Prof. Yasuo Ikeda described the use of a quartz crystal microbalance for the evaluation of platelet deposition onto protein-coated surfaces. In spite of problems in analysing the cellular overlayers with standard equations applicable to molecular reactions, due to viscoelasticity of the cells, quantitative analyses were feasible and provided real-time measurements of platelet deposition under various pathological conditions. The clinical usefulness of this device was described for a variety of situations, including von Willebrand's disease, aspirin-induced bleeding, and Glantzmann's thrombasthenia. Dr. Bruce Lages, on behalf of Dr. Conan Li, from Xylum, gave a detailed outline of the Clot Signature Analyser. The instrument generates an orifice with flow through both the orifice and a channel containing a collagen fiber.
Native blood is used, with both platelet function and clotting times readily monitored.
Useful data from a number of clinical situations were reviewed. In particular, low molecular weight heparin had more effect on PHT, likely related to thrombin formation affecting platelet function and not fibrin formation. Bedside data output is provided by computer interface analysis of platelet surface coverage and aggregate size. The relative usefulness of native polystyrene versus ECM-coated plastic was described. A number of clinical situations were described which could be 'characterised' from changes in these platelet parameters.