Overview
Purge Cassette: device used to support the Abiomed Impella heart pumps by pumping dextrose into the heart pump to equalize pressure and prevent backflow of blood through the pump’s catheter
Project was developed to redesign the pumping mechanism in order to improve product performance and reduce manufacturing cycle time save time and money during production
After preliminary testing, areas for improvement on the pump cylinder arose that needed redesign
My role: aid with design improvements to the pump cylinder (see figure) and spearhead all modeling using SolidWorks
Process
Redesigned outflow (pressure) port to match ISO 80369-7:2016 for small-bore connectors for liquids and gases in healthcare applications
Created new inflow (suction) port with modified tubing stops to prevent occlusion and add ease of assembly
Drew and released r02 SolidWorks part for pump cylinder
Drew and released r02 SolidWorks drawings for pump cylinder, rack, and piston head
Gen 1 Pump Assembly currently in production
Gen 2 Pump Assembly (r02) designed by me
r02 Pump Cylinder, indicating the locations of the pressure port and suction port that were redesigned
Complications
Had to interpret ISO 80369-7 drawings in order to fit design of cylinder pressure port
Had to “fill in” ports and rebuild them entirely in order to make changes to part because SolidWorks part was imported as STEP file from Pro E
Part drawing format at Abiomed changed during the project and I had to learn the new format while also updating the existing drawing
Isometric view of pressure port
Top view of redesigned suction port, with three-quarter ring tubing stops
Cross sectional view showing factors considered when converting pressure port to ISO 80369-7:2016 standards
Cross sectional view showing modified tubing stop height
Results
Released r02 part design for pump cylinder with port improvements to resolve complications during preliminary testing
Released r02 drawings for pump cylinder, rack (syringe plunger body), and piston (syringe plunger head)
Created and released article specifications for all three components
Tested ports on molded parts to confirm increased strength and ease of purge cassette assembly
Purge cassette redesign projected to save the organization $3 million annually
Skills Developed
Product design techniques in SolidWorks, especially through modifying imported models
Official drawing and document release process with doc control and supplier communications
Adapting designs and drawings to account for injection molding process
r01 Drawing, with my redline markups
r02 Drawing with revisions made to part, notes, injection molding indications, and format