Pressure sensing intravascular devices with reduced drift and associated systems and methods
Intravascular devices, systems, and methods are disclosed. In some embodiments, the intravascular devices include at least one pressure sensing component positioned within a distal portion of the device. In some instances, a plurality of conductors are electrically coupled to the pressure sensing component and a potting material covers the electrical connections between the plurality of conductors and the pressure sensing component. In some instances, the potting material has a durometer hardness between about 20 Shore A and about 50 Shore A, a moisture absorption rate of about 0% per twenty-four hours, a linear shrinkage of 0%, a coefficient of thermal expansion (m/m/-° C.) of between about 1.0×10 −5 and about 5.0×10 −4 , and a volume resistivity (Ω-cm) between about 6.0×10 13 and about 1.0×10 14 . Methods of making and/or assembling such intravascular devices/systems are also provided.
1. A guide wire, comprising:
a flexible elongate body having a proximal portion, a distal portion, and a lumen extending along a length of the flexible elongate body between the proximal and distal portions;
a sensor housing disposed at the distal portion of the flexible elongate body, wherein the sensor housing has a proximal portion and a distal portion;
a pressure sensor within the distal portion of the sensor housing;
a plurality of conductors electrically coupled to the pressure sensor and extending from the pressure sensor through the lumen to the proximal portion of the flexible elongate body;
a potting material within the distal portion of the sensor housing, the potting material covering electrical connections between the plurality of conductors and the pressure sensor, the electrical connections being at the distal portion of the sensor housing, wherein the potting material has a durometer hardness between about 20 Shore A and about 50 Shore A to minimize forces imparted on the pressure sensor; and
an adhesive within the proximal portion of the sensor housing, wherein the adhesive is in contact with the plurality of conductors at the proximal portion of the sensor housing.
2. The guide wire of claim 1 , wherein the potting material has a durometer hardness of approximately 25-30 Shore A.
3. The guide wire of claim 1 , wherein the potting material has a moisture absorption rate of about 0% per twenty-four hours.
4. The guide wire of claim 1 , wherein the potting material is a UV-cured potting material.
5. The guide wire of claim 4 , wherein the UV-cured potting material includes a secondary humidity cure.
6. The guide wire of claim 1 , wherein the potting material has a linear shrinkage of 0%.
7. The guide wire of claim 1 , wherein the potting material has a coefficient of thermal expansion (m/m/-° C.) of between about 1.0×10 −5 and about 5.0×10 −4 .
8. The guide wire of claim 7 , wherein the potting material has a coefficient of thermal expansion (m/m/-° C.) of about 2.89×10 −4 .
9. The guide wire of claim 1 , wherein the potting material has a volume resistivity (Ω-cm) between about 6.0×10 13 and about 1.0×10 14 .
10. The guide wire of claim 9 , wherein the potting material has a volume resistivity (Ω-cm) of about 8.3×10 13 .
11. The guide wire of claim 1 , further comprising a first flexible element extending distally from the sensor housing and a second flexible element extending proximally from the sensor housing.
12. The guide wire of claim 11 , wherein at least one of the first and second flexible elements comprises a coil.
13. The guide wire of claim 12 , wherein at least one of the first and second flexible elements comprises a polymer tubing.
14. The guide wire of claim 1 , wherein the sensor housing comprises a further lumen, wherein the potting material partially fills the further lumen at the distal portion of the sensor housing, and wherein the adhesive completely fills the further lumen at the proximal portion of the sensor housing.
15. The guide wire of claim 1 , further comprising a further adhesive in contact with the sensor and the sensor housing, the further adhesive longitudinally overlapping the potting material at the distal portion of the sensor housing and the adhesive at the proximal portion of the sensor housing.