  Neurogenic Bladder Dysfunction has detrimental effects on day-to-day life of
millions of people. Some of the most common symptoms faced by these patients
include urinary incontinence, urgency and retention. Since elevated bladder
pressure due to prolonged urine storage inside bladder may have adverse impacts
on patient's renal health, urologists recommend clean-intermittent
catheterization (CIC) every 2 to 4 hours throughout the day to relieve bladder
pressure. However, since urine production by kidneys is an intermittent process
and most of these patients have limited mobility, such frequent trips to
washroom can prove to be challenging. Sometimes, bladder fills to capacity
before the recommended CIC time is reached causing embarrassing situation due
to leakage. Hence, time-based CIC strategy is difficult to implement and has
high chances of failure. As such, continence is the primary concern for most of
these patients but sadly there are no practical solutions available in the
market that address this concern. A real-time notification system that could
give feedback to patients on when "bladder is almost-full" could help these
patients to better plan their bathroom trips. This work explores the
feasibility of using a near infrared-light based wearable, non-invasive
spectroscopy technique that can sense amount of urine present inside the
bladder and give details on developing a bladder state estimation device.
  We present preliminary results by testing our device on optical phantoms and
performing ex vivo measurements on porcine bladder and intestines. We later
explored the possibility of using the device on human subjects, after study was
approved by the UC Davis Institution Review Board (IRB).
