ENDOSCOPIC MEASUREMENT SYSTEM AND METHOD

• US 20160287141A1
• Filed: 02/25/2015
• Published: 10/06/2016
• Est. Priority Date: 03/02/2014
• Status: Active Grant

• Current Assignee: V.T.M (Virtual Tape Measure) Technologies
• Original Assignee: DVP Technologies Ltd.
• Inventors: SIDLESKY, Avishay
• Granted Patent: US 9,545,220 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 1/06 with illuminating arrangements
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 5/0064 Body surface scanning
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/1072 measuring distances on the body, e.g. measuring length, height or thickness A61B5/1076 takes precedence
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/1079 using optical or photographic means
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: G01B 11/2513 with several lines being projected in more than one direction, e.g. grids, patterns
• CPC Class Codes: G02B 23/2415 Stereoscopic endoscopes
• CPC Class Codes: G02B 23/2461 Illumination
• CPC Class Codes: G02B 23/2484 Arrangements in relation to a camera or imaging device processing or control of video signals generated by an endoscope H04N23/60, H04N23/70
• CPC Class Codes: G02B 27/09 Beam shaping, e.g. changing the cross-sectional area, not otherwise provided for adapting the beam shape of a laser diode G02B19/0052; adapting the beam shape of an LED G02B19/0061; coupling into light guides using intermediate optical elements G02B6/4204; beam shaping specially adapted for lasers H01S3/005
• CPC Class Codes: G06T 2207/10068 Endoscopic image
• CPC Class Codes: G06T 7/0012 Biomedical image inspection
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing

Abstract

The invention is a system and method for measuring 3D distances and dimensions of objects in endoscopic images by using a light plane to make Euclidean and geodesic measurements. The endoscopic measurement system of the invention comprises a flexible or rigid endoscopic device equipped with standard visualization means and a module containing components for generating a light plane. Based on triangulation, the intersection curve between the light lane and the object of interest is measureable in 3D in the coordinate system of the visualization means.

Claims

1. A system for measuring 3D distances and dimensions of objects that are visible in endoscopic images, the system comprising:

a) a flexible or rigid endoscopic device comprising visualization means;

b) a conventional endoscopy system adapted to operate the endoscopic device and to obtain and display images gathered by the visualization means;

c) a light plane generating module comprising a light source and optical elements configured to generate a light plane; and

d) a processing station comprising;

processing means, dedicated software modules adapted for making both Euclidian and geodesic measurements, a graphical user interface (GUI), software, a pointing device, and a display adapted to present to the user of the system images acquired by the visualization means overlaid with graphics and text.

2. The system of claim 1 wherein some or all components of the processing station are integrated into the conventional endoscopy system.

3. The system of claim 1 comprising a docking station for calibration of at least one of projection parameters of the visualization means, distortions of the visualization means, and light plane parameters.

4. The system of claim 1 wherein the dedicated software modules comprise programs that automatically perform at least one of the following operations:

a) assigning 3D coordinates to each pixel along the intersection curves of the light plane with the object;

b) making Euclidean and geodesic measurements between at least two points overlaid by the user on an image displayed on the display;

c) providing and displaying measurements of the Euclidean distance of gaps or diameters of holes and making geodesic measurements of curve segments to determine the diameter of objects seen in the images according to preprogrammed requests of the user or by pointing at a single point on the screen; and

d) determining the projection parameters and distortions of the visualization means and light plane parameters from images recorded during a calibration process.

5. The system of claim 1 wherein the light plane generating module comprises one of the following:

a) a light source and a single lens;

b) a light source and an optical arrangement comprising at least one lens;

c) a light source and a diffractive optical element (DOE);

d) a light source and an optical arrangement comprising at least one DOE;

e) a light source positioned at the proximal end of an optical fiber leading to a diffraction grating at the distal tip of the endoscope; and

f) a light source positioned at the proximal end of an optical fiber leading to a lens at the distal tip of the endoscope.

6. The system of claim 1 wherein the light source is one of:

a) a laser diode;

b) a LED; and

c) a light source that produces colored light.

7. The system of claim 1 wherein the light plane generating module is integrated in a specific design for a dedicated depth measuring endoscopic device.

8. The system of claim 1 wherein the light plane generating module is a separate measurement device that can be mounted as an add-on to an existing, regular flexible or rigid endoscopic device.

9. The system of claim 8 wherein the light plane generating module is mounted on the endoscopic device in one of the following ways:

a) in a working channel of the endoscopic device; and

b) in one channel of a two channel sheath wherein the insertion section of the endoscopic device is slid into the other channel; and

c) a clip or a band attached to the outside of the distal tip of the endoscopic device.

10. The system of claim 1 wherein the light plane generating module is mounted below the objective lens of the visualization means in a pivoting arm configured to allow the distance between the focal point of the visualization means and the light plane to be changed.

11. The system of claim 1 comprising at least one of:

a) multiple light planes;

b) light planes having different line patterns or color coding.

12. The system of claim 1 comprising at least one of:

a) a single light plane that is rotated or swept manually; and

b) a single light plane that is rotated or swept in sync with an image acquisition camera.

13. The system of claim 12 wherein rotation or sweep is achieved by one of:

a) MEMS mirrors;

b) a rotation mechanism; and

c) a combination of MEMS mirrors and a rotation mechanism.

14. The system of claim 1 wherein a reticle is superimposed on images from the visualization means displayed on the display.

15. A method for measuring 3D distances and dimensions of objects that are visible in endoscopic images, the method comprising the following steps:

a) supplying a system according to claim 1;

b) for a non-integrated add-on light plane generating module, mounting the light plane generating module at the tip of the endoscopic device and performing calibration;

c) for an integrated or a non-integrated add-on light plane generating module, manipulating the endoscopic device such that the light plane coincides with the object to be measured;

d) acquiring an image;

e) repeating steps c and d for additional images if desired;

f) selecting an image to be analyzed and using the GUI software to mark at least two points on the intersection curves of the light plane with the object;

g) using the dedicated software module to measure and display the Euclidian distances between the marked points and, if the points lie on the same curve segment, to measure the geodesic distances along the segment;

h) repeating steps f and g to measure additional objects if desired;

i) recording the measurement data and related overlaid graphics if desired; and

j) repeating steps f, g, h, and i for additional images.

16. The method of claim 15 wherein in step f only one point is marked on the image and step g further provides and displays measurements of the Euclidean distance of gaps or diameters of holes and geodesic measurements of curve segments to determine the diameter of objects seen in the images.

17. The method of claim 15 wherein in step f curve segments or gaps are automatically identified and analyzed by the dedicated software module of the processing station and in step g the resulting measurements are displayed automatically, thereby automatically measuring geodesic lengths or diameters of tubular objects or gaps or diameters of holes.

18. The method of claim 16 wherein the curve segments are displayed in a separate view, thereby generating a non-distorted quantitative profile of the objects in the endoscopic view and, for cases where in step c the light plane is aligned with the longitudinal axis of a tubular object, the longitudinal cross-section profile of the tubular object is provided.

19. The method of claim 15 wherein steps f to j are performed off-line after the procedure has been completed or on-line on the recently acquired image during the procedure.

20. The method of claim 16 wherein the steps d and e are replaced with on-line real-time automatic processing of video input during the procedure.

21. The method of claim 15 wherein a spray of water, saline vapor, or the like is used to create haze to enable visualization of the laser plane.

22. The method of claim 15 wherein in step b the calibration is automatically performed by inserting the tip of the endoscopic device into a calibration docking station.