# US 10,441,704 B2 · Automatic detection and adjustment of a pressure pod diaphragm

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- Number: US 10,441,704 B2
- Document ID: US10441704B2
- Status: Granted
- Kind: B2
- Application number: 15/832,095
- Filed: 2017-12-05
- Published: 2018-04-05
- Granted: 2019-10-15
- Earliest claimed: 2013-12-23
- Assignees: Fresenius Medical Care Holdings, Inc.
- Applicants: Fresenius Medical Care Holdings, Inc.
- Inventors: Martin Crnkovich; Lee Tanenbaum; Michael Emmanuel Kotsos; Fei Wang; Alex Brown
- Web page: https://patentgrep.com/patent/US10441704B2

## CPC

- A61M 1/3639: {Blood pressure control, pressure transducers specially adapted therefor}
- A61M 1/16: with membranes
- A61M 1/34: Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
- A61M 1/3403: {Regulation parameters}
- A61M 1/3607: {Regulation parameters}
- A61M 1/3641: {Pressure isolators}
- G01L 7/088: {correcting or regulating means for flexible diaphragms}
- A61M 2205/3331: Pressure; Flow
- A61M 2205/3344: Measuring or controlling pressure at the body treatment site
- A61M 2205/3379: Masses, volumes, levels of fluids in reservoirs, flow rates
- A61M 2205/50: with microprocessors or computers
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)

## 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.

## Claims

### Claim 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 (1) receive a pressure signal generated by the pressure sensor, (2) compare the pressure signal received to a predetermined pressure signal that corresponds to a signal generated during normal operation of the pressure pod, under normal operating pressures and where the diaphragm is properly or optimally positioned, (3) calculate a difference between the pressure signal received from the pressure sensor and the predetermined pressure signal, and (4) control the valve in response to the calculated difference, 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 3)

The system of claim 3, 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.

### Claim 5 (depends on 4)

The system of claim 4, 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.

### Claim 6 (depends on 1)

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.

### Claim 7 (depends on 1)

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.

### Claim 8 (depends on 1)

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.

### Claim 9 (depends on 1)

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.

### Claim 10

A method for automatically adjusting the position of a diaphragm in a pressure pod, the method comprising;
forcing a fluid a through a flow-through fluid side of a pressure pod, using a pump, the pressure pod comprising a diaphragm, the flow-through fluid side being disposed on one side of the diaphragm, and a 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 predetermined pressure signals that correspond to a signal generated during normal operation of the pressure pod, under normal operating pressures and where the diaphragm is properly or optimally positioned; 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,
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.

### Claim 11 (depends on 10)

The method of claim 10, wherein the comparing comprises comparing the pressure signal to a plurality of predetermined pressure signals.

### Claim 12 (depends on 10)

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.

### Claim 13 (depends on 10)

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.

### Claim 14 (depends on 10)

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.

### Claim 15 (depends on 10)

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.

### Claim 16 (depends on 10)

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

### Claim 17 (depends on 10)

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

### Claim 18 (depends on 10)

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.

### Claim 19 (depends on 10)

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 the flow-through fluid side.

### Claim 20 (depends on 19)

The method of claim 19, wherein the determining that the new pressure signal does not substantially deviate from the average pressure signal comprises determining whether the new pressure signal corresponds to a pressure that is at least 5 mmHg higher or lower than the average pressure signal.

### Claim 21 (depends on 10)

The method of claim 10, wherein the releasing, pressurizing, or both, results in an adjustment of the position of the diaphragm and a new pressure signal, and the method further comprises, after the releasing, pressurizing, or both, immediately comparing the new pressure signal to one or more predetermined signals.