The Cytocam video microscope. A new method for visualising the microcirculation using Incident Dark Field technology.
We report a new microcirculatory assessment device, the Braedius Cytocam, an Incident Dark Field (IDF) video microscope, and compare it with a precursor device utilising side stream dark field (SDF) imaging.


METHODS
Time matched measurements were made with both devices from the sublingual microcirculation of pigs subjected to traumatic injury and hemorrhagic shock at baseline and during a shock phase. Images were analysed for vessel density, microcirculatory flow and image quality.


RESULTS
There were no differences in density or flow data recorded from the two devices at baseline [TVD IDF 14.2 ± 2.4/TVD SDF 13.2 ± 2.0, p 0.17] [MFI IDF 3 (2.8-3.0)/MFI SDF 3 (2.9-3.0), p 0.36] or during the shock state [TVD IDF 11.64 ± 3.3/TVD SDF 11.4 ± 4.0 p = 0.98] [MFI IDF 1.9 (0.6-2.7)/MFI SDF 1.7 (0.3-2.6) p 0.55]. Bland and Altman analysis showed no evidence of significant bias. Vessel contrast was significantly better with the IDF device for both capillaries [17.1 ± 3.9 (IDF) v 3.4 ± 3.6 (SDF), p = 0.0006] and venules [36.1 ± 11.4 (IDF) v 26.4 ± 7.1 (SDF) p 0.014]


CONCLUSIONS
The Braedius Cytocam showed comparable vessel detection to a precursor device during both baseline and low flow (shock) states.
Biophysics division, Defence Science and Technology Laboratory, Porton Down, Salisbury, UK.|Department of Critical Care, Kings College Hospital, Denmark Hill, London, UK.
Sam
S
Hutchings
Biophysics division, Defence Science and Technology Laboratory, Porton Down, Salisbury, UK.
Sarah
S
Watts
Biophysics division, Defence Science and Technology Laboratory, Porton Down, Salisbury, UK.
Emrys
E
Kirkman
D000818:Animals; D001331:Automation; D001783:Blood Flow Velocity; D002196:Capillaries / Q000000981:diagnostic imaging*; D008833:Microcirculation; D008853:Microscopy / Q000379:methods; D018715:Microscopy, Video / Q000295:instrumentation* / Q000379:methods*; D012769:Shock / Q000000981:diagnostic imaging; D012984:Software; D013552:Swine
Microcirculation; haemorrhagic shock; incident dark field imaging; sidestream dark field imaging