Catheter With Inner Surface Pressure Sensor for Providing a Vascular Pressure Measurement for Determining Fractional Flow Reserve

A catheter comprising:

• an elongate shaft including a proximal portion and a distal portion extending from the proximal portion to a distal opening at a distal end of the shaft, the shaft defining a guidewire lumen, wherein the proximal portion has a first outer diameter and the distal portion has a second outer diameter smaller than the first outer diameter;
• and
• a differential pressure sensor coupled to the proximal portion, wherein the differential pressure sensor includes an inner pressure sensing surface facing the guidewire lumen in the proximal portion and an outer pressure sensing surface facing outside of an outer surface of the elongate shaft,
• wherein the guidewire lumen is configured to receive a guidewire and to provide fluid communication between the differential pressure sensor and the distal opening, and
• wherein when the catheter is tracked to a treatment site within the vasculature, the differential pressure sensor is disposed proximal the treatment site, the distal opening is disposed distal to the treatment site, and the guidewire lumen fills with blood to the location of the differential pressure sensor such that the differential pressure sensor senses a pressure difference between blood outside of the elongate shaft adjacent the outer pressure sensing surface of the differential pressure sensor and blood at the distal end of the shaft sensed by the inner pressure sensing surface of the differential blood pressure via the blood filling the guidewire lumen.

A catheter comprising:

• an elongate shaft including a proximal portion and a distal portion extending from the proximal portion to a distal opening at a distal end of the shaft, the elongate shaft defining a guidewire lumen, wherein the proximal portion has a first outer diameter and the distal portion has a second outer diameter smaller than the first outer diameter;
• a first pressure sensor coupled to the proximal portion such that a first pressure sensing surface of the first pressure sensor faces the proximal guidewire lumen;
• and
• a second pressure sensor coupled to the proximal portion such that a second pressure sensing surface of the second pressure sensor faces an outside surface of the shaft,
• wherein the proximal guidewire lumen and distal guidewire lumen are configured to receive a guidewire and to provide fluid communication between the pressure sensor and the distal opening, and
• wherein when the catheter is tracked to a treatment site within the vasculature, the pressure sensor is disposed proximal to the treatment site, the distal opening is disposed distal to the treatment site, the guidewire lumen fills with blood such that the blood is contact with the first pressure sensing surface and the first pressure sensor senses a pressure of the blood at the distal end of the shaft, and the second pressure sensing surface is in contact with blood outside of the elongate shaft proximal to the treatment site such that second pressure sensor senses a pressure of the blood outside of the elongate shaft proximal of the treatment site.