Associated with the injection system and method for determining blood pressure and blood flow in the arteries of the individual patient, the present invention is a composite catheter that combines a pressure sensor mounted to the injection catheter, the distal portion of the guidewire, and placed in the artery so that it is placed distal to the artery to be investigated, the distal end of the infusion catheter is proximal to the distal pressure sensor, the composite catheter, measure the blood pressure at the sensor at rest The, using the infusion catheter, at a known concentration and injection rate known, while injecting engorgement agent into an artery, it is injected into the blood stream Chi-zai, to measure blood pressure at the sensor And then constitute the step of calculating the arterial blood flow using the formula based on the amount the measured and known. Furthermore, the method may include the step of associating a steady flow values associated with the blood flow value was calculated, related fractional flow reserve value, the related blood flow resistance.本発明は、患者の個々の動脈内の血流と血圧を決定する方法と注入システムに関連し、注入カテーテルと、ガイドワイヤの遠位部分に搭載された圧力センサを結合させた複合カテーテルを、調査する動脈の遠位に配置し、該複合カテーテルを、該注入カテーテルの遠位末端が該遠位圧力センサの近位となるよう動脈の中に配置し、安静時に該センサにて血圧を測定し、該注入カテーテルを用いて、既知の注入率と既知の濃度にて、動脈に充血剤を注入し、該充血剤を血流の中へ注入している間、該センサにて血圧を測定し、既知かつ測定された該量に基づき式を用いて動脈の血流を計算するステップを構成する。該方法はさらに、算定された血流値を、関連する定常流動値、関連血流予備量比値、関連血流抵抗と関連付けるステップを含みうる。
