Electrothermographic apparatus for detection and pinpointing of malignancies in human bodies

#The present invention relates to apparatus for detecting and pinpointing localized changes in body temperature. More particularly, the invention relates to electrothermographic apparatus for detection and pinpointing or displaying of tumors, especially cancerous tumors in female breasts. Still more particularly, the invention relates to improvements in apparatus for monitoring selected portions of human bodies and for evaluating thermal radiation signals which are generated in the course of the monitoring operation.

#It is known that the region of a malignancy in a human body develops temperatures exceeding those of the neighboring healthy tissue. The reason for such phenomenon is that a malignancy entails an increased localized tissue change activity which is promoted by increasing production of lymphatic and blood vessels. In the case of histologically confirmed malignant tumors, this leads to a rise of 1.degree.-7.degree. C. above the temperature of the neighboring or surrounding healthy tissue. In the case of benign changes of tissue, the temperature rise of the affected area is much less pronounced, normally less than 1.degree. C. As explained above, the number of blood vessels in a malignant tumor is greatly increased, i.e., the circulation of blood is much greater than in a healthy tissue with attendant rise of temperature of the affected portion of the body or an organ. The rise in temperature can be detected and localized with a reasonable degree of accuracy and sharpness.

#It is also known to detect the presence or absence of malignancies in a human body by resorting to thermographic apparatus which monitor a selected portion of the body and generate signals denoting those spots or regions of the selected portion where the temperature deviates from the temperature of healthy tissue, and to utilize the results of such monitoring operation for pinpointing of actual or suspected malignancies. A presently known electrothermographic apparatus which is utilized for detection of malignant tumors comprises evaluating means in the form of a thermographic plate which contains liquid crystals. The plate records the temperature differences by changing the color or colors of one or more liquid crystals. The crystals are embedded in the plate and their color changes from red to green and thereupon to blue in response to increasing temperature. The temperature response is just the opposite (i.e., from blue to green and back to red) during cooling of the liquid crystals. It has been found that a thermographic plate can furnish reasonably sharp images of malignant and healthy areas, i.e., the outline of a malignant tumor can be seen with a relatively high degree of accuracy.

#FIG. 1 is a diagrammatic view of certain constituents of an apparatus which embodies the invention;

#FIG. 1a is a diagram showing the relationship between color values and the intensities of standardized voltage signals denoting various colors; and

#FIG. 2 is a diagrammatic view of the evaluating circuitry which is interposed between a signal storing unit and a vidicon tube.

#FIG. 1 shows that the object to be examined is a mamma 1. The distribution of temperatures in different regions of the object 1 is imaged by an optical system 2, an oscillating mirror 3, an optical band pass filter 4 and a pyroelectric infrared detector 5 with a self-scanning circuit. The thermal image of the object 1 is scanned by the mirror 3, line-by-line, and each line comprises a predetermined number of image points or dots. The parts 2-4 transmit the thermal image of the object 1 to the detector 5.

#The mirror 3 constitutes a component of a scanning system 4' further including an oscillatable loop or coil S of the type known from the field of galvanometers. The terminal 6 receives impulses for operation of the system 4' so that the mirror 3 images the object 1, line-by-line, onto the detector 5 via band pass filter 4. The purpose of the filter 4 is to ensure that thermal radiation of the object 1 can be evaluated without interference from other sources of thermal radiation. To this end, the optical band pass filter 4 is designed to transmit signals solely within a range corresponding to that of the radiation frequencies of a human body.

#The pyroelectric detector 5 evaluates a radiation spectrum of between 1 .mu.m and approximately 50 .mu.m. The mode of evaluation is analogous to that in a so-called CCD (charge coupled device) line. Reference may be had to the article by Carlos B. Roundy entitled "Pyroelectric self-scanning infrared detector arrays" published in the Apr. 1, 1979 issued of APPLIED OPTICS (Vol. 18, No. 7). The disclosure of the corresponding U.S. Pat. No. 4,072,863 granted Feb. 7, 1978 to Roundy is incorporated herein by reference.