Thermography as potential real-time technique to assess changes in flow distribution in hemofiltration  J.K. Unger, A.-J. Lemke, C. Grosse-Siestrup  Kidney International  Volume 69, Issue 3, Pages 520-525 (February 2006) DOI: 10.1038/sj.ki.5000143 Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 1 Protocols for investigations of the flow distributions in the blood compartment. The time needed from start of a maneuver to the time when profiles reached the filter area of interest (middle third of the filter) is given in seconds. Letters (A, B, C) refer to locations on the filter surface – identical in all images – for which readouts of ‘point trends’ were obtained (see Figures 2a, b and 3c). (a) Schematically shows the principle of the in vitro system and defines symbols used to encode the maneuver performed to generate each of the figures. (b) A longitudinal front view during ‘warm blood reperfusion’ of the filter after a stop of blood and filtration pump for 5 min. Schematic black lines: double-peak patterns of temperature profiles assumed to indicate the blood flow distribution in the blood compartment; schematic black dotted line: leading edge of the flow distribution; black and white dotted line × 1: area for which temperature and densitometric profiles are shown in Figure 3a and b. (c) Longitudinal front view record during cold bolus injection into the arterial bloodline. Schematic black dotted line: leading edge of the changes in temperature profile; CT measurements: black and white pictures. (d) Surface temperature of the blood inflow port only one part of each (1 inflow, 1 outflow) (upper pictures, 15 and 30 s) and the outflow port only one part of each (1 inflow, 1 outflow) (lower pictures 120 and 140 s) during cold bolus injection to the arterial bloodline. Kidney International 2006 69, 520-525DOI: (10.1038/sj.ki.5000143) Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 2 Tests performed to investigate temperature profiles arising from flow distribution inside the filtrate compartment and readouts associated with Figure 1b and c. (a) Representative readouts for ‘point’ trends associated with images of Figure 1b and c; profile readout locations on the filter surface, marked by letters A B C, were kept constant during different experiments. (b) Thermograms for test IIa including the point trend readout. (c) Cold bolus injection into the filtrate compartment (test IIb); schematic white line: double-peak pattern induced by the fluid distribution in the filtrate compartment; schematic black line: double-peak pattern found for the blood compartment (Figure 1). (d) CT measurements of forced filtrate flux analogous to test IIb. Kidney International 2006 69, 520-525DOI: (10.1038/sj.ki.5000143) Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 3 Quantification of regional temperature and densitometric profiles; Min: minimum; Max: maximum; Ave: average; Δt: time difference between Min and Max or vice versa; temp: temperature. (a, b) Semiquantitative comparison of the two methods for regional signal values of the horizontal line (× 1) indicated in Figure 1c; densitometric values are given in Hounsfield units (HU); (c) Repetition (arrows) of cold bolus injection into the bloodline for investigation of the inflow port; data are given as readouts of point trends (A B C localized as indicated in Figure 1d and as point (A B C)-related numeric values in an additional table. Kidney International 2006 69, 520-525DOI: (10.1038/sj.ki.5000143) Copyright © 2006 International Society of Nephrology Terms and Conditions