System for creating microscopic digital montage images

Abstract

An imaging apparatus. The imaging apparatus may find an area in which a specimen is present, then focus on the specimen and capture images of the specimen during continuous stage motion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. patent application Ser. No. 09 / 919,452, filed Jul. 31. 2001, which in turn is a continuation-in-part of U.S. patent application Ser. No. 09 / 757,703, filed Jan. 11, 2001, U.S. patent application Ser. No. 09 / 758,037, filed Jan. 11, 2001, and U.S. patent application Ser. No. 09 / 788,666, filed Feb. 21, 2001, all of which are currently pending and assigned to the assignee of the present invention.FIELD OF THE INVENTION [0002] The present invention relates to microscopic digital imaging of complete tissue sections for medical and research use. In particular, it describes a method for high throughput montage imaging of microscope slides using a standard microscope, digital video cameras, and an illumination system. BACKGROUND OF THE INVENTION [0003] Laboratories in many biomedical specialties, such as anatomic pathology, hematology, and microbiology, examine tissue under a microscope for the pr...

AI Technical Summary

Benefits of technology

[0014] The present invention relates to a method and system for creating a high throughput montage image of microscope slides. The system includes an optical system, components that are used in a pre-scan processing, and components for auto-focusing by enabling accurate focus control of optical elements without requiring the stage to be stopped and refocused at each tile location. The optical system includes at least one camera, a motorized stage for moving a slide while an image of the slide is captured, a pulsed light illumination system that optically stops motion on the motorized stage while allowing continuous physical movement of the motorized stage, and a stage position detector that controls firing of the pulsed light illumination system at predetermined positions of the motorized stage. The components that are used in the pre-scan processing include an image-cropping component, a tissue finding component and a scan control component. The image-cropping component and tissue finding component identify tissue regions on the slide in the optical system and determine exact locations of tissue on the slide. The scan control component uses information about the locations to generate control parameters for the motorized stage and the camera. The components for auto-focusing include a focal point selection component, a focal surface determination component, and a scan component. The focal point selection component and the focal surface determination component use the control parameters to ensure that a high-quality montage image is captured. The scan component is able to capture a high-quality montage image by maintaining motion of the motorized stage and synchronization of the optical system. The scan component controls the stage position to maintain in-focus imaging during the scanning process without stopping the stage and refocusing at each location and fires a pulsed-illumination source at the appropriate position to guarantee image alignment between sequential camera images.

Problems solved by technology

Though numerous studies have shown that digital image quality is acceptable for most clinical and research use, some aspects of microscopic digital imaging are limited in application.

Perhaps the most important limitation to microscopic digital imaging is a “subsampling” problem encountered in all single frame images.

The field of view problem limits an investigator looking at a single frame because what lies outside the view of an image on a slide cannot be determined.

The resolution-based problem occurs when the investigator looking at an image is limited to viewing a single resolution of the image.

However, these systems may not lend themselves to significant collaborations, documentation or computer based analysis.

To be successful, remote transmission requires lossy video compression techniques to be used in order to meet the network bandwidth requirements, or requires significant delays in the image display if lossless transmission is used.

In addition, lossy compression on the order required for real-time remote transmission, severely limits computer-based analysis, as well as human diagnosis, due to the artifacts associated with lossy compression techniques.

The “virtual slide” option has some limitations, however.

One of the limitations is file size.

A much more difficult limitation with the prior systems is an image capture time problem.

Given today's technology, the rate of slide motion is a significant limiting factor largely because the existing imaging systems require the slide to come to a stop at the center of each field to capture a blur free image of the field.

Continuous light, however, is a significant limitation for digital imaging in that the slide, which must move to capture an entire image, but must be stationary with respect to the camera during CCD integration, thus moving the slide from the light.

Moreover, slide motion during integration results in a blurred image.

This pattern requires precise, expensive mechanics, and its speed is inherently limited by the inertia of the stage.

The three-dimensional characteristic of a typical tissue sample and the slide places additional limitations on the imaging system.

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