Wireless recharging of battery over large distance for implantable bladder pressure chronic monitoring

This paper presents a wireless power recharging system design for implantable bladder pressure chronic monitoring application. The power recharging system consists of an external 6-turn 15-cm-diameter powering coil and a silicone-encapsulated implantable 18-turn spiral coil with a dimension of 7 mm × 17 mm × 2.5 mm, which encloses a 3-mm-diameter 12-mm-long rechargeable battery, two ferrite rods, an ASIC and a tuning capacitor. For a constant charging current of 100 µA, an RF power of 700 µW needs to be coupled into the implantable microsystem through the tuned coils. Analyses and experiments confirm that with the two coils aligned coaxially or with a tilting angle of 30° and 6 cm offset in coils axes, an external power of 3.5W or 10W is required, respectively, to achieve a large coupling distance of 20 cm at an optimal frequency of 3 MHz.

[1]  Warren M Grill,et al.  Electrical stimulation for the treatment of bladder dysfunction: Current status and future possibilities , 2002, Neurological research.

[2]  K. Najafi,et al.  A wireless single-chip telemetry-powered neural stimulation system , 1999, 1999 IEEE International Solid-State Circuits Conference. Digest of Technical Papers. ISSCC. First Edition (Cat. No.99CH36278).

[3]  Paolo Dario,et al.  An implantable telemetry platform system for in vivo monitoring of physiological parameters , 2004, IEEE Transactions on Information Technology in Biomedicine.

[4]  K. Wise,et al.  An implantable CMOS circuit interface for multiplexed microelectrode recording arrays , 1992 .

[5]  Warren M Grill,et al.  Minimally‐invasive electrical stimulation of the pudendal nerve: A pre‐clinical study for neural control of the lower urinary tract , 2007, Neurourology and urodynamics.

[6]  Robert Puers,et al.  An autonomous bladder pressure monitoring system , 2002 .

[7]  C. V. Scaldazza,et al.  Effect of Different Sized Transurethral Catheters on Pressure-Flow Studies in Women with Lower Urinary Tract Symptoms , 2005, Urologia Internationalis.

[8]  A. Wein,et al.  Evaluation of lower urinary tract symptoms in females , 2003, Current opinion in urology.

[9]  D.J. Young,et al.  Wireless implantable EMG sensing microsystem , 2008, 2008 IEEE Sensors.

[10]  Nattapon Chaimanonart,et al.  Wireless power recharging for implantable bladder pressure sensor , 2009, 2009 IEEE Sensors.

[11]  Amit K. Gupta,et al.  The reproducibility of urodynamic findings in healthy female volunteers: Results of repeated studies in the same setting and after short‐term follow‐up , 2004, Neurourology and urodynamics.

[12]  D. Linden.  Handbook Of Batteries , 2001 .

[13]  Nattapon Chaimanonart,et al.  Wireless power recharging for implantable bladder pressure chronic monitoring , 2010, 2010 IEEE 5th International Conference on Nano/Micro Engineered and Molecular Systems.

[14]  Darrin J. Young,et al.  Wireless micromanometer system for chronic bladder pressure monitoring , 2009, 2009 Sixth International Conference on Networked Sensing Systems (INSS).