The BladderPill: An in-body system logging bladder pressure

This paper introduces the BladderPill: an in vivo sensor system which is inserted into the bladder cavity through minimal invasive cystoscopy. It allows the autonomous monitoring and logging of the internal bladder pressure. Prototype circuits have been realized and tested in various layouts, to gradually approach the final pill-shaped form, measuring 40 mm in length and 5 mm in diameter. Constructed out of off-the-shelf components and embedded into silicone as a protective encapsulation, a low-cost flexible implant is created. The circuits fit on a double-sided flex measuring 4.2 mm × 18 mm and consume on average 350 μ A. Operation for over 24 h is thus assured on a 13 mAh lithium cell with a diameter of 3 mm.