Methods, systems and apparatus for temporal calibration of an intravascular imaging system
In part, the disclosure relates to systems for imaging a blood vessel using intravascular image data and extravascular image data and methods to calibrate such systems. In one embodiment, multiple calibration trials are performed to determine a plurality of time lag values. A minimum time lag value is used to align intravascular image data and extravascular time lag data in one embodiment.
1. A calibration system comprising:
an optical coherence tomography (OCT) probe comprising a marker, wherein the probe is configured to collect OCT data, wherein the probe is disposed within an imaging zone of an angiography system;
an optical coherence tomography data processing system comprising
a computing device comprising a processor, the computing device programmed to generate frames of OCT images based upon received intravascular probe signals and to receive angiography data comprising angiography frames, the processor configured to cause the computing device to determine a minimum time delay between an initial OCT frame and an initial angiography frame from a set of time delays; and
one or more memory devices in electrical communication with the computing device; and
a controller programmed to initiate a plurality of pullbacks of the OCT probe, in response to a control signal, during which OCT data is collected, and transmit each pullback initiation time to the one or more memory devices.
2. The system of claim 1 wherein the computing device comprises a calibration method stored in the one or more memory devices as instructions to cause the computing device to determine an initial frame of the OCT probe for each pullback.
3. The system of claim 1 wherein the computing device comprises a calibration method stored in the one or more memory devices as instructions to cause the computing device to determine an initial angiography frame that corresponds to an initial frame of OCT probe pullback.
4. The system of claim 1 wherein the computing device comprises a calibration method stored in the one or more memory devices as instructions to cause the computing device to determine a time delay between an initial OCT frame and an initial angiography frame.
5. The system of claim 4 wherein the calibration method further comprises instructions to cause the computing device to align OCT frames and angiography frames using the time delay.
6. The system of claim 1 further comprising a display in electrical communication with the optical coherence data processing system, wherein the computing device is programmed to align one or more OCT frames and one or more angiography frames using the minimum time delay and display one or more of such aligned frames.
7. The system of claim 1 wherein a frame rate of the optical coherence tomography data processing system is greater than a frame rate of the angiography system.
8. The system of claim 1 wherein the computing device is programmed to track pixel changes in angiography frames to identify marker movement.
9. The system of claim 8 wherein the computing device is programmed to use to marker movement to determine an initial angiography frame.
10. The system of claim 8 wherein the computing device is programmed to align an OCT frame with an angiography frame in response to tracked marker positions.
11. The system of claim 1 wherein the computing device is programmed to store a time an OCT pullback is initiated in the one or more memory devices.
12. The system of claim 1 wherein the computing device is programmed to determine a time delay between an angiography frame and an OCT frame.