An Ultra-Low Power Implantable Wireless System for Long-Term Ambulatory Urodynamics

Pho­to­graph of UP-Link Hard­ware Plat­form (front)
Pho­to­graph of UP-Link Hard­ware Plat­form (back)
UP-Link Hard­ware Architecture 
UP-Link Mea­sured Pow­er Consumption
UP-Link Soft­ware Flow Chart
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Mon­i­tor­ing of blad­der pres­sure, known as cys­tom­e­try, is a key diag­nos­tic tool in uro­dy­nam­ic stud­ies of patients that exhib­it low­er uri­nary tract symp­toms. Over the past few years, there has been an increased inter­est in ambu­la­to­ry uro­dy­nam­ics due to the increased con­ve­nience and more real­is­tic mon­i­tor­ing envi­ron­ment. This paper presents an ultra-low pow­er implantable wire­less plat­form, UP-Link, for long-term ambu­la­to­ry blad­der pres­sure mon­i­tor­ing. The pro­posed plat­form, which is built using off-the-shelf com­po­nents and uses the MICS (Med­ical Implant Com­mu­ni­ca­tion Ser­vice) radio fre­quen­cy band for com­mu­ni­ca­tion, enables more cost-effec­tive and rapid devel­op­ment com­pared to exist­ing ASIC-based solu­tions. The UP-Link plat­form is pow­ered by two coin cell bat­ter­ies with a total capac­i­ty of 560mAh and has an esti­mat­ed bat­tery life of sev­er­al months to years. Results obtained through in vit­ro exper­i­ments demon­strate that the pres­sure data mea­sured using UP-Link shows excel­lent agree­ment (0.995 using the intr­a­class cor­re­la­tion coef­fi­cient method) with mea­sure­ments obtained using a com­mer­cial pres­sure gauge. An accel­er­at­ed bat­tery-life test was also per­formed, the results of which val­i­date our life­time esti­mates. The longevi­ty of the UPLink plat­form enables ambu­la­to­ry uro­dy­nam­ic stud­ies at much longer time scales than cur­rent practice.
  1. Woo Suk Lee, Albert Kim, Babak Ziaie, Charles R. Pow­ell, and Vijay Raghu­nathan, “Up-Link: an Ultra-Low Pow­er Implantable Wire­less Sys­tem for Long-Term Ambu­la­to­ry Uro­dy­nam­ics,” IEEE Bio­med­ical Cir­cuit and Sys­tem Con­fer­ence (Bio­CAS 2014), pp.384–387, Lau­sanne, Switzer­land, Oct 2014.