1. Field of the Invention
This invention relates to the fields of biomedical screening devices and dermoscopy. Specifically, the present invention provides a handheld medical device and software useful for skin cancer screening in real time.
2. Description of the Related Art
Skin cancer is the most common form of cancer, representing about half the number of all cancer types. The most deadly form of skin cancer is melanoma for which incidences increase by 3% annually. Frequent screening of suspicious skin pigmentations and other lesions is of paramount importance since at an early stage skin cancer has a high cure rate and, in most cases, requires a simple treatment.
The American Cancer Society predicts that one in six individuals will develop skin cancer and one in nine will develop melanoma during their lifetime. The risk of melanoma is much higher in patients with dysplastic or clinically-abnormal pigmented nevi. A nevus, or mole, is a common skin growth composed of special pigment-producing cells called melanocytes, which determine the color of the hair and skin. Dysplastic nevi, occasionally referred as early melanomas, are skin lesions that carry high risk for melanoma.
Early detection of melanoma in patients with dysplastic nevi is life saving. If detected at an early stage, skin cancer has one of the highest cure rates, and in most cases, the treatment is quite simple and involves excision of the lesion. Moreover, at an early stage, skin cancers are very economical to treat, while at a later stage, cancerous lesions usually result in near fatal consequences and have extremely high costs associated with treatment.
In the case of malignancy, early changes in the nevus usually consist of an irregular pigmentation pattern, before it becomes lethal. Studies show that visual detection by a dermatologist has the average diagnostic accuracy of only 58 percent and about 30 percent for nonexperts, i.e., dermatologists who do not specialize in early melanoma detection. It is also known that diagnostic accuracy can be improved 80-93% by using imaging techniques like epiluminescence microscopy, to better visualize the pigmentation pattern, and by combining it with a clinically accepted quantitative scoring methods used by dermatologists for classification of lesions, such as the well-known A (asymmetry), B (border), C (color), and D (differentiation) rule and Menzies method, which is based on number of colors, symmetry of pattern, and the positive features of the lesion.
Existing imaging modalities rely mainly on pigmentation features of a lesion, such as shape, color, and texture. However, recent studies have demonstrated a correlation between increased blood flow and the development of new blood vessels by a malignant tumor (angiogenesis) to meet the high metabolic rate of a growing tumor.
Existing devices used to observe skin surface can only acquire pictures in one modality at a time, and the acquired pictures can not be readily processed. Though such devices find interesting uses, they present great limitations to users since the acquired images must be transferred to a personal computer for further analysis. Existing software only performs limited image analysis and fails to provide physicians with an unambiguous diagnosis.
Thus, there is a recognized need in the art for an integrated solution that combines image acquisition and automated image analysis in medical devices for skin cancer screening. More, specifically the prior art is deficient in portable handheld devices and software for skin cancer screening in real time. The present invention fulfills this long-standing need and desire in the art.