Abstract: An interactive injection system for use with a catheter of the type adapted for insertion into a patient's vascular system for thermodilution measurements and the like includes a chamber for storing liquid injectate, means for connecting the chamber to the catheter lumen, and a drive for operating on the chamber to flow liquid injectate from the chamber into the lumen for discharge as a bolus from the lumen into the vascular system of a patient. In preferred embodiments, a temperature sensing probe is connected between the injection chamber and the catheter for monitoring the temperature of injectate as it is introduced into the catheter.

Abstract: Method and apparatus for the simultaneous automatic analysis and sequential displaying in digital form of a plurality of parameters of whole or hemolyzed blood samples, such as total hemoglobin, percent oxyhemoglobin, percent carboxyhemoglobin, percent methemoglobin (in each case percent meaning percentage of total hemoglobin) and oxygen content. The apparatus is an electro-optical instrument including a servo-controlled spectral line source, such as a hollow cathode lamp, a laser etc., a ratiometric logarithmic amplifier of minimized dynamic range, a fluid-flow system of improved design that combine to measure the absorbances of blood samples at a plurality of wavelengths defined and generated by the spectral line source, to calculate the above parameters based on the absorbances by the use of a micro-computer and associated circuitry absorbances, to display automatically and digitally one of the parameters, and then to display digitally seriatim the remaining parameters responsive to operator intervention.