Coil winding pattern for enhanced motor efficiency

An intravascular blood pump for insertion into a patient's body, the pump comprising:

• an elongate housing having a proximal end connected to a catheter and a distal end connected to the pump, the housing having a longitudinal axis;
• and
• a slotless permanent magnet motor contained within the housing, the motor having p magnet pole pairs and n phases, where p is an integer greater than one, and n is an integer ≥3, the motor comprising:
• a stator winding having 2np coils wound to form two coils per phase per magnet pole pair such that a coil from each phase is circumferentially arranged next to a coil from a different phase in a sequential order of phase, the arrangement repeated along the stator winding such that each coil of the 2np coils spans 360/(2np) mechanical degrees about a cross section of the stator winding each coil having an inner layer and an outer layer, the outer layer overlaid on the inner layer, and
• a permanent magnet rotor supported for rotation and configured to generate a magnetic flux for interaction with the stator winding,
• wherein the two coils per phase per magnet pole pair of the stator winding are connected in series such that a direction of current flow through a first coil of the two coils is opposite to a direction of current flow in a second coil of the two coils, the current flow in the first coil and the current flow in the second coil interacting with opposite polarities of the magnetic flux of the rotor for producing torque in the same direction, thereby facilitating rotation of the rotor for a flow of blood through the pump.