Optical sensor assemblies and methods
An optical connector including a first optical fiber having a first diameter and having a core that includes a thermally expanded core portion adjacent a first end of the first optical fiber, a second optical fiber spliced to a second end of the first optical fiber, the second optical fiber having a second diameter less than the first diameter, and a connector bore having a first bore portion configured to receive the first end of the first optical fiber.
1. An apparatus comprising:
an elongated assembly, at least a portion of which is sized, shaped, or otherwise configured to be inserted into a human body to measure a physiological parameter at an internal location within the body, wherein the elongated assembly includes:
a guidewire having a length and having guidewire coils;
an optical fiber extending longitudinally along the guidewire, the optical fiber configured to communicate light between a location outside of the body and a portion of the optical fiber that is to be located at or near the internal location within the body at which the physiological parameter is to be measured;
a pressure sensor coupled to the optical fiber;
a core wire including a cradle integrally formed with the core wire, wherein the cradle is sized and arranged to support the pressure sensor and being covered by the guidewire coils, and wherein the core wire is coupled to the guidewire;
a pressure sensor housing, wherein the cradle defines a portion of the pressure sensor housing, and wherein the pressure sensor is cantilevered within the cradle; and
a collar bonded to the pressure sensor housing and to the optical fiber such that the pressure sensor is physically isolated from the pressure sensor housing and the guidewire,
wherein the pressure sensor is bonded to a distal end region of the optical fiber, wherein the pressure sensor is positioned distal to and spaced apart from the collar, and wherein the pressure sensor is positioned within and spaced apart from the pressure sensor housing.
2. The apparatus of claim 1 , wherein the collar comprises at least one of fused silica and borosilicate glass.
3. The apparatus of claim 1 , wherein the collar is a cylindrical tube.
4. The apparatus of claim 1 , wherein the optical fiber is bonded using at least one of solder glass bonding techniques and fusion splicing.
5. The apparatus of claim 1 , wherein the pressure sensor housing includes:
a proximal housing portion and a distal housing portion separated by a window portion.
6. The apparatus of claim 5 , wherein the window portion includes a gasket.
7. The apparatus of claim 6 , wherein the gasket is made of at least one material capable of deforming or bending without fracture or cracking.
8. The apparatus of claim 1 , wherein the pressure sensor includes a sensing region having first and second fiber Bragg gratings located in an optical fiber core of the optical fiber.
9. The apparatus of claim 8 , wherein one of the first and second fiber Bragg gratings located in the optical fiber core of the optical fiber extends distally beyond a distal end of a housing of the pressure sensor.
10. The apparatus of claim 8 , wherein each of the first and second fiber Bragg gratings includes a phase shift.
11. The apparatus of claim 8 , comprising:
a non-reflective termination adjacent to a distal end of the second fiber Bragg grating.
12. The apparatus of claim 1 , wherein the pressure sensor is temperature compensated.
13. The apparatus of claim 12 , wherein the temperature compensated pressure sensor includes a sensing region having first and second fiber Bragg gratings (FBG).
14. The apparatus of claim 13 , wherein the first FBG is configured to measure both pressure and temperature and the second FBG is configured to measure temperature.
15. An apparatus comprising:
an elongated assembly, at least a portion of which is sized, shaped, or otherwise configured to be inserted into a human body to measure a physiological parameter at an internal location within the body, wherein the elongated assembly includes:
a guidewire having a length and having guidewire coils;
an optical fiber extending longitudinally along the guidewire, the optical fiber configured to communicate light between a location outside of the body and a portion of the optical fiber that is to be located at or near the internal location within the body at which the physiological parameter is to be measured;
a pressure sensor coupled to the optical fiber;
a solid core wire extending through guidewire coils of the guidewire, the solid core wire including a cradle integrally formed with the core wire, wherein the cradle is sized and arranged to support the pressure sensor and being covered by the guidewire coils, and wherein the solid core wire is coupled to the guidewire;
a pressure sensor housing, wherein the cradle defines a portion of the pressure sensor housing, wherein the cradle only partially encloses the pressure sensor, and wherein the pressure sensor is cantilevered within the cradle; and
a collar bonded to the pressure sensor housing and to the optical fiber such that the pressure sensor is physically isolated from the pressure sensor housing and the guidewire,
wherein the pressure sensor is bonded to a distal end region of the optical fiber, wherein the pressure sensor is positioned distal to and spaced apart from the collar, and wherein the pressure sensor is positioned within and spaced apart from the pressure sensor housing.
16. The apparatus of claim 15 , wherein the collar comprises at least one of fused silica and borosilicate glass.
17. The apparatus of claim 15 , wherein the collar is a cylindrical tube.
18. The apparatus of claim 15 , wherein the optical fiber is bonded using at least one of solder glass bonding techniques and fusion splicing.