Verification of a system utilizing heartbeat‑induced acoustic pulse waves for estimating the time at which bladder urine increases to a level requiring drainage among individuals with spinal cord injury

Spinal cord injury (SCI) can disrupt urinary sensation, leading to difficulties with urination. The study explores using heartbeat-induced acoustic pulse waves (HAPWs) to estimate when individuals with SCI need to drain their bladder, preventing complications like autonomic dysreflexia. The system monitors autonomic nervous activity through HAPWs to detect when urine volume increases to a level requiring drainage. It adapts an algorithm (ATUI) previously tested on healthy individuals, modifying thresholds to suit SCI patients. The adapted algorithm showed promising results in detecting the need for urinary drainage in SCI patients without missing urination times or identifying false alarms, suggesting a practical solution for managing urinary health and preventing related complications.

• 1
  The original algorithm, developed using data from healthy participants, showed an F-score of 0.70 when applied to individuals with SCI, indicating moderate accuracy in detecting the need for urinary drainage.
• 2
  Adapting the algorithm by modifying three thresholds significantly improved its accuracy, achieving an F-score of 1.00. This suggests the potential for personalized adjustments to enhance the system's performance for SCI patients.
• 3
  The study found that the heart rate variability (HRV) in ultralow/very low frequency bands is important for autonomic nervous activity associated with increased urine in the bladder.