To study the physiology of the stomach and intestines, it is often necessary to measure the blood flow in a localized area in the wall of these organs. One standard method is to measure the washout...

To study the physiology of the stomach and intestines, it is often necessary to measure the blood flow in a localized area in the wall of these organs. One standard method is to measure the washout (clearance) of a known amount of hydrogen gas. This technique is difficult. More recently, an easier method has been developed based on measuring the Doppler shift in laser light scattered from flowing blood cells. One problem with laser Doppler flow measurement is determining a calibration factor so that absolute flow can be computed. To assess the feasibility of computing a calibration factor, Gana and coworkers † compared laser Doppler L to hydrogen clearance H estimates of gastric flow in four dogs (the data are in Table D-35, Appendix D). Are the relationships between L and H different in the different dogs? Perform the analysis using OLS.

Table D-35