A novel algorithm is presented that can continuously monitor changes in total peripheral resistance (TPR) using peripheral arterial blood pressure values alone. The algorithm was tested on previously recorded swine data sets containing blood flow and pressure measurements. It estimated TPR from the blood pressure waveforms with an average 14% error compared to calculations using direct flow and pressure measurements. This new TPR estimation method shows potential for reliably monitoring vascular resistance changes and could enable prediction of astronauts' risk of post-flight orthostatic intolerance from their pre-flight blood pressure data.

1. A Novel Algorithm to Continuously Monitor Change of Total Peripheral Resistance using Peripheral Arterial Blood Pressure Values for Prediction of Orthostatic Intolerance Tatsuya Arai 1 , Kichang Lee 2 , and Richard J. Cohen 2 Cohen Laboratory 1 Department of Aeronautics and Astronautics, 2 Health Sciences and Technology Massachusetts Institute of Technology

2. Model and Hypothesis End diastolic pressure, beat duration, time from the onset to the peak of systole, and mean arterial pressure are relatively insensitive to distortion TPR AC Flow BP Waveform distortion

3. Algorithm Aortic Compliance (AC) Vascular Resistance (TPR)

4. Method and Results Five Yorkshire Swine data sets previously recorded (blood flow, blood pressure) Vascular resistance calculated from measured blood flow and pressure Vascular resistance estimated from blood pressure Algorithm achieved 14% vascular resistance estimation error Swine A Swine B Swine C Swine D Swine E

5. Conclusion and Future Work New TPR estimation method can reliably monitor changes of vascular resistance Potentially applicable to human data sets Future work includes prediction of astronauts’ post-flight orthostatic intolerance using pre-flight blood pressure data For the detail , please visit our poster