Bo Hjorth Bentzen | Searcharxiv

arXiv2022

Small animal biomagnetism applications

The functioning of the human brain, nervous system and heart is based on the conduction of electrical signals. These electrical signals also create magnetic fields which extend outside the human body. Highly sensitive magnetometers, such as superconducting quantum interference device magnetometers or optically pumped magnetometers, placed outside the human body can detect these biomagnetic fields and provide non-invasive measurements of e.g. brain activity, nerve impulses, and cardiac activity. Animal models are used widely in medical research, including for disease diagnostics and for drugs testing. We review the topic of biomagnetic recordings on animal models using optically pumped magnetometers, and present our experiments on detecting nerve impulses in the frog sciatic nerve and the heart beat in an isolated guinea pig heart.

physics.med-ph↗

arXiv2018

Magnetocardiography on an isolated animal heart with a room-temperature optically pumped magnetometer

Optically pumped magnetometers are becoming a promising alternative to cryogenically-cooled superconducting magnetometers for detecting and imaging biomagnetic fields. Magnetic field detection is a completely non-invasive method, which allows one to study the function of excitable human organs with a sensor placed outside the human body. For instance, magnetometers can be used to detect brain activity or to study the activity of the heart. We have developed a highly sensitive miniature optically pumped magnetometer based on cesium atomic vapor kept in a paraffin-coated glass container. The magnetometer is optimized for detection of biological signals and has high temporal and spatial resolution. It is operated at room- or human body temperature and can be placed in contact with or at a mm-distance from a biological object. With this magnetometer, we detected the heartbeat of an isolated guinea-pig heart, which is an animal widely used in biomedical studies. In our recordings of the magnetocardiogram, we can in real-time observe the P-wave, QRS-complex and T-wave associated with the cardiac cycle. We also demonstrate that our device is capable of measuring the cardiac electrographic intervals, such as the RR- and QT-interval, and detecting drug-induced prolongation of the QT-interval, which is important for medical diagnostics.

physics.med-ph↗