Device for measurement and evaluation of cardiac function on the basis of thoracic impedance

A cardiac function measurement and evaluation device that is a device for measuring and evaluating cardiac function in a subject, the device comprising:

• a thoracic impedance measuring unit;
• an electrocardiogram measuring unit;
• an arithmetic unit;
• a storage unit;
• and
• a display unit,
• wherein
• the thoracic impedance measuring unit includes drive electrodes for applying an electrical current, and receive electrodes for extracting an impedance signal, and measures a plurality of continuous sets of thoracic impedances,
• the electrocardiogram measuring unit includes a signal detection module that detects electrocardiogram signals from electrodes applied to the subject, and measures a plurality of continuous sets of electrocardiogram signals,
• the arithmetic unit calculates (dZ/dt)min values of the plurality of continuous sets of thoracic impedances measured by the thoracic impedance measuring unit, and preceding RR intervals (RR1), pre-preceding RR intervals (RR2), and RR1/RR2 values of continuous sets of electrocardiogram data from R waves of the electrocardiogram signal obtained by the electrocardiogram measuring unit,
• the storage unit stores, as a data set:
• a (dZ/dt)min value of each of the sets of thoracic impedance data corresponding to an RR1 value, RR2 value, and RR1/RR2 value of each of the calculated plurality of continuous sets of electrocardiogram data,
• (dZ/dt)min values where RR1/RR2≤1 are extracted as first (dZ/dt)min values which correspond to values reflecting Frank-Starling mechanism and mechanical restitution in which postextrasystolic potentiation is not involved,
• (dZ/dt)min values where RR1/RR2>1 are extracted as second (dZ/dt)min values which correspond to values reflecting Frank-Starling mechanism and mechanical restitution in which postextrasystolic potentiation is involved, and
• a total of the respective (dZ/dt)min values are calculated by the arithmetic unit, and
• the display unit displays the total (dZ/dt)min values as a bar graph.

A cardiac function measurement and evaluation device that is a device for measuring and evaluating cardiac function in a subject, the device comprising:

• a thoracic impedance measuring unit;
• an electrocardiogram measuring unit;
• an arithmetic unit;
• a storage unit;
• and
• a display unit,
• wherein
• the thoracic impedance measuring unit includes drive electrodes for applying an electrical current, and receive electrodes for extracting an impedance signal, and measures a plurality of continuous sets of thoracic impedances,
• the electrocardiogram measuring unit includes a signal detection module that detects electrocardiogram signals from electrodes applied to the subject, and measures a plurality of continuous sets of electrocardiogram signals,
• the arithmetic unit calculates (dZ/dt)min values of the plurality of continuous sets of thoracic impedances measured by the thoracic impedance measuring unit, and preceding RR intervals (RR1), pre-preceding RR intervals (RR2), and RR1/RR2 values of continuous sets of electrocardiogram data from R waves of the electrocardiogram signal obtained by the electrocardiogram measuring unit,
• the storage unit stores, as a data set:
• a (dZ/dt)min value of each of the sets of thoracic impedance data corresponding to an RR1 value, RR2 value, and RR1/RR2 value of each of the calculated plurality of continuous sets of electrocardiogram data,
• the display unit displays each of the (dZ/dt)min values corresponding to each of the RR1 value, RR2 value, and RR1/RR2 value,
• (dZ/dt)min values where RR1/RR2≤1 are extracted as first (dZ/dt)min values which correspond to values reflecting postextrasystolic potentiation, Frank-Starling mechanism, and mechanical restitution in which postextrasystolic potentiation is not involved,
• (dZ/dt)min value where RR1/RR2>1 are extracted as second (dZ/dt)min value which correspond to values reflecting postextrasystolic potentiation, Frank-Starling mechanism, and mechanical restitution in which postextrasystolic potentiation is involved, and
• respective (dZ/dt)min values of the thoracic impedance data extracted as the first and second (dZ/dt)min values are distinguishably plotted as a three-dimensional scatter plot on the display unit, wherein the respective (dZ/dt)min value is plotted as a value of a Z axis, corresponding RR1 value as a value of an X axis, and RR1/RR2 value as a value of a Y axis.

A cardiac function measurement and evaluation device that is a device for measuring and evaluating cardiac function in a subject, the device comprising:

• a thoracic impedance measuring unit;
• an electrocardiogram measuring unit;
• an arithmetic unit;
• a storage unit;
• and
• a display unit,
• wherein
• the thoracic impedance measuring unit includes drive electrodes for applying an electrical current, and receive electrodes for extracting an impedance signal, and measures a plurality of continuous sets of thoracic impedances,
• the electrocardiogram measuring unit includes a signal detection module that detects electrocardiogram signals from electrodes applied to the subject, and measures a plurality of continuous sets of electrocardiogram signals,
• the arithmetic unit calculates (dZ/dt)min values of the plurality of continuous sets of thoracic impedances measured by the thoracic impedance measuring unit, and preceding RR intervals (RR1), pre-preceding RR intervals (RR2), and RR1/RR2 values of continuous sets of electrocardiogram data from R waves of the electrocardiogram signal obtained by the electrocardiogram measuring unit,
• the storage unit stores, as a data set:
• a (dZ/dt)min value of each of the sets of thoracic impedance data corresponding to an RR1 value, RR2 value, and RR1/RR2 value of each of the calculated plurality of continuous sets of electrocardiogram data,
• the display unit displays each of the (dZ/dt)min values as a scatter plot corresponding to each RR1/RR2 value,
• (dZ/dt)min values where RR1/RR2>1 are extracted as first (dZ/dt)min values which correspond to values reflecting postextrasystolic potentiation, Frank-Starling mechanism, and mechanical restitution in which postextrasystolic potentiation is involved.

A cardiac function measurement and evaluation device that is a device for measuring and evaluating cardiac function in a subject, the device comprising:

• a thoracic impedance measuring unit;
• an electrocardiogram measuring unit;
• an arithmetic unit;
• a storage unit;
• and
• a display unit,
• wherein
• the thoracic impedance measuring unit includes drive electrodes for applying an electrical current, and receive electrodes for extracting an impedance signal, and measures a plurality of continuous sets of thoracic impedances,
• the electrocardiogram measuring unit includes a signal detection module that detects electrocardiogram signals from electrodes applied to the subject, and measures a plurality of continuous sets of electrocardiogram signals,
• the arithmetic unit calculates (dZ/dt)min values of the plurality of continuous sets of thoracic impedances measured by the thoracic impedance measuring unit, and preceding RR intervals (RR1), pre-preceding RR intervals (RR2), and RR1/RR2 values of continuous sets of electrocardiogram data from R waves of the electrocardiogram signal obtained by the electrocardiogram measuring unit,
• the storage unit stores, as a data set:
• a (dZ/dt)min value of each of the sets of thoracic impedance data corresponding to an RR1 value, RR2 value and RR1/RR2 value of each of the calculated plurality of continuous sets of electrocardiogram data, and standard data
• the display unit displays each of the (dZ/dt)min values corresponding to at least one of the RR1 value, RR2 value, and RR1/RR2 value,
• the arithmetic unit includes a determination module that compares obtained data of the subject with the standard data and determines cardiac function, and
• the determination module further performs comparison with past data of same subject stored in the storage unit, and determines the course of cardiac function.