Image rotation in an endoscopic laser mapping imaging system

1. A system for endoscopic imaging, the system comprising:

an emitter for emitting a plurality of pulses of electromagnetic radiation;

an image sensor comprising a pixel array for sensing reflected electromagnetic radiation, wherein the image sensor is disposed within a lumen of an endoscope;

a rotation sensor for detecting rotation of one or more of the lumen of the endoscope or a handpiece of the endoscope; and

a controller in electronic communication with the emitter and the image sensor configured to synchronize operations of the emitter and the image sensor to generate a plurality of exposure frames;

wherein at least a portion of the plurality of pulses of electromagnetic radiation emitted by the emitter comprises a visible pulse comprising a visible wavelength of electromagnetic radiation and a laser mapping pulse comprising electromagnetic radiation emitted in a laser mapping pattern for determining one or more of a topology of a scene, a dimension of one or more objects within the scene, or a distance; and

wherein the plurality of exposure frames comprises a visible exposure frame sensed in response to an emission of the visible pulse and a laser mapping exposure frame sensed in response to an emission of the laser mapping pulse.

2. The system of claim 1 , wherein the lumen is rotatable about an axis of the endoscope and with respect to the handpiece.

3. The system of claim 1 , further comprising:

an image signal processing pipeline for performing rotation transformations on the plurality of exposure frames sensed by the image sensor based on the rotation detected by the rotation sensor;

wherein the image signal processing pipeline rotates the exposure frames counter to the rotation detected by the rotation sensor to maintain a consistent image horizon of a scene being imaged by the image sensor.

4. The system of claim 1 , wherein the rotation sensor is a rotation-detecting Hall-effect sensor and is located in the handpiece of the endoscope.

5. The system of claim 4 , further comprising a diametrically polarized, magnetic annulus, and wherein the rotation sensor generates a voltage that is used to detect an angle of the diametrically polarized, magnetic annulus.

6. The system of claim 1 , wherein the rotation sensor generates a voltage that is used to detect the rotation of the lumen relative to the handpiece.

7. The system of claim 1 , wherein the rotation sensor is a potentiometer comprising a carbon filament, wherein the carbon filament is disposed within the lumen of the endoscope.

8. The system of claim 1 , wherein the rotation sensor comprises a light source and a photo diode that rotate relative to a gradient disc, and wherein the photo diode detects electromagnetic energy emitted by the light source that is reflected off the gradient disc.

9. The system of claim 1 , further comprising an image signal processing pipeline for performing rotation transformations on the plurality of exposure frames sensed the image sensor based on the rotation detected by the rotation sensor, wherein calculating the image rotation transformation comprises:

identifying integer (x,y) coordinates for pixel data in an exposure frame a pixel of the pixel array;

applying a rotation kernel to the integer (x,y) coordinates to transform the integer (x,y) coordinates to real number pixel coordinates;

truncating the real number pixel coordinates to integer values; and

assigning values to blank pixel data in the exposure frame using values of nearby, filled pixel data from the exposure frame.

10. The system of claim 1 , further comprising an image signal processing pipeline for performing rotation transformations on exposure frames the image sensor based on the rotation detected by the rotation sensor, wherein calculating the image rotation transformation comprises:

identifying integer (x,y) coordinates for pixel data in an exposure frame a pixel of the pixel array;

applying an inverse rotation kernel to the integer (x,y) coordinates to transform the integer (x,y) coordinates to real number (x,y) coordinates; and

estimating a pixel value at the real number (x,y) coordinates using data from one or more closest integer coordinate locations;

wherein the estimating is performed using one of nearest neighbor substitution, bilinear interpolation, or bicubic interpolation.

11. The system of claim 1 , wherein each of the plurality of exposure frames corresponds to a pulse of electromagnetic radiation emitted by the emitter.

12. The system of claim 1 , wherein the pixel array of the image sensor senses reflected electromagnetic radiation to generate the plurality of exposure frames during a readout period of the pixel array, and wherein the readout period is a duration of time when active pixels in the pixel array are read.

13. The system of claim 1 , wherein the emitter is configured to emit, during a pulse duration, a plurality of sub-pulses of electromagnetic radiation having a sub-duration shorter than the pulse duration.

14. The system of claim 1 , wherein one or more of the plurality of pulses of electromagnetic radiation emitted by the emitter comprises electromagnetic radiation emitted at two or more wavelengths simultaneously as a single pulse or a single sub-pulse.

15. The system of claim 1 , wherein at least a portion of the plurality of pulses of electromagnetic radiation emitted by the emitter is a fluorescence excitation emission that results in a fluorescence exposure frame sensed by the image sensor, and wherein the controller is configured to provide the fluorescence exposure frame to a corresponding system that determines a location of a tissue structure within a scene based on the fluorescence exposure frame.

16. The system of claim 15 , wherein the fluorescence excitation emission comprises one or more of:

electromagnetic radiation having a wavelength from about 770 nm to about 790 nm; or

electromagnetic radiation having the wavelength from about 795 nm to about 815 nm.

17. The system of claim 16 , wherein the controller is further configured to:

receive the location of the tissue structure from the corresponding fluorescence system;

generate an overlay frame comprising the location of the tissue structure; and

combine the overlay frame with a color image frame depicting the scene to indicate the location of the tissue structure within the scene.

18. The system of claim 17 , wherein sensing the reflected electromagnetic radiation by the pixel array comprises generating a laser mapping exposure frame by sensing reflected electromagnetic radiation resulting from the emitter pulsing the laser mapping pattern, and wherein the controller is further configured to:

provide the laser mapping exposure frame to a corresponding laser mapping system that determines the topology of the scene, the dimension of one or more objects within the scene, or the distance;

provide the location of the tissue structure to the corresponding laser mapping system; and

receive a topology and/or dimension of the tissue structure from the corresponding laser mapping system.

19. The system of claim 18 , wherein the tissue structure comprises one or more of a nerve, a ureter, a blood vessel, an artery, a blood flow, or a tumor.

20. The system of claim 1 , wherein the controller is configured to synchronize timing of the plurality of pulses of electromagnetic radiation during a blanking period of the image sensor, and wherein the blanking period corresponds to a time between a readout of a last row of active pixels in the pixel array and a beginning of a next subsequent readout of active pixels in the pixel array.

21. The system of claim 1 , wherein two or more pulses of electromagnetic radiation emitted by the emitter result in two or more instances of reflected electromagnetic radiation that are sensed by the pixel array to generate two or more exposure frames that are combined to form an image frame.

22. The system of claim 1 , wherein the image sensor comprises a first image sensor and a second image sensor such that the image sensor can generate a three-dimensional image.

23. The system of claim 1 , wherein the emitter is configured to emit a sequence of pulses of electromagnetic radiation repeatedly sufficient for generating a video stream comprising a plurality of image frames, wherein each image frame in the video stream comprises data from two or more of the plurality of exposure frames, and wherein each of the plurality of exposure frames corresponds to a pulse of electromagnetic radiation.

24. The system of claim 1 , wherein the plurality of pulses of electromagnetic radiation are emitted in a pattern of varying wavelengths of electromagnetic radiation, and wherein the emitter repeats the pattern of varying wavelengths of electromagnetic radiation.

25. The system of claim 1 , wherein at least a portion of the plurality of pulses of electromagnetic radiation emitted by the emitter comprises a red emission, a green emission, a blue emission, and the laser mapping pattern such that reflected electromagnetic radiation sensed by the pixel array corresponding to each of the red emission, the green emission, the blue emission, and the laser mapping pattern can be processed to generate a color RGB image frame comprising an overlay of laser mapping data.

26. The system of claim 1 , wherein the reflected electromagnetic radiation sensed by the pixel array can be processed to generate a YCbCr image frame comprising an overlay of laser mapping data.

27. The system of claim 1 , wherein sensing the reflected electromagnetic radiation by the pixel array comprises generating a laser mapping exposure frame by sensing reflected electromagnetic radiation resulting from the emitter pulsing the laser mapping pattern, and wherein the laser mapping exposure frame comprises information for determining real time measurements comprising one or more of:

a distance from an endoscope to an object;

an angle between an endoscope and the object; or

surface topology information about the object.

28. The system of claim 1 , wherein the laser mapping exposure frame comprises information for determining real time measurements to an accuracy of less than 10 centimeters, and wherein the laser mapping pattern comprises one or more of vertical hashing, horizontal hashing, a raster grid of discrete points, an occupancy grid map, or a dot array.

29. The system of claim 1 , wherein the laser mapping exposure frame comprises information for determining real time measurements to an accuracy of less than one millimeter.

30. The system of claim 1 , wherein at least a portion of the plurality of pulses of electromagnetic radiation emitted by the emitter comprises a plurality of tool-specific laser mapping patterns for each of a plurality of tools within a scene.

31. The system of claim 1 , wherein the electromagnetic radiation in the laser mapping pattern emitted by the emitter comprises a first output and a second output that are independent from one another, wherein the first output is for light illumination and the second output is for tool tracking.

32. The system of claim 1 , wherein at least a portion of the plurality of pulses of electromagnetic radiation emitted by the emitter is a hyperspectral emission that results in a hyperspectral exposure frame created by the image sensor, and wherein the controller is configured to provide the hyperspectral exposure frame to a corresponding hyperspectral system that determines a location of a tissue structure within the scene based on the hyperspectral exposure frame.

33. The system of claim 32 , wherein the hyperspectral emission comprises:

electromagnetic radiation having a wavelength from about 513 nm to about 545 nm and electromagnetic radiation having a wavelength from about 900 nm to about 1000 nm; or

electromagnetic radiation having a wavelength from about 565 nm to about 585 nm and electromagnetic radiation having a wavelength from about 900 nm to about 1000 nm.

34. The system of claim 33 , wherein the controller is further configured to:

receive the location of the tissue structure from the corresponding hyperspectral system;

generate an overlay frame comprising the location of the tissue structure; and

combine the overlay frame with a color image frame depicting the scene to indicate the location of the tissue structure within the scene.

35. The system of claim 34 , wherein the controller is further configured to:

provide the laser mapping exposure frame to a corresponding laser mapping system that determines the topology of the scene, the dimension of one or more objects within the scene, or the distance;

provide the location of the tissue structure to the corresponding laser mapping system; and

receive a topology and/or dimension of the tissue structure from the corresponding laser mapping system.

36. The system of claim 35 , wherein the tissue structure comprises one or more of a nerve, a ureter, a blood vessel, an artery, a blood flow, or a tumor.