A monitoring apparatus includes a clip assembly configured to be secured on a patient's digit. The clip assembly houses an accelerometer which measures acceleration in three dimensions. A microcontroller is configured to receive acceleration data from the accelerometer representative of the acceleration measured in each of the three dimensions. A processor is configured to analyze the acceleration data and determine and output a train-of-four ratio based the acceleration measured in each of the three dimensions.

Full Patent: Train-of-Four Measuring Clip