Stem cell harvesting device with passive flexible drilling unit for bone marrow transplantation

A novel device is described for efficiently harvesting bone marrow in bone marrow transplantation that uses a newly developed passive flexible drilling unit and suction mechanism. The device reduces the invasiveness of bone marrow harvesting by collecting stem cells from the iliac bone with minimal punctures and by reducing the operation time and the contamination by T cells. The device is inserted into the medullary space from the iliac crest and aspirates the bone marrow while an end-mill on the tip of the drilling unit drills through the cancellous bone to create a curved path. In-vitro and in-vivo pig studies showed that the device can be inserted into the medullary space of the pig iliac bone, 131 mm by 32.1 mm/min, and used to harvest about six times as much bone marrow per puncture as the conventional aspiration method. They also showed that the device can generate higher and longer negative pressure (–76.9 kPa for 5.96 sec) than the aspiration method (–41.8 kPa for 4.97 sec). The device, when applied in clinical study, will reduce invasiveness by harvesting denser graft from a wider area of the iliac bone compared to the conventional aspiration method, although minimal puncturing is required. Index Terms — biomedical equipment, bone marrow transplantation, drilling, flexible device, hematopoietic stem cells