# US 11,298,456 B2 · Infusion system and method which utilizes dual wavelength optical air-in-line detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,456 B2 - Document ID: US11298456B2 - Status: Granted - Kind: B2 - Application number: 16/505,479 - Filed: 2019-07-08 - Published: 2020-03-05 - Granted: 2022-04-12 - Earliest claimed: 2014-02-28 - Assignees: ICU Medical, Inc. - Applicants: ICU Medical, Inc. - Inventors: Gary David Shubinsky; Tamas Ban; Brian G. Markey - Web page: https://patentgrep.com/patent/US11298456B2 ## CPC - A61M 5/14: Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor - 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 5/365: {Air detectors (A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626)} - A61M 5/172: electrical or electronic - A61M 2205/3313: used specific wavelengths - 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)} ## Abstract Infusion fluid is flowed through a fluid delivery line of an infusion system. Optical signals having different wavelengths are transmitted through the fluid delivery line. The transmitted optical signals having the different wavelengths are received. At least one processor determines whether air or infusion fluid is disposed in the fluid delivery line based on the received optical signals having the different wavelengths. ## Claims ### Claim 1 A method of determining whether air is disposed in infusion fluid in a fluid delivery line of an infusion system: transmitting a first optical signal at a first wavelength through the fluid delivery line; transmitting a second optical signal at a second wavelength that is different than the first wavelength through the fluid delivery line; directing the transmitted first optical signal and the transmitted second optical signal along a same optical axis through the fluid delivery line; and receiving the first and second optical signals after propagation through the fluid delivery line; determining a ratio corresponding to the received first optical signal and the received second optical signal along the optical axis; and determining whether air is disposed in the infusion fluid in the fluid delivery line based on the ratio corresponding to the received first and second optical signals. ### Claim 2 (depends on 1) The method of claim 1, wherein the same optical axis lies inside the fluid delivery line. ### Claim 3 (depends on 1) The method of claim 1, wherein the directing is performed by a beam splitter. ### Claim 4 (depends on 1) The method of claim 1, wherein the ratio enables self calibration. ### Claim 5 (depends on 1) The method of claim 1, wherein the first wavelength is selected such that when air is disposed in the fluid delivery line, the air will have a substantially greater impact on the first optical signal than on the second optical signal. ### Claim 6 (depends on 1) The method of claim 1, wherein the first wavelength and the second wavelength are selected based on a particular type of the infusion fluid disposed in the fluid delivery line to achieve maximum differentiation between the air disposed in the fluid delivery line and the infusion fluid disposed in the fluid delivery line. ### Claim 7 A method for determining whether air is disposed in infusion fluid in a fluid delivery line of an infusion system, the method comprising: receiving a first optical signal of a first wavelength propagating through the fluid delivery line; receiving a second optical signal of a second wavelength that is different than the first wavelength propagating through the fluid delivery line, wherein the first optical signal and the second optical signal are directed along a same optical axis through the fluid delivery line; determining a ratio corresponding to the received first optical signal and the received second optical signal along the optical axis; and determining whether air is disposed in the infusion fluid in the fluid delivery line based on the ratio. ### Claim 8 (depends on 7) The system of claim 7, wherein the same optical axis lies inside the fluid delivery line. ### Claim 9 (depends on 7) The method of claim 7, wherein the directing is performed by a beam splitter. ### Claim 10 (depends on 7) The method of claim 7, wherein the ratio enables self calibration. ### Claim 11 (depends on 7) The method of claim 7, wherein the first wavelength is selected such that when air is disposed in the fluid delivery line, the air will have a substantially greater impact on the first optical signal than on the second optical signal. ### Claim 12 (depends on 7) The method of claim 7, wherein the first wavelength and the second wavelength are selected based on a particular type of the infusion fluid disposed in the fluid delivery line to achieve maximum differentiation between the air disposed in the fluid delivery line and the infusion fluid disposed in the fluid delivery line. ### Claim 13 A system for determining whether air is disposed in infusion fluid in a fluid delivery line of an infusion system, the system comprising one or more hardware processors configured to: receive a first optical signal of a first wavelength propagating through the fluid delivery line; receive a second optical signal of a second wavelength that is different than the first wavelength propagating through the fluid delivery line, wherein the first optical signal and the second optical signal are directed along a same optical axis through the fluid delivery line; determining a ratio corresponding to the received first optical signal and the received second optical signal along the optical axis; and determine whether air is disposed in the infusion fluid in the fluid delivery line based on the ratio corresponding to the received first and second optical signals. ### Claim 14 (depends on 13) The system of claim 13, wherein the same optical axis lies inside the fluid delivery line. ### Claim 15 (depends on 13) The system of claim 13, wherein the directing is performed by a beam splitter. ### Claim 16 (depends on 13) The system of claim 13, wherein the ratio enables self calibration. ### Claim 17 (depends on 13) The system of claim 13, wherein the first wavelength is selected such that when air is disposed in the fluid delivery line, the air will have a substantially greater impact on the first optical signal than on the second optical signal.