(19)
(11) EP 1 277 435 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION

(48) Corrigendum issued on:
25.06.2003 Bulletin 2003/26

(43) Date of publication:
22.01.2003 Bulletin 2003/04

(21) Application number: 02102493.0

(22) Date of filing: 23.09.1997
(51) International Patent Classification (IPC)7: A61B 5/087, A61M 16/00, A61B 5/085
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV RO SI

(30) Priority: 23.09.1996 AU PO247496
14.08.1997 WO PCT/AU97/00517

(62) Application number of the earlier application in accordance with Art. 76 EPC:
00104511.1 / 1005829
97939877.3 / 0996358

(71) Applicant: RESMED LIMITED
North Ryde, New South Wales 2113 (AU)

(72) Inventor:
  • Berthon-Jones, Michael
    Leonay, New South Wales 2750 (AU)

(74) Representative: Asquith, Julian Peter 
Marks & Clerk, 4220 Nash Court, Oxford Business Park South
Oxford, Oxfordshire OX4 2RU
Oxford, Oxfordshire OX4 2RU (GB)

 
Remarks:
This application was filed on 25 - 10 - 2002 as a divisional application to the application mentioned under INID code 62.
 


(54) Apparatus for determining instantaneous elastic recoil pressure during ventilatory support


(57) An apparatus for determining an instantaneous elastic recoil pressure during the provision of respiratory assistance, comprises:
  • an air supply means controllable to supply breathable air to a subject's airway continually at a selectable pressure elevated above atmospheric pressure as a function of an instantaneous elastic pressure;
  • a flow sensor means to generate a flow signal representative of respiratory airflow; and
  • a processor means to process a flow signal from said flow sensor and to control said air supply means, wherein said processor is programmed to:receive as input an elastance value for a subject;calculate an index value representing an extent to which any leak is suddenly changing using sampled flow values from said flow signal;calculating an inspired volume of airflow as a function of said measure of respiratory airflow and said index value; andcalculating said instantaneous elastic recoil pressure as a function of said inspired volume and said elastance value.