Pressure-limited, time-cycled pulmonary ventilation with volume-cycle override
US5540220A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1994 |
| Grant date | Jul 30, 1996 |
| Priority date | — |
| Expiry date | Dec 8, 2014 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2016/0036
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A pressure-limited, time-cycled pulmonary ventilator includes a pressurized gas system that supplies respiratory gas to a patient at a selected inspiratory flow rate; an exhalation valve that (a) opens an expiratory flow path in response to the elapsing of a selected inspiratory time period, and (b) maintains a selected proximal pressure limit during the inspiratory time period; and a volume-cycle override system that actuates the exhalation valve so as to open the expiratory flow path if the patient's tidal volume reaches or exceeds a selected volume limit during the inspiratory time period. The volume-cycle override system includes a flow sensor that outputs an inhalation flow rate signal. The flow rate signal is integrated to derive a measured tidal volume signal. An operator control produces a volume limit signal, indicating a selected volume limit, that is compared with the measured tidal volume signal to yield a difference signal. The exhalation valve opens the expiratory flow path in response to the difference signal having a value indicating that the measured tidal volume is equal to or greater than the selected volume limit, as long as the proximal pressure exceeds a selec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.