Table 5.

Correlation between the number of turns of catheter, the cycle time and activation pressure throughout flow rates

Dependent variable	Direction	Flowrates $[$ml/h$]$	Null hypothesis	Test	N	Sig.${}^{\text{a},\text{b}}$		Decision $[$Null hypothesis acceptation$]$
Cycle	Forward	20	The distribution of cycle time from	Independent-	47		0.896	Accept
time		40	the flow rate is the same across	Samples	47		0.842	Accept
		60	categories of catheters in forward	Mann-Whitney	67		0.836	Accept
		80	experiments	U test	54		0.222	Accept
		100			69		0.001	Reject
	Reverse	20	The distribution of cycle time from	Independent-	25		0.043${}^{\text{c}}$	Reject
		40	the flow rate is the same across	Samples	21		0.508${}^{\text{c}}$	Accept
		60	categories of catheters in forward experiments	Mann-Whitney U test	32		0.008${}^{\text{c}}$	Reject
Activation	Forward	20	The distribution of pressure from	Independent-	47		0.046	Reject
pressure		40	flow rates is the same across	Samples	47		0.093	Accept
		60	categories of catheters in forward	Mann-Whitney	67		0.001	Reject
		80	experiments	U test	54		0.401	Accept
		100			69		0.001	Reject
	Reverse	20	The distribution of cycle time from		36		0.001${}^{\text{c}}$	Reject
		40	flow rates is the same across categories of catheters in reverse	Independent samples $T$-test	36		0.001${}^{\text{d},\text{f}}$	Reject
		60	experiments	Independent-Samples Mann-Whitney U test	46		0.001	Reject

${}^{\text{a})}$The significance level is 0.05; ${}^{\text{b})}$Asymptotic significance is displayed; ${}^{\text{c})}$Exact significance is displayed; ${}^{\text{d})}$Mean differences: $-$0.733; ${}^{\text{f})}$95% confidence interval lower: $-$1.110, upper: $-$0.356.