Wireless ophthalmic surgical footswitch
Disclosed is a surgical footswitch, comprising a base, a pedal mounted to the base, and a variable air capacitor mechanically coupled to the pedal, such that movement of the pedal is operative to vary the capacitance of the variable air capacitor. The footswitch further comprises a capacitance-sensing controller circuit electrically connected to the variable air capacitor and configured to measure a capacitance of the variable air capacitor and to produce a control signal based on the measured capacitance, such that the control signal reflects a position of the pedal or a change in the position of the pedal, and a wireless interface electrically connected to the capacitance-sensing controller circuit and configured to wirelessly relay the control signal to a surgical console.
1. A surgical footswitch, comprising:
a base;
a pedal mounted to the base;
first and second variable air capacitors mechanically coupled to the pedal, such that rotation of the pedal in a vertical plane is operative to vary the capacitance of the first variable air capacitor and movement of the pedal in a horizontal plane is operative to vary the capacitance of the first variable air capacitor;
a capacitance-sensing controller circuit electrically connected to the first and second variable air capacitors and is configured to produce first and second control signals or a composite control signal based on the respective capacitances of the first and second variable air capacitors, such that the control signal reflects a position of the pedal or a change in the position of the pedal; and
a wireless interface electrically connected to the capacitance-sensing controller circuit and configured to wirelessly relay the first and second control signals or the composite control signal to the surgical console to a surgical console.
2. The surgical footswitch of claim 1 , further comprising an eddy current brake mechanism mechanically coupled to the pedal, such that the movement of the pedal is operative to cause the eddy current brake mechanism to generate a mechanically resistive force opposing the movement.
3. The surgical footswitch of claim 2 , wherein the eddy current brake mechanism is a brushed direct-current (DC) motor.
4. The surgical footswitch of claim 3 , wherein the eddy current brake mechanism comprises an electrically variable load resistance.
5. The surgical footswitch of claim 1 , further comprising one or more non-rechargeable batteries configured to power the capacitance-sensing controller circuit.
6. The surgical footswitch of claim 5 , wherein the capacitance-sensing controller circuit further comprises a battery sense circuit configured to monitor a voltage level of the one or more non-rechargeable batteries, and wherein the capacitance-sensing controller circuit is configured to relay a low-battery signal to the surgical console, via the wireless interface, responsive to detecting that the monitored voltage level is below a predetermined threshold level.