Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
J Heart Lung Transplant. 2010 Jan;29(1):32-6. doi: 10.1016/j.healun.2009.09.004.
Although some continuous-flow left ventricular assist device algorithms have been created to respond to varying patient physiology, very little research has been conducted on control of right ventricular support in uni- or biventricular application. The purpose of this study was to develop and evaluate a simple and reliable fixed-flow algorithm for the DexAide right ventricular assist device (RVAD). This algorithm automatically adjusts speed to maintain a target flow while preventing ventricular suction when a requested target flow exceeds available tricuspid flow.
Fixed-flow control mode was evaluated in 17 DexAide RVAD long-term bovine studies, with a duration ranging from 14 to 90 days (33 +/- 24 days). Targeted fixed-flow levels ranged from 4.0 to 6.5 liters/min. Data were monitored on an hourly basis. Pump-flow data were also recorded on a weekly basis to document the speed increment required to increase pump flow from 5 to 8 liters/min at 0.5-liter/min increments.
The fixed-flow control mode was evaluated for a total duration of 5,283 hours without complications related to pump flow or left/right circulation imbalance. The pump speed varied between 2,000 and 3,220 rpm to maintain the flow constant at each target level. The average absolute mismatch between the target flow and measured flow was 0.6 +/- 0.5 liter/min.
Fixed-flow control mode with a pre-determined maximum automatic pump speed can be used safely and effectively in the DexAide RVAD. It can provide target flows by adjusting the pump speed while monitoring pump-flow response to automatic speed increment requests.
虽然已经开发了一些针对不同患者生理状况的连续血流左心室辅助装置算法，但对于单心室或双心室应用中的右心室支持控制的研究却很少。本研究旨在开发和评估 DexAide 右心室辅助装置（RVAD）的简单可靠的固定流量算法。该算法在请求的目标流量超过可用三尖瓣流量时，自动调整速度以保持目标流量，同时防止心室抽吸。
在 17 项 DexAide RVAD 长期牛研究中评估了固定流量控制模式，持续时间从 14 天到 90 天不等（33 ± 24 天）。目标固定流量水平范围从 4.0 到 6.5 升/分钟。每小时监测数据。每周还记录泵流量数据，以记录以 0.5 升/分钟的增量从 5 升/分钟增加泵流量所需的速度增量。
在没有与泵流量或左右循环失衡相关的并发症的情况下，固定流量控制模式总共评估了 5283 小时。泵速在 2000 到 3220 rpm 之间变化，以在每个目标水平保持流量恒定。目标流量和测量流量之间的平均绝对差值为 0.6 ± 0.5 升/分钟。
使用预定的最大自动泵速的固定流量控制模式可以在 DexAide RVAD 中安全有效地使用。它可以通过调整泵速来提供目标流量，同时监测泵流量对自动速度增量请求的响应。
