Home-based monitoring of lower urinary tract health: simultaneous measures using wearable near infrared spectroscopy and linked wireless scale

Abstract

Background: Worldwide <4 billion people suffer from urinary tract symptoms that negatively affect quality of life and incur significant cost. Currently, clinical assessment requires invasive urodynamic testing; as this involves catheterization in clinic/hospital settings, only periodic assessment is possible. This is problematic as treatment requirements vary over time; home-based monitoring/assessment able to optimize care would benefit patients and physicians. Methods: A monitoring system integrating a wireless uroflow scale with a wearable transcutaneous near infrared spectroscopy (NIRS) device was designed incorporating end-user feedback, and the feasibility of home use to asses voiding function tested. The NIRS device is worn superior to the pubis during voiding. Light emitting diodes (wavelengths of 760 and 850 nm) allow transcutaneous monitoring of changes in chromophore concentration in the bladder detrusor muscle. The scale collects the urine voided, recording volume increments of 1cc. Data are transmitted wirelessly; incorporated software generates graphs of NIRS chromophore parameters indicative of hemodynamic and oxygenation effects as the bladder contracts, and uroflow data (total volume, mean and average flow rate, peak flow and pattern of uroflow). Results: Serial measures were recorded during spontaneous voiding by an asymptomatic 59-year-old male and a 78-yearold male with lower urinary tract symptoms. During each void, consistent NIRS-derived changes in chromophore concentrations individual to each subject were seen, and simultaneous uroflow measurements successfully recorded. Conclusion: Home based non-invasive NIRS monitoring of bladder function with simultaneous measurement of uroflow is feasible. This technology is capable of providing the repeated measures required to optimize disease monitoring and treatment.