Fig 1.
Photos of the primary prototypes.
Panel A: Photos of the five primary prototypes presented to participants in the focus group. Panel B: Components of prototype number four (Purring and Breathing), to demonstrate internal components of the cushions; C) outer soft casing, D-F) inner padding, G) Adafruit Gemma circuit board, H) power cable, I) servo motor, J) acrylic disks to hold servo motor.
Table 1.
Descriptions of the embedded mechanisms that drive the behaviours of the five prototypes shown in Fig 1.
Fig 2.
Participant ratings of the primary prototypes.
Mean and standard deviation (std) of the valence ratings given by 23 of the 24 participants for each cushion. One participants’ data was excluded due to missing values. Confidence intervals of 90% and 95% are included for visual reference calculated using the Cousineau-Morey correction [79]. Participants recorded ratings as integer values between 0 (unpleasant) to 10 (pleasant).
Fig 3.
Diagram and photos of the final haptic interface.
Panel A: Diagram of the mechanism driving the haptic sensation; E) Arduino, F) cooling fan, G) transistor, H) power cable to motor, I) motor (hidden) to drive crank, J) crank and slider, K) syringe pump that drives the inflation and deflation of the interface. Panel B: Photos of the interface front and back. Panel C: Inner parts of the interface; L) access zip, M) delrin casing for pneumatic chamber, N) smooth fabric to reduce audible friction, O) pneumatic chamber. Panel D: Photo of the interface being held in a home environment.
Fig 4.
Flow diagram illustrating the nine stages of the experiment. The four anxiety measures T1, T2, T3 and T4 are highlighted. The symbols * and △ label the intervention phases (*) and the anxiety-inducing mathematics test (△), as used in results figures later.
Fig 5.
STAI anxiety scores for within-subjects factor.
Comparison of within-subjects factor (time) for mean STAI Anxiety measures at each time T1 (baseline), T2 (post intervention 1, anticipating test), T3 (post test, pre intervention 2) and T4 (post intervention 2), including standard deviation (Std) errorbars, as well as the 90% and 95% confidence intervals (CI). Confidence intervals are calculated using the Cousineau-Morey correction [79] and therefore provide visual reference as to statistically significant changes over the within-subjects factor of time.
Fig 6.
STAI anxiety scores against baseline Test-Anxiety scores between T1 and T2.
Relationship between the participants’ change in STAI Anxiety scores and their baseline Test-Anxiety (WTAS) scores—from T1 (baseline) to T2 (post intervention 1, anticipating test). Line of best fit (LSR) shown for each condition using a linear Least Squares Regression model. Shaded regions highlight negative change in STAI, i.e. reduction in anxiety.