| Pulmonetic Systems, Inc. Patent applications |
| Patent application number | Title | Published |
|---|
| 20100111736 | ROOTS-TYPE BLOWER ROTOR ALIGNMENT METHOD AND APPARATUS - Roots-type blowers with helical cycloidal rotors exhibit variation in leakback flow with angular position intrinsic to these rotor geometries. Calibration of individual blowers using a combination of high-resolution alignment and enhanced detection of residual noise phenomena permits noise in as-produced blowers to be significantly attenuated. Intrinsic lower limits of noise induced by leakback variation are associated with manufacturing tolerances, necessary clearances, and particular geometric considerations. Gross alignment errors (excluding contact between rotors) produce a characteristic noise pulse rate that is three times the shaft rate. Proper alignment suppresses this and reveals a pulse sequence at double this rate and at about half of the amplitude of faulty alignment. The novel process explains the error mechanisms and defines repeatable calibration methods for a mass-production environment, introducing appropriate gauges and methods for the task. | 05-06-2010 |
| 20090250059 | FLOW SENSOR - A bi-directional flow sensor is adapted for reducing pneumatic noise during pressure sensing with a flow passing through the flow sensor. The flow sensor comprises a hollow, tubular member having a throat section disposed between a ventilator end and a patient end. A flow restrictor is disposed in the throat section and is adapted to measure differential pressure in the flow. A baffle is mounted at the ventilator end and is adapted to minimize non-axial flow at pressure taps located on opposing ends of the flow restrictor. The patient end includes a flow obstruction configured to promote uniform velocity across the flow at the pressure taps during exhalation flow from the patient end to the ventilator end. The flow sensor minimizes pneumatic noise to less than 0.1 LPM to allow accurate patient flow measurement and triggering of inhalation and exhalation phases at flow rates of 0.2 LPM. | 10-08-2009 |
| 20090142213 | ROOTS-TYPE BLOWER REDUCED ACOUSTIC SIGNATURE METHOD AND APPARATUS - A Roots-type blower with helical cycloidal rotors features relief recesses in the chamber walls, isolated from the input and output ports. The relief recesses counter variation in leakback flow with angular position intrinsic to helical cycloidal rotors, attenuating a noise source. | 06-04-2009 |
