Figures (7)  Tables (1)

    • Figure 1. 

      Head posture monitoring system's architecture. (a) System overview. The posture monitor was controlled by the app. The posture data are transferred to the app, which uploaded it to the backend website. (b) The backend website provides basic information and the posture compliance data of each patient for health professionals. (c) The control app controls the monitor, sets the target posture, and demonstrates the compliance results for each session. (d) The head posture monitor can detect posture and provides vibration alerts.

    • Figure 2. 

      (a) An example of three-axis posture angles changes over time at night. The dashed line indicates the start of the selected nighttime data. (b) Unstable posture angles with maximum change > 100°. (c) Stable posture angle with changes in all three axes < 2°.

    • Figure 3. 

      Direction of the heatmap corresponding to the patient's posture. The posture data on the angle and direction of rotation along the axis were projected onto a spherical surface as a point. The distribution of posture data for each second generated a heatmap. The reference point indicates the original posture.

    • Figure 4. 

      Patient's compliance was higher in the alert-on period compared with the alert-off period during both daytime and nighttime (a), and for both prone posture and Fowler's posture (b), although the difference for Fowler's posture did not reach statistical significance.

    • Figure 5. 

      Scatter plot showing statistically significant correlations between hourly compliance improvements and patient compliance in the alert-off period.

    • Figure 6. 

      Patient's average compliance over time. (a) All postures. (b) Prone posture. (c) Fowler's posture. The alert-on periods are marked in yellow.

    • Figure 7. 

      Heatmap of patients' posture in prone and Fowler's postures.

    • Day Night
      Age Median (min, max) 65 (25, 70) 62 (17, 75)
      Gender Male/female 17/9 8/13
      Tamponade Air/C3F8/silicon oil 4/7/15 5/8/9
      Body position Prone/Fowler's 21/5 17/4

      Table 1. 

      Demographic and clinical characteristics of the included patients