Automatic detection and adjustment of a pressure pod diaphragm

Patent metadata

Field	Value
Publication number	US-9833554-B2
Application number	US-201415022932-A
Country	US
Kind code	B2
Filing date	Nov 25, 2014
Priority date	Dec 23, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A system for controlling the position of a diaphragm in a diaphragm-containing pressure pod, is provided. The system can include a peristaltic pump, a pressure pod having a flow-through fluid side and a gas side that are separated by a diaphragm, and a pressure sensor operatively connected to the gas side. The pressure sensor is configured to sense pulses of pressure resulting from movement of the diaphragm and caused by the action of the peristaltic pump. A gas source and a valve can be in fluid communication with the gas side of the pressure pod and can be configured to provide gas to, or vent gas from, the gas side. A controller receives pressure signals from the pressure sensor and controls the valve in response, and in so doing, controls the position of the diaphragm. Methods for positioning the diaphragm are also included.

First claim

What is claimed is:

1. A system for controlling the position of a diaphragm in a diaphragm-containing pressure pod, the system comprising:
a fluid pump;
a pressure pod comprising an interior defining a flow-through fluid side and a gas side, the flow-through fluid side and the gas side being separated from one another by a diaphragm;
a fluid conduit in fluid communication with the flow-through fluid side and operatively positioned with respect to the fluid pump such that the pump can move fluid through the conduit and force fluid through the flow-through fluid side of the pressure pod;
a pressure sensor operatively connected to the gas side of the pressure pod and configured for sensing pressure resulting from movement of the diaphragm;
a gas source in fluid communication with the gas side of the pressure pod and comprising a valve configured to provide fluid communication between the gas side and the gas source, the valve also being configured to interrupt communication between the gas side and the gas source; and
a controller configured to receive a pressure signal generated by the pressure sensor and configured to control the valve in response to the signal received, while fluid is being moved through the flow-through fluid side, wherein the control of the valve controls pressure in the gas side of the pressure pod, which in-turn controls the position of the diaphragm.

2. The system of claim 1 , wherein the fluid pump comprises a peristaltic pump and the pressure sensor is configured for sensing pulses of pressure caused by the peristaltic pump moving fluid through the flow-through fluid side.

3. The system of claim 1 , wherein the controller is further configured such that, after controlling the valve and in-turn controlling the position of the diaphragm to make an adjustment, the controller immediately compares a new pressure signal resulting from the adjustment, to one or more predetermined signals.

4. The system of claim 1 , wherein the valve is configured to move between an open position and a closed position, and the valve is configured in the open position to provide a gaseous communication between the gas side and an ambient atmosphere while fluid is being moved through the flow-through fluid side.

5. The system of claim 1 , further comprising a fluid within the conduit, wherein the fluid comprises blood and the gas source comprises pressurized gas under a pressure of greater than 1 atmosphere.

6. The system of claim 1 , wherein the controller comprises an oscilloscope, is configured to display pressure signals it receives from the pressure sensor as a waveform on the oscilloscope, and is configured to compare the waveform to one or more predetermined waveforms.

7. The system of claim 6 , wherein the controller comprises a memory, the one or more predetermined waveforms are stored in the memory, and the one or more predetermined waveforms include a first waveform corresponding to a signal received when the diaphragm is in a first extreme position, and a second waveform corresponding to a signal received when the diaphragm is in a second extreme position opposite the first extreme position.

8. The system of claim 7 , wherein the first extreme position of the diaphragm is a position wherein the flow-through fluid side of the pressure pod has a maximum volume and the gas side of the pressure pod has a minimum volume, and the second extreme position of the diaphragm is a position wherein the volume of the flow-through fluid side of the pressure pod is minimized and the volume of the gas side of the pressure pod is maximized.

9. The system of claim 1 , wherein the controller is configured to compare a pressure signal received from the pressure sensor to a predetermined pressure signal corresponding to normal operation of the pressure pod, and the controller is configured to determine whether the pressure signal received is within an acceptable degree of variance relative to the predetermined pressure signal.

10. A method for automatically adjusting the position of a diaphragm in a pressure pod, the method comprising:
forcing a fluid through a flow-through fluid side of a pressure pod, using a pump, the pressure pod comprising a diaphragm, the flow-through fluid side, and a gas side, the flow-through fluid side being disposed on one side of the diaphragm and the gas side being disposed on a side of the diaphragm opposite the flow-through fluid side;
generating a pressure signal corresponding to the pressure of fluid flowing through the flow-through fluid side of the pressure pod, over time;
comparing the pressure signal to one or more threshold values; and
(i) releasing pressure from the gas side of the pressure pod, (ii) pressurizing the gas side of the pressure pod, or both (i) and (ii), based on the comparison, while fluid is being moved through the flow-through fluid side,
wherein the releasing pressure, the pressurizing, or both, are used to properly position the diaphragm between the flow-through fluid side and the gas side of the pressure pod.

11. The method of claim 10 , wherein the releasing pressure, pressurizing, or both, comprises actuating a valve that is in fluid communication with the gas side of the pressure pod, to maintain the diaphragm in a mid-body position in the pressure pod.

12. The method of claim 10 , wherein the releasing pressure, pressurizing, or both, comprises pressurizing the gas side of the pressure pod, and the pressurizing comprises opening a valve to form a fluid communication between the gas side of the pressure pod and a pressurized gas source so that pressurized gas from the pressurized gas source enters the gas side of the pressure pod, to maintain the diaphragm in a mid-body position in the pressure pod.

13. The method of claim 10 , wherein the releasing pressure, pressurizing, or both, comprises releasing pressure from the gas side of the pressure pod, and the releasing pressure comprises opening a valve to form a fluid communication between the gas side of the pressure pod and an ambient atmosphere, the opening causing pressurized gas in the gas side of the pressure pod to vent gas from the gas side to the ambient atmosphere, to maintain the diaphragm in a mid-body position in the pressure pod.

14. The method of claim 10 , wherein the pump comprises a peristaltic pump and the pressure signal comprises pressure pulses resulting from the peristaltic pump moving the fluid through the flow-through fluid side of the pressure pod.

15. The method of claim 10 , wherein the comparing comprises comparing the pressure signal to one or more predetermined pressure signals.

16. The method of claim 10 , wherein the comparing comprises comparing the pressure signal to one or more predetermined waveforms.

17. The method of claim 10 , wherein the comparing comprises calculating an average deviation of the generated pressure signal relative to a predetermined signal, and determining whether the calculated average deviation is within an acceptable range of deviation.

18. The method of claim 10 , wherein the releasing, pressurizing, or both, comprises:
venting gas from the gas side of the pressure pod;
generating a new pressure signal, after the venting, corresponding to the pressure of fluid flowing through the flow-through fluid side of the pressure pod;
determining that the new pressure signal does not substantially deviate from an average pressure signal;
pressurizing the gas side of the pressure pod after generating the new pressure signal; and
generating yet another pressure signal, all while fluid is being moved through t

Assignees

• Fresenius Medical Care Holdings Inc

Inventors

• Crnkovich Martin
• Tanenbaum Lee
• Kotsos Michael Emmanuel
• Wang Fei
• Brown Alex

Classifications

• A61M2205/3344

  Measuring or controlling pressure at the body treatment site · CPC title

• A61M2205/50

  with microprocessors or computers · CPC title

• A61M1/3641

  Pressure isolators · CPC title

• A61M1/34

  Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration · CPC title

• A61M1/3607

  Regulation parameters · CPC title