You are designing a pulse oximetry device for your senior design project. In your lab, you have LED lights available in the following wavelengths: 410 nm, 540 nm, 660 nm, 740 nm, 810 nm, 940 nm. a. Based on the tabulated data for the molar extinction coefficients of hemoglobin and oxyhemoglobin (available at https://omlc.org/spectra/hemoglobin/summary.html), select the best pair of LED wavelength for your pulse oximeter. Also, consider the optical window in Figure 2, where absorption by melanin and water is acceptably low. Justify your answer. b. You want to test your prototype on your team partner. Your device measures the absorption signal at each one of the two wavelengths selected above. For the lower wavelength, the intensity of the transmitted signal oscillates between 2900 and 2930 mV. For the higher wavelength, the signal oscillates between 3000 and 3095 mV. Calculate the SpO of your partner. Absorbance 100 80 0.01 Optical Window water Hb -HbO2 --Melanin 400 600 800 1000 1200 1400 1600 1800 2000 wavelength (nm) Figure 2. The so-called optical window in biological tissue.