Heart beat identification and pump speed synchronization
A method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle includes obtaining a signal from a motor of a heart assist pump device and filtering the signal to remove noise. The method also includes determining a speed synchronization start point at which time the motor of the heart assist pump device will begin a change in speed of operation based on the filtered signal. The method further includes modulating a speed of the motor of the heart assist pump device to a target speed at the speed synchronization start point, thereby synchronizing the change in speed of operation with a patient's cardiac cycle.
1. A heart assist pump device, comprising:
a motor; and
a controller, wherein the controller is configured to:
identify two consecutive prior pulses of a heart beat;
determine, for at least two consecutive prior pulses, that each of the at least two consecutive prior pulses are complete;
determine a pulse period based on the two consecutive prior pulses;
determine a speed synchronization start point at which time the motor will begin a change in speed of operation based on the pulse period; and
begin changing the speed of the motor to a target speed at the speed synchronization start point.
2. The heart assist pump device of claim 1 , wherein:
the two consecutive prior pulses are identified based on a signal from the motor.
3. The heart assist pump device of claim 2 , wherein:
the controller is further configured to filter out a portion of the signal comprising high frequency noise data that is out of a general heart beat range.
4. The heart assist pump device of claim 3 , wherein:
the general heart beat range comprises a frequency of less than 5 Hz.
5. The heart assist pump device of claim 1 , wherein:
the motor is configured to operate using one or more of a set current, a set motor speed, or a set flow rate.
6. The heart assist pump device of claim 1 , wherein:
the controller is further configured to redetermine the speed synchronization start point after a predetermined number of synchronized heart beat counts.
7. The heart assist pump device of claim 6 , wherein:
the predetermined number of synchronized heart beat counts comprises 10 or fewer synchronized heart beat counts.
8. A method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle, comprising:
identifying two consecutive prior pulses of a heart beat;
determining, for at least two consecutive prior pulses, that each of the at least two consecutive prior pulses are complete;
determining a pulse period based on the two consecutive prior pulses;
determining a speed synchronization start point at which time a motor of a heart assist pump device will begin a change in speed of operation based on the pulse period; and
beginning to change the speed of the motor to a target speed at the speed synchronization start point.
9. The method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle of claim 8 , wherein:
the two consecutive prior pulses are identified based on a signal from the motor.
10. The method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle of claim 9 , wherein:
the signal comprises a current signal or a power signal.
11. The method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle of claim 8 , wherein:
changing the speed of the motor comprises one or both of increasing the speed during a systolic phase and decreasing the speed during a diastolic phase.
12. The method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle of claim 8 , wherein:
changing the speed of the motor comprises one or both of increasing the speed before a systolic phase and decreasing the speed before an end of the systolic phase.
13. The method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle of claim 8 , further comprising:
redetermining the speed synchronization start point after a predetermined number of synchronized heart beat counts.
14. The method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle of claim 13 , wherein:
the predetermined number of synchronized heart beat counts comprises 10 or fewer synchronized heart beat counts.
15. A non-transitory machine readable medium having instructions stored thereon, wherein the instructions are executable by one or more processors to at least:
identify two consecutive prior pulses of a heart beat;
determine, for at least two consecutive prior pulses, that each of the at least two consecutive prior pulses are complete;
determine a pulse period based on the two consecutive prior pulses;
determine a speed synchronization start point at which time a motor of a heart assist pump device will begin a change in speed of operation based on the pulse period; and
begin changing the speed of the motor to a target speed at the speed synchronization start point.
16. The non-transitory machine readable medium of claim 15 , wherein:
the two consecutive prior pulses are identified based on a signal from the motor.
17. The non-transitory machine readable medium of claim 15 , wherein:
changing the speed of the motor comprises increasing the speed of the motor corresponding to an increase in a rate of a cardiac cycle of a patient.
18. The non-transitory machine readable medium of claim 15 , wherein:
determining whether a pulse is complete is based on at least one selection from a group consisting of:
a mean amplitude of three or more previous pulses;
a maximum amplitude of the pulse;
a minimum amplitude of the pulse;
t f (first falling-crossing time);
t r (first rising-crossing time);
t min (minimum peak time point); and
t max (maximum peak time point).
19. The non-transitory machine readable medium of claim 15 ,
wherein the instructions further cause the one or more processors to:
redetermine the speed synchronization start point after a predetermined number of synchronized heart beat counts.
20. The non-transitory machine readable medium of claim 19 , wherein:
the predetermined number of synchronized heart beat counts comprises 10 or fewer synchronized heart beat counts.