Pediatric VAD by Gryffindor 501

Firebolt Pump with Novel Technique to Create Pulsatile Flow
by Gryffindor - 501
Farida Akberali, Risa Aprilria, Kristina Barsten, Nicholas Brown, Cody Covington, Christine Elkins, Mark Felder, Lauren Fife

Pump design background:

• Based off of current technology from the Hemopump Cardiac Assist System and the Impella by Abiomed
• Both devices are used to assist/unload the heart
  
• Very small; can be implanted in the heart by a catheter inserted into the femoral artery
• The tiny pump uses axial flow to reduce myocardial workload and oxygen consumption, while increasing cardiac output, coronary- and end-organ perfusion

Our pump design:

• All parts are made out of titanium
• The impeller is magnetically levitated in the middle of the shell
• reduces hemolysis
• no "wear and tear"
• Parts are shell, front magnetic bearing, impeller, rear magnetic bearing, motor, and battery
• The device has a diameter of 4.5 mm, length of 55 mm, and weight of 15 g.
• Can generate:
• Flow rate of 0.5 - 3.2 L/min
• Pressure of 100 - 140 mmHg
• Angular velocity of impeller is 19,000 - 22,000 rpm
• Requires a power of 3.5 - 4.2 Watts
• Designed for patients over 10 kg
• Inserted into the left ventricle and stabilized just above the aortic valve
  

Muscular surgery:

• A strand of muscle will be wrapped around the aorta, just above the pump, to create a pulsatile flow
  
• Left latissimus dorsi will be cut where it terminates on the side of the ribs under the shoulder and peeled back until there is a strand 0.75 - 1 inch wide; do not denervate or detach the muscle
• Encircle the muscle around aorta and suture the free end to the strand so that it sits snuggly around the aorta without compressing it
• Insert the electrode from a modified pacemaker for muscular stimulation
• The chosen pacemaker is a Cardiomyostimulator Medtronic Model 4,710 Transform
• The pacemaker should be positioned in the left abdominal wall pocket
• One lead is connected to electrode and another to the pump
• The pacemaker will act as an integrating signal that integrates flow measurements and frequency of stimulation needed to increase/decrease pulsatility rate
• A voltage of 3.5 V is needed for stimulation of the muscle
• The muscle has a resistance of 200 ohms, therefore the necessary power is 0.06125 Watts
• This power will create a pulse of 95 bpm

Gryffindor's technique and pump are both designed as a bridge to recovery.