Counterpulsation device driver apparatus, method and system
A method of operating a counterpulsation device (CPD) in a human or animal subject is disclosed, the method including: receiving a heart beat signal indicative of the heart beat of the subject; providing counterpulsation therapy by controlling the pressure supplied to a CPD drive line in pneumatic communication with the CPD to cause the CPD to alternately fill with blood and eject blood with a timing that is determined at least in part based on the heart beat signal; while providing counterpulsation therapy, receiving a CPD drive line pressure signal indicative of the pressure in the CPD drive line; and adjusting the pressure supplied to the drive line based at least in part on the drive line pressure signal.
1. An apparatus for controlling operation of a counterpulsation device (CPD) in a human or animal subject, the apparatus comprising a controller configured to:
provide counterpulsation therapy by controlling pressure supplied to a CPD drive line;
while providing counterpulsation therapy, receive a CPD drive line pressure signal indicative of the pressure in the CPD drive line; and
adjust the pressure supplied to the drive line based at least in part on the drive line pressure signal, by performing at least one of: exposing the drive line to a negative pressure of a vacuum chamber to fill a CPD chamber as a heart is contracting and exposing the driveline to a positive pressure of a pressure chamber to empty the CPD chamber as the heart is relaxing.
2. The apparatus of claim 1 , wherein the CPD drive line is in pneumatic communication with the CPD.
3. The apparatus of claim 1 , wherein the controller is further configured to receive a pressure upper limit corresponding to an upper limit of the pressure in the CPD drive line and a pressure lower limit corresponding to a lower limit of the pressure in the CPD drive line, wherein the controller adjusts the pressure supplied to the CPD drive line by:
in response to determining that the pressure in the CPD drive line exceeds the pressure upper limit, venting the pressure chamber until the pressure in the CPD drive line is below the pressure upper limit, and
in response to determining that the pressure in the CPD drive line is below the pressure lower limit, opening a valve corresponding to the vacuum chamber until the pressure in the CPD drive line is above the pressure lower limit.
4. The apparatus of claim 3 , wherein venting the pressure chamber induces a negative pressure in the drive line, causing the CPD to fill with blood from the subject, and opening the valve corresponding to the vacuum chamber induces a positive pressure in the CPD drive line, causing the CPD to empty of blood.
5. The apparatus of claim 1 , wherein the controller is configured to adjust the pressure supplied to the CPD drive line based at least in part on the CDP drive line pressure signal by analyzing the CPD drive line pressure signal to determine a full or an empty condition of the CPD by analyzing change in drive line pressure as a function of time.
6. The apparatus of claim 5 , wherein:
the CPD comprises a drive chamber in pneumatic communication with the drive line and a blood chamber that is sealed from the drive chamber by a membrane, and
the controller analyzes the CPD drive line pressure signal to determine the full or the empty condition of the CPD by detecting a feature in the drive line pressure signal indicative of the membrane reaching a substantially stationary end position.
7. The apparatus of claim 5 , wherein the controller is further configured to:
detect a temporal location of the full or the empty condition during an operational cycle of the CPD;
compare the temporal location to a desired range; and
if the temporal location is outside of the desired range, adjust the pressure supplied to the CPD drive line.
8. The apparatus of claim 7 , wherein the controller is further configured to, during emptying of the CPD:
determine if the temporal location of the empty condition occurs at a time earlier than the desired range and, if so, adjust the drive line pressure to slow the emptying; and
determine if the temporal location of the empty condition occurs at a time later than the desired range or does not occur and, if so, adjust the drive line pressure to speed up the emptying.
9. The apparatus of claim 7 , wherein the controller is further configured to, during filling of the CPD:
determine if the temporal location of the full condition occurs at a time earlier than the desired range and, if so, adjust the drive line pressure to slow the filling;
and determine if the temporal location of the full condition occurs at a time later than the desired range or does not occur and, if so, adjust the drive line pressure to speed up the filling.
10. The apparatus of claim 1 , wherein the controller is configured to adjust the pressure supplied to the drive line by adjusting one or more operating parameters of a pump device pneumatically coupled to the CPD drive line.
11. A method for controlling operation of a counterpulsation device (CPD) in a human or animal subject, the method comprising:
providing counterpulsation therapy by controlling pressure supplied to a CPD drive line;
while providing counterpulsation therapy, receiving a CPD drive line pressure signal indicative of the pressure in the CPD drive line; and
adjusting the pressure supplied to the drive line based at least in part on the drive line pressure signal, by performing at least one of: exposing the drive line to a negative pressure of a vacuum chamber to fill a CPD chamber as a heart is contracting and exposing the driveline to a positive pressure of a pressure chamber to empty the CPD chamber as the heart is relaxing.
12. The method of claim 11 , wherein the CPD drive line is in pneumatic communication with the CPD.
13. The method of claim 12 , further comprising receiving a pressure upper limit corresponding to an upper limit of the pressure in the CPD drive line and a pressure lower limit corresponding to a lower limit of the pressure in the CPD drive line, wherein adjusting the pressure supplied to the CPD drive line comprises:
in response to determining that the pressure in the CPD drive line exceeds the pressure upper limit, venting the pressure chamber until the pressure in the CPD drive line is below the pressure upper limit, and
in response to determining that the pressure in the CPD drive line is below the pressure lower limit, opening a valve corresponding to the vacuum chamber until the pressure in the CPD drive line is above the pressure lower limit.
14. The method of claim 13 , wherein venting the pressure chamber induces a negative pressure in the drive line, causing the CPD to fill with blood from the subject, and wherein opening the valve corresponding to the vacuum chamber induces a positive pressure in the CPD drive line, causing the CPD to empty of blood.
15. The method of claim 11 , wherein adjusting, based at least in part on the CDP drive line pressure signal, the pressure supplied to the CPD drive line by analyzing the CPD drive line pressure signal to determine a full or an empty condition of the CPD by analyzing change in drive line pressure as a function of time.
16. The method of claim 15 , wherein:
the CPD comprises a drive chamber in pneumatic communication with the drive line and a blood chamber that is sealed from the drive chamber by a membrane, and
and wherein analyzing the CPD drive line pressure signal to determine the full or the empty condition of the CPD comprises detecting a feature in the drive line pressure signal indicative of the membrane reaching a substantially stationary end position.
17. The method of claim 15 , further comprising:
detecting a temporal location of the full or the empty condition during an operational cycle of the CPD;
comparing the temporal location to a desired range; and
if the temporal location is outside of the desired range, adjusting the pressure supplied to the CPD drive line.
18. The method of claim 17 , further comprising, during emptying of the CPD:
determining if the temporal location of the empty condition occurs at a time earlier than the desired range and, if so, adjusting the drive line pressure to slow the emptying; and
determining if the temporal location of the empty condition occurs at a time later than the desired range or does not occur and, if so, adjusting the drive line pressure to speed up the emptying.
19. The method of claim 17 , further comprising, during filling of the CPD:
determining if the temporal location of the full condition occurs at a time earlier than the desired range and, if so, adjusting the drive line pressure to slow the filling;
and determining if the temporal location of the full condition occurs at a time later than the desired range or does not occur and, if so, adjusting the drive line pressure to speed up the filling.
20. The method of claim 11 , wherein adjusting the pressure supplied to the drive line comprises adjusting one or more operating parameters of a pump device pneumatically coupled to the CPD drive line.