Preventive equipment for urinary incontinence: a device employing lower abdominal impendance changes

The object of this work was to develop a monitoring device for measuring the volume of urine in the bladder to signal, in advance, the need to urinate and thus help prevent urinary incontinence. A high-frequency electric current of 50 KHz transmitter was applied to a pair of terminals placed on the surface of a human body. The constant current was 2mA (p-p). A pair of voltage electrodes was placed in the path of the electric current to pick up high-frequency voltage signals. The best position for current electrodes was found to be on the surface of both femoral joints. Positioning the voltage electrode above the bladder on the lower abdomen was most efficient for detecting the volume of urine. New current electrodes sutured onto underpants were fitted on the surface above the femoral joints, which did not shift in the case of movement by the subjects. The reproducibility and stability were remarkably good with this electrode. The alarm level which foretold both maximum storage volume and maximum desire to void was examined. After that, when the alarm level was set within the range of impedance charge, 60% to 70%, the possibility of prediction of urination exists.