Smart actuator for valve

• US 10,019,020 B2
• Filed: 04/26/2016
• Issued: 07/10/2018
• Est. Priority Date: 11/11/2013
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius Medical Care AG)
• Inventors: Byler, Terry Lynn
• Primary Examiner(s): Sanchez-Medina, Reinaldo
• Assistant Examiner(s): Morales, David Colon
• Application Number:
  US15/139,144
• Publication Number:
  US 20170023953A1
• Time in Patent Office: 805 Days
• Field of Search: 25112911, 25112912, 25112913, 251 4, 251 7, 251 8, 251331, 2513352, 25112904
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00 ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 2039/226 Spindles or actuating means
• CPC Class Codes: A61M 2205/10 with powered movement mechanisms
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: F16K 31/04 using a motor
• CPC Class Codes: F16K 37/0083 by measuring valve parameters
• CPC Class Codes: G05D 16/202 actuated by an electric motor
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

A system and method of monitoring and controlling the open and close states of a manifold diaphragm type valve includes using an actuator mechanism with feedback control. A pressure transducer and/or force gauge located on the contact end of the actuator mechanism monitors the pressure and/or force applied to the end of the actuator mechanism. A controller instructs the actuator mechanism to move forward or backward an appropriate distance based on the monitored pressure and/or force. Temperature and pressure changes in the system and material changes to the diaphragm are sensed immediately and positioning correction is applied to the actuator in real-time, thereby maintaining the same valve state while monitoring pressure separately. The linear actuator functions as a ‘smart’ actuator, capable of fine tune adjustments without additional outside monitoring and providing a more accurate and reliable method of closing the valve in a dynamic environment.

Claims

1. A method for monitoring and maintaining a state of a valve in a dialysis machine, the method comprising:

providing a valve actuator configured to open and close the valve having a diaphragm positioned adjacent a flow path in a fluid circuit, the valve actuator system comprising;

a displacement member configured to be displaced linearly and having a contact end wherein the contact end is configured to push the diaphragm into the flow path to close the valve and not push the diaphragm into the flow path to open the valve;

at least one pressure transducer positioned on the contact end; and

a controller for receiving data from the pressure transducer and for controlling the displacement member;

extending the displacement member to extend the contact end and push the diaphragm into the flow path of the fluid circuit to close the valve;

sensing a pressure applied by the diaphragm against the pressure transducer;

comparing the sensed pressure to a pre-determined pressure value; and

retracting the displacement member to withdraw the diaphragm out of the flow path such that the sensed pressure is matched to the pre-determined pressure value.

2. The method of claim 1, wherein comparing the sensed pressure to the pre-determined pressure value comprises executing, by a processing unit, a plurality of programmatic instructions stored in a memory of the controller for comparing the sensed pressure to the pre-determined value stored in the memory.

3. The method of claim 1, wherein retracting the displacement member to withdraw the diaphragm out of the flow path comprises using the controller to activate a motor coupled with the displacement member, wherein the activation is based upon the comparison of the sensed pressure to the pre-determined pressure value.

4. The method of claim 3, wherein the motor is at least one of a DC motor and a stepper motor.

5. The method of claim 1, wherein the diaphragm is part of a disposable manifold positioned within the dialysis machine and the displacement member is fixedly attached to the dialysis machine.

6. The method of claim 1, wherein the pre-determined pressure value is at least 2 psi.

7. The method of claim 1, further comprising using an encoder to determine an amount of displacement of the displacement member.

8. A method for maintaining a valve in an open state, the method comprising:

providing a valve actuator system configured to open the valve having a diaphragm positioned parallel to a flow path in a fluid circuit, the valve actuator system comprising;

a displacement member configured to be linearly displaced perpendicular to the flow path and having a contact end wherein said contact end is configured to push said diaphragm into the flow path;

a pressure transducer positioned on the contact end; and

a controller for receiving data from the pressure transducer and for controlling the displacement member;

retracting the displacement member to retract the contact end and pull the diaphragm out of the flow path of the fluid circuit to open the valve;

sensing a pressure applied by the diaphragm against the pressure transducer;

comparing the sensed pressure to a pre-determined threshold pressure value; and

further retracting the displacement member to withdraw the diaphragm out of the flow path such that the sensed pressure is less than the pre-determined pressure threshold value.

9. The method of claim 8, wherein comparing the sensed pressure to the pre-determined pressure threshold value comprises executing, by a processing unit, a plurality of programmatic instructions stored in a memory of the controller for comparing the sensed pressure to the pre-determined pressure threshold value stored in the memory.

10. The method of claim 8, wherein further retracting the displacement member to withdraw the diaphragm out of the flow path such that the sensed pressure is less than the pre-determined pressure threshold value comprises using the controller to activate a motor coupled with the displacement member based upon the comparison of the sensed pressure to the pre-determined pressure threshold value.

11. The method of claim 10 wherein the motor is one of a DC motor and a stepper motor.

12. The method claim 8, wherein the diaphragm is part of a disposable manifold positioned within a dialysis machine and the displacement member is fixedly attached to the dialysis machine.

13. The method claim 8, wherein the controller retracts the displacement member to withdraw the diaphragm until the sensed pressure reaches zero, signifying that the pressure transducer has disengaged from the diaphragm, the diaphragm is in a relaxed configuration, and the valve is open.

14. A method for maintaining a valve in a closed state, the method comprising:

providing a valve actuator system configured to close the valve having a diaphragm positioned parallel to a flow path in a fluid circuit, the valve actuator system comprising;

a displacement member configured to be linearly displaced perpendicular to the flow path and having a contact end wherein the contact end is configured to push the diaphragm into the flow path;

at least one pressure transducer positioned on the contact end;

at least one force gauge positioned on the contact end; and

a controller for receiving data from the pressure transducer and force gauge and for controlling the displacement member;

extending the displacement member to extend the contact end and push the diaphragm into the flow path of the fluid circuit to close the valve;

sensing a pressure applied by the diaphragm against the pressure transducer;

sensing a force applied by the diaphragm against the force gauge;

comparing the sensed pressure to a pre-determined pressure value;

comparing the sensed force to a pre-determined force value; and

extending the displacement member to push the diaphragm into the flow path to match the sensed pressure value to the pre-determined pressure and the sensed force to the pre-determined force value.

15. The method of claim 14 wherein comparing the sensed pressure to the pre-determined pressure value and comparing the sensed force to the pre-determined force value comprises executing, by a processing unit, a plurality of programmatic instructions stored in a memory of the controller for comparing the sensed pressure to the pre-determined pressure value stored in the memory and comparing the sensed force to the pre-determined force value stored in the memory.

16. The method of claim 14 wherein extending the displacement member to push the diaphragm into the flow path to match the sensed pressure value to the pre-determined pressure value and the sensed force to the pre-determined force value comprises using the controller to activate a motor coupled with the displacement member based upon the comparison of the sensed pressure to the pre-determined pressure value and the sensed force to the pre-determined force value.

17. The method of claim 16 wherein the motor is one of a DC motor and a stepper motor.

18. The method of claim 14, wherein the diaphragm is part of a disposable manifold positioned within a dialysis machine and the displacement member is fixedly attached to the dialysis machine.

19. The method of claim 18, wherein the pre-determined pressure value is at least 2 psi.

20. The method of claim 14, further comprising using an encoder to determine an amount of displacement of the displacement member.