Ventilatory assistance for treatment of cardiac failure and cheyne-stokes breathing
US6532959B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1999 |
| Grant date | Mar 18, 2003 |
| Priority date | — |
| Expiry date | May 21, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2230/42
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Method and apparatus for the treatment of cardiac failure, Cheyne-Stokes breathing or central sleep apnea are disclosed. A subject is provided with ventilatory support, for example positive pressure ventilatory support using a blower and mask. Respiratory airflow is determined. From the respiratory airflow are derived a measure of instantaneous ventilation (for example half the absolute value of the respiratory airflow) and a measure of longterm average ventilation (for example the instantaneous ventilation low pass filtered with a 100 second time constant). A target ventilation is taken as 95% of the longterm average ventilation. The instantaneous ventilation is fed as the input signal to a clipped integral controller, with the target ventilation as the reference signal. The output of the controller determines the degree of ventilatory support. Clipping is typically to between half and double the degree of support that would do all the respiratory work. A third measure of ventilation, for example instantaneous ventilation low pass filtered with a time constant of 5 seconds, is calculated. Ventilatory support is in phase with the subject's respiratory airflow to the fuzzy extent th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.