System for ventricular function abnormality detection and characterization
A system for heart performance characterization and abnormality detection includes an interface for receiving signal data representing an electrical signal indicating electrical activity of a patient heart over multiple heart beat cycles. A filter extracts first signal component data in a first selected bandwidth and first heart cycle portion of the received signal data and second signal component data in a different second selected bandwidth and second heart cycle portion of the received signal data. A signal processor uses the received signal data in calculating a ratio of a first value derived from the first signal component data to a second value derived from the second signal component data. A patient monitor in response to the calculated ratio or value derived from the calculated ratio, generates an alert message associated with the threshold.
1. A system for heart performance characterization and abnormality detection for a patient, comprising:
an interface configured to receive signal data representing an electrical signal indicating electrical activity of a patient heart over a plurality of heart beat cycles;
a filter configured to extract:
first signal component data in a first selected bandwidth and first heart cycle portion of the received signal data and
second signal component data in a different second selected bandwidth and second heart cycle portion of the received signal data;
a signal processor configured to:
determine a first value based on the first signal component data, the first value comprising a first energy value derived from the first signal component data or a first entropy value derived from the first signal component data, and
determine a second value based on the second signal component data, the second value comprising second energy value derived from the second signal component data or a second entropy value derived from the first signal component data;
calculate a ratio of the first value to the second value;
a comparator configured to compare the calculated ratio or a value derived from the calculated ratio with a threshold value to provide a comparison indicator; and
a patient monitor configured to generate, in response to said comparison indicator indicating a calculated signal characteristic value exceeds the threshold value, an alert message associated with the threshold.
2. A system according to claim 1 , wherein
said signal data is digitally sampled data.
3. A system according to claim 1 , wherein
the first value and second value are energy values and the first and second heart cycle portions comprise a depolarization procedure associated portion of a heart cycle.
4. A system according to claim 3 , wherein
the energy values are calculated using a function of the form,
Energy
:
E
(
sub_bandwidth
_component
_signal
)
=
∑
i
∈
signal_Q
V
Q
(
i
)
2
Where the sub_bandwidth_signal is a ventricular depolarization associated signal, V Q (i) is a discrete digitized value set of ventricular sub-component signal Q (depolarization).
5. A system according to claim 1 , wherein
the first value and second value are entropy values and the first and second heart cycle portions comprise a depolarization procedure associated portion of a heart cycle.
6. A system according to claim 5 , wherein
the entropy values are calculated using a function of the form,
entropy
(
sub_bandwidth
_signal
)
=
-
∑
i
=
1
x
∈
sub_bandwidth
_component
z
p
(
x
i
)
log
(
p
(
x
i
)
)
where the sub_bandwidth_signal is a ventricular depolarization associated signal, x i is discrete digital data within the sub_bandwidth_signal, p(x i ) is the probability of the x i within the sub_bandwidth_signal; Z is the total number of the digital data set of the sub_bandwidth_signal.
7. A system according to claim 1 , wherein
the first value and second value are energy values, the first and second selected bandwidths are substantially the same bandwidths and the first heart cycle portion comprises a depolarization procedure associated portion of a heart cycle and the second heart cycle portion comprises the QRS wave and T wave portion of a heart cycle.
8. A system according to claim 1 , wherein
the first value and second value are entropy values, the first and second selected bandwidths are substantially the same bandwidths and the first heart cycle portion comprises a depolarization procedure associated portion of a heart cycle and the second heart cycle portion comprises the QRS wave and T wave portion of a heart cycle.
9. A system according to claim 1 , wherein
the first value and second value are energy values,
the first heart cycle portion comprises a depolarization procedure associated portion of a heart cycle and
the second heart cycle portion comprises a repolarization procedure associated portion of a heart cycle.
10. A system according to claim 1 , wherein
the first value and second value are entropy values, the first heart cycle portion comprises a depolarization procedure associated portion of a heart cycle and,
the second heart cycle portion comprises a repolarization procedure associated portion of a heart cycle.
11. A system according to claim 1 , wherein
the first value and second value are energy values and the first and second heart cycle portions comprise a repolarization procedure associated portion of a heart cycle.
12. A system according to claim 1 , wherein
the first value and second value are entropy values and the first and second heart cycle portions comprise a repolarization procedure associated portion of a heart cycle.
13. A system according to claim 1 , wherein
the first value and second value are energy values, the first and second selected bandwidths are substantially the same bandwidths and the first heart cycle portion comprises a repolarization procedure associated portion of a heart cycle and the second heart cycle portion comprises the QRS wave and T wave portion of a heart cycle.
14. A system according to claim 1 , wherein
the first value and second value are entropy values, the first and second selected bandwidths are substantially the same bandwidths and the first heart cycle portion comprises a repolarization procedure associated portion of a heart cycle and the second heart cycle portion comprises the QRS wave and T wave portion of a heart cycle.
15. A system according to claim 1 , wherein
said threshold value is derived from recorded electrical signal data for said patient.
16. A system according to claim 1 , wherein
said threshold value is derived from recorded electrical signal data for a population of patients.
17. A system according to claim 16 , wherein
said population of patients has similar demographic characteristics including at least two of, (a) age, (b) weight (c) gender and (d) height, to those of said patient.
18. A system according to claim 1 , wherein
said signal processor dynamically adjusts said threshold value in response to a determined sensitivity of arrhythmia detection.
19. A system according to claim 1 , wherein
said signal processor calculates a standard deviation of the calculated ratio over a plurality of heart cycles and
said patient monitor, in response to an additional comparison indicator indicating a calculated standard deviation value exceeds a predetermined threshold value, generates an additional alert message.
20. A system according to claim 1 , including
a repository of mapping information, associating ranges of the calculated ratio with corresponding medical conditions and
said comparator compares the calculated ratio with said ranges to provide a second comparison indicator identifying a medical condition and
said patient monitor generates a second alert message identifying said medical condition.
21. A system according to claim 20 , wherein
said mapping information associates ranges of a calculated ratio with particular patient demographic characteristics and with the corresponding medical conditions and said system uses patient demographic data including at least one of, age weight, gender and height in comparing the ratio with said ranges and generating a third alert message indicating a potential medical condition.
22. A system for heart performance characterization and abnormality detection, comprising:
an interface configured to receive signal data representing an electrical signal indicating electrical activity of a patient heart over a plurality of heart beat cycles;
a filter configured to extract first signal component data in a first selected bandwidth and first heart cycle portion of the received signal data and second signal component data in a different second selected bandwidth and second heart cycle portion of the received signal data;
a signal processor configured to:
determine a first value based on the first signal component data, the first value comprising a first energy value derived from the first signal component data or a first entropy value derived from the first signal component data, and
determine a second value based on the second signal component data, the second value comprising second energy value derived from the second signal component data or a second entropy value derived from the first signal component data;
calculate a ratio of the first value to the second value; and
a patient monitor configured to generate, in response to comparing the calculated ratio or value derived from the calculated ratio with a threshold value, an alert message associated with the threshold.
23. A method for heart performance characterization and abnormality detection, the method comprising:
receiving signal data representing an electrical signal indicating electrical activity of a patient heart over a plurality of heart beat cycles;
extracting first signal component data in a first selected bandwidth and first heart cycle portion of the received signal data and second signal component data in a different second selected bandwidth and second heart cycle portion of the received signal data;
determining a first value based on the first signal component data, the first value comprising a first energy value derived from the first signal component data or a first entropy value derived from the first signal component data, and
determining a second value based on the second signal component data, the second value comprising second energy value derived from the second signal component data or a second entropy value derived from the first signal component data;
calculating a ratio of the first value to the second value;
in response to comparing the calculated ratio or a value derived from the calculated ratio with a threshold value, generating an alert message associated with the threshold.