These sensors can detect the micro electric current propagating in the heart to identify medical imperfections.
Electric currents propagate all across the human body. A little imbalance of these current propagation and tissue imperfections take place. Many heart problems, including tachycardia and fibrillation, are the result of such imperfections. Identifying these imperfections is a very difficult task as the process consists of highly invasive procedures and exposure to X-ray radiation.
Magnetocardiography (MCG) is a promising alternative approach to measuring heart currents indirectly. The technique involves sensing minute changes in the magnetic field near the heart caused by cardiac currents.
Scientists have developed a novel setup to perform MCG at higher resolutions. Their approach is based on a diamond quantum sensor comprising nitrogen vacancies, which act as special magnetic “centers” that are sensitive to the weak magnetic fields produced by heart currents.
The sensor used in the device easily absorbs light at specific frequencies and then re-emits them at different frequencies. The intensity of the light re-emitted at the nitrogen vacancies changes depending on the intensity and direction of the external magnetic field. The MCG setup was created using a 532 nm (green) laser to excite the diamond sensor and a photodiode to capture the re-emitted photons (light particles).
A mathematical model maps these captured photons with the corresponding magnetic fields and, in turn, with the cardiac currents responsible for them. The system will be able to create detailed two-dimensional maps of the cardiac currents measured in the hearts of laboratory rats using an unprecedented spatial resolution of 5.1 mm (0.20 inches).
The MCG sensors require cryogenic temperatures which allowed researchers to position their sensor extremely close to the heart tissue, which amplified the measured signals.
“The advantages of our contactless sensor combined with our current models will allow for more precise observations of cardiac imperfections using small mammalian model animals,” highlights Associate Professor Takayuki Iwasaki of Tokyo Institute of Technology (Tokyo Tech), Japan. “Our technique will enable the study of the origin and progression of various cardiac arrhythmias, as well as other biological current-driven phenomena.” adds Dr. Iwasaki.