Selective Laser Stimulator of C and A delta fibers

描述（由申请人提供）：第一阶段SBIR的目标是设计、开发、构建和测试一种新的红外激光热刺激器原型，该原型可用于人类C和a - δ纤维（伤害感受器）的差异激活。C和a - δ纤维痛觉感受器能传导和介导不同来源的疼痛，因此负责向中枢神经系统传递不同类型的疼痛信息。这两种疼痛纤维类型的激活可以不同地介导不同基础病理的临床疼痛。因此，患者C或a - δ纤维伤害感受器的差异激活能力可能允许更具体的诊断，更好的药物处方预测能力，以及更好的能力跟踪潜在疾病的临床进展。目前，还没有工具可以对人体C和A δ纤维进行可重复的选择性激活，临床使用的热刺激器依赖于电子控制的接触加热器（Peltier热模）。然而，这些方法需要通过皮肤表层对疼痛纤维进行导电加热。同样，通常用于研究目的的激光刺激器（二氧化碳和铥）将能量完全沉积在皮肤表面，而伤害感受器位于皮肤深处。因此，对于珀尔帖热模和这些激光器，直接加热/激活伤害感受器是不可能的，但需要潜在危险的高表面温度。我们建议开发的激光刺激系统将使用红外相干光，由于其波长，可以直接刺激包含伤害感受器末梢的底层组织。此外，我们的初步证据表明，通过改变激光刺激的参数，我们可以选择性地激活C或a -delta纤维，这可能成为一种非常有用的临床工具。因此，本提案描述了开发和实验工作，这应该允许开发一种原型刺激器，允许在人类中选择性激活C或a -delta纤维

DESCRIPTION (provided by applicant): The goal of this Phase I SBIR is to design, develop, build and test a new prototype of infra red laser thermal stimulator that can be used for differential activation of C and A-delta fibers (nociceptors) in humans. C and A-delta fiber nociceptors transduce and mediate pain of different sources, and are therefore responsible for carrying different types of pain information to the central nervous system. Clinical pain of different underlying pathologies can be differentially mediated by the activation of these two pain fiber types. Thus, the capacity of differential activation of C or A-delta fiber nociceptors in patients may allow for more specific diagnosis, better predictive power in pharmaceutical prescription, and better capacities to follow the clinical progress of the underlying disease. Currently, no tool is available to do the reproducible selective activation of C and A delta fibers in humans and clinically used thermal stimulators rely on electronically controlled contact heaters (Peltier thermodes). These, however, require conductive heating of pain fibers through overlying layers of skin. Similarly, laser stimulators commonly in use for research purposes (CO2 and Thullium) deposit energy entirely on the skin surface, whereas the nociceptors are located deeper in the skin. Thus, for both Peltier thermodes and these lasers, direct heating/activating of nociceptors is impossible, but requires potentially dangerous, high surface temperatures. The laser stimulation system that we propose to develop will use infrared coherent light that, due to its wavelength, allows for direct stimulation of underlying tissue that contains the nociceptor endings. Furthermore, our preliminary evidence suggests that, by altering the parameters of the laser stimulus, we can selectively activate either C or A-delta fibers, potentially allowing for a highly useful clinical tool. Thus, this proposal describes development and experimental work, which should allow for the development of a prototype stimulator that allows for selective activation of C or A-delta fibers in humans