# US 12,214,116 B2 · Methods and systems for providing control stability in a vacuum generation system using cascade proportional-integral-derivative (PID) controller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,116 B2 - Document ID: US12214116B2 - Status: Granted - Kind: B2 - Application number: 17/460,630 - Filed: 2021-08-30 - Published: 2022-03-17 - Granted: 2025-02-04 - Earliest claimed: 2020-09-14 - Assignees: Alcon Inc. - Applicants: Alcon Inc. - Inventors: Brian T. Chiem - Web page: https://patentgrep.com/patent/US12214116B2 ## CPC - A61M 1/74: {Suction control (underwater drainage A61M1/61)} - A61M 1/804: {using Laval or Venturi jet pumps} - A61M 1/73: {comprising sensors or indicators for physical values} - A61M 1/743: {by changing the cross-section of the line, e.g. flow regulating valves (A61M1/7413 takes precedence)} - G05D 16/2066: {using controlling means acting on the pressure source} - A61F 9/00736: {Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments (A61F9/008 takes precedence)} - A61F 9/00745: {using mechanical vibrations, e.g. ultrasonic} - A61M 2205/3331: Pressure; Flow - A61M 2205/50: with microprocessors or computers - A61M 2210/0612: Eyes - 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)} - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract Certain embodiments provide a vacuum generation system with a cascade PID controller, a proportional valve, and a vacuum generator. The cascade PID controller allows the vacuum generation system to control the operating range of supply air pressure that is provided to the vacuum generator. By controlling the operating range of the supply air pressure, the vacuum generation system is able to avoid entering the decreasing or non-monotonic region of the vacuum generator. ## Claims ### Claim 1 A method of controlling vacuum pressure in a vacuum generation system, the method comprising: receiving a vacuum pressure sensor reading from a vacuum pressure sensor; calculating a first error between the vacuum pressure sensor reading and a vacuum pressure set point; calculating a supply air pressure set point based on the first error; receiving a supply air pressure sensor reading from a supply air pressure sensor; calculating a second error between the supply air pressure sensor reading and the supply air pressure set point; calculating a voltage level for controlling a proportional valve based on the second error; providing the voltage level to the proportional valve; causing, using the proportional valve, supply air pressure to be provided to a vacuum generator based on the voltage level; and providing, using the vacuum generator, vacuum pressure based on the supply air pressure to a surgical tool. ### Claim 2 (depends on 1) The method of claim 1, wherein calculating the supply air pressure set point is performed by a first proportional-integral-derivative (PID) controller. ### Claim 3 (depends on 2) The method of claim 2, wherein calculating the voltage level is performed by a second PID controller. ### Claim 4 (depends on 1) The method of claim 1, wherein calculating the supply air pressure set point based on the first error comprises limiting the supply air pressure set point to a range that corresponds to a monotonic operating range of the vacuum generator. ### Claim 5 (depends on 1) The method of claim 1, wherein calculating the supply air pressure set point based on the first error comprises limiting the supply air pressure set point to a range of 0-60 psig (pounds per square inch gauge). ### Claim 6 (depends on 1) The method of claim 1, wherein calculating the voltage level for controlling the proportional valve comprises limiting the voltage level to an operating voltage range of the proportional valve. ### Claim 7 A vacuum generation system, comprising: a first proportional-integral-derivative (PID) controller, configured to: receive a first error between a vacuum pressure sensor reading associated with a vacuum generator and a vacuum pressure set point; calculate a supply air pressure set point based on the first error; a second PID controller, configured to: receive a second error between a supply air pressure sensor reading and the supply air pressure set point; calculate a voltage level based on the second error; the proportional valve, configured to: receive the voltage level; cause supply air pressure to be provided to a vacuum generator based on the voltage level; the vacuum generator, configured to: provide vacuum pressure based on the supply air pressure to a surgical tool. ### Claim 8 (depends on 7) The vacuum generation system of claim 7, further comprising: a vacuum pressure sensor, configured to provide the vacuum pressure sensor reading; and a supply air pressure sensor, configured to provide the supply air pressure sensor reading. ### Claim 9 (depends on 7) The vacuum generation system of claim 7, wherein the first PID controller being configured to calculate the supply air pressure set point based on the first error comprises the first PID controller being configured to limit the supply air pressure set point to a range that corresponds to a monotonic operating range of the vacuum generator. ### Claim 10 (depends on 7) The vacuum generation system of claim 7, wherein the first PID controller being configured to calculate the supply air pressure set point based on the first error comprises the first PID controller being configured to limit the supply air pressure set point to a range of 0-60 psig (pounds per square inch gauge). ### Claim 11 (depends on 7) The vacuum generation system of claim 7, wherein the second PID controller being configured to calculate the voltage level for controlling the proportional valve comprises the second PID controller being configured to limit the voltage level to an operating voltage range of the proportional valve. ### Claim 12 A vacuum generation system, comprising: a memory comprising executable instructions; a processor in data communication with memory and configured to execute the instructions, which configured the processor to; receive a first error between a vacuum pressure sensor reading associated with a vacuum generator and a vacuum pressure set point; calculate a supply air pressure set point based on the first error; receive a second error between a supply air pressure sensor reading and the supply air pressure set point; calculate a voltage level based on the second error; cause the voltage level to be provided to the proportional valve; the proportional valve, configured to: cause supply air pressure to be provided to a vacuum generator based on the voltage level; the vacuum generator, configured to: provide vacuum pressure based on the supply air pressure to a surgical tool. ### Claim 13 (depends on 12) The vacuum generation system of claim 12, further comprising: a vacuum pressure sensor, configured to provide the vacuum pressure sensor reading; and a supply air pressure sensor, configured to provide the supply air pressure sensor reading. ### Claim 14 (depends on 12) The vacuum generation system of claim 12, wherein calculating the supply air pressure set point based on the first error comprises limiting the supply air pressure set point to a range that corresponds to a monotonic operating range of the vacuum generator. ### Claim 15 (depends on 12) The vacuum generation system of claim 12, wherein calculating the supply air pressure set point based on the first error comprises limiting the supply air pressure set point to a range of 060 psig (pounds per square inch gauge).