How it works
Mark O'Connell
Co-founder Probe Scientific Ltd
Demonstrates the simple to use MicroEye®
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The Probe Scientific MicroEye® sits within a standard blood catheter and is locked into position via its luer-lock nut, securing and sealing the blood catheter.
The tip of the MicroEye® extends into circulating blood and a low volume of physiological fluid such as saline is perfused through the MicroEye® using a standard clinical infusion pump.
The only thing separating this physiological fluid (the perfusate) from blood, at the tip of the MicroEye®, is a very thin membrane across which substances can pass, which they do because of the concentration gradient between the two fluids.
Passage (dialysis) continues until equilibrium is achieved between blood and the perfusate (which is now termed dialysate). The dialysate emerging from the MicroEye® can now be measured to determine the blood concentration of substances.
Different membranes can selectively affect this dialysis process but generally blood cells, platelets, micro-particles and foreign organisms are excluded from passing through these membranes.
(left: The MicroEye ® sitting in a conventional 18G venous access device inserted in a patient)
Indeed much coarser membranes are used to ‘sterilise’ fluids used for cell cultures, so the membranes used in the MicroEye® are even more effective in excluding such material.