Early 1980’s? Used a vortex-shedding sensor to measure expiratory flow. From: a DotMed listing.
One thought on “Spirometer, CDX Autospiro”
The Chest Autospiro (Marketed by CDX) was not a hot wire. It used a technology called ‘vortex shedding’. The vane inside caused vortices which gave pulses of air, which were detected by a sensitive thermocouple. So in effect it was a massflowmeter. As with most fluid measuring technologies for gasses, apart from pneumotachographs, it was very poor at measuring low flows.
The Chest Autospiro (Marketed by CDX) was not a hot wire. It used a technology called ‘vortex shedding’. The vane inside caused vortices which gave pulses of air, which were detected by a sensitive thermocouple. So in effect it was a massflowmeter. As with most fluid measuring technologies for gasses, apart from pneumotachographs, it was very poor at measuring low flows.