Open AccessCannula Tip With Integrated Volume Sensor for Rotary Blood Pump Control: Early-Stage Development
Author(s) -
Joshua Cysyk,
Ray Newswanger,
Eric Popjes,
Walter E. Pae,
Choon-Sik Jhun,
Jenelle Izer,
W. Jason Weiss,
Gerson Rosenberg
Publication year - 2019
Publication title -
asaio journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 66
eISSN - 1538-943X
pISSN - 1058-2916
DOI - 10.1097/mat.0000000000000818
Subject(s) - cannula , biomedical engineering , materials science , conductance , peristaltic pump , waveform , ventricle , suction , electrode , voltage , cardiology , medicine , electrical engineering , surgery , chemistry , mechanical engineering , engineering , mathematics , combinatorics
The lack of direct measurement of left ventricular unloading is a significant impediment to the development of an automatic speed control system for continuous-flow left ventricular assist devices (cf-LVADs). We have developed an inlet cannula tip for cf-LVADs with integrated electrodes for volume sensing based on conductance. Four platinum-iridium ring electrodes were installed into grooves on a cannula body constructed from polyetheretherketone (PEEK). A sinusoidal current excitation waveform (250 μA pk-pk, 50 kHz) was applied across one pair of electrodes, and the conductance-dependent voltage was sensed across the second pair of electrodes. The conductance catheter was tested in an acute ovine model (n = 3) in conjunction with the HeartMate II rotary blood pump to provide circulatory support and unload the ventricle. Echocardiography was used to measure ventricular size during pump support for verification for the conductance measurements. The conductance measurements correlated linearly with the echocardiography dimension measurements more than the full range of pump support from minimum support to suction. This cannula tip will enable the development of automatic control systems to optimize pump support based on a real-time measurement of ventricular size.