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The purpose in this article is to investigate the measurement method and normal values of the total peripheral resistance (TPR) and total peripheral resistance index (TPRI) measured by the reconstructed impedance cardiogram (RICG). Methods The cardiac output and cardiac index of 180 normal adults is measured by means of the RICG. The computed formula of the TPR and TPRI are deduced, and the TPR and TPRI are calculated. The subjects are divided to the different groups according to the sex and age. The TPR and TPRI are calculated statistically. Results The TPR and TPRI are increased with the increase of the age, and there is significant difference between the young and elder groups (P0.05). The normal value of the TPR is less than 1650 dyn.s.cm-5, and that of the TPRI is less than 2650 dyn.s.cm-5.m2. Conclusion The TPR and TPRI measured by the RICG can reflect the hemodynamic changes of the normal or abnormal body.

A controlled massage head is designed to vary the massage intensity rapidly. It bases on the property of magnetorheological fluid stiffness influenced by magnetic field. In this paper, we draw on relevant methods, design electromagnetic structures with numerical analysis software. The method of positive and negative current with permanent magnet compensation is presented to achieve a bigger range of magnetic field strength adjustment. Further, the massage head prototype is manufactured and tested. The experiment data are processed and indicates the design of the magnetic field strength and massage strength can meet the requirements.