Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Reexamination Certificate
1998-09-15
2001-07-03
Jaworski, Francis J. (Department: 3737)
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
Reexamination Certificate
active
06256530
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains in general to the detection of cancer in various types of human tissue and, more particularly, to a novel procedure and instrumentation for in-vivo detection of cancerous cells using fluorescence excitation in tissue that is optically accessible for examination.
2. Description of the Related Art
Several techniques and instruments have been described by investigators for the purpose of detecting cancerous cells. For example, U.S. Pat. No. 5,062,431 to Potter (1991) utilizes in-vivo fluorescence detection of abnormal tissue by irradiating a photosensitized diagnostic region simultaneously with at least two excitation wavelengths. Fluorescent light emitted from the diagnostic region is detected and a signal is generated relating to the intensity of the fluorescence. A difference signal between the two wavelengths is used to distinguish the fluorescence of normal tissue from that of diseased cells.
In U.S. Pat. No. 5,106,387 (1992), Kittrell et al. disclose a method for identifying atheromaterial in a vascular lumen for diagnosis of arterial or vascular obstructions. Diagnosis is accomplished by spectrally analyzing the return radiation with or without a reference spectrum. U.S. Pat. No. 5,115,137 to Andersson-Engels et al. (1992) describes a method for detecting atherosclerosis and blood disorders by utilizing fluorescence excitation at wavelengths less than 500 nm. The intensity of a plurality of wavelengths, at least two of which have substantially equal absorption by blood, is used to evaluate the character of the tissue being tested.
U.S. Pat. No. 5,131,398 to Alfano et al. (1992) describes diagnosis of cancerous cells by using a substantially monochromatic excitation light and two detection bands at about 340 and 440 nm of the fluorescent emissions. The ratio of the fluorescent intensities at the two wavelengths for normal tissue is then calculated and used as a reference for comparison for identifying cancerous tissue. The invention is based on the discovery that when tissue is excited with monochromatic light at wavelength of about 300 nm, the resulting native fluorescence spectrum over the region from about 320 nm to 600 nm in cancerous tissue is substantially different from that of either benign or healthy tissue. The patent further teaches that avoiding the use of fluorescent emissions between about 380 nm and 430 nm, one can ignore the effect on the fluorescence intensity resulting from blood absorption. In addition, the patent teaches that at excitation wavelengths above 315 nm the ratios of fluorescent-emission intensities are indistinguishable between cancerous and benign cells.
In spite of the progress illustrated by the prior art, it still remains difficult to identify cancerous tissue by direct in-vivo examination. The use of monochromatic or narrow bandwidth for excitation and emission light (such as the 20 nm bandwidth taught by Alfano et al.) requires sophisticated and expensive instrumentation capable of detecting very low light intensities and of functioning with low signal-to-noise ratios. Therefore, it would be very useful to devise a technique that allows the use of wideband radiation and reception and that produces visible light signals for manual operation of the detection instrument. The present invention is directed at providing such improvements to prior-art devices and procedures.
BRIEF SUMMARY OF THE INVENTION
It is a general object of this invention to provide a self-contained, manually-operated diagnostic instrument for the measurement of human-tissue surfaces to determine whether they are cancerous, precancerous or benign.
A further object of the invention is that such diagnostic instrument be simple and inexpensive, so that it can be used by primary care physicians.
It is a still further objective of the invention that the diagnostic instrument be convenient to use.
Yet another object is that such diagnostic instrument be noncontact and aseptic.
Also an object of the invention is that the instrument be capable of defining the area to be diagnosed unambiguously.
A related and essential goal of the invention is to develop a detection technique that makes it possible to implement these objectives with acceptable reliability.
Finally, an objective of the invention is a procedure and corresponding apparatus that are suitable for direct implementation using existing optical and electronic apparatus.
Therefore, according to these and other objectives, the present invention consists of a hand-held, gimbaled or tripod-mounted instrument that contains a light source capable of producing radiant energy in the spectral range between approximately 370 and approximately 410 nm, and an optical direction system for irradiating a target tissue by producing an illuminated spot thereon. A collection system is provided for receiving and directing fluorescent emissions returned from the target area to a detector. A processing system is used to determine the state of the tissue by using at least two and up to five spectral bands, preferably each being larger than 45 nm. Pairs of ratios of fluorescent intensities are compared to identify cancerous cells. An alphanumeric and/or audio signal is immediately provided to inform a user of the state of the tissue.
Various other purposes and advantages of the invention will become clear from its description in the specification that follows and from the novel features particularly pointed out in the appended claims. Therefore, to the accomplishment of the objectives described above, this invention consists of the features hereinafter illustrated in the drawings, fully described in the detailed description of the preferred embodiment and particularly pointed out in the claims. However, such drawings and description disclose but one of the various ways in which the invention may be practiced.
REFERENCES:
patent: 5062431 (1991-11-01), Potter
patent: 5106387 (1992-04-01), Kittrell et al.
patent: 5111821 (1992-05-01), Potter
patent: 5115137 (1992-05-01), Anderson-Engels et al.
patent: 5131398 (1992-07-01), Alfano
patent: 5328488 (1994-07-01), Daikuzono
patent: 5421337 (1995-06-01), Richards-Kortum et al.
patent: 5470331 (1995-11-01), Daikuzono
patent: 5590660 (1997-01-01), Macaulay et al.
patent: 5612540 (1997-03-01), Richards-Kortum et al.
patent: 5647368 (1997-07-01), Zeng et al.
patent: 5769792 (1998-06-01), Palcic et al
patent: 6026319 (1998-06-01), Hayashi
Denvu, L.L.C.
Durando Antonio R.
Jaworski Francis J.
Mantis Mercader Eleni
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