Medical device for evaluating a pulsatile signal

A medical system for determining a resistance parameter of a patient to be treated, which resistance parameter indicates a peripheral vascular resistance, the medical system comprising:

• a measuring device configured to measure a measured value curve of the patient, which measured value curve indicates a blood pressure curve or the blood volume curve, and to provide the measured value curve as a pulsatile output signal;
• and
• a medical device for determining the resistance parameter of a patient to be treated, which resistance parameter indicates the peripheral vascular resistance, the medical device comprising:
• a reception module configured to receive the pulsatile output signal;
• a reading module connected to the reception module, the reading module being configured to read a number of predefined curve parameters from the received pulsatile output signal and to provide corresponding read measured values for a number of predefined curve parameters;
• a calculation module connected to the reading module, the calculation module being configured to instantaneously calculate the resistance parameter of the patient, in real time, with the use of a predefined estimation function based on the read measured values and based on a predefined parameter indicating the cardiac output of the patient and being configured to output the resistance parameter, wherein the number of predefined curve parameters is based on an end-diastolic value of a particular pulse of the pulsatile signal and on an end-systolic value of the particular pulse of the pulsatile signal, wherein the predefined estimation function is a function of a difference between the end-systolic value and the end-diastolic value, wherein the number of predefined curve parameters comprises a time constant of the pulsatile signal, which is determined via a curve of the pulsatile signal in the area of at least one diastole, wherein the calculation module is further configured to calculate an arterial compliance of the patient based on the resistance parameter of the patient and based on the time constant and to output the calculated arterial compliance of the patient;
• and
• an output module or an interface module configured to provide the calculated arterial compliance.

A process for determining a resistance parameter of a patient to be treated, which resistance parameter indicates a peripheral vascular resistance, the process comprising the steps of:

• receiving a pulsatile signal, wherein the pulsatile signal indicates a blood pressure curve or a blood volume curve of the patient;
• reading of a number of predefined curve parameters from the pulsatile signal received;
• providing read measured values for a number of predefined curve parameters;
• instantaneously calculating the resistance parameter of the patient, in real time, using a predefined estimation function, based on the read measured values and on a predefined parameter indicating a cardiac volume of the patient, wherein the number of predefined curve parameters is based on an end-diastolic value of a particular pulse of the pulsatile signal and on an end-systolic value of the particular pulse of the pulsatile signal, wherein the predefined estimation function is a function of a difference between the end-systolic value and the end-diastolic value, wherein the number of predefined curve parameters comprises a time constant of the pulsatile signal, which is determined via a curve of the pulsatile signal in the area of at least one diastole, wherein the calculation module is further configured to calculate an arterial compliance of the patient based on the resistance parameter of the patient and based on the time constant and to output the calculated arterial compliance of the patient;
• outputting the resistance parameter;
• and
• providing the calculated arterial compliance via an output module or an interface module.