# US 12,246,119 B2 · Patient line blockage detection

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,246,119 B2
- Document ID: US12246119B2
- Status: Granted
- Kind: B2
- Application number: 18/144,729
- Filed: 2023-05-08
- Published: 2023-08-31
- Granted: 2025-03-11
- Earliest claimed: 2016-06-30
- Assignees: Fresenius Medical Care Holdings, Inc.
- Applicants: Fresenius Medical Care Holdings, Inc.
- Inventors: William Scott Crawford; Robert Matthew Ohline
- Web page: https://patentgrep.com/patent/US12246119B2

## CPC

- 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}
- A61M 1/154: {with sensing means or components thereof}
- A61M 1/155: {with treatment-fluid pumping means or components thereof}
- A61M 1/159: {specially adapted for peritoneal dialysis}
- A61M 1/28: Peritoneal dialysis {; Other peritoneal treatment, e.g. oxygenation}
- A61M 1/285: {Catheters therefor}
- A61M 1/3656: {Monitoring patency or flow at connection sites; Detecting disconnections}
- A61M 5/16831: {Monitoring, detecting, signalling or eliminating infusion flow anomalies (low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066)}
- A61M 5/16854: {by monitoring line pressure}
- A61M 1/1522: {the interface being evacuated interfaces to enhance contact}
- A61M 1/1524: {the interface providing means for actuating on functional elements of the cassette, e.g. plungers}
- 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}
- A61M 1/1565: {Details of valves}
- A61M 1/3661: {for haemodialysis}
- A61M 5/16863: {Occlusion detection}
- A61M 2205/18: with alarm
- A61M 2205/3331: Pressure; Flow
- A61M 2205/3355: Controlling downstream pump pressure
- A61M 2205/3362: with minimised length of fluid lines; Taking into account the elastic expansion of fluid lines to increase accuracy
- A61M 2205/50: with microprocessors or computers
- A61M 2205/52: with memories providing a history of measured variating parameters of apparatus or patient
- A61M 2205/70: with testing or calibration facilities
- A61M 2205/702: automatically during use
- A61M 2209/02: Equipment for testing the apparatus
- A61M 2210/1017: Peritoneal cavity
- 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)}

## Abstract

A dialysis machine (e.g., a peritoneal dialysis (PD) machine) can include a pressure sensor mounted at a proximal end of a patient line made of a distensible material that provides PD solution to a patient through a catheter. During treatment, an occlusion can occur at different locations in the patient line and/or the catheter. When an incremental volume of additional solution is provided to the patient line while the occlusion is present, a change in pressure results. The change in pressure depends on dimensions and a distensibility of a non-occluded portion of the patient line. If the change in pressure, the incremental volume, properties related to the distensibility of the patient line, and some of the dimensions of the patient line are known, a location of the occlusion can be inferred. An occlusion type can be inferred based on the inferred location.

## Claims

### Claim 1

A method comprising:
providing or withdrawing a fluid to or from a distensible medical tube connected to a medical device at a volumetric flow rate over time, the medical tube including a patient line region and a catheter region separated by a fluid capacitive element;
measuring, by a pressure sensor at the patient line region, a plurality of pressures over time of the fluid; and
determining whether an occlusion in the medical tube is present in the patient line region or the catheter region based at least partly on a fluidic resistance of the patient line region detected by a measurement of a transient component of the measured plurality of pressures over time and a fluidic resistance of the catheter region detected by the measurement of the transient component of the measured plurality of pressures over time.

### Claim 2 (depends on 1)

The method of claim 1, wherein the medical device comprises a dialysis machine.

### Claim 3 (depends on 1)

The method of claim 1, wherein the providing or the withdrawing the fluid to or from the distensible medical tube connected to the medical device at the volumetric flow rate comprises abruptly stopping the providing the fluid or the withdrawing the fluid.

### Claim 4 (depends on 1)

The method of claim 1, wherein the providing or the withdrawing the fluid to or from the distensible medical tube connected to the medical device at the volumetric flow rate comprises one or more of a steady-state introduction of the fluid, a ramped introduction of the fluid, a parabolic introduction of the fluid, and a cyclical introduction of the fluid.

### Claim 5 (depends on 1)

The method of claim 1, wherein the fluid is at least partially blocked by the occlusion.

### Claim 6 (depends on 5)

The method of claim 5, wherein the fluid being at least partially blocked by the occlusion causes an increase in pressure in the medical tube or a decrease in pressure in the medical tube.

### Claim 7 (depends on 5)

The method of claim 5, wherein the fluid being at least partially blocked by the occlusion causes a distension in the medical tube.

### Claim 8 (depends on 1)

The method of claim 1, comprising inferring a type of the occlusion based at least in part on a determined location of the occlusion.

### Claim 9 (depends on 8)

The method of claim 8, wherein the type of the occlusion comprises one or more of a pinch of the medical tube, a kink in the medical tube, a deposit in the medical tube, and a deposit blocking a hole of a catheter in the catheter region at a distal end of the medical tube.

### Claim 10 (depends on 1)

The method of claim 1, wherein the determining whether the occlusion in the medical tube is present in the patient line region or the catheter region is further based on one or more of the volumetric flow rate, a second fluidic resistance of the patient line region detected by a steady-state measurement, a second fluidic resistance of the catheter region detected by the steady-state measurement, and a characteristic frequency of the transient component of the measured plurality of pressures over time.

### Claim 11

A medical device comprising:
a distensible medical tube connected to a port of the medical device, the medical tube including a patient line region and a catheter region separated by a fluid capacitive element;
one or more pumps configured for providing or withdrawing a fluid to or from the medical tube at a volumetric flow rate;
a pressure sensor at the patient line region, the pressure sensor configured for measuring a plurality of pressures over time of the fluid; and
a processor configured for determining whether an occlusion in the medical tube is present in the patient line region or the catheter region based at least partly on a fluidic resistance of the patient line region detected by a measurement of a transient component of the measured plurality of pressures over time and a fluidic resistance of the catheter region detected by the measurement of the transient component of the measured plurality of pressures over time.

### Claim 12 (depends on 11)

The medical device of claim 11, wherein the medical device comprises a dialysis machine.

### Claim 13 (depends on 12)

The medical device of claim 12, wherein the dialysis machine comprises a peritoneal dialysis (PD) machine.

### Claim 14 (depends on 11)

The medical device of claim 11, wherein the medical tube comprises a catheter in the catheter region at a distal end of the medical tube.

### Claim 15 (depends on 11)

The medical device of claim 11, wherein the processor is configured to infer a type of the occlusion based at least in part on a determined location of the occlusion.

### Claim 16 (depends on 11)

The medical device of claim 11, wherein the processor is configured to determine whether the occlusion in the medical tube is present in the patient line region or the catheter region further based on one or more of the volumetric flow rate, a second fluidic resistance of the patient line region detected by a steady-state measurement, a second fluidic resistance of the catheter region detected by the steady-state measurement, and a characteristic frequency of the transient component of the measured plurality of pressures over time.

### Claim 17 (depends on 11)

The medical device of claim 11, wherein the fluid capacitive element is distended by pressure in the medical tube.

### Claim 18 (depends on 11)

The medical device of claim 11, wherein the fluid capacitive element is integrated into the medical tube.

### Claim 19 (depends on 11)

The medical device of claim 11, wherein the fluid capacitive element has a distensibility that is substantially greater than a distensibility of the medical tube.

### Claim 20 (depends on 11)

The medical device of claim 11, wherein the fluid capacitive element is configured to store additional fluid volume relative to the medical tube with a concomitant increase in pressure.