US5638459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting a microscope slide coverslip
Assignee: TriPath Imaging Inc
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Filing: 1994-09-20
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Granted: 1997-06-10
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Expires: 2014-09-20
Abstract
Abstract Coverslip detection locating all four coverslip edges. A field of view processor receives image data from a charge coupled device camera. The charge coupled device camera images a slide and coverslip that is mounted on a movable frame. The slide and coverslip are illuminated from below with a uniform light source. The moveable frame is under computer control and moves in response to the field of view processor. The field of view processor locates the coverslip by first positioning the movable frame to view a portion of the slide on a predetermined potion of the slide within a predetermined area of the slide. The slide is then re-imaged after the movable frame moves the slide toward a chosen edge of direction. Edge type objects are located and followed over multiple fields of view. If the edge object satisfies a set of predetermined criteria the coverslip edge has been found. The edge is extended to find all four corners of the coverslip. The edge objects are processed using morphological operators.
Inventors
- 👤 Mikel D. Rosenlof
- 👤 Robert C. Schmidt
- 👤 Shih-Jong J. Lee
- 👤 Chih-Chau L. Kuan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:04
CPC Classifications
G; G06; G06V; G06V20/00; G06V20/60; G06V20/69; G06V10/00; G06V10/20; G06V10/24; G06V10/245
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
96 words
A microscope slide coverslip detection apparatus comprising: (a) a movable stage for mounting a microscope slide having a microscope slide coverslip, where the microscope slide coverslip has microscope slide coverslip edges; (b) an imaging means for obtaining an image of the microscope slide coverslip; (c) an image processor means for receiving and processing the image and for automatically detecting and locating the microscope slide coverslip edges wherein the image processor means performs a crossing search and a following search to locate the coverslip edges; and (d) a light source positioned to illuminate the microscope slide coverslip.
Claim 2
Dependent Claim
96 words
A microscope slide coverslip detection apparatus comprising: (a) a movable stage for mounting a microscope slide having a microscope slide coverslip, where the microscope slide coverslip has microscope slide coverslip edges; (b) an imaging means for obtaining an image of the microscope slide coverslip; (c) an image processor means for receiving and processing the image and for automatically detecting and locating the microscope slide coverslip edges wherein the image processor means performs a crossing search and a following search to locate the coverslip edges; and (d) a light source positioned to illuminate the microscope slide coverslip.
Claim 3
Dependent Claim
48 words
The apparatus of claim 1 wherein the image processor means comprises: (a) at least one field of view processor connected to the image processor means to process images from the image processor means; and (b) a host computer to control the at least one field of view processors.
Claim 4
Dependent Claim
20 words
The apparatus of claim 1 where the image processor means searches in a predefined area of the microscope slide coverslip.
Claim 5
Dependent Claim
21 words
The apparatus of claim 1 where the image processor means performs at least one morphological operation to generate an edge image.
Claim 6
Dependent Claim
40 words
The apparatus of claim 2 wherein the field of view processor performs a 35×1 horizontal dilate, a 1×65 vertical dilate and a 13×1 horizontal closing to generate a thick edge image, a thin edge image and a combined edge image.
Claim 7
Dependent Claim
35 words
The apparatus of claim 1 further comprising means for providing a combined edge image; and a means for processing the combined edge image wherein the combined edge image is processed into a filtered edge image.
Claim 8
Dependent Claim
18 words
The apparatus of claim 1 wherein the microscope slide further comprises a specimen prepared by the Papanicolaou method.
Claim 9
Dependent Claim
13 words
The apparatus of claim 1 wherein the imaging means comprises a CCD camera.
Claim 10
Dependent Claim
13 words
The apparatus of claim 1 wherein the light source is a arc lamp.
Claim 11
Dependent Claim
14 words
The apparatus of claim 1 wherein the light source is a strobed arc lamp.
Claim 12
Dependent Claim
52 words
The apparatus of claim 1 further comprising a means, coupled to the image processor means, for accumulating at least one set of point coordinates from an object of interest on the microscope slide coverslip, wherein the at least one set of point coordinates are fit to a line with a predetermined fit.
Claim 13
Dependent Claim
15 words
The apparatus of claim 11 wherein the predetermined fit is a least squares error fit.
Claim 14
Dependent Claim
46 words
The apparatus of claim 11 wherein the accumulating means further comprises means for line fitting wherein a plurality of sets of point coordinates are fit with the predetermined fit and one of the plurality of sets of point coordinates that satisfies a predetermined criteria is selected.
Claim 15
Dependent Claim
88 words
The apparatus of claim 13 wherein the line fitting means further comprises means for calculating a calculated position of each of the plurality of sets of point coordinates wherein the predetermined fit has a number of points, and wherein the predetermined criteria has a total error defined by a difference substantially equal to a measured position subtracted from the calculated position of each of the plurality of sets of point coordinates, and wherein the total error is normalized by the number of points used in the predetermined fit.
Claim 16
Dependent Claim
27 words
The apparatus of claim 1 further comprising a means for checking whether the microscope slide coverslip edges are substantially perpendicular to each other within a predetermined tolerance.
Claim 17
Dependent Claim
25 words
The apparatus of claim 1 wherein the image processor means further comprises a plurality of field of view processors to process multiple fields of view.
Claim 18
Independent Claim
172 words
A method of evaluating a microscope slide by measuring a coverslip on the microscope slide, the method comprising the steps of: (a) finding a left edge of the coverslip relative to a predetermined window region; (b) finding a bottom edge of the coverslip relative to the predetermined window region; (c) finding a top edge of the coverslip relative to the predetermined window region; (d) finding a right edge of the coverslip relative to the predetermined window region: (e) calculating a corner of each intersecting pair of edges by calculating an intersection of adjacent edge pairs; (f) determining that each corner is square; (g) rejecting the microscope slide if each corner is not square within a predetermined set of limits; (h) rejecting the microscope slide if a calculated length of the coverslip is not a multiple of a predetermined distance; (i) rejecting the microscope slide if a calculated coverslip width is not within predetermined limits; and (j) rejecting the microscope slide if a calculated coverslip skew angle is not within predetermined skew limits.
Claim 19
Independent Claim
172 words
A method of evaluating a microscope slide by measuring a coverslip on the microscope slide, the method comprising the steps of: (a) finding a left edge of the coverslip relative to a predetermined window region; (b) finding a bottom edge of the coverslip relative to the predetermined window region; (c) finding a top edge of the coverslip relative to the predetermined window region; (d) finding a right edge of the coverslip relative to the predetermined window region: (e) calculating a corner of each intersecting pair of edges by calculating an intersection of adjacent edge pairs; (f) determining that each corner is square; (g) rejecting the microscope slide if each corner is not square within a predetermined set of limits; (h) rejecting the microscope slide if a calculated length of the coverslip is not a multiple of a predetermined distance; (i) rejecting the microscope slide if a calculated coverslip width is not within predetermined limits; and (j) rejecting the microscope slide if a calculated coverslip skew angle is not within predetermined skew limits.
Claim 20
Dependent Claim
31 words
The method of claim 17 wherein the first distance is 10 mm, the second distance is 40 mm, the third distance is 50 mm, and the fourth distance is 60 mm.
Claim 21
Dependent Claim
124 words
An automated method for coverslip slide edge selection on a slide, the method comprising the steps of: (a) performing a crossing search on the slide to find an edge; (b) doing a following search on the slide to obtain a plurality of candidate edges; (c) ranking each one of the plurality of candidate edges according to a predetermined set of criteria; (d) selecting at least one candidate edge; (e) determining whether the at least one candidate edge qualifies as a coverslip edge when measured against a set of edge qualifications, and if the at least one candidate edge qualifies, accepting the at least one candidate edge, otherwise selecting a next highest ranking edge; and (f) selecting only edges that qualify as a coverslip edge.
Claim 22
Dependent Claim
124 words
An automated method for coverslip slide edge selection on a slide, the method comprising the steps of: (a) performing a crossing search on the slide to find an edge; (b) doing a following search on the slide to obtain a plurality of candidate edges; (c) ranking each one of the plurality of candidate edges according to a predetermined set of criteria; (d) selecting at least one candidate edge; (e) determining whether the at least one candidate edge qualifies as a coverslip edge when measured against a set of edge qualifications, and if the at least one candidate edge qualifies, accepting the at least one candidate edge, otherwise selecting a next highest ranking edge; and (f) selecting only edges that qualify as a coverslip edge.
Claim 23
Dependent Claim
95 words
The method of claim 19 wherein the crossing search further comprises the steps of: (a) positioning the slide to view a portion of the slide within a predetermined area of the slide; (b) obtaining a second image of the slide after positioning; (c) locating edge objects within the predetermined area; (f) correlating a plurality of located edge objects over multiple fields of view to produce a correlated edge object; and (e) determining if a correlated edge object satisfies a predetermined set of criteria, and if it does determining that a coverslip edge has been found.
Claim 24
Dependent Claim
37 words
The method of claim 20 wherein the step of determining if a correlated edge object satisfies a predetermined set of criteria further checking whether the edge objects are substantially perpendicular to each other within a predetermined tolerance.
Claim 25
Dependent Claim
28 words
The method of claim 20 wherein step of determining further includes determining whether a detected edge is no more than first distance away from a predetermined edge location.
Claim 26
Dependent Claim
88 words
The method of claim 19 wherein the following search comprises the steps of: (a) dividing a slide coverslip image into a plurality of unique images of the field of view such that each one of the plurality of unique images contains data elements from a slide coverslip edge; (b) determining an object hit for each data element to produce a plurality of object hits; and (c) correlating the plurality of object hits in each of the unique images so as to form a microscope slide coverslip edge image.
Claim 27
Dependent Claim
31 words
The method of claim 23 wherein the step of dividing the image further includes the step of filtering the plurality of unique images to provide data elements including filtered edge images.
Claim 28
Dependent Claim
20 words
The method of claim 24 wherein the step of filtering includes applying a low pass filter on the data elements.
Claim 29
Dependent Claim
31 words
The method of claim 23 further comprising the step of applying a threshold to the data elements wherein the data elements representing the edge are thresholded to determine the object hits.
Claim 30
Dependent Claim
32 words
The method of claim 23 further comprising the step of filtering the plurality of unique images with at least one morphological operator to produce a data element having a filtered edge image.
Claim 31
Dependent Claim
26 words
The method of claim 27 wherein the at least one morphological operator is selected from a group consisting of erosions, dilations, vertical erosions and vertical dilations.
Claim 32
Dependent Claim
34 words
The method of claim 28 comprising the step of dividing the plurality of unique images into a plurality of partial images such that the partial images each contain a portion of an edge image.
Claim 33
Dependent Claim
44 words
The method of claim 29 further including a step of applying a threshold to the filtered edge image, wherein the filtered edge image is thresholded and each occurrence of a region projection exceeding a filtered threshold projection is determined to be an object hit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-09 | 2000-12-09 | 2001-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-09 | 2004-12-09 | 2005-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-09 | 2008-12-09 | 2009-06-10 | $7700.00 | Window Closed / Lapsed |