In Vitro Performance Analysis of a Novel Pulsatile Diagonal Pump in a Simulated Pediatric Mechanical Circulatory Support System *Shigang Wang, †Allen R. Kunselman, and *‡§Akif Ündar *Pediatric Cardiovascular Research Center, Penn State Hershey Children’s Hospital, Penn State Milton S. Hershey Medical Center, Department of Pediatrics, Penn State Hershey College of Medicine; †Department of Public Health Sciences, Penn State Hershey College of Medicine; ‡Department of Surgery, Penn State Milton S. Hershey Medical Center, Penn State Hershey College of Medicine, Pennsylvania State University, Hershey; and §Department of Bioengineering, College of Engineering, Pennsylvania State University, University Park, PA, USA Abstract: The objective of this study was to evaluate the pump performance of the third-generation Medos diagonal pump, the Deltastream DP3, on hemodynamic profile and pulsatility in a simulated pediatric mechanical circulatory support (MCS) system. The experimental circuit consisted of a Medos Deltastream DP3 pump head and console (MEDOS Medizintechnik AG, Stolberg, Germany), a 14-Fr Terumo TenderFlow Pediatric arterial cannula and a 20-Fr Terumo TenderFlow Pediatric venous return cannula (Terumo Corporation, Tokyo, Japan), and 3ft of tubing with an internal diameter of 1 /4 in. for both arterial and venous lines. Trials were conducted at flow rates ranging from 250 mL/min to 1000 mL/min (250-mL/min increments) and rotational speeds ranging from 1000 to 4000 rpm (1000-rpm increments) using human blood (hematocrit 40%). The postcannula pressure was main- tained at 60 mm Hg by a Hoffman clamp. Real-time pressure and flow data were recorded using a Labview- based acquisition system. The pump provided adequate nonpulsatile and pulsatile flow, created more hemodynamic energy under pulsatile mode, and generated higher positive and negative pressures when the inlet and outlet of the pump head, respectively, were clamped. After the conver- sion from nonpulsatile to pulsatile mode, the flow rates and the rotational speeds increased. In conclusion, the novel Medos Deltastream DP3 diagonal pump is able to supply the required flow rate for pediatric MCS, generate adequate quality of pulsatility, and provide surplus hemo- dynamic energy output in a simulated pediatric MCS system. Key Words: Pulsatile flow—Diagonal pump— Pediatric mechanical circulatory support—Pediatrics. Left/right ventricular mechanical supports are life- saving devices for terminal heart failure patients. They serve as a bridge to recovery or cardiac trans- plantation, or as “destination therapy” in some patients who cannot undergo transplantation (1–4). The mechanical circulatory support (MCS) system includes a blood pump, arterial/venous cannulae, and tubing. Shorter tubing and a more compact pump can be used in a MCS system. Because of the absence of the hollow-fiber membrane oxygenator in the MCS system, lower circuit resistance allows a wide variety of blood pumps to be used in MCS systems, such as pneumatic pumps, rotary pumps (including centrifu- gal pumps, diagonal pumps, and axial pumps), and even roller pumps (5,6). Different pumps have differ- ent characteristics (4). Pneumatic pumps have inher- ent pulsatile flow for single or biventricular support, different stroke volumes suitable for different body weights, and excellent durability and mobility for short/long-term support. However, the mechanical valves used to maintain unidirectional flow carry a potential risk for valve-related thrombosis. Axial- flow pumps are suitable for ventricular support due doi:10.1111/aor.12181 Received May 2013; revised July 2013. Address correspondence and reprint requests to Dr. Akif Ündar, Penn State Hershey College of Medicine, Department of Pediatrics—H085, 500 University Drive, P.O. Box 850; Hershey, PA 17033-0850, USA. E-mail: aundar@psu.edu Presented in part at the 9th International Conference on Pedi- atric Mechanical Circulatory Support and Pediatric Cardiopulmo- nary Bypass held, May 8–11, 2013 in Hershey, PA, USA. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation Artificial Organs 2013, ••(••):••–••