This paper presents the design and implementation of an integrated wireless microsystem platform that provides the possibility to support versatile implantable neural sensing devices in free laboratory rats. Inductive coupled coils with low dropout regulator design allows true long-term recording without limitation of battery capacity. A 16-channel analog front end chip located on the headstage is designed for high channel account neural signal conditioning with low current consumption and noise. Two types of implantable electrodes including grid electrode and 3D probe array are also presented for brain surface recording and 3D biopotential acquisition in the implanted target volume of tissue. The overall system consumes less than 20 mA with small form factor, 3.9 × 3.9 cm 2 mainboard and 1.8 × 3.4 cm 2 headstage, is packaged into a backpack for rats. Practical in vivo recordings including auditory response, brain resection tissue and PZT-induced seizures recording demonstrate the correct function of the proposed microsystem. Presented achievements addressed the aforementioned properties by combining MEMS neural sensors, low-power circuit designs and commercial chips into system-level integration.
References
[1]
Schwartz, A.B.; Cui, X.T.; Weber, D.J.; Moran, D.W. Brain-controlled interfaces: Movement restoration with neural prosthetics. Neuron 2006, 52, 205–220.
[2]
Peng, C.; Chaimanonart, N.; Ko, W.H.; Young, D.J. A Wireless and batteryless 10-bit implantable blood pressure sensing microsystem with adaptive RF powering for real-time laboratory mice monitoring. IEEE J. Solid-State Circuits 2009, 44, 3631–3644.
[3]
Yin, M.; Ghovanloo, M. A low-noise clockless simultaneous 32-channel wireless neural recording system with adjustable resolution. Analog. Integr. Circuits Process 2011, 66, 417–431.
Deadwyler, S.A.; Hampson, R.E.; Collins, V. A wireless recording system that utilizes Bluetooth technology to transmit neural activity in freely moving animals. J. Neurosci. Meth. 2009, 182, 195–204.
[6]
Denisov, A.; Yeatman, E. Ultrasonic vs. Inductive Power Delivery for Miniature Biomedical Implants. Proceedings of 2010 International Conference on Body Sensor Networks (BSN), London, UK, 7– 9 June 2010; pp. 84–89.
[7]
Stieglitz, T.; Boretius, T.; Ordonez, J.; Hassler, C.; Henle, C.; Meier, W.; Plachta, D.T.T.; Schuettler, M. Miniaturized neural interfaces and implants. Proc. SPIE 2012, 8251, doi:10.1117/12.912526.
[8]
Chang, C.W.; Chen, Y.J.; Hung, S.H.; Chiou, J.C. A Wireless and Batteryless Microsystem with Implantable Grid Electrode/3-dimensional Probe Array for ECoG and Extracellular Neural Recording on Rat. Proceedings of 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS), Beijing, China, 5– 9 June 2011; pp. 2176–2179.
[9]
Sun, T.; Park, W.T.; Cheng, M.Y.; An, J.Z.; Xue, R.F.; Tan, K.L.; Je, M. Implantable polyimide cable for multichannel high-data-rate neural recording microsystems. IEEE Trans. Biomed. Eng. 2012, 59, 390–399.
[10]
Chang, C.-W.; Hou, K.-C.; Shieh, L.-J.; Hung, S.-H.; Chiou, J.-C. Wireless powering electronics and spiral coils for implant microsystem toward nanomedicine diagnosis and therapy in free-behavior animal. Solid-State Electron 2012, 77, 93–100.
[11]
Vaillancourt, P.; Djemouai, A.; Harvey, J.F.; Sawan, M. EM Radiation Behavior upon Biological Tissues in a Radio-Frequency Power Transfer Link for a Cortical Visual Implant. Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Chicago, IL, USA, 30 October– 2 November 1997; Voume 6, pp. 2499–2502.
[12]
Chang, C.W.; Chiou, J.C. Development of a three dimensional neural sensing device by a stacking method. Sensors 2010, 10, 4238–4252.
[13]
Wise, K.D.; Sodagar, A.M.; Yao, Y.; Gulari, M.N.; Perlin, G.E.; Najafi, K. Microelectrodes, microelectronics, and implantable neural microsystems. Proc. IEEE 2008, 96, 1184–1202.
[14]
Bai, Q.; Wise, K.D. Single-unit neural recording with active microelectrode arrays. IEEE Trans. Biomed. Eng. 2001, 48, 911–920.
[15]
Merriam, S.M.E.; Srivannavit, O.; Gulari, M.N.; Wise, K.D. A Three-Dimensional 64-Site Folded Electrode Array Using Planar Fabrication. J. Microelectromech. Syst. 2011, 20, 594–600.
[16]
Yao, Y.; Gulari, M.N.; Wiler, J.A.; Wise, K.D. A microassembled low-profile three-dimensional microelectrode array for neural prosthesis applications. J. Microelectromech. Syst. 2007, 16, 977–988.
[17]
Rubehn, B.; Bosman, C.; Ostenveld, R.; Fries, P.; Stieglitz, T. A MEMS-based flexible multichannel ECoG-electrode array. J. Neural. Eng. 2009, 6, 036003.
[18]
Finkenzeller, K. RFID Handbook—Fundamentals and Applications in Contactless Smart Cards and Identification, 2nd ed. ed.; John Wiley & Sons: West Sussex, UK, 2003.
[19]
Kendir, G.A.; Liu, W.T.; Wang, G.X.; Sivaprakasam, M.; Bashirullah, R.; Humayun, M.S.; Weiland, J.D. An optimal design methodology for inductive power link with class-E amplifier. IEEE Trans. Circuits Syst. I 2005, 52, 857–866.
[20]
Jow, U.M.; Ghovanloo, M. Design and optimization of printed spiral coils for efficient transcutaneous inductive power transmission. IEEE Trans. Biomed. Circuits Syst. 2007, 1, 193–202.
[21]
Jow, U.M.; Ghovanloo, M. Modeling and optimization of printed spiral coils in air, saline, and muscle tissue environments. IEEE Trans. Biomed. Circuits Syst. 2009, 3, 339–347.
[22]
Ko, W.; Liang, S.; Fung, C. Design of radio-frequency powered coils for implant instruments. Med. Biol. Eng. Comput. 1977, 15, 634–640.
[23]
Harrison, R.R.; Designing, Efficient; Inductive, Power. Links for Implantable Devices. Proceedings of IEEE International Symposium on Circuits and Systems, ISCAS 2007, New Orleans, LA, USA, 27– 20 May 2007; pp. 2080–2083.
[24]
Kurs, A.; Karalis, A.; Moffatt, R.; Joannopoulos, J.D.; Fisher, P.; Soljacic, M. Wireless power transfer via strongly coupled magnetic resonances. Science 2007, 317, 83–86.
[25]
Rincon-Mora, G.A.; Allen, P.E. A low-voltage, low quiescent current, low drop-out regulator. IEEE J. Solid-State Circuits 1998, 33, 36–44.
[26]
Seese, T.M.; Harasaki, H.; Saidel, G.M.; Davies, C.R. Characterization of tissue morphology, angiogenesis, and temperature in the adaptive response of muscle tissue to chronic heating. Lab. Invest. 1998, 78, 1553–1562.
[27]
Depaulis, A.; Vergnes, M.; Marescaux, C. Endogenous control of epilepsy—The nigral inhibitory system. Prog. Neurobiol 1994, 42, 33–52.
[28]
Szuts, T.A.; Fadeyev, V.; Kachiguine, S.; Sher, A.; Grivich, M.V.; Agrochao, M.; Hottowy, P.; Dabrowski, W.; Lubenov, E.V.; Siapas, A.G.; et al. A wireless multi-channel neural amplifier for freely moving animals. Nat. Neurosci. 2011, 14, U263–U363.
[29]
Roy, S.; Wang, X. Wireless multi-channel single unit recording in freely moving and vocalizing primates. J. Neurosci. Meth. 2012, 203, 28–40.
[30]
Thomas, S.J.; Harrison, R.R.; Leonardo, A.; Reynolds, M.S. A battery-free multichannel digital neural/emg telemetry system for flying insects. IEEE Trans. Biomed. Circuits Syst. 2012, 6, 424–436.
