Blood flow distribution in a polymyxin coated fibrous bed for endotoxin removal. Effect of a new blood path design

The analysis of flow distribution in cartridges designed for hemoperfusion is extremely important Taking advantage of a new imaging technique, based o n the analysis of a helical scanner-generated imaging sequence, we studied the blood flow distribution in a series of cartridges for extracorporeal re moval of endotoxin. Cartridges with improved design were compared to cartri dges with a standard design. The improved design consists in a different st ructure of the holes of the distributor of the flow within the adsorbent un it Cartridges were studied in vitro with human blood from voluntary donors at blood flows of 100 and 250 ml/min. The progression of density in specifi c regions of interest (ROI) was analyzed to detect the distribution of the dye injected in the blood circuit. The study demonstrates that both at 100 ml/min and at 250 ml/min of blood flow, the progression of flow appears mor e homogeneous in the devices with improved design. In detail, the flow dist ribution measured by the incremental density values detected in the ROIs of the proximal corners (close to the arterial port) and in the ROIs of the c entral region of the device (close to the inner wall of the case) displays a significant difference between the standard and the improved device. The ROIs studied in the standard devices display a slower increase in density a nd significantly lower absolute values expressed in Hounsfield units. The e xperimental method utilized to analyze flow distribution seems to represent an important means to study the performance and design of this type of dev ice.