TY - JOUR
T1 - A Sensorless Modular Multiobjective Control Algorithm for Left Ventricular Assist Devices
T2 - A Clinical Pilot Study
AU - Maw, Martin
AU - Schlöglhofer, Thomas
AU - Marko, Christiane
AU - Aigner, Philipp
AU - Gross, Christoph
AU - Widhalm, Gregor
AU - Schaefer, Anne-Kristin
AU - Schima, Michael
AU - Wittmann, Franziska
AU - Wiedemann, Dominik
AU - Moscato, Francesco
AU - Kudlik, D'Anne
AU - Stadler, Robert
AU - Zimpfer, Daniel
AU - Schima, Heinrich
N1 - Publisher Copyright:
Copyright © 2022 Maw, Schlöglhofer, Marko, Aigner, Gross, Widhalm, Schaefer, Schima, Wittmann, Wiedemann, Moscato, Kudlik, Stadler, Zimpfer and Schima.
PY - 2022/4/25
Y1 - 2022/4/25
N2 - BACKGROUND: Contemporary Left Ventricular Assist Devices (LVADs) mainly operate at a constant speed, only insufficiently adapting to changes in patient demand. Automatic physiological speed control promises tighter integration of the LVAD into patient physiology, increasing the level of support during activity and decreasing support when it is excessive.METHODS: A sensorless modular control algorithm was developed for a centrifugal LVAD (HVAD, Medtronic plc, MN, USA). It consists of a heart rate-, a pulsatility-, a suction reaction-and a supervisor module. These modules were embedded into a safe testing environment and investigated in a single-center, blinded, crossover, clinical pilot trial (clinicaltrials.gov, NCT04786236). Patients completed a protocol consisting of orthostatic changes, Valsalva maneuver and submaximal bicycle ergometry in constant speed and physiological control mode in randomized sequence. Endpoints for the study were reduction of suction burden, adequate pump speed and flowrate adaptations of the control algorithm for each protocol item and no necessity for intervention via the hardware safety systems.RESULTS: A total of six patients (median age 53.5, 100% male) completed 13 tests in the intermediate care unit or in an outpatient setting, without necessity for intervention during control mode operation. Physiological control reduced speed and flowrate during patient rest, in sitting by a median of -75 [Interquartile Range (IQR): -137, 65] rpm and in supine position by -130 [-150, 30] rpm, thereby reducing suction burden in scenarios prone to overpumping in most tests [0 [-10, 2] Suction events/minute] in orthostatic upwards transitions and by -2 [-6, 0] Suction events/min in Valsalva maneuver. During submaximal ergometry speed was increased by 86 [31, 193] rpm compared to constant speed for a median flow increase of 0.2 [0.1, 0.8] L/min. In 3 tests speed could not be increased above constant set speed due to recurring suction and in 3 tests speed could be increased by up to 500 rpm with a pump flowrate increase of up to 0.9 L/min.CONCLUSION: In this pilot study, safety, short-term efficacy, and physiological responsiveness of a sensorless automated speed control system for a centrifugal LVAD was established. Long term studies are needed to show improved clinical outcomes.CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT04786236.
AB - BACKGROUND: Contemporary Left Ventricular Assist Devices (LVADs) mainly operate at a constant speed, only insufficiently adapting to changes in patient demand. Automatic physiological speed control promises tighter integration of the LVAD into patient physiology, increasing the level of support during activity and decreasing support when it is excessive.METHODS: A sensorless modular control algorithm was developed for a centrifugal LVAD (HVAD, Medtronic plc, MN, USA). It consists of a heart rate-, a pulsatility-, a suction reaction-and a supervisor module. These modules were embedded into a safe testing environment and investigated in a single-center, blinded, crossover, clinical pilot trial (clinicaltrials.gov, NCT04786236). Patients completed a protocol consisting of orthostatic changes, Valsalva maneuver and submaximal bicycle ergometry in constant speed and physiological control mode in randomized sequence. Endpoints for the study were reduction of suction burden, adequate pump speed and flowrate adaptations of the control algorithm for each protocol item and no necessity for intervention via the hardware safety systems.RESULTS: A total of six patients (median age 53.5, 100% male) completed 13 tests in the intermediate care unit or in an outpatient setting, without necessity for intervention during control mode operation. Physiological control reduced speed and flowrate during patient rest, in sitting by a median of -75 [Interquartile Range (IQR): -137, 65] rpm and in supine position by -130 [-150, 30] rpm, thereby reducing suction burden in scenarios prone to overpumping in most tests [0 [-10, 2] Suction events/minute] in orthostatic upwards transitions and by -2 [-6, 0] Suction events/min in Valsalva maneuver. During submaximal ergometry speed was increased by 86 [31, 193] rpm compared to constant speed for a median flow increase of 0.2 [0.1, 0.8] L/min. In 3 tests speed could not be increased above constant set speed due to recurring suction and in 3 tests speed could be increased by up to 500 rpm with a pump flowrate increase of up to 0.9 L/min.CONCLUSION: In this pilot study, safety, short-term efficacy, and physiological responsiveness of a sensorless automated speed control system for a centrifugal LVAD was established. Long term studies are needed to show improved clinical outcomes.CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT04786236.
UR - https://www.scopus.com/pages/publications/85138684922
U2 - 10.3389/fcvm.2022.888269
DO - 10.3389/fcvm.2022.888269
M3 - Journal article
C2 - 35548436
SN - 2297-055X
VL - 9
SP - 888269
JO - Frontiers in Cardiovascular Medicine
JF - Frontiers in Cardiovascular Medicine
M1 - 888269
ER -