Abstract: A gearbox assembly for an actuator is provided. The gearbox assembly includes a rack, a spur pinion, a bevel pinion, and a bevel gear. Vertical translation of the rack causes rotation of the spur pinion and bevel pinion around a horizontal axis. The rotation of the bevel pinion causes rotation of the bevel gear around a vertical axis. The gearbox assembly may be coupled to a movable member of a valve so that actuation of the gearbox assembly moves the movable member. Systems including the gearbox assembly and methods of operation are also disclosed.

Abstract: Generally described, one or more embodiments of the present disclosure are directed to pulse oximeter test instruments for testing pulse oximeters. The pulse oximeter test instruments are configured to linearize a relationship between an input signal and an output signal of a light emitting diode (LED). In some embodiments, the linearized relationship may be obtained by minimizing an amount of ambient light detected by a photosensor in a feedback loop. The photosensor may be located in a housing that limits the amount of ambient light that may be detected.

Abstract: Generally described, one or more embodiments of the present disclosure are directed to pulse oximeter test instruments and methods for testing pulse oximeters. The pulse oximeter test instruments may be configured to sense light at different wavelengths simultaneously. In some embodiments, light pulses having a wavelength above a particular threshold may be detected and used to test measurements made by a pulse oximeter. In that regard, the pulse oximeter test instruments disclosed herein are able to provide improved accuracy and more reliable test results over prior art pulse oximeter test instruments.

Abstract: Generally described, one or more embodiments of the present disclosure are directed to pulse oximeter test instruments for testing pulse oximeters. The pulse oximeter test instruments are configured to linearize a relationship between an input signal and an output signal of a light emitting diode (LED). In some embodiments, the linearized relationship may be obtained by minimizing an amount of ambient light detected by a photosensor in a feedback loop. The photosensor may be located in a housing that limits the amount of ambient light that may be detected.

Abstract: A gearbox assembly for an actuator is provided. The gearbox assembly includes a rack, a spur pinion, a bevel pinion, and a bevel gear. Vertical translation of the rack causes rotation of the spur pinion and bevel pinion around a horizontal axis. The rotation of the bevel pinion causes rotation of the bevel gear around a vertical axis. The gearbox assembly may be coupled to a movable member of a valve so that actuation of the gearbox assembly moves the movable member. Systems including the gearbox assembly and methods of operation are also disclosed.