WO2010061293A2

WO2010061293A2 - System and method for measuring objects viewed through a camera

Info

Publication number: WO2010061293A2
Application number: PCT/IB2009/007747
Authority: WO
Inventors: James Mahon; Donncha Ryan; Nicolas Sezille; Derek Cassidy
Original assignee: Haptica Limited
Priority date: 2008-11-26
Filing date: 2009-11-25
Publication date: 2010-06-03
Also published as: WO2010061293A3

Abstract

A measurement system includes a camera, a scaling member, and a computer configured to approximate the size of an object, the size being based on at least one camera image of the scaling member. The measurement system also includes a display device configured to receive data from the computer and display information regarding the approximate size of the object.

Description

SYSTEM AND METHOD FOR MEASURING OBJECTS VIEWED THROUGH A CAMERA

Description

This application claims priority to U.S. Provisional Patent Application No. 61/193,424, filed November 26, 2008, the contents of which are incorporated herein by reference.

Technical Field

[0001] The present disclosure relates to a system and method for measuring objects viewed through a camera and, more particularly, to a system and method for measuring objects using an endoscopic camera during a surgical or simulated surgical procedure.

Background

[0002] The rapid pace of recent health care advancements offers tremendous promise for those with medical conditions previously requiring traditional surgical procedures. Specifically, many procedures routinely done in the past as "open" surgeries can now be carried out far less invasively, often on an outpatient basis. In many cases, exploratory surgeries have been completely replaced by these less invasive surgical techniques. [0003] In traditional open surgeries, the operator has a substantially full and uninterrupted view of the surgical site. This is rarely so with less invasive techniques, in which the surgeon is working in a much more confined space through a smaller incision and cannot directly see the area of operation. To successfully perform a less invasive surgery therefore involves not only complex surgical techniques but unique surgical equipment to effect those techniques. In addition to specially tailored instruments, such a procedure typically requires an endoscope, a device that can be inserted in either a natural opening or a small incision in the body. Endoscopes are typically tubular in structure and provide light to and visualization of an interior body area through use of a camera system. Methods of image acquisition with an endoscope may depend on whether the endoscope is rigid or flexible, and may include the use of, for example, a system of lenses, fiber optic bundles, or video chip technology (e.g., charged coupling device ("CCD") chips with additional electronics) for video imaging. The endoscopic cameras themselves are typically connected to video monitors for viewing during the procedure or, in some applications, to a head-mounted display worn by the operating surgeon. In use, the surgeon or an endoscope operator positions the endoscope according to the visualization needs of the operating surgeon.

[0004] While endoscopic procedures offer enormous benefits, one impediment to operating in such an environment is the difficulty in efficiently ascertaining measurements of various targeted objects, such as tumors, organs, blood vessels, or foreign bodies, within the area of operation. Accurate and easily obtainable measurements would quickly increase the information available to the surgeon and allow the surgeon to more effectively decide which instruments and other equipment are best for a particular procedure. Acquiring such information using the instruments already within the surgical site would further increase the speed of such decisions while also reducing trauma and potential risk to the patient through introduction of a separate implement dedicated to measurement. It may therefore be desired to measure the dimensions of any object within the area of an endoscopic operation using the endoscope and existing surgical instruments, and to do so regardless of the means of endoscopic image acquisition.

[0005] The present disclosure is directed to overcoming one or more of the impediments set forth above and/or other shortcomings in existing technology.

Summary

A method of approximating a size of an object viewed through a camera includes receiving a camera image including an object and a scaling member in the image, approximating a size of the object based on the position of the scaling member in the image, and sending information regarding the approximate size of the object to a display device. A measurement system for use in a surgical procedure includes an endoscope, the endoscope including a camera for obtaining images, and a scaling member, the scaling member including at least two identifying markers, wherein the markers are of a known size and separated by a known distance. The measurement system also includes a computer configured to approximate a size of an object, the size being based on at least one camera image of the at least two identifying markers positioned adjacent the object, and a display device configured to receive data from the computer and display the image, a measurement scale, and information regarding the approximate size of the object.

Brief Description of the Drawings

[0006] Fig. 1 is a view of an endoscopic surgical site with a measurement system in accordance with the present disclosure;

[0007] Fig. 2 is a perspective view showing a marked scaling member of the measurement system;

[0008] Fig. 3 is a display view showing a measurement scale of the measurement system used with a single image;

[0009] Fig. 4 is a display view showing a measurement scale of the measurement system used with multiple images; and

[0010] Fig. 5 is a display view showing a derived measurement scale of the measurement system.

Detailed Description

[0011] In accordance with this disclosure and Figs. 1-5, the system 10 includes an endoscope 12, a scaling member 14, a computer 16, and a display device 18. The system 10 may be used in a surgical environment 20 associated with an actual surgery or a simulated surgery. The endoscope 12 includes a camera 22 that acquires images corresponding to what is viewed from a distal end 25 of the endoscope 12. The endoscope 12 may be a conventional endoscope, including, for example, a rigid or flexible endoscope, and is not limited in its method of image acquisition, which may include a system of lenses, fiber optics, or video chip technology, as examples. [0012] The scaling member 14 may include any device that can be introduced into the surgical environment and includes a plurality of markers of a known size and distance separation. For example, the scaling member 14 may merely be a rod-type element, or it may be a conventional medical or surgical instrument, such as a grasper 15, as shown in Fig. 1. For the remainder of this disclosure, the scaling member 14 will be discussed in reference to a grasper 15, but it is understood that the aspects discussed below with respect to the grasper 15 could be used on any other type of scaling member 14.

[0013] As shown in Fig. 2, the grasper 15 includes markers 26, 28 of a known size located at a distal end portion or tip of grasper 15. For example, the markers 26, 28 may be in the range of approximately 0.5 mm to 1.0 mm in size. The markers 26, 28 may be in the form of a dot, line, or other indicator, and may extend around the entire grasper 15, at angular intervals of the grasper 15, or only at one location along the grasper 15. The markers 26, 28 may number two in total, or may include more than two. The markers 26, 28 are separated by a known distance 30. For example, the markers 26, 28 may be 5 mm apart. [0014] Returning to Fig. 1, the grasper 15 may be capable of moving within the surgical environment 20 to contact, or be positioned adjacent, various objects 32, 34 within the surgical environment. Such objects 32, 34 could include various organs of the body, but are not limited to any specific objects within the surgical environment. [0015] The computer 16 may be any conventional computer configured to analyze the images from the camera 22 of the endoscope 12 and provide those images to the display device 18 as a scene 24. As part of the analysis of the scene 24 images, computer 16 is configured to identify the markers 26, 28 and the movement of the markers 26, 28 through the scene 24 images over time. Based on the known size and/or separation between markers 26, 28, the computer 16 is configured to determine the approximate size of objects adjacent the markings 26, 28. For example, as shown in Fig. 3, by positioning the grasper 15 adjacent a small object 34, the computer can approximate the size of the object 34 and provide a measurement scale, in the form of a grid, for example, overlaid on the scene 24 image on the display device 18, the grid providing a scaling based on the distance between the markers 26, 28. The known marker size can additionally be used as a check. In this case, a single image frame can generate the measurement grid at a single distance from the endoscope. The measurement scale or grid can be used to measure a specific object in the scene. [0016] The computer 16 may also be configured to determine a three-dimensional size of an object within the surgical environment 20. For example, the computer 16 may include a mouse 36 (Fig. 1) or other operator-triggered device that allows the operator to identify two or more positions of the grasper 15. With the two or more positions of the grasper 15 identified, the computer can determine a linear distance between the two positions. Similar to the single-position determination discussed above, this plural-position determination uses the known size and/or separation between markings 26, 28 to determine an approximate size of an object 32 within a plane normal to the scene 24 at each grasper position (see positions A, B, and C of Fig. 4). From there, the computer 16 can determine the distance (and varying scale) between grasper positions. An actual linear distance between the identified grasper positions can be provided on the display device 18 and in addition or alternatively, a grid 33 (see Fig. 4) may be overlaid or a linear measurement scale 35 (as shown between positions A and B of Fig. 5) can be derived and overlaid on the scene 24 images on the display device 18. The grid 33 and/or linear measurement scale 35 can be used to measure a specific object in the scene, as both linear and area measurements may be taken at multiple positions of grasper 15 (see Fig. 4).

[0017] Ideally the camera 22 will not move between the plural positions of the grasper 15. However, if that occurs, it will be possible to correlate the two images together to compensate for this movement. As a result, the camera 22 can be hand-held without losing synchronization of the scene. Such a movement compensation is known in the art using, for example, normalized cross correlation or other template matching techniques. [0018] The above described system may be used with any type of camera to determine the size of an object viewed through the camera. Accordingly, the system and method is not limited to surgical or simulated surgical procedures. The system and method does, however, have beneficial use in any medical/surgical environment where knowing the size of objects in the environment can assist in the surgical procedure. For example, the above described system can be used in a hernia procedure to measure the size of the hernia to size an appropriate hernia patch, or to size a tumor.

[0019] It will be apparent to those skilled in the art mat various modifications and variations can be made to the disclosed system and method disclosed without departing from the scope of this disclosure. For example, the markers may be omitted if the scaling member is otherwise identifiable as a scale. As another example, the computer system could be configured to recognize the scaling member based on shape and have stored therein distances associated with the shape. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed method and apparatus. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.

Claims

ClaimsWhat is claimed is:

1. A measurement system, comprising: a camera; a scaling member; a computer configured to approximate a size of an object, the size being based on at least one camera image of the scaling member; and a display device configured to receive data from the computer and display information regarding the approximate size of the object.

2. The measurement system according to claim 1, wherein the computer is further configured to provide a linear measurement between two positions of the scaling member.

3. The measurement system of claim 1, wherein the computer is further configured to approximate the size of the object in three dimensions.

4. The measurement system of claim 1, wherein the display device is further configured to display an image of the object and a measurement scale.

5. The measurement system of claim 4, wherein the measurement scale is in the form of a grid.

6. The measurement system of claim 4, wherein the measurement scale is linear.

7. The measurement system of claim 1, wherein the scaling member includes a plurality of markings that are used by the computer to approximate the size of the object.

8. The measurement system of claim 1, wherein the system is configured for use in a surgical procedure.

9. The measurement system of claim 1, wherein the scaling member is a surgical instrument.

10. The measurement system of claim 1, wherein the camera is an endoscopic camera.

11. A method for approximating a size of an object viewed through a camera, comprising: receiving a camera image including an object and a scaling member in the image; approximating a size of the object based on the position of the scaling member in the image; and sending information regarding the approximate size of the object to a display device.

12. The method of claim 11, wherein the approximating a size of the object includes identifying markers on the scaling member.

13. The method according to claim 11, wherein the approximating a size of the object includes positioning the scaling member adjacent the object.

14. The method according to claim 11, wherein the approximating a size of the object includes positioning the scaling member at a plurality of positions adjacent the object.

15. The method according to claim 11, wherein the approximating a size of the object includes approximating the size of the object in three dimensions.

16. The method according to claim 11, wherein sending information regarding the approximate size of the object to a display device includes providing a measurement scale for display.

17. The method according to claim 16, wherein the measurement scale is in the form of a grid.

18. The method according to claim 11, wherein the scaling member includes a plurality of markers located at a distal end portion of the instrument.

19. The method according to claim 11, wherein the camera scene is received from an endoscopic camera.

20. A measurement system for use in a surgical procedure, comprising: an endoscope, the endoscope including a camera for obtaining images; a scaling member, the scaling member including at least two identifying markers, wherein the markers are of a known size and separated by a known distance; a computer configured to approximate a size of an object, the size being based on at least one camera image of the at least two identifying markers positioned adjacent the object; and a display device configured to receive data from the computer and display the image, a measurement scale, and information regarding the approximate size of the object.