Breath sampling methodology having improved reliability
First Claim
1. An improved method of breath sampling, comprising the steps of:
- providing a solenoid having a coil and a core coupled to a piston mounted in a housing of a piston pump;
coupling a pin projecting outwardly from the pump housing to the solenoid core and locating a switch exterior to the pump to be activated by the pin;
sending a drive signal to the piston pump solenoid coil to draw a breath sample into a sensing chamber, the pump having an input line connected to the sensing chamber;
monitoring the operational status of the pump by monitoring a state of the switch, the switch being adapted to change state when contacted by the pin when the pump piston is withdrawn into its pump housing as a proper reaction of the pump to its drive signal and return to its original state when the pin ends contact with the switch when the pump piston is no longer withdrawn;
utilizing the state of the switch to confirm proper pump operation in drawing the breath sample into the chamber;
if proper pump operation is confirmed, accepting the breath sample for further processing and analysis; and
if proper pump operation is not confirmed, generating a malfunction signal.
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Accused Products
Abstract
An improved method of breath sampling, particularly adapted for use in connection with motor vehicle alcohol breath monitoring devices, comprises the sending of a drive signal to a piston pump to draw a breath sample into a sensing chamber, the pump being connected to the sensing chamber. The operational status of the pump is monitored by monitoring the condition of a switch associated with the pump which is adapted to change state when the pump piston is withdrawn into its pump housing as a proper reaction of the pump to its drive signal and return to its original state when the pump piston is no longer withdrawn. The state condition of the of the switch is used to confirm proper pump operation in drawing the breath sample into the chamber; if proper pump operation is confirmed, the breath sample can be accepted for further processing and analysis.
27 Citations
6 Claims
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1. An improved method of breath sampling, comprising the steps of:
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providing a solenoid having a coil and a core coupled to a piston mounted in a housing of a piston pump; coupling a pin projecting outwardly from the pump housing to the solenoid core and locating a switch exterior to the pump to be activated by the pin; sending a drive signal to the piston pump solenoid coil to draw a breath sample into a sensing chamber, the pump having an input line connected to the sensing chamber; monitoring the operational status of the pump by monitoring a state of the switch, the switch being adapted to change state when contacted by the pin when the pump piston is withdrawn into its pump housing as a proper reaction of the pump to its drive signal and return to its original state when the pin ends contact with the switch when the pump piston is no longer withdrawn; utilizing the state of the switch to confirm proper pump operation in drawing the breath sample into the chamber; if proper pump operation is confirmed, accepting the breath sample for further processing and analysis; and if proper pump operation is not confirmed, generating a malfunction signal. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification