness effect
- Gender × pulling duration effect
- Gender effects
- Device thickness effects
- Pulling duration effects
- Pulling forces
- Limitations
Regarding %MVC FCR for ForceP, the effects of device thickness and duration of pull were significant. The Gender × Pull Duration effect was significant on %MVC ECR for ForceP and ForceA. For %MVC PD, FCR and ECR with both ForceP and ForceA, the effects of pull duration were significant (p<0.006).
Conclusion
General Discussion and Conclusions
General discussion
- Shapes and dimensions of smart device (object)
- Smartphone as a multi-tasking device (task)
- Should hand anthropometry be considered for ergonomic experiments?
In Study 4, device thickness affected grip comfort (for the right hand with GripFF, the thicker the device, the higher the grip comfort). In Study 4, grip regions and grip comfort were significantly different depending on grip methods. In Study 1 (about non-flexible smartphone rear interaction), the size of the index finger touch area during each task varied across levels of hand length.
Conclusions
- Major outcomes
- Limitations
- Expected contributions and future work
Præsenteret i Proceedings of the Sixth International Conference on Tangible, Embedded and Embodied Interaction (s. I Proceedings of the 7th international conference on Human computer interaction with mobile devices &. Proceedings of the 33rd Annual ACM Conference Extended Abstracts on Human Factors in Computing Systems ( pp.
