Stand Alone Cylindrical Blood Heat Exchanger With Spiral Volute

A standalone blood heat exchanger comprising:

• a first fluid path containing a heated liquid;
• a second fluid path containing blood from a patient;
• an annular cylinder comprising a network of hollow tubes oriented longitudinally along the length of the annular cylinder, the interior of the hollow tubes defining the first fluid path;
• a cylindrical body containing the annular cylinder, the cylindrical body having an interior wall and having a defined space between the inner wall of the cylindrical body and an outer surface of the annular cylinder;
• and
• a central volume running longitudinally at the center of the annular cylinder, the second fluid path being disposed between the defined space between the inner wall of the cylindrical body and the outer surface of the annular cylinder and the central volume, passing through spaces between the hollow tubes, wherein the defined space between the inner wall of the cylindrical body and the outer surface of the annular cylinder is selected to reduce stagnation of flow of the patient’s blood while the patient’s blood travels along the second fluid path.