Stroke — when blood does not reach the brain — generally means rushing first to a diagnostic centre for a CT scan to detect which type of stroke it is.
If the cause is a clogged artery or vein (ischaemic), the doctor would prescribe a medicine to melt away the block.
If, on the other hand, the cause is a ruptured blood vessel, leading to bleeding (haemorrhagic), the treatment involves creating a clot to plug the leak.
The standard treatment today for a paralytic stroke is physiotherapy, which may, at best, yield partial results.
Prof Shubhajit Roy Chowdhury of the Biomedical Systems Laboratory, School of Computing and Electrical Engineering, IIT-Mandi, Himachal Pradesh, has come up with a portable ‘point of care’ device, resembling a medium-sized suitcase, to detect the type of stroke and treat it.
To detect the type of stroke, a wearable ‘near infra-red spectroscopy’ (NIRS) device emits light of 650-950 nm wavelength, which interacts with blood chromophores after penetrating the tissue.
The reflected light is collected by a photodiode, which can tell whether the stroke is ischaemic or not, since light reflected by a block (clot) is different from that reflected by blood.
The next problem is determining how to revive brain function. Prof Chowdhury explained to Quantum that while the damaged neurons (brain cells) are gone forever, it is possible to coax the remaining neurons to assume the full functions of the brain. This is done by exposing the brain to a low-density direct current — 0.5-0.6 ampere per sq m against the brain’s tolerance limit of 250 ampere per sq m.
This ‘transcranial direct current stimulation’ (tDCS) has been shown to help revive paralysed parts of the body.
While tDCS is nothing new, the heart of Prof Chowdhury’s invention is a new type of electrode, a button-shaped device with near-invisible hair-like protrusions (spikes).
This special design is crucial. Why? As we know, the brain is full of folds. Through tDCS, current easily reaches the raised folds (gyri) but not the grooves (sulci). Prof Chowdhury’s ‘spiking electrode’ can reach the sulci too.
Bharat Electronics Ltd, the Bengaluru-based government-owned company, seems to be impressed by the device, which, according to Prof Chowdhury, is at a ‘technological readiness level’ of 4.
BEL is in the process of commercialising the device, he told Quantum.