Method and apparatus for performing stereoscopic zooming on a head display unit

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No. 16/506,073, filed Jul. 9, 2019, which is a Continuation of U.S. patent application Ser. No. 15/878,463, filed Jan. 24, 2018, now U.S. Pat. No. 10,795,457, which is a Continuation-in-Part of U.S. patent application Ser. No. 14/877,442, filed Oct. 7, 2015, now U.S. Pat. No. 9,980,691, which is a Continuation-in-Part of U.S. patent application Ser. No. 12/176,569 , filed Jul. 21, 2008, now U.S. Pat. No. 9,349,183, which is a Continuation-in-Part of U.S. patent application Ser. No. 11/941,578, filed Nov. 16, 2007, now U.S. Pat. No. 8,384,771, which claims the benefit of and priority under 35 U.S.C. § 119(e) to U.S. patent application Ser. No. 60/877,931, filed Dec. 28, 2006, each of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

Aspects of this disclosure are generally related to radiological imaging, and more particularly to blood vessel appearance using extended reality headsets.

BACKGROUND

One of the challenges that physicians face when viewing a volume with an augmented reality, virtual reality or mixed reality headset is visualization of blood flow.

SUMMARY

All examples, aspects and features mentioned in this document can be combined in any technically possible way.

In accordance with some implementations a method of denoting blood flow within a 3D volume on a head display unit (HDU), comprises: generating a 3D volumetric dataset containing at least one blood vessel; generating at least one pointer; determining the direction of blood flow; modifying the 3D volumetric dataset by placing the at least one pointer in proximity to the at least one blood vessel in a direction aligned with a direction of blood flow; displaying, in said HDU, a left eye image based on said modified 3D volumetric dataset and a right eye image based on said modified 3D volumetric dataset, wherein said left eye image and said right eye image are alternate three-dimensional images; and displaying, in said HDU, the at least one pointer advancing in the direction of blood flow. In some implementations placing the at least one pointer in proximity to the at least one blood vessel comprises placing a 2D arrow. In some implementations placing the at least one pointer in proximity to the at least one blood vessel comprises placing a 3D arrow. Some implementations comprise displaying, in said HDU, the pointer with changing color. Some implementations comprise displaying, in said HDU, the pointer advancing in the direction of blood flow faster in arteries than veins.

BRIEF DESCIPTION OF FIGURES

FIG. 1 illustrates the method for using pointers to denote blood flow direction within a 3D volumetric dataset and viewing with a head display unit.

FIG. 2 illustrates advancing pointers to depict the direction of the blood flow.

FIG. 3 illustrates placement of a 2D pointer into the 3D volume.

FIG. 4 illustrates placement of a 3D pointer into the 3D volume.

FIG. 5 illustrates placement of a 3D pointer into the 3D volume wherein the appearance of the 3D pointer can be modified.

FIG. 6 illustrates variable pointer rates of movement.

DETAILED DESCIPTION OF FIGURES

Some aspects, features and implementations described herein may include machines such as computers, electronic components, radiological components, optical components, and processes such as computer-implemented steps. It will be apparent to those of ordinary skill in the art that the computer-implemented steps may be stored as computer-executable instructions on a non-transitory computer-readable medium. Furthermore, it will be understood by those of ordinary skill in the art that the computer-executable instructions may be executed on a variety of tangible processor devices. For ease of exposition, not every step, device or component that may be part of a computer or data storage system is described herein. Those of ordinary skill in the art will recognize such steps, devices and components in view of the teachings of the present disclosure and the knowledge generally available to those of ordinary skill in the art. The corresponding machines and processes are therefore enabled and within the scope of the disclosure.

FIG. 1 illustrates an implementation of a method for using pointers to denote blood flow direction within a 3D volumetric dataset and viewing with a head display unit. In the first step 100, a 3D volumetric dataset containing at least one blood vessel is generated. In the second step 102, at least one pointer is generated. In the third step 104, the direction of blood flow is determined. In the fourth step 106, at least one pointer in proximity to a blood vessel in a direction aligned with the direction of blood flow is placed such that the 3D volumetric dataset is modified. In the fifth step 108, an image for said left eye based on said modified 3D imaging volume, said view point for said left eye and said volume of interest is displayed, in the left eye display of the said HDU. In the sixth step 110, an image for said right eye based on said modified 3D imaging volume, said view point for said right eye, and said volume of interest and wherein said image for said left eye and said image for said right eye produce an alternate three-dimensional image to said user. In the seventh step 112, at least point pointer is advanced in the direction of blood flow such that the imaging volume is modified. Some portions of this process can be repeated such that multiple modified 3D imaging volumes are created and displayed on the HDU. This would serve to provide the visualization of moving arrows and help the imager better understand blood flow.

FIG. 2 illustrates advancing pointers (or arrows) to depict the direction of the blood flow. In the human body, it is common for blood in most arteries to be directed away from the heart and for blood in most veins to be directed towards the heart. However, in some situations in the body (e.g., subclavian steal with retrograde flow in the vertebral artery), this rule does not apply. It can be difficult for even an experienced imager to readily determine which structures are arteries and which structures are veins. Additionally, even if an imager is able to identify a structure as an artery, it can be difficult to determine its orientation without carefully tracing it back to its origin. Through advances in computer processing, these vessels and the direction of blood flow therein can be determined. An effective visual representation method is required. In this method, advancing pointers along an artery can be performed to indicate the direction of blood flow. Similarly, advancing pointers can be performed in a vein. The color of the pointers can be changed to designate to the user whether it is an artery or vein. Further, the rate of advance of the pointers can also be varied, such as to match the natural blood flow rate for a realistic understanding of the hemodynamics of the patient. The pointers could be located in close proximity to (or within the blood vessels, such as within the center of the blood vessel). As a blood vessel curves through the 3D volume space, the path of the pointers would also curve to match that of the normal blood flow. In FIG. 2A, the pointers 204 are shown within the blood vessel lumen 202 in an initial position with respect to the blood vessel wall 200 and position of the remainder of structures within the imaging volume, which are not shown. This would represent the appearance of the imaging volume at an initial time point. In FIG. 2B, the pointers 204 are shown within the blood vessel lumen 202 in an second, slightly advanced position with respect to the blood vessel wall 200 and position of the remainder of structures within the imaging volume, which are not shown. This would represent the appearance of the imaging volume at a subsequent time point. In FIG. 2C, the pointers 204 are shown within the blood vessel lumen 202 in an third, even further advanced position with respect to the blood vessel wall 200 and position of the remainder of structures within the imaging volume, which are not shown. This would represent the appearance of the imaging volume at an additional subsequent time point. The volume that would displayed to the user on an extended reality (i.e., augmented reality, mixed reality or virtual reality headset) would therefore be dynamic and change over time. Even if the user were looking at a particular structure without moving his or her head, some items within the 3D volume would appear to be moving.

FIG. 3 illustrates placement of a 2D pointer into the 3D volume. In FIG. 3A, a 2D pointer 300 is placed into the blood vessel 200 within the 3D imaging volume. Note that this image illustrates a side view wherein the user's left and right eye view points and left and right eye viewing angles show the side of the 2D pointer 300 and the side of the blood vessel 200 within the 3D volume. In FIG. 3B, the 2D pointer 300 is placed into the blood vessel 200 within the 3D volume. Note that this image illustrates a top down view wherein the user's left and right eye view points and left and right eye viewing angles show the 2D pointer 300 and the top of the blood vessel 200 within the 3D volume. Note that since the 2D pointer is a planar slice, it nearly disappears when viewing from a near top position. A true top position with a planar 2D slice would completely disappear unless the 2D arrow was reoriented. Non-planar slices could also be used, which would be seen from any viewing angle and could be beneficial for viewing direction of blood on a curved vessel.

FIG. 4 illustrates placement of a 3D pointer into the 3D volume. In FIG. 4A, a 3D pointer 400 is placed into the blood vessel 200 within the 3D imaging volume. Note that this image illustrates a side view wherein the user's left and right eye view points and left and right eye viewing angles show the side of the 3D pointer 400 and the side of the blood vessel 200 within the 3D volume. In FIG. 4B, the 3D pointer 400 is placed into the blood vessel 200 within the 3D volume. Note that this image illustrates a top down view wherein the user's left and right eye view points and left and right eye viewing angles show the 3D pointer 400 and the top of the blood vessel 200 within the 3D volume. Note that since the pointer is 3D, it is clearly visualized when viewing from a near top position. Such a pointer could be constructed by arranging a series of 2D non-planar slices to form a cone abutting a cylinder (also made of combination of planar and non-planar slices) yielding a 3D pointer 400. By inserting this into the 3D volume, the volume would be modified.

FIG. 5 illustrates placement of a 3D pointer into the 3D volume wherein the appearance of the 3D pointer can be modified. In FIG. 5A, a 3D pointer 500 is placed into the blood vessel 200 within the 3D volume. Note that the appearance of the 3D pointer 500 is black. In FIG. 5B, the 3D pointer 502 is placed into the blood vessel 200 within the 3D volume. Note that the appearance of the 3D pointer 502 is gray. In FIG. 5C, a 3D pointer 504 is placed into the blood vessel 200 within the 3D volume. Note that the appearance of the 3D pointer 504 is red. Note that the appearance of the pointer can vary. It can be 2D or 3D. It can be a wide range of colors. It can be a wide range of shapes. It can have a wide range of textures.

FIG. 6 illustrates variable pointer rates of movement. In FIG. 6A, the black 3D pointer 500 is located within the proximal portion of an artery 600 at time point=x. In FIG. 6B, the black 3D pointer 500 has moved and is located distally towards the end of the artery 600 at time point=x+n. In FIG. 6C, the pointer 500 is located within the distal portion of a vein 602 at time point=x. In FIG. 6D, the pointer 500 is located with the mid portion of the vein 602 at time point=x+n. Note that the 3D pointer 500 is moving faster in the artery 600 as compared to the vein 602.

Several features, aspects, embodiments, and implementations have been described. Nevertheless, it will be understood that a wide variety of modifications and combinations may be made without departing from the scope of the inventive concepts described herein. Accordingly, those modifications and combinations are within the scope of the following claims.