Method and apparatus for rapid control of set inspired gas concentration in anesthesia delivery systems
US6216690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1998 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Oct 13, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2016/1035
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method and system for rapid control of set inspired gas concentration is disclosed for operating a medical anesthesia delivery system and for controlling the flow and concentration of gases and anesthesia vapor delivered to a patient. Control of the inspired gas and agent concentration is accomplished by operating in different control priority modes. In a flow priority control mode, the user may set, either directly or indirectly, the total fresh gas flow rate. The total fresh gas flow rate can then be slowly be varied by the control algorithm, while the vaporizer concentration is actively controlled to achieve the user set inspired gas concentration. The invention includes a process for switching from the flow priority control mode into a concentration priority mode for low flow rates. By throttling the flow, the patient will receive nearly an instantaneous change in the amount of agent and fresh gas without having the transport delay associated with a change in the agent concentration. Sensors are used to monitor agent concentration and minute volume, and a processor is programmed to estimate the concentration of the agent in the pipeline to select the control priority mode, an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.