T. Rath et al.: J Extra Corpor Technol 2026, 58, 19 – 31 23
Figure 3. GAMPT bubble count display. Gampt BCC300 bubble number display screen with a logarithmic scale showing a real-time display of bubble number( count) with intervention changes. Overlayed reservoir level( 200 mL, 500 mL, 1000 mL) is shown left to right with the corresponding sucker speeds( 25 RPM with no air, 25 RPM with air, 50 RPM with air, 75 RPM with air, and 100 RPM with air).
The first three minutes( 180 s) of bubble data were summed for each intervention. Figure 3 shows the Gampt BCC300 bubble number display screen, which features a logarithmic scale, providing a real-time display of the bubble number( count) with changes resulting from interventions.
Twenty-five trials were completed at a reservoir level of 200 mL, and 23 at reservoir levels of 500 mL and 1000 mL. Of these trials, ten were completed using Medtronic Affinity Fusion, and six were completed using Terumo CAPIOX FX25 Advance at each reservoir level( 200 mL, 500 mL, and 1000 mL). The LivaNova SORIN Inspire 8F reservoir underwent nine trials at 200 mL, 7 trials at 500 mL, and seven trials at 1000 mL.
Statistical analysis
Three minutes( 180 s) of bubble count was recorded for each of the three sensors and each intervention, and the results were averaged for all trials. The statistical software used to analyze the collected data was“ R” [ 39 ], which is used for statistical computing and graphics. Box plots were made to visualize the group differences in mean and variability. A two-way ANOVA was utilized to test differences in the average total number of GME( dependent variable) with two independent variables: suction flow rate and reservoir level. A post-hoc Tukey Honest Significant Difference( HSD) test was performed to determine whether the mean difference between specific pairs of groups was statistically significant. The alpha level for statistical significance is 0.05.
Results Venous GME count Summary statistics describing the total number of GME measured over 3 min( 180 s) by the“ venous” sensor are shown( Figure 4), along with a box plot illustrating data from all reservoirs tested( Medtronic Affinity Fusion, LivaNova SORIN Inspire 8F, and Terumo CAPIOX FX25) combined. Box plots were made to visualize the group differences in Mean and variability. The independent variables, four suction flow rates( 25 RPM( 0.32 L / min), 50 RPM( 0.65 L / min), 75 RPM( 0.99 L / min), and 100 RPM( 1.32 L / min) and three reservoir levels( 200, 500, 1,000) mL are shown on the x-axis with GME number on the y-axis. The results of the Multivariate Shapiro-Wilk normality test indicate that the data are not normal( p < 0.0001). However, given the sample size of 284 observations in the data, the detection of minor discrepancies in non-normality is expected.
The results of the two-way ANOVA examining differences in the average total number of GME for the venous sensor, by roller pump suction flow rate and reservoir level, indicate a statistically significant interaction between roller pump suction flow rate and reservoir level( p-value < 0.0001). This tells us that the combined effect( interaction) of the suction flow rate and the reservoir level on the GME number is statistically significant. GME number increased with increased sucker flow rate and decreased with increased reservoir level( Figure 4).
Table 2 shows post-hoc comparisons of the average difference in GME number by roller pump suction speed at constant venous reservoir levels. Statistically significant differences are denoted by p <. 05 and are shown in bold, with adjustments made using the Tukey HSD method. The effect of suction speed was most pronounced at the lowest reservoir level( 200 mL). GME number increased significantly as sucker speed increased, except between 25 and 50 RPM. As the level increased to 500 mL, the GME number significantly increased as sucker speed increased, except between 25 – 50 RPM and 50 – 75 RPM. At the highest level tested( 1000 mL), the effect of suction speed was least evident. The only significant difference in GME number was detected between 25 – 100 RPM and 50 – 100 RPM.
Table 3 presents post hoc comparisons of the average difference in GME number by venous reservoir level at a constant roller pump suction speed to examine the venous data from a