It involves putting a needle, a fairly large needle into usually one of the pelvic bones and collecting marrow from which is tissue that's deep inside those bones.

先要用针头,相当大的针头刺进你的盆骨,然后进行收集,这些在骨头深处的骨髓

耶鲁公开课 - 生物医学工程探索课程节选