# US 2021/0330871 A1 · 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 2021/0330871 A1 - Document ID: US20210330871A1 - Status: Published application - Kind: A1 - Application number: 17/369,372 - Filed: 2021-07-07 - Published: 2021-10-28 - 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/US20210330871A1 ## 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 the dimensions and the distensibility of the non-occluded portion of the patient line. If the change in pressure, the incremental volume, the properties related to the distensibility of the patient line, and some of the dimensions of the patient line are known, the location of the occlusion can be inferred. The occlusion type can be inferred based on the determined location. ## Claims ### Claim 1 A method of operating a medical device, the method comprising: providing or withdrawing, by a pump of the medical device and at a fixed volumetric flow rate, a fluid to or from a first portion of a distensible medical tube connected to the medical device, wherein an occlusion is present in the medical tube at a location that defines a boundary between the first portion and a second portion of the medical tube; while providing or withdrawing the fluid at the fixed volumetric flow rate, measuring, by a pressure sensor of the medical device, an initial steady-state pressure of the fluid in the first portion of the medical tube that results from: (i) the fixed volumetric flow rate of the fluid provided to or withdrawn from the first portion of the medical tube and (ii) the occlusion; in response to measuring the initial steady-state pressure of the fluid in the first portion of the medical tube, ceasing the pump to stop providing or withdrawing the fluid at the fixed volumetric flow rate, wherein the pump is ceased at a first time; in response to ceasing the pump, measuring, by the pressure sensor, a plurality of pressure versus time values of the fluid in the first portion of the medical tube while the fluid in the first portion of the medical tube is allowed to passively change from the initial steady-state pressure to a final steady-state pressure; and determining a length of the first portion of the medical tube using: (i) the first time, (ii) the plurality of pressure versus time values, (iii) the initial steady-state pressure, and (iv) the final steady-state pressure. ### Claim 2 (depends on 1) The method of claim 1, wherein the medical device comprises a dialysis machine. ### Claim 3 (depends on 2) The method of claim 2, wherein the dialysis machine comprises a peritoneal dialysis (PD) machine. ### Claim 4 (depends on 1) The method of claim 1, wherein the length of the first portion represents the location of the occlusion relative to a proximal end of the medical tube connected to the medical device. ### Claim 5 (depends on 1) The method of claim 1, wherein the fluid provided to or withdrawn from the first portion of the medical tube is at least partially blocked by the occlusion. ### Claim 6 (depends on 5) The method of claim 5, wherein the fluid provided to or withdrawn from the first portion of the medical tube being at least partially blocked by the occlusion causes an increase or a decrease of pressure in the medical tube. ### Claim 7 (depends on 5) The method of claim 5, wherein the fluid provided to or withdrawn from the first portion of the medical tube 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, wherein the medical tube comprises a catheter at a distal end of the medical tube. ### Claim 9 (depends on 1) The method of claim 1, further comprising inferring a type of the occlusion based at least in part on a determined location of the occlusion in the medical tube. ### Claim 10 (depends on 9) The method of claim 9, 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 at a distal end of the medical tube. ### Claim 11 (depends on 10) The method of claim 10, wherein at least one of the deposit in the medical tube or the deposit blocking the hole of the catheter comprises omental fat. ### Claim 12 (depends on 1) The method of claim 1, wherein the determining the length of the first portion of the medical tube is also uses one or more of: (a) dimensions of the medical tube, (b) a material composition of the medical tube, and (c) a volume of the fluid provided to or withdrawn from the first portion of the medical tube. ### Claim 13 A medical device comprising: a pressure sensor; one or more pumps; and a control unit configured to: operate the one or more pumps to provide or withdraw a fluid, at a fixed volumetric flow rate, to or from a medical tube connected to a port of the medical device; measure, using the pressure sensor and while the one or more pumps are providing or withdrawing the fluid at the fixed volumetric flow rate, an initial steady-state pressure of the fluid in a first portion of the medical tube that results from: (i) the fixed volumetric flow rate of the fluid provided to or withdrawn from the medical tube and (ii) an occlusion present in the medical tube at a location that defines a boundary between the first portion and a second portion of the medical tube; in response to measuring the initial steady-state pressure of the fluid in the first portion of the medical tube, cease the one or more pumps at a first time to stop providing or withdrawing the fluid at the fixed volumetric flow rate; in response to ceasing the one or more pumps, measure, using the pressure sensor, a plurality of pressure versus time values of the fluid in the first portion of the medical tube while the fluid in the first portion of the medical tube is allowed to passively change from the initial steady-state pressure to a final steady-state pressure; and determine a length of the first portion of the medical tube using: (i) the first time, (ii) the plurality of pressure versus time values, (iii) the initial steady-state pressure, and (iv) the final steady-state pressure. ### Claim 14 (depends on 13) The medical device of claim 13, wherein the medical device comprises a dialysis machine. ### Claim 15 (depends on 14) The medical device of claim 14, wherein the dialysis machine comprises a peritoneal dialysis (PD) machine. ### Claim 16 (depends on 13) The medical device of claim 13, wherein the length of the first portion of the medical tube represents the location of the occlusion relative to a proximal end of the medical tube. ### Claim 17 (depends on 13) The medical device of claim 13, wherein the medical tube comprises a catheter at a distal end of the medical tube. ### Claim 18 (depends on 13) The medical device of claim 13, wherein the length of the first portion of the medical tube represents the location of the occlusion relative to a proximal end of the medical tube, and wherein the control unit is configured to infer a type of the occlusion based at least in part on the location of the occlusion in the medical tube. ### Claim 19 (depends on 13) The medical device of claim 13, wherein the control unit is configured to determine the length of the first portion of the medical tube based on one or more of: (a) dimensions of the medical tube, (b) a material composition of the medical tube, and (c) a volume of the fluid provided to or withdrawn from the first portion of the medical tube.