IN VIVO OPTICAL SENSOR FOR MEASURING LOBSTER VITALITY

IN VIVOOPTICAL SENSOR FOR MEASURING LOBSTER VITALITY

By Brian R.A. Tomassetti

Thesis Advisor: John Vetelino

An Abstract of the Thesis Presented

in Partial Fulfillment of the Requirements for the

Degree of Master of Science

(in Electrical Engineering)

December, 2010

Abstract: The vitality of the American Lobster (Homarus americanus) is correlated to the total hemolymph protein (THP) in lobster hemolymph (blood). The standard technique for determining lobster vitality is to draw blood from a lobster and measure THP with a refractometer. This technique is invasive and endangers the lobster’s health since blood must be drawn from the lobster. In the present work an optical sensor is developed to measure a lobster’s vitality in vivo. It is comprised of a broadband light source, a monochromator, a fiber optic reflection probe, a spectrometer and a computer. This sensor measures THP concentrations by exciting a lobster with 280nm and 334nm wavelength light sources and measuring the corresponding absorbance peaks for THP and the fluorescence peak for hemocyanin (Hc), the majority protein in hemolymph. In this work several lobsters are tested. For each lobster, absorbance and fluorescence peaks are measured using the sensor and protein concentrations are measured using a refractometer. The absorbance and fluorescence peaks are compared to the protein concentration for each lobster. It is found that the shell thickness and muscle density, which correspond directly to protein concentration and the molting stage of the lobster have a significant effect on the absorbance and fluorescence measurements. It is also found that within specific molting stages, such as pre-molt and post-molt, protein concentration measured with a refractometer correlates linearly to absorbance and fluorescence measurements with the optical sensor.