Low-Power CMOS Interface for Recording and Processing Very Low Amplitude Signals

  • A. Harb
  • Y. Hu
  • M. Sawan
  • A. Abdelkerim
  • M.M. Elhilali


In this paper, we describe a low-power low-voltage CMOS very low signal acquisition analog front-end of sensor electronic interfaces. These interfaces are mainly dedicated to biomedical implantable devices. In this work, we focus on the implantable bladder controller. Since the nerve signal has very low amplitude and low frequency, it is, at first fed to a low-voltage chopper amplifier to reduce the flicker (1/f) noise and then amplified with a programmable gain high CMRR instrumentation amplifier. This is followed by an analog signal processing circuit to rectify and bin-integrate (RBI) the amplified signal. The resulting RBI is then converted to digital and transferred to the implant's central processor where information about bladder can be extracted. The numerous analog modules of the system have been implemented in CMOS 0.35 μm, 3.3 V technology. The design, simulation and measurement results of the proposed interface are presented. At supply voltage of 2.2 V the power dissipation is less than 1.4 mW, the input equivalent noise is 56 nV/\(\sqrt {{\text{Hz}}} \) and the error in RBI calculation is less than 0.15%.

analog signal processing sensor interfaces low-amplitude signals chopper preamplifier CMOS technology rectify and bin-integrate implantable devices 


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  1. 1.
    S. Boyer, M. Sawan, M. Abdel-Gawad, S. Robin, and M.M. Elhilali, “Implantable selective stimulator to improve bladder voiding: Design and chronic experiments in dogs.” IEEE Trans. Rehab. Eng., vol. 8, no. 4, pp. 464–470, 2000.Google Scholar
  2. 2.
    T.A. Perkins, “Versatile three-channel stimulation controler for restoration of bladder function in paraplegia.” J. Biomed. Eng., no. 8, pp. 268–271, 1986.Google Scholar
  3. 3.
    A. Lickel, “Restoration of lateral hand grasp in tetraplegic patient applying natural sensory feedback.” Ph.D. dissertation, 1998.Google Scholar
  4. 4.
    B. Upshaw and T. Sinkjaer, “Digital signal processing algorithms for the detection of afferent nerve activity recorded from cuff electrodes.” IEEE Trans. Rehab. Eng., vol. 6, no. 2, pp. 172–181, 1998.Google Scholar
  5. 5.
    M.K. Haugland and T. Sinkjaer, “Cutaneous whole nerve recording used for correction of footdrop in hemiplegic man.” IEEE Trans. Rehab. Eng., vol. 3, no. 4, pp. 307–317, 1995.Google Scholar
  6. 6.
    R.B. Stein, D. Charles, L. davis, J. Jhamandas, A. Mannard, and T.R. Nichols, “Principles underlying new methods for chronic neural recording.” Can. J. Neurol. Sci., pp. 235–244, 1975.Google Scholar
  7. 7.
    E.V. Goodall, T.M. Lefurge, and K.W. Horch, “Information contained in sensory nerve recordings made with intrafascular electrodes.” IEEE Trans. Biomed. Eng., vol. 38, no. 9, pp. 846–850, 1991.Google Scholar
  8. 8.
    M. Haugland, T. Sinkjaer, and J. Haase, “Force information in whole human sensory nerve recordings,” in Proceedings of the 4th Vienna Workshop on FES, 1992, pp. 130–133.Google Scholar
  9. 9.
    T. Sinkjaer, M. Haugland, and J. Haase, “The use of natural sensory nerve signals as an advanced heel-switch in drop foot patients,” in Proceedings of the 4th Vienna Workshop on FES, 1992, pp. 134–137.Google Scholar
  10. 10.
    B.S. Nashold, H. Friedman, and R. Boyarsky, “Electrical activation of micturition by spinal-cord stimulation.” J. Surg. Res., vol. 11, no. 3, pp. 144–147, 1971.Google Scholar
  11. 11.
    E.A. Tanagho and R.A. Schmidt, “Electrical stimulation in the clinical management of the neurologic bladder.” J. Urology, vol. 140, pp. 1331–1339, 1988.Google Scholar
  12. 12.
    J.S. Li, M. Hassouna, M. Sawan, F. Duval, and M.M. Elhilali, “Role of electric stimulation in bladder evacuation following spinal cord transection.” J. Urology, vol. 147, pp. 1429–1434, 1992.Google Scholar
  13. 13.
    N.J.M. Rijkhoff et al., “Sacral root stimulation in tile dog: Reduction of urethral resistance,” in Proc. IEEE EMBS, San Diego, 1993, pp. 1257–1258.Google Scholar
  14. 14.
    A. Ba, E. Schneider, A. Abdel-Karim, M. Sawan, and M.M. Elhilali, “New dual stimulator to improve the bladder functions: Chronic experiments in dogs.” IFESS, Lubljana, June 2002.Google Scholar
  15. 15.
    B. Provost and M. Sawan, “Proposed new bladder volume monitoring device based on impedance measurement.” Med. Biol. Eng. Comput., no. 35, pp. 691–694, 1997.Google Scholar
  16. 16.
    E. L. Koldewin et al., “Bladder pressure sensors in an animal model.” J. Urology., vol. 151, pp. 1379–1384, 1994.Google Scholar
  17. 17.
    K. Takayam, M. Takei, T. Soejima, and J. Kumazawa, “Continuous monitoring of bladder pressure in dogs in a completely physiological state.” Br. J. Urol., no. 60, pp. 428–432, 1987.Google Scholar
  18. 18.
    J.A. Woljen et al., “Bladder mobility detection using the Hall effect,” IEEE Trans. Biomed. Eng., pp. 295–299, 1973.Google Scholar
  19. 19.
    J.C. Denniston and L.E. Baker, “Measurement of urinary bladder emptying using electrical impedance,” Med Biol. Eng. Comput., pp. 305–306, 1975.Google Scholar
  20. 20.
    M. Sawan, K. Arabi, and B. Provost, “Implantable volume monitor and miniaturized stimulator dedicated to bladder control.” Artificial Organs Journal, vol. 21, no. 3, pp. 219–222, 1997.Google Scholar
  21. 21.
    M.A. Crampon, M. Sawan, V. Brailovski, and F. Trochu, “New easy to install nerve cuff electrode using SMA armature.” Artificial Organs Journal, vol. 23, no. 5, 1999, pp. 392–395.Google Scholar
  22. 22.
    J.A. Hoffer and M.K. Haugland, in R.B. Stein, P.H. Peckham, and D.B. Popovic (Eds.), Neural Prostheses: Replacing Motor Function after Disease or Disability, Oxford University Press: New York, 1992.Google Scholar
  23. 23.
    S. Jezernik et al., “Whole nerve cuff recordings from nerves signal innervating the urinary bladder.” Proc. IFESS, 1997, pp. 45–46.Google Scholar
  24. 24.
    D.B. Popovic, R.B. Stein, K.L. Jovanovic, R. Dai, A. Kostovand, and W.W. Armstrong, “Sensory nerve recording for closed-loop control to restore motor function.” IEEE Trans. Biomed. Eng., vol. 40, no. 10, pp. 1024–1031, 1993.Google Scholar
  25. 25.
    C.C. Enz, E.A.Vittoz, and F. Krummenacher, “A CMOS chopper amplifier.” IEEE J. Solid-State Circ. vol. 22, pp. 335–342, 1987.Google Scholar
  26. 26.
    C.C. Enz, and G.C. Temes, “Circuit techniques for reducing the effects of op-amp imperfections: Autozeroing, correlated double sampling, and Chopper stabilization.” Proceedings of the IEEE. vol. 84, pp. 1584–1614, 1996Google Scholar
  27. 27.
    D.L. Feucht, Handbook of Analog Circuit Design. Academic Press Inc.: San Diego, 1990.Google Scholar
  28. 28.
    C. Menolfi and Q. Huang, “A low-noise CMOS instrumentation amplifier for thermoelectric infrared detectors.” IEEE J. Solid-State Circ. vol. 32, pp. 968–976, 1997.Google Scholar
  29. 29.
    F. Krumenacher and N. Joehl, “A 4-MHz CMOS continuous time filter with on-chip automatic tuning.” IEEE J. Solid-State Circuits, vol. 34, no. 1, pp. 107–110, 1999.Google Scholar
  30. 30.
    E. Bruun and P. Shah, “Dynamic range of low-voltage cascode current mirrors,” in Proc. ISCAS, 1995, pp. 1328–1331.Google Scholar
  31. 31.
    P.J. Crawley and G.W. Roberts, “High-swing current mirror with arbitrarily high output resistance.” Electronics Letters, vol. 28, pp. 361–361, 1992.Google Scholar
  32. 32.
    R. Unbehauen and A. Cichocki, MOS Switched-Capacitor and Continuous-Time Integrated Circuits and Systems. Spring-Verlag: Berlin, 1989.Google Scholar
  33. 33.
    H. Matsumoto and K. Watanabe, “Spike-free switched capacitor circuits.” Electronics Letters, vol. 23, no. 8, pp. 428–429, 1987.Google Scholar
  34. 34.
    U. Gatti, F. Maloberti, and G. Palmisano, “An accurate CMOS sample-and-hold circuit.” IEEE J. Solid-State Circ. vol. 27, no. 1, pp. 120–122, 1992.Google Scholar
  35. 35.
    K. Nagaraj, J. Vlach, T.R. Viswanathan, and K. Singhal, “Switched-capacitor integrator with reduced sensitivity to amplifier gain.” Electron. Lett., vol. 24, pp. 1104–1106, 1986.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • A. Harb
  • Y. Hu
  • M. Sawan
  • A. Abdelkerim
  • M.M. Elhilali

There are no affiliations available

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