Automated peritoneal dialysis system using stepper motor

• US 10,137,235 B2
• Filed: 12/12/2014
• Issued: 11/27/2018
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Inventors: Busby, Don, Hopping, Peter, Childers, Robert, Din, Shahid, Lauman, Brian, Kienman, Rick, Richardson, Ian, Bowman, Jr., Joseph H., Lundtveit, Loren M., Alvaro, Jose, Ming-Da Eu, Bruce, Shang, Sherwin
• Primary Examiner(s): Mehta, Bhisma
• Assistant Examiner(s): Bui, Anh
• Application Number:
  US14/568,832
• Publication Number:
  US 20150088054A1
• Time in Patent Office: 1,446 Days
• Field of Search: 604140, 604141, 604146, 604147
• CPC Class Codes: A61M 1/152 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/153 the cassette being adapted for heating or cooling the treating fluid, e.g. the dialysate or the treating gas
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1561 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/1565 Details of valves
• CPC Class Codes: A61M 1/159 specially adapted for peritoneal dialysis
• CPC Class Codes: A61M 1/1664 with temperature control
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/282 Operational modes
• CPC Class Codes: A61M 1/288 Priming priming in extracorporeal blood circuits A61M1/3643
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/121 interface between cassette and base
• CPC Class Codes: A61M 2205/122 using evacuated interfaces to enhance contact
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/125 with incorporated filters
• CPC Class Codes: A61M 2205/126 with incorporated membrane filters
• CPC Class Codes: A61M 2205/127 with provisions for heating or cooling
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/505 : Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/581 : by audible feedback
• CPC Class Codes: A61M 2205/583 : by visual feedback
• CPC Class Codes: A61M 5/14224 : Diaphragm type
• CPC Class Codes: A61M 5/145 : using pressurised reservoirs, e.g. pressurised by means of pistons
• CPC Class Codes: A61M 5/14593 : the diaphragm being actuated by fluid pressure

Abstract

An embodiment of a peritoneal dialysis system includes an enclosure, a door hingedly attached to the enclosure, a stepper motor housed by the enclosure, a solid pump piston in operable communication with the stepper motor and including a solid pump shaft attached to or integrally formed with a solid pump head, and a disposable unit contacting the enclosure and the door. The disposable unit includes a moveable membrane operable with the solid pump head. The stepper motor is configured to move the solid pump head towards and away from the disposable unit. The system further includes a position detection apparatus operable with the stepper motor and located to provide an output indicative of a position of the solid pump head relative to a reference position.

Claims

1. A peritoneal dialysis system comprising:

an enclosure;

a stepper motor housed by the enclosure;

a solid pump piston including a solid piston shaft attached to or integrally formed with a solid pump head, the solid pump piston in operable communication with the stepper motor;

a disposable unit including at least one flexible membrane attached to a rigid piece, the enclosure and the disposable unit structured and arranged to allow the flexible membrane to move beyond a relaxed position of the flexible membrane, the enclosure structured and arranged to receive the disposable unit such that the stepper motor can move the solid pump head towards and away from the disposable unit to allow (i) the flexible membrane adjacent to the solid pump head to move outwardly beyond the rigid piece as the solid pump head is moved away from the disposable unit, and (ii) the flexible membrane adjacent to the solid pump head to move within the rigid piece as the solid pump head is moved towards the disposable unit; and

an encoder operable with the stepper motor, the encoder configured to provide an output indicative of a position of the solid pump head after the solid pump head has moved towards or away from the disposable unit.

2. The peritoneal dialysis system of claim 1, which includes a controller configured to receive the output from the encoder to indicate the position of the solid pump head after the solid pump head has moved towards or away from the disposable unit.

3. The peritoneal dialysis system of claim 1, which includes a ball screw in operable communication with the stepper motor and the solid pump head, the ball screw operable to convert a rotational output of the stepper motor to a translational motion of the solid pump head.

4. The peritoneal dialysis system of claim 1, wherein the encoder includes a linear encoder.

5. The peritoneal dialysis system of claim 1, wherein the encoder is configured to provide information indicative of a position of the solid pump head after a power loss.

6. The peritoneal dialysis system of claim 1, wherein the encoder is configured to provide information indicative of how far from a home position the solid pump head has traveled.

7. The peritoneal dialysis system of claim 6, wherein the home position is a zero degree position for the encoder.

8. The peritoneal dialysis system of claim 1, wherein the rigid piece and the at least one membrane define at least one of a valve portion or a pump portion of the disposable unit.

9. A peritoneal dialysis system comprising:

an enclosure;

a door hingedly attached to the enclosure;

a stepper motor housed by the enclosure;

a solid pump piston including a solid pump shaft attached to or integrally formed with a solid pump head, the solid pump piston in operable communication with the stepper motor;

a disposable unit contacting the enclosure and the door, the disposable unit including a moveable membrane attached to a frame, the moveable membrane operable with the solid pump head, the stepper motor configured to move the solid pump head towards and away from the disposable unit to allow the moveable membrane to move outwardly beyond the frame, while the membrane contacts the pump head, as the solid pump head is moved away from the disposable unit; and

a position detection apparatus operable with the stepper motor and located to provide an output indicative of a position of the solid pump head relative to a reference position.

10. The peritoneal dialysis system of claim 9, which includes a controller configured to receive the output from the position detection apparatus to indicate the position of the solid pump head relative to the reference position.

11. The peritoneal dialysis system of claim 9, which is configured such that the moveable membrane of the disposable unit moves with the solid pump head as the solid pump head is moved towards or away from the disposable unit.

12. The peritoneal dialysis system of claim 9, wherein the position detection apparatus enables the position of the solid pump head to be known upon power-up of the peritoneal dialysis system.

13. The peritoneal dialysis system of claim 9, wherein the position detection apparatus includes an encoder, a proximity sensor, a magnetic pick-up, or a combination thereof.

14. The peritoneal dialysis system of claim 9, which is operable with a battery back-up to power at least the position detection apparatus.

15. The peritoneal dialysis system of claim 9, wherein the reference position is a fully opened or fully closed position of the moveable membrane of the disposable unit.

16. The peritoneal dialysis system of claim 9, which is configured to move the solid pump head automatically until the reference position is sensed by the position detection apparatus.

17. A peritoneal dialysis system comprising:

an enclosure;

a door hingedly attached to the enclosure;

a stepper motor housed by the enclosure;

a solid pump piston including a solid piston shaft attached to or integrally formed with a solid pump head, the solid pump piston in operable communication with the stepper motor;

a disposable unit operable with the enclosure and the door, the disposable unit including a moveable membrane attached to a frame, the movable membrane operable with the solid pump head, the stepper motor configured to move the solid pump head towards and away from the disposable unit to allow the moveable membrane to move outwardly beyond the frame, while the membrane contacts the pump head, as the solid pump head is moved away from the disposable unit; and

a position detection apparatus located to provide an output indicative of a position of the solid pump head relative to a reference position, and

wherein the peritoneal dialysis system is programmed to move the solid pump head automatically until the reference position is sensed.

18. The peritoneal dialysis system of claim 17, wherein the stepper motor is programmed to control at least one of (i) velocity of the stepper motor, or (ii) acceleration of the stepper motor for controlling a pressure of the fluid to be pumped by the solid pump piston.

19. The peritoneal dialysis system of claim 17, wherein the stepper motor is programmed to include at least one of (i) a preset velocity for the stepper motor, or (ii) a preset acceleration for the stepper motor.

20. The peritoneal dialysis system of claim 17, which includes a pump chamber, and which is configured to control a pressure within the pump chamber by controlling a velocity of the stepper motor.

21. The peritoneal dialysis system of claim 17, wherein the position detection apparatus includes an encoder.

22. The peritoneal dialysis system of claim 17, which is configured to move the solid pump piston automatically upon power-up until the reference position is sensed.