PRESSURE SENSING ELECTRIC TOOTHBRUSH

摘要

The toothbrush includes a sensor system for determining pressure on the teeth by a direct force measurement such as displacement, and a system for determining pressure on the teeth by a dynamic load measurement system, such as phase shift. These different pressure results are combined with peak-to-peak bristle motion values of Hall effect output values and compared to a table to obtain a more accurate value of bristle pressure against the teeth and to raise, lower or maintain the trigger threshold of excessive pressure accordingly.

主权项

1. A power toothbrush with a pressure sensor, comprising:
a drive train, responsive to a drive signal, for producing a brushing action in bristles of a brushhead assembly coupled to the toothbrush; a magnet coupled at a rear end of the drive train; a system that includes a Hall-effect sensor for use in determining a direct force measurement of pressure applied against a user's teeth by the bristles of the brushhead assembly, wherein as force is applied to the bristles, the rear end of the drive train pivots, including the magnet, producing a lateral displacement of the magnet in a direction of the Hall-effect sensor; a system that includes another Hall-effect sensor for use in determining a dynamic force measurement of pressure applied against the user's teeth by the bristles of the brushhead assembly, wherein the another Hall-effect sensor detects a change in phase between the drive signal and a mechanical response of the brushhead assembly produced by movement of the magnet as pressure on the bristles changes; and a processing system responsive to the direct force measurement of pressure and the dynamic force measurement of pressure for adjusting a trigger point as either of unchanged or decreased relative to a pre-set trigger point of 300 grams or other set value, wherein the trigger point corresponds to an amount of pressure indicative of an excessive bristle force applied against the user's teeth relative to dynamic loads produced by various portions of a user's mouth.