Event Abstract Back to Event The First Biomagnetic SQUID Measurement: Some Recollections David Cohen1, 2* 1 Mass. General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, United States 2 Massachusetts Institute of Technology, Francis Bitter Magnet Lab, United States I have been asked to say a few words on this 40th anniversary of our paper [1], which introduced the SQUID detector into the area of biomagnetism. In particular, I have been asked to offer some recollections of that work, performed at the Francis Bitter Magnet Lab, at MIT. I find that some of the details seem to be as fresh in my mind today as if they happened yesterday (typical of the aging mind!). A general history of the early biomag work at MIT has already been written [2], but I here concentrate on the first SQUID measurement. I first relate how I happened to arrive at MIT to do this work. Earlier I had been at the University of Illinois at Chicago where I built a modest shielded room to measure the MCG and MEG. I was a young physicist who could gamble on a totally new career, but measuring weak fields of the body was considered really weird by my traditional physics colleagues, and I lacked internal support. Nevertheless, I did complete the measurements that interested me, using the best ac detector then available, which was a room-temperature copper coil, intrinsically very noisy. The next job was to look for a more sympathetic home, and I indeed found it at the MIT Francis Bitter lab, and moved there in 1969. I built a good 5-layer shielded room of roughly spherical shape, but what was needed was a very low-noise detector, to match the low background noise in this new, good room. So, in the fall of 1969, the stage was set for a new detector. I had been hearing about a new superconducting detector, with very low noise. Ed Edelsack, a funding officer who had given me a small grant, told me that he was also funding Jim Zimmerman, who had just co-invented the point-contact SQUID [3]. Ed put me in touch with Jim, and it was arranged that Jim would bring one of his first SQUIDs to MIT, to look for biomagnetic signals in the new room. Jim arrived near the end of December, with his SQUID equipment. After mounting it in the room, we looked at the easiest biomagnetic signal: the human heart. Jim was the subject. The resulting raw MCG signal was almost as clear as a routine ECG and several orders of magnitude better that the raw MCG due to a coil detector. A bit later we wrote our paper [1]. At the time, we had no idea that the use of the SQUID in bio-magnetism would eventually lead to a grand conference in Dubrovnik, 40 years later…