August 2014

Congratulations to Temi for winning the best student paper competition award at the IEEE EMBC'14. All of us here at the GT Bionics lab are proud of you!

GT Bionics participated in the 36th Annual IEEE Engineering in Medicine and Biology Conference in Chicago with 6 papers.

July 2014

A new story featuring the Tongue Drive System was published in the New Scientist. Here's the twitter link:

Congratulations to Dr. Mehdi Kiani for accepting a faculty position at Penn State. We at the GT Bionics lab look forward to you making us all proud. We'll miss you!

Congratulations to Dr. Mehdi Kiani for accepting a faculty position at Penn State. We at the GT Bionics lab look forward to you making us all proud. We'll miss you!

Congratulations to Temi for her EMBC'14 paper being selected among the Open Finalists for the student competition. Her paper was titled "Tracheal Activity Recognition Based on Acoustic Signals".

June 2014

Both Shurjo and Justin were awarded PURA (President's Undergraduate Research Award) salaries for the fall of 2014. Congratulations guys!

May 2014

Congratulations to Dr. Kiani and Dr. Lee for their great achievement: Graduating from GT-Bionics Lab with their PhD degrees!

March 2014

Temi was awarded a travel award at the Georgia Tech Research and Innovation Conference 2014. Temi’s winning abstract/poster was titled “A Wireless, Wearable Neckwear System for Health Monitoring”. Congratulations Temi!

Hyung-Min Lee successfully defended his thesis titled “A Power-Efficient Wireless Neural Stimulating System with Inductive Power Transmission.” Congratulatiosn Hyung-Min!

Mehdi Kiani was chosen for Sigma Xi PhD thesis awards which will be presented at the Georgia Tech Sigma Xi Awards Dinner on April 10th. Mehdi's thesis was entitled "Wireless Power and Data Transmission to High-Performance Implantable Medical Devices." Congratulations Mehdi!

January 2014

NIH-NIBIB coverage of the results of the TDS clinical study: Tongue-Driven Wheelchair Out-Maneuvers the Competition

December 2013

Dr. Mehdi Kiani successfully defends his Ph.D. thesis and starts a post-doc position at GT-Bionics Lab. Congratulations Mehdi!

November 2013

Georgia Tech coverage of the results of the TDS clinical study: Tongue Drive Wheelchair

Shepherd Center coverage of the results of the TDS clinical study: Tongue Piercing Put to Medical Use

Washington Post coverage of the results of the TDS clinical study: Tongue pierce lets the paralyzed drive wheelchairs

BBC coverage of the results of the TDS clinical study: Body piercing controls wheelchair

Radio Interview: BBC World Business Report

Results of the TDS clinical study is published in Science Translational Medicine (Impact factor > 10).

October 2013

Abner's proposal was accepted to the Wireless RERC’s App Factory on design and development for a proportionally tongue-controlled mouse. Congratulations Abner!

Hyung-Min's paper titled “A Power-Efficient Switched-Capacitor Stimulating System for Electrical/Optical Deep Brain Stimulation” was accepted for presentation at ISSCC 2014. ISSCC is the flagship of IEEE conference in solid-state circuits design and system-on-a-chip. The paper was ranked 2nd among all bio-related papers and 5th in all the papers submitted to the IMMD subcommittee. Congratulations Hyung-Min!

July 2013

Shurjo was awarded PURA (President's Undergraduate Research Award) for Fall 2013 from the Undergraduate Research Opportunities Program. Congratulations Shurjo!

May 2013

Hyung-Min and Hangue's paper was accepted to IEEE J. Solid-State Circuits.

April 2013

Mallika and Jessica won ORS's People's Choice Research Award. Jessica also won the Outstanding Service Award. Congratulations!

Mehdi's paper was accepted to IEEE Trans. Circuits Syst. II.

March 2013

Mehdi passed his PhD proposal.

February 2013

Xueliang's , et al., journal paper accepted for publication in IEEE TNSRE.

Hangue's 3rd journal paper was accepted for publication in ALOG.

Seung-Bae's , et al., journal paper accepted for publication in IEEE TBME.

December 2012

Hangue and Jeonghee won Best Demo at the 2012 IEEE BioCAS Conference. Congratulations!

November 2012

Watch Dr. Ghovanloo's 2012 TEDx Peachtree talk!

April 2012

Dr. Ghovanloo and Dr. Huo had one of the most cited papers in the Journal of Neural Engineering in 2010!

Low-Power Head-Mounted
Deep Brain Stimulator

This project seeks to develop wireless circuit interface and associated electronics for an implantable neural stimulating microsystem with a large number of stimulating sites for use in neural prostheses. The implantable microsystem should be inductively powered, button-sized, with 1024 sites, arranged in a 3-D configuration, with 128 simultaneous channels, each capable of sourcing ±100mA. The major challenges towards this goal are the implant size, microassembly method, large number of sites, effective and safe stimulation, low power consumption, and wideband wireless link between the implant and the external world.

The electrical connection to the neural tissue is formed through either a group of metal microwire electrodes or a micromachined silicon microelectrode array. For every recording channel, a low-noise low-power amplifier (LNA), which is capable of amplifying signals from mHz to kHz range, is used to amplify the acquired neural signals. A capacitive highpass filter at the input of every LNA rejects the large DC offset generated at the electrode-tissue interface but not the low-frequency evoked potentials that may contain significant neural information. 32 identical neural recording channels plus 4 monitoring channels that marks the beginning of each frame are multiplexed by a 36 to 1 multiplexer that is controlled by circular shift register (SHR). The SHR is run at 720 kHz by a triangular waveform generator, taking 20k samples/sec from every channel. This sampling rate should be enough for reconstruction of the neural signals which have a bandwidth of 8~10 kHz. A sample and hold (S&H) circuit follows the TDM to stabilize the acquired samples before pulse width modulation (PWM). The PWM is dedicated to convert the analog signal at the output of the S&H to a pseudo-digital signal that is more robust against noise. Using a pulse width modulator instead of an analog to digital converter (ADC) results in less power consumption, easier synchronization, and less complexity in the implantable device.

A voltage controlled oscillator (VCO) converts the PWM signal to a frequency shift keyed (FSK) carrier in the industrial, scientific, and medical (ISM) band. Due to the short range application of the system (within the animal cage), the VCO output can be directly applied to a miniature patch antenna with a proper off-chip matching circuit. A custom-designed ISM-band receiver is used as the external part of the system. The received PWM signal is directly converted to digitized samples using Time-to-Digital Conversion (TDC) technique on an FPGA, and transferred to a PC through USB. Finally by demultiplexing the TDM samples, the original neural signals are reconstructed. The wireless neural recording system also contains a receiver coil followed by an on-chip rectifier, filter, and regulator that provide the rest of the implant with a clean DC supply. The power carrier frequency is selected to have minimum interference with the neural signals and ISM carrier.

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