Fault protection system for a respiratory conduit heater element
AssigneeFisher & Paykel Limited
InventorPaul John Seakins
Life of this patent
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Abstract
A fault protection circuit for a respiratory conduit heater element in a respirator humidification system is disclosed. The circuit includes a spark detector as well as overcurrent detector. Several variations are included for the spark detector including a two winding transformer, a center tapped two winding transformer), and a high pass filtered inductor. A semiconductor switching configuration is also disclosed. Once the protection circuit detects a change in current over a certain level, or the average level raises above a threshold, then the current in the heater element is interrupted for a preset period.
Claims16
A fault protection system adapted for use with a heater element comprising:
- detecting means which include means to detect a rapid change in current in said heater element,
- current interruptor means adapted to be in series with said heater element, and
- timing means configured to activate said current interruptor means to interrupt the current in the heater element when said rapid change in current exceeds a first predetermined threshold.
A fault protection system adapted for use with a heater element comprising:
- detecting means which includes a peak current detector for detecting peak current in said heater element and means to detect a rapid change in current in said heater element,
- current interruptor means adapted to be in series with said heater element, and
- timing means configured to activate said current interruptor means to interrupt the current in said heater element when said rapid change in current exceeds a first predetermined threshold and configured to activate said current interruptor means to interrupt the current in said heater element when said peak current exceeds a second predetermined threshold.
A fault protection system adapted for use with a heater element comprising:
- detecting means which includes a peak current detector for detecting peak current in said heater element,
- current interruptor means adapted to be in series with said heater element, and
- timing means configured to activate said current interruptor means to interrupt said current in the heater element when said peak current exceeds a predetermined threshold.
In a respiratory humidification system wherein a conduit supplies humidified gases to a patient from a humidifier, said conduit or said gases being heated by a respiratory conduit heater element, the improvement comprising that said system includes a fault protection system for said heater element comprising:
- detecting means which include means to detect a rapid change of current in said heater element,
- current interruptor means in series with said heater element, and
- timing means configured to activate said current interruptor means to interrupt the current in said heater element when said rapid change in current exceeds a first predetermined threshold.
In a respiratory humidification system wherein a conduit humidified gases to a patient from a humidifier, said conduit or said gases being heated by a respiratory conduit heater element, the improvements comprising that said system includes a fault protection system for said heater element comprising:
- detecting means which includes a peak current detector for detecting a peak current in said heater element and means to detect a rapid change in current in said heater element,
- current interruptor means adapted to be in series with said heater element, and
- timing means configured to activate said current interruptor means to interrupt the current in said heater element when said rapid change in current exceeds a first predetermined threshold and configured to activate said current interruptor means to interrupt the current in said heater element when said peak current exceeds a second predetermined threshold.
In a respiratory humidification system wherein a conduit delivers humidified gases to a patient from a humidifier, said conduit being heated by a respiratory conduit heater element, the improvement comprising that said system includes a fault protection system for said heater element comprising:
- detecting means which includes a peak current detector for detecting peak current in said heater element,
- current interruptor means in series with said heater element, and
- timing means configured to activate said current interruptor means to interrupt the current in said heater element when said peak current exceeds a predetermined threshold.
Dependencies are inferred from the claim text.