Microactuated Rheometer for Point of Care Coagulopathy Applications

描述（由申请人提供）：我们建议开发一种新技术，以满足对定量和敏感护理点（POC）粘弹性止血测定（VHA）能力的需求，以表征对指导创伤性出血治疗至关重要的凝血参数。我们提出的技术采用一系列磁驱动的微观表面附着桩（sap），其对流体条件的动态机械响应提供了流变参数的定量测量。sap在大小和长宽比上类似于生物纤毛，并且可以在Hz到10s的大振幅下“跳动”

DESCRIPTION (provided by applicant): We propose development of a new technology that addresses the need for quantitative and sensitive point of care (POC) viscoelastic hemostatic assay (VHA) capability to characterize coagulation parameters that are crucial to guiding therapies for traumatic hemorrhage. Our proposed technique employs an array of magnetically actuated microscopic surface attached posts (SAPs), whose dynamic mechanical response to fluid conditions provides a quantitative measure of rheological parameters. The SAPs resemble biological cilia in size and aspect ratio and can be "beat" at large amplitudes in the Hz to 10s of Hz frequency range. The SAPs are arranged in an array on the device's active surface; they are actuated with an external magnetic field and their amplitude is monitored optically. The temporal progression of the clotting process, from clotting time to clot lysis, can be monitored. In recent years increasing evidence has pointed to trauma induced coagulopathy (TIC) as a major factor in complications leading to hemorrhage related death; 25-35% of trauma cases involve TIC. Mechanisms of TIC are still an active area of research, but it is clear that trauma can compromise healthy coagulation both by inhibiting clotting and amplifying lysis. Diagnostic tests that can rapidly evaluate hemostasis-related parameters from clotting to lysis are critical in developing effective therapeutic strategies for TIC. It is also crucial that these diagnostics are available where the need is greatest: near the accident prior to and during movement of the patient. Traditional laboratory coagulation tests such as prothrombin time (PT) and activated partial thromboplastin time (APTT) are both impractical and ineffective at providing these diagnostics. These plasma-based tests assess only the very beginning of the coagulation process (no information on lysis), require blood processing, and provide no mechanical information (clot strength). Within the context of this project, we will validate the ability the SP based viscoelastic measurements to provide information relevant to medical decisions. We will focus on developing a new approach to the underserved TIC problem in the field and during transportation of patients. We have successfully developed a fabrication protocol for SAPs, demonstrated their actuation in fluids, and have preliminary data demonstrating their ability to measure clot properties during coagulation. In the first year of this project we will characterize our system using reference viscous and viscoelastic fluids. In the second year we will demonstrate reproducible blood clotting measurements using the SAP system and validation by correlating these measurements with standard clinical and laboratory tests (using laboratory-based TEG instruments). Measurements on normal and factor deficient canine plasmas and whole blood will be performed including clotting time, clot stiffness, and clot lysis time.