6 unit 3 Foundations of Perfusion Technology and Techniques (1).pptx

Perfusion Program Foundations of Perfusion Technology & Techniques What we will cover: Unit 3 - different types of pumps used during CPB and their function - safety concerns and methods of servoregulating each type of pump Blood Pumps in Perfusion Blood Pumps in Perfusion Sigma motor pump wi...

Perfusion Program Foundations of Perfusion Technology & Techniques What we will cover: Unit 3 - different types of pumps used during CPB and their function - safety concerns and methods of servoregulating each type of pump Blood Pumps in Perfusion Blood Pumps in Perfusion Sigma motor pump with series of keys pressing in sequence against resilient tubing. Used in cross-circulation by Dr. C. Walton Lillehei Diagram of Debakey–Schmidt pump utilized in the Gibbon–IBM cardiopulmonary bypass machine Dodrill-GMR mechanical pump being used in the animal laboratory with the row of finger cot pumps being adjusted. Blood Pumps in Perfusion • Initial HLM technology in the 1950s used peristaltic pumps (aka roller pumps), and the technology has not greatly changed from its inception • Peristaltic pumps or “roller pumps” are positive displacement pumps used for moving fluid • During historical development of equipment capable of supporting a patients circulatory and respiratory needs, the majority of time that was spent on development was for oxygenation and de-airing. • The first roller pump was patented in 1855 by Porter and Bradley and was hand operated • A modification first named "surgical pump", designed and manufactured by E. E. Allen in 1887, was intended for direct blood transfusion • Truax, who also distributed and promoted the Allen pump with one roller, developed the first double roller pump in 1899 “Surgical Pump” (1887), designed and manufactured by E. E. Allen. Probably the first published illustration of a roller pump for the transportation of blood The Allen Surgical Pump (1889), as manufactured and distributed by Charles Truax. From the title page of his prospectus. Note the rich ornamentation on the pump, common at this time ** Obviously, there were no safety features in these early iterations, and only in the 1950s were pressure-based servo-regulation safety features introduced Blood Pumps in Perfusion Roller Pumps • length of tubing located inside a curved raceway at the perimeter of the travel of rollers mounted on the ends of rotating arms (usually two, 180° apart), arranged in such a way that one roller compresses the tubing at all times • Flow of blood is induced by compressing the tubing, thereby pushing the blood ahead of the moving roller • Safety: roller pumps perform independent of afterload • The circuit must be monitored • Sudden occlusion of the inlet of the roller head can create extreme negative pressure to the point where the tubing may cavitate and create air bubbles in the circuit; occlusion of the outlet of the roller head can result in rupture of tubing within the raceway and/or ECC. Servo-regulation: provides automatic reduction and/or cessation of roller head function due to high transduced line pressure as well as low venous reservoir volume (measured by a level sensor). Blood Pumps in Perfusion Centrifugal Pumps • non-occlusive pumps and utilize a magnet and impeller combination to propel blood through the CPB circuit • The first centrifugal pump was developed in the 17th century by Denis Papin (1687) • In 1976, the Medtronic centrifugal pump became available • The centrifugal pump used for heart surgery consists of an impeller with flanges mounted on a rotating central shaft, inside a plastic housing 1687 French-born inventor Denis Papin develops the first true centrifugal pump, one with straight vanes used for local drainage. • When the console is turned on and the rpms are increased, the cones or fins spin rapidly, creating positive pressure that propels fluid forward Medtronic Affinity CP ** Servo-regulation: provides automatic reduction of centrifugal head speed due to high transduced line pressure as well as low venous reservoir volume (measured by a level sensor); also activates in-line auto-clamp (if equipped) to cause cessation of forward flow when low venous reservoir level is triggered. Blood Pumps in Perfusion Alternative Pumps Heartmate XVE Blood Pumps in Perfusion Syncardia (TAH) Total Artificial Heart Blood Pumps in Perfusion Impella CP Blood Pumps in Perfusion • Archimedes screw, machine for raising water, invented by the ancient Greek scientist Archimedes for removing water from the hold of a large ship. • consists of a circular pipe enclosing a helix and inclined at an angle of about 45 degrees to the horizontal with its lower end dipped in the water • rotation of the device causes the water to rise in the pipe • Other forms consist of a helix revolving in a fixed cylinder or a helical tube wound around a shaft. Blood Pumps in Perfusion Rotary Piston Pumps • the blood flow is pulsatile instead of a non-physiological continuous flow • risk of flow-induced blood damage and platelet activation may be reduced due to low shear stress to the blood Blood Pumps in Perfusion https://youtu.be/cMmwb3JmL00? si=uVPxqUQUbQ-Q6uI0 https://youtu.be/TgBAN AOI-J4?si=TGm0nPSc_rz MyGM3 https://youtu.be/OH8_56HCBXE?si= OwlZoxmEI__GuBRw https://youtu.be/Asa6miVcUKA?si =KjMcJAZuxELFkr2Y Positive Displacement Pumps https://youtu.be/1ca-rXDqMMo?si=-ybgNf K0bmlBt5Bd https://youtu.be/IxIio2r_bQE?si=dJJYZAWmf G2ZQWRy Blood Pumps in Perfusion Servoregulation • the control of speed (velocity) and position of a motor based on a feedback signal. (sciencedirect.com) • With centrifugal or roller pumps, this is observed as: • Slowing of pump speed upon feedback • Low reservoir volume • High line pressure • After servoregulation occurs, alarm stop functions are embedded in the software to trigger safety devices to cease the cause of the alarm. • This looks like: • The closing of an “arterial autoclamp” for centrifugal pumps due to low reservoir level alarm. • The complete cessation of a roller pump due to low reservoir level. Or • * The complete cessation of a roller pump due to high arterial line pressure Blood Pumps in Perfusion