RT Journal Article SR Electronic T1 Assisted ventilation. 5. Non-invasive and domiciliary ventilation: negative pressure techniques. JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 131 OP 135 DO 10.1136/thx.46.2.131 VO 46 IS 2 A1 J M Shneerson YR 1991 UL http://thorax.bmj.com/content/46/2/131.abstract AB