Bone marrow is the seat of stem cells which give rise to the cells that circulate in blood. These cells are:
Red cells (erythrocyte) – carry oxygen
White cells (leukocyte) – fight infections
Platelets (thrombocyte) – help with blood clotting
Image source: Wikipedia
There are a number of diseases in which the bone marrow stem cells may die, be replaced by fibrous tissue or by cancer which then leads to decreased blood cells. This defect will then lead to fatigue, tiredness (due to decreased red cells), repeated infections (due to decreased white cells) and easy bleeding (due to decreased platelets).
The technique of harvesting stem cells from a donor bone marrow for transplant to a recipient whose marrow is not functioning is a life saving procedure. However, the technique for harvesting these cells is very old, painful and has a fair share of complications.
In this TED talk, Daniel Kraft demonstrates a new device which aims to make the whole process of bone marrow harvesting for stem cell transplant safer and simpler (Link to Video).
More information on Stem Cell Transplantation – Mayo Clinic


