See www.lorrca.com for more information.
Laser Optical Rotational Red Cell Analyzer
Lorrca Maxsis osmoscan (Lorrca®) is a unique instrument which combines Red Blood Cell (RBC) deformability by ektacytometry, osmoscan and aggregometry; all temperature controlled. It is capable of fully automated measurement and calculation of various phenomena of RBC’s by analysis of their rheological behavior. The technique accurately detects deformability as a function of shear stress, pre-hemolytic stability and aggregation of the RBC’s and is of added value for hematology analysis.
Possible measurements of the instrument
Evaluation of the rheology of blood in different parts of the body is a very specific task, therefore it is important to have a technique available that can accurately measure the RBC properties. Lorrca incorporates a variety of techniques to perform these specific measurements:
• Deformability: Laser diffraction ektacytometry, Parameterization of deformation curve, Cell- and cell membrane stability
• Osmoscan: Deformability under an osmotic gradient, Osmotic Resistance Test
• Aggregation & dis-aggregation: Syllectometry – Extent of aggregation, aggregation kinetics and tendency
• Oxygenscan; Measuring the relative oxygen pressure at the critical point the red blood cells start to sickle
Red blood cell deformability, expressed as the Elongation Index (El), is presented in a deformability curve. A thin layer of RBC’s, suspended in PVP, is sheared between two concentric cylinders. A known shear stress is applied to the cells, resulting in the elongation (deformation) of the RBC’s. This process is measured by a laser beam diffraction pattern; captured with a video camera and analyzed by a computer.
RBC deformability curve
The osmoscan measures the RBC deformability under various osmotic conditions. This results in a continuous curve.
Typical osmoscan curves
Aggregation & dis-aggregation
Lorrca measures the speed at which rouleaux formation occurs and is presented in a syllectogram. By means of a photodiode (which measures the change in light absorption) the tendency and kinetics of aggregation are displayed, as well as the minimal shear rate (threshold) needed to prevent RBC aggregation.