Changes

Bi-Level Lowenstein models like the '''Prisma25ST''' and '''Prisma30ST''' offer an array of features for bi-level therapy. All of the modes described sofar and those immediately following form the main body of machines offering what is known as '''pressure targeted ventilation'''(PTV). This is in contrast to '''volume targeted ventilation'''(VTV). '''PTV''' aims to hit settable pressure targets like IPAP and EPAP, leaving volumes variable, whereas '''VTV''' aims to hit a settable Volume target where pressure remains variable. PTV is a universal ventilation mode used by all manufacturers for a majority of non invasive ventilation machines like those used for home OSA therapy. VTV ventilators are generally used for intubated critical care patients, where the seal can be ensured and the 'work of breathing' left largely to the machine. Some specialized mix of the two modes are available for home use in specially developed models by some manufacturers.

*If '''BiSoft0''' (Off) is useful if you have good exhalation shape but late collapse of inspiration, you may select level 0 to apply all . This mode will delay maximum pressure support to that period arriving later in your breathinginspiration.*As '''BiSoft1''' & '''BiSoft2''' will delivery some instability become obvious in early/exhalation support but direct a good amount of pressure support at the earl to mid inspiration, you may apply level 1 or 2inpiration.*Level 4 (Tri-level), '''TRILevel''' can be used to apply most pressure during end of expiration with only minimal pressure support . This is iseal for those with collapsing exhalation and instability during time at zero before inspiration.