Control device for controlling a measurement system for measuring blood pressure

A control device for controlling a measurement system for measuring blood pressure of a subject, wherein the measurement system comprises a) a shell configured to encase a part of the subject, through which blood flows, b) a pressure applicator configured to apply, from outside the shell, pressure to the shell and thereby to the encased part of the subject, and c) a pressure sensor configured to measure the pressure (TP) on the skin of the encased part of the subject, wherein the control device is configured to control the measurement system such that:

• the pressure applicator increases the applied pressure in a measurement time period and decreases the applied pressure in a following post-blood-pressure-measurement time period,
• the pressure sensor measures the pressure on the skin at least during the measurement time period,
• wherein the measured pressure (TP) comprises a plurality of pressure pulses, wherein the control device is configured to determine, for each pressure pulse of at least some of the plurality of pressure pulses, several features comprising at least:
• (i) a duration of a respective features determination pulse (t(pulse));
• (ii) an area of the respective features determination pulse (TPA/TPA.norm);
• (iii) a difference (TPP) between a features determination pulse's maximum systolic pressure (TPsys) and a features determination pulse's pressure at the end-diastolic point (TPdia);
• and
• (iv) a width at half maximum (W50) of the respective features determination pulse, which characterize the respective pressure pulse, to determine an end measurement time point, at or after which the measurement time period is to be stopped, based on the features TPP, t(Pulse), TPA/TPA.norm, and W50 determined for the at least some of the plurality of pressure pulses, and to control the pressure applicator such that, when or after the end measurement time point has been reached, said pressure applicator decreases the applied pressure to start the following post-blood-pressure-measurement time period;
• wherein the control device is configured to, in order to determine for a respective pressure pulse several features, provide a features determination pulse based on the respective pressure pulse, and determine at least two of the following features:
• (i) the difference (TPP) between the features determination pulse's maximum systolic pressure (TPsys) and the features determination pulse's pressure at the end-diastolic point (TPdia);
• (ii) the duration (t(pulse)) of the respective features determination pulse;
• (iii) the area (TPA/TPA.norm) of the respective features determination pulse;
• and
• (iv) the width at half maximum (W50) of the respective features determination pulse;
• and
• wherein the control device is configured to determine an end determination combination value (TPWP_E) for a respective pressure pulse based on at least one of the following calculations:
• (1) multiplying
• a) the area (TPA/TPA.norm) to the power of a predetermined first exponent (exp1) with b) the difference (TPP) to the power of a predetermined second exponent (exp2);
• (2) dividing
• a) the area (TPA/TPA.norm) to the power of a predetermined third exponent (exp3) by b) the duration (t(pulse)) to the power of a predetermined fourth exponent (exp4) to produce a first resulting quotient;
• and multiplying the first resulting quotient with c) the difference (TPP) to the power of a predetermined fifth exponent (exp5).