MicroTools enables automated quantification of capillary density and red blood cell velocity in handheld vital microscopy

Abstract

Direct assessment of capillary perfusion has been prioritized in hemodynamic management of critically ill patients in addition to optimizing blood flow on the global scale. Sublingual handheld vital microscopy has enabled online acquisition of moving image sequences of the microcirculation, including the flow of individual red blood cells in the capillary network. However, due to inherent content complexity, manual image sequence analysis remained gold standard, introducing inter-observer variability and precluding real-time image analysis for clinical therapy guidance. Here we introduce an advanced computer vision algorithm for instantaneous analysis and quantification of morphometric and kinetic information related to capillary blood flow in the sublingual microcirculation. We evaluated this technique in a porcine model of septic shock and resuscitation and cardiac surgery patients. This development is of high clinical relevance because it enables implementation of point-of-care goal-directed resuscitation procedures based on correction of microcirculatory perfusion in critically ill and perioperative patients.

Capillary Leukocytes, Microaggregates, and the Response to Hypoxemia in the Microcirculation of Coronavirus Disease 2019 Patients

“…Sublingual microcirculatory measurements were performed using handheld vital microscopes based on incident dark field microscopy imaging ( 22 ) (Braedius Medical, Huizen, The Netherlands) and automatically analyzed by using full-frame analysis of the MicroTools automatic software ( Supplemental Table 1 , http://links.lww.com/CCM/G161 ; and Supplemental Fig. 1 A , http://links.lww.com/CCM/G162 [legend, http://links.lww.com/CCM/G170 ]) ( 16 , 17 ) (Active Medical, Leiden, The Netherlands). Microcirculatory leucocytes and RBC microaggregates were analyzed using spacetime diagrams ( 18 , 19 ).…”

“…These have shown a high sensitivity and specificity for identifying the underlying pathophysiology and for predicting outcome in septic shock patients independent of changes in systemic hemodynamic variables ( 13 – 15 ). Recently, we developed and clinically validated an automatic image analysis platform for quantitative analysis of microcirculatory hemodynamic parameters ( 16 , 17 ) and developed methodologies to measure microcirculatory leukocyte-endothelial interactions from sublingual microcirculatory images ( 18 , 19 ).…”

Identification of novel sublingual parameters to analyze and diagnose microvascular dysfunction in sepsis: the NOSTRADAMUS study

“…Despite tremendous efforts to improve video quality and standardize reporting, the quantitative analysis of functional measures remains challenging and is often performed manually [6]. Several visual scoring systems and specialized (semi-) automated analysis tools have been developed to shorten time-to-result and improve accuracy [14][15][16][17]. Common to all these approaches is the (automated) selection and pooled analysis of microvessels with a diameter < 20 (rarely < 10) µm.…”

Successful Reduction of Creatine Kinase and Myoglobin Levels in Severe Rhabdomyolysis Using Extracorporeal Blood Purification (CytoSorb®)

“…Six packs of red blood cells were transfused. Sublingual microcirculation measurement showed a rich and mostly perfused vessel density, which was analyzed by dedicated software [11]: total vessel density (TVD): 22.73 mm/mm 2 , percentage of perfused vessels (PPV): 0.93 (online suppl. Video 1; for all online suppl.…”