Magnetoencephalogram(MEG)
Indira Gandhi Centre for Atomic Research (IGCAR), at Kalpakkam has established a SQUID based Magnetoencephalography (MEG) system as the first such facility in India for non-invasive studies of human brain. MEG is a relatively new and powerful tool for probing the dynamics of the brain and maps the neuromagnetism due to neural currents in the brain using SQUIDs, which are magnetic sensors of unparalleled sensitivity. The indigenous development of this important bio-medical instrumentation has been supported by the Department of Science & Technology (DST), Govt. of India as a sequel to the successful development of SQUID sensors at IGCAR.
The multichannel MEG (Magnetoencephalography) system comprises a cryostat containing the SQUID array, electronics and control instrumentation - all inside a custom built Magnetically Shielded Room (MSR). The project has been implemented in two phases. In the first phase, the MSR capable of attenuating low frequency electric and magnetic noise by 70 dB (at 1 Hz) increasing to 100 dB (>10 Hz) connected by shielded conduits to a RF shielded room (attenuation 100 dB >1 MHz) was established and a single channel MEG instrument complete with the SQUID, readout electronics and a FRP cryostat was set up. Spontaneous brain activity (typically 1 to 10 pico-Tesla) as well as the evoked response (typically 0.1 pico-Tesla) could be demonstrated. In the second phase, taken up subsequently, mutichannel MEG instruments with 4 SQUID channels and 13 SQUID channels were developed and commissioned successively. The overall system noise, measured in each channel, is under 12 fT/√Hz.
Magnetocardiography (MCG) , which measures the cardiac magnetic fields, shares a common infrastructure with the MEG. Using these systems, several biomagnetic fields (magnetocardiogram, α-rhythm of brain and auditory evoked response) have been successfully measured with high signal-to-noise ratio. Several MCG investigations on subjects and patients (the latter referred by the Hospital at Kalpakkam) have been made. Cardiac anomalies like Left Bundle Branch Block and fragmented QRS have been seen. Non -invasive "His Bundle" tracking has been made on a number of healthy subjects. it is evident that MCG shows features that are far more resolved compared to the standard hospital ECG, highlighting the potential of MCG as a powerful diagnostic tool complementing the ECG. Using the MCG data, iso-field contour maps have been generated. The source of the cardiac electrical activity was modeled as an equivalent current dipole (ECD) and the direction of the (ECD) has been inferred at different instants of the cardiac cycle and has been represented in a video format.
Subsequently, assembly of two large systems has been initiated: a 37 channel system in a flat bottom cryostat for MCG and a 86 channel system in a helmet shaped cryostat for MEG. The latter is being supported by a new project grant (2011-2014) by the DST and will include clinical trials in collaboration with the neurologists at the Sri Chitra Tirunal Institute of Medical Science and Technology (SCTIMST). These will enable simultaneous recording of biomagnetic signals at a large number of locations without the necessity to move the subject or the cryostat.
The project offers further challenges and calls for multifarious skills in disciplines like cryogenics, low temperature physics, superconductivity, specialized mathematical algorithms and imaging techniques, extremely low noise analog electronics circuits and system integration. There are possibilities for collaboration from interested scientists, engineers and medical professionals in the country.
The programme has received much attention from scientists including medical professionals, VIP visitors and media. These are reflected elsewhere in this report. A few articles in the media can be seen in the following links:
Scientists devise new way for detecting brain, heart ailments
by Lalitha Vaidyanathan
http://news.in.msn.com/national/article.aspx?cp-documentid=4808022
Kalpakkam (TN), January 16 2011 (PTI) -- Scientists of Indira Gandhi Centre for Atomic Research (IGCAR) here have developed a novel technique for effective diagnosis of dysfunctions of heart and brain making use of body's biomagnetic field. Magneto-Encephalogram (MEG) and Magneto-Cardiogram (MCG) techniques have been developed using the Superconducting Quantum Interference Devices (SQUID) to measure the extremely weak magnetic fields associated with the physiological activities of human brain and human heart.
Brain Imaging with SQUIDs in India
Priyamvada Sivasubramanian
Ethical Technology; Posted: Jun 5, 2007
Institute for Ethics and Emerging Technologies
http://ieet.org/index.php/IEET/more/priya20070605/
Priya interviews Dr. T. S. Radhakrishnan on the use of Superconducting Quantum Interference Device (SQUIDs) to image brains at the Indira Gandhi Centre for Atomic Research, about 60 kilometers south of Chennai (Madras).
Magnetoencephalography (MEG) is a completely noninvasive, non-hazardous technique for functional brain mapping. A MEG facility is being established at the Material Science division, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam through an entirely indigenous effort by a team headed by Mr. M. P. Janawadkar and Dr. T. S. Radhakrishnan.
IGCAR device to treat mentally challenged people
Chennai: The Indira Gandhi Centre for Atomic Research (IGCAR) has developed the country's first Superconducting Quantum Interference Devices (SQUID), a device that can help to treat mentally challenged people and heart ailments, a IGCAR top official said today.
SQUID's sensitivity is so high that it is possible to detect even the tiny magnetic field associated with physiological activities of human heart and brain, IGCAR director Dr Baldev Raj told reporters on the sidelines of Ramachandra Universities' foundation day celebrations.
Mail your queries and suggestions and interest to
M.P.Janawadkar
Outstanding Scientist
Head, SQUIDs and Applications Section
Condensed Matter Physics Division
Materials Science Group
Indira Gandhi Centre for Atomic Research
Kalpakkam, Tamilnadu—603102, India
Tel : 044-27480500(Ext:22776)
Fax : 044-27870081
Email :
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