A handheld scanner for clinical oximetry

描述（由申请人提供）：通过皮肤的经皮氧灌注测量在临床上用于测量身体某一区域的血流量，并作为伤口愈合潜力的指示性测量。局部血氧测定也可用于跟踪周围血管疾病（PVD）。目前，用于此目的的唯一临床应用技术是使用基于电极的传感器的经皮氧监测（TCOM），该技术需要一个主动加热元件来促进氧气通过皮肤的扩散。皮下（皮肤表面以下2 - 3mm）组织氧测量将有助于确定用于重建手术的带血管的游离组织皮瓣或慢性伤口周围组织的血流。

DESCRIPTION (provided by applicant): Measurement of transcutaneous oxygen perfusion through the skin is used clinically as a measure of blood flow to a region of the body, and serves as an indicative measure of wound healing potential. Topical oximetry may also be useful for tracking peripheral vascular disease (PVD). Currently, the only clinically-applied technique used for this purpose is transcutaneous oxygen monitoring (TCOM) using electrode based sensors, which require an active heating element to encourage diffusion of oxygen through the skin. Subcutaneous (2 - 3 mm below the skin surface) tissue oxygen measurements would be useful in determining blood flow in vascularized free tissue flaps used for reconstructive surgery or in tissues surrounding chronic wounds. Our group has demonstrated that biopolymer-encapsulated probes used in electron paramagnetic resonance (EPR) oximetry can be used for such applications when applied topically to the region of interest, or implanted below the skin. The use of EPR for such measurements is currently not feasible in a clinical setting due to the size, weight, and space restrictions presented by existing instrumentation. We therefore propose to design, build, and test a new, portable EPR system for clinical oximetry applications. The envisioned device will be similar to a clinical ultrasound unit, with a "wand" assembly that will be placed in contact with the skin to obtain oximetry measurements from the probe sensors placed on the body, or implanted just below the surface. We will use computer modeling to determine the optimum arrangement of magnets and resonator prior to construction of a working prototype device. We will then test and characterize the oxygen-sensitive probes to be used. We will then use the prototype device to quantify tissue oxygenation in a rat chronic wound model, and continue with validation measurements using the portable EPR unit on human volunteers to compare this new technology with the existing electrode-based TCOM.