2010

Fast, Quantitative Diagnostic Reader for Multiple Medical Tests

Any test that attenuates light is a candidate for use with the device — potentially thousands of different tests.

While most physicians have easy access to lab tests, those tests can be slow and expensive. Consumer versions of tests are inaccurate and have limited scope, and often involve sending a sample to a lab. Physicians, emergency rooms, EMTs, patients, visiting nurses, and caregivers may all need access to quick, accurate tests without waiting for results and making callbacks. Some chronic tests require the mixing of reagents, and so are difficult to perform at home.

Quantitative Diagnostic Reader features a unique lancet that avoids injury to the red blood cells that takes place in finger sticks." class="caption" align="left">This all-in-one, handheld diagnostic reader can handle such tests and report results in as few as ten minutes. The reader measures the color density of a sample; thus, it can perform any optical test or assay where the sample is measured by the attenuation of light. Any bodily fluid that attenuates light, such as blood, urine, or sputum, can be used.

The prototype performs three identical tests on a single, whole-blood sample for accuracy, but a greater number of simultaneous tests could be performed, or a battery of tests could be performed on the same sample. Programming and circuit board design determine the tests that an individual unit performs. All sample handling takes place inside the device.

A unique lancet draws blood for the system. It slices the skin and creates a pressure differential to avoid injuring the red blood cells by “milking” (typical of finger sticks). In the prototype, the action of using the lancet activates the electronics of the system. One-button activation isolates a specific region of the Pre-Analytic System, transfers the plasma sample to the main test strip, applies diluents to it, and activates the electronic test protocol. Different activities could be designed into the unit for different tests.

In the prototype, a typical sample size is 3 - 5 microliters, so as to provide about 1.5 microliters of plasma, enough for the tests that the sample units perform. This requirement eliminates alternate site testing for the prototype unit; but other tests requiring less sample volume, or tests requiring fluids other than blood, would have their own sample size requirements based on the amount of analyte the system requires.

Any test or assay that attenuates light is a candidate for use with the device — potentially thousands of different tests. The current design includes three photodiodes on a single chip, and so can do three tests at a time. Those three tests can be three iterations of the same test (for accuracy) or three different tests (for a particular diagnostic protocol). The addition of a larger number of LEDs or detectors could make possible a larger number of simultaneous tests. The number of tests depends on the real estate available on the circuit board of the device, and affects the overall size of the device.

Tests that can be performed with the device include those for heart health, diabetes, cholesterol, thyroid function, bacterial infection, ulcers, alcohol or drug use, tuberculosis, various forms of cancer, pneumonia, pregnancy, bone health/osteoporosis, strep, HPV, allergies, and asthma.

This technology is offered by Kimberly-Clark Corp. For more information, view the yet2.com TechPak at http://info.hotims.com/28055-157.