Managing pump speed when power constrained in a fully implanted lvad system

A control circuit for controlling a speed of an implantable blood pump, the control circuit being in communication with an internal battery and a transcutaneous energy transfer system (TETS), the control circuit comprising:

• processing circuitry configured to:
• start the pump to a programmed set speed;
• decrease the speed of the pump from the programmed set speed to a minimum set speed if either a capacity of the internal battery is less than a predetermined reserve level and TETS power is unavailable, or there is insufficient power headroom;
• and
• progressively decrease the speed of the pump from the programmed set speed if there is insufficient power to maintain the programmed set speed.

A control circuit for controlling a speed of an implantable blood pump, the control circuit being in communication with an internal battery and a transcutaneous energy transfer system (TETS), the control circuit comprising:

• processing circuitry configured to:
• start the pump to a programmed set speed;
• decrease the speed of the pump from the programmed set speed to a minimum set speed if either a capacity of the internal battery is less than a predetermined reserve level and TETS power is unavailable, or there is insufficient TETS power to maintain the programmed set speed;
• if there is insufficient power to maintain the minimum set speed, progressively decrease the speed of the pump from the minimum set speed
• if power is sufficient to maintain the minimum set speed, increase the speed of the pump to the programmed set speed after progressively decreasing the speed of the pump from the minimum set speed;
• and
• if the pump speed is less than a critical cutoff speed following progressively decreasing the speed of the pump, turn off the pump.