Wearable device tells children when to pee
SENS-U, a small and wireless wearable sensor, accurately monitors natural bladder filling during activities of daily living and can notify children when the bladder is almost full, according to a new study.
“The current pilot study was initiated to clinically assess the performance of the SENS-U of natural bladder filling in children during activities of daily living,” researcher said, noting that the findings indicated that the device provides “an accurate, easy to use and patient-accepted method for detecting the bladder filling and notifying children before a full bladder.”
Fifteen children (mean age, 11.5±1.7 years; eight girls) were included in the study, almost half of whom (47 percent) had been diagnosed with urge incontinence/overactive bladder; 27 percent had dysfunctional voiding and 26 had other conditions, such as underactive bladder and small bladder capacity. The mean body mass index in the overall cohort was 18.5±2.9 kg/m2. [J Pediatr Urol 2019;doi:10.1016/j.jpurol.2019.04.006]
A total of 56 uroflowmetry readings were documented over the study duration. The SENS-U was able to monitor the natural filling of the bladder while the wearers were performing activities of daily living. It was able to deliver personalized notifications to the children based on a preset volume threshold, resulting in a median notification rate of 92.9 percent.
One patient reported not receiving any notification. In all the remaining cases, children voided their bladders before the maximum volume threshold was reached.
Thirteen children opted to receive a vibration notification from the SENS-U prior to voiding. Over the study period, 41 of these notifications were delivered. In 39 of these cases, children were able to respond positively, resulting in median level of response of 100 percent.
In the two other cases, the children involved failed to inform a urotherapist or researcher about the notification. Both instances were considered as outliers.
In terms of usability, researchers observed a clear and strong preference toward discreet vibrational notifications (93 percent), while 13 percent also agreed that a smartphone-based notification would be useful. Twenty percent also suggested other potential notifications, such as a small sound that resembled wetting alarms or the provision of a direct notification to the urotherapist.
It is worth noting, however, that in two participants, the SENS-U sensor could not detect the bladder properly, a problem that was attributed to device misalignment a relatively obese abdomen. “Therefore, it is advised to be aware of the influence of the abdominal curvature when implementing the SENS-U during clinical practice,” said researchers.
“[I]nitial sensor positioning also influenced the notification rate in some patients,” they added. In two patients, the device was placed a bit too low, leading to acoustic interference by the pubic bone. Further optimization of the sensor algorithm is thus needed to allow for such human lapses in placement.
In the present study, children who were admitted for inpatient bladder training were eligible for enrolment. Each participant was fitted with the SENS-U device, which uses ultrasonic waves to determine bladder dimensions and filling status. A personalized bladder threshold was then determined for each child, basing off of the respective maximum voided volume. Notifications were sent to the wearer at 80 percent and 100 percent of the threshold.
“Future research will focus on investigating the efficacy of the SENS-U in comparison to daily clinical practice, eg, as a new adjunct in bladder training (compared to timed voiding, alarm wrist watches) and to assist in guiding the timing for volume-dependent intermittent catheterization,” said researchers.