Pressure sensing system and method for an electric toothbrush

A pressure sensing toothbrush, comprising:

• a toothbrush body having a handle, a head, and a neck extending between the handle and the head, the head having an upper surface supporting a plurality of cleaning elements, the toothbrush body defining an internal cavity;
• a substrate within the internal cavity, the substrate defining an upper surface and a lower surface opposite the upper surface, a first end and a second end, wherein the first end is closer to the head and the second end is closer to the handle, the substrate including a contact arm extending from the substrate, the contact arm having a contact surface;
• a sensor contact spaced from the contact surface of the contact arm;
• a power source within the internal cavity;
• and a signal element on the toothbrush body;
• wherein a force on the upper surface of the head causes the substrate to flex from an unflexed state to a flexed state, and wherein the flexing of the substrate to the flexed state moves the contact surface of the contact arm toward the sensor contact, and upon the amount of the force reaching a predetermined threshold, the substrate is flexed to a threshold flexed state, wherein the contact surface contacts the sensor contact and completes an electrical connection between the sensor contact, the power source, the contact surface of the contact arm, and the signal element, thereby activating the signal element;
• wherein the contact arm is centrally disposed within an opening defined in the substrate.

A pressure sensor for a toothbrush, the toothbrush having a toothbrush body including a head, a handle, and a neck between the head and the handle, the toothbrush body defining an internal cavity extending through at least a portion of the handle and the neck, the pressure sensor comprising:

• a printed circuit board disposed within the internal cavity, the printed circuit board including a contact arm having a base end connected to the printed circuit board and a free end opposite from the base end and unconnected to the remainder of the circuit board;
• a power source within the internal cavity;
• a signal element mounted on the circuit board and connected to the power source;
• a sensor contact mounted on the circuit board adjacent to the free end of the contact arm;
• wherein the printed circuit board is positioned such that a force on the head of the toothbrush in a first direction flexes the printed circuit board and moves the contact arm in an opposite direction between an unflexed position in which the contact arm is spaced from the sensor contact, and a flexed position in which the contact arm moves toward the sensor contact, and when the amount of the force on the head reaches a predetermined threshold, the contact arm is moved to a threshold flexed position in which the contact arm contacts the sensor contact to complete a circuit between the power source and the signal element to activate the signal element
• wherein the free end is spaced from the remainder of the substrate, the free end positioned adjacent to the sensor contact, wherein the free end is flexed and separates away from the remainder of the substrate to contact the sensor contact when the substrate is in the threshold flexed state.