Ophthalmic instrument probe detection method
AssigneeReichert, Inc.
InventorsDavid G. Kelkenberg, John W. Taylor, Eric V. Palmer, David J. Cash
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Abstract
A method of detecting presence or absence of a magnetic measurement probe at a measurement launch position in an electromagnetic coil of an ophthalmic instrument includes applying a temporary current pulse to the electromagnetic coil, detecting a counter-electromotive force voltage spike induced in the electromagnetic coil by the current pulse, evaluating a decay behavior of the counter-electromotive force voltage spike, and correlating the decay behavior of the counter-electromotive force voltage spike to presence or absence of the measurement probe at the measurement launch position.
Claims18
A method of detecting presence or absence of a measurement probe at a measurement launch position in an ophthalmic instrument, the measurement probe comprising a magnetic shaft, the ophthalmic instrument comprising an electromagnetic coil defining a core passageway for receiving at least a portion of the magnetic shaft when the magnetic shaft is at the measurement launch position, the method comprising the steps of:
- applying a temporary current pulse to the electromagnetic coil;
- detecting a counter-electromotive force voltage spike induced in the electromagnetic coil by the current pulse;
- evaluating a decay behavior of the counter-electromotive force voltage spike;
- and
- correlating the decay behavior of the counter-electromotive force voltage spike to presence or absence of the measurement probe at the measurement launch position.
An ophthalmic instrument comprising:
- an electromagnetic coil defining a core passageway;
- drive electronics configured to connect a first voltage to the electromagnetic coil to apply a temporary current pulse in the electromagnetic coil;
- measurement electronics configured to detect a counter-electromotive force voltage spike induced in the electromagnetic coil by the current pulse and generate a probe detection signal representing the counter-electromotive force voltage spike;
- and
- processing electronics configured to evaluate a decay behavior of the counter-electromotive force voltage spike and correlate the decay behavior of the counter-electromotive force voltage spike to presence or absence of a disposable measurement probe at a measurement launch position within the core passageway.
Dependencies are inferred from the claim text.