A. Field of the Invention
The Invention is an apparatus and method for detecting blood in feces or urine in water in a toilet bowl for the purpose of non-invasive medical monitoring or screening. The blood may be occult or non-occult.
B. Description of the Related Art
According to the National Cancer Institute, colorectal cancer (CRC) is the second leading cause of cancer related mortality in the United States, with around 148,500 new cases per year and about 56,000 deaths, accounting for 10% of all cancer-related deaths in the US. It is believed that more than 50% of these deaths may have been prevented through the use of better and earlier screening tests. However, compliance with current screening recommendations and procedures is poor. For example in 2002 only 40% of adults aged 50 years and older had either a sigmoidoscopy or colonoscopy in the last 5 years and only 22% had received a fecal occult blood test in the past 12 months. The low rate of participation in CRC screening especially in comparison to breast and cervical cancer screening is due to a number of factors, including patient discomfort, cost, lack of awareness, and poor acceptability of current screening methods.
Colorectal cancer prognosis worsens significantly with advanced disease. Patients with metastases (stage IV) have only a 5% five-year survival rate. Patients with early disease (stage I) have over a 90% five-year survival rate. With the prognosis for advanced disease so poor and survival for early disease so favorable, early detection remains the primary option for CRC control and a simple, noninvasive reliable screening method for early detection of colorectal cancer has been a long-standing goal.
Detection of blood in fecal material can serve as a screening tool for CRC since these tumors bleed readily and so can be discovered at an early stage. The presence of blood alerts the patient to visit a doctor to evaluate the source of the blood.
Prior art screening tests for fecal blood include the stool guaiac test, fecal immunochemical testing (FIT), immunochemical fecal occult blood test (iFOBT), fecal porphyrin quantification, and fecal DNA testing. However, all require the handling of fecal material. For example, in the stool guaiac test, fecal material from a digital rectal examination or from soiled toilet tissue is smeared on a paper that is attached to a film coated with guaiac. Hydrogen peroxide is applied to the opposite side of the film. The hydrogen peroxide and the guaiac react. The reaction is catalyzed by heme, a component of hemoglobin in blood. The reaction causes a rapid color change if blood is present.
Detection of blood in urine can also be useful in screening for bladder cancer. Bladder cancer is the fourth most commonly diagnosed cancer in men and the ninth most commonly diagnosed cancer in women in the United States. An estimated 70,980 new cases of bladder cancer were diagnosed in the United States during 2009, and approximately 14,330 people died of the disease. Bladder tumors classically produce painless hematuria as their dominant and sometimes only clinical manifestation. Consequently, an estimated one fourth of all cases of bladder cancer have already metastasized at the time of diagnosis. Again, a simple non-invasive and reliable method of screening could identify bladder cancer at earlier stages, when it may be more easily and effectively treated.
Current techniques for detecting blood in urine include ‘dipstick’ tests in which a test strip is wetted with a urine sample and the color change of the test strip noted. The dipstick test requires that a technician physically handle the dipstick and place the dipstick in direct contact with the urine.
The prior art does not teach the screening apparatus or method of the invention.
USPTO Backgrounds
USPTO Backgrounds