Force-Sensing Personal Care Device Motion Control for Optimal Application

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Solution Overview

Problem

Existing personal care devices lack guidance for users to apply a predetermined optimum force when using the personal care head, leading to inefficiencies and potential misuse.

Innovation Solution

A personal care device equipped with a force sensor that adjusts motion parameters based on applied force, providing visual, audible, or haptic feedback to guide users within an optimal force range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the personal care device starts with high motion intensity, then the working implement is ready for immediate use, but toothpaste is splattered around when not in the oral cavity

Engineering Contradiction:
Improvemotion intensity of working implementVSAvoidtoothpaste splatter
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The control unit is configured to reduce the motion intensity of the working implement during an initial period after activation, before the user places it in the oral cavity. This preliminary low-intensity state prevents toothpaste splatter while the user positions the device, and only after detection of proper placement does the motion intensity increase to the intended operating level.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the personal care device provides real-time force feedback, then user guidance for optimal force application is improved, but device complexity increases

Engineering Contradiction:
Improveuser guidance for force applicationVSAvoiddevice structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The device incorporates a force sensor that detects the force applied by the user and provides real-time feedback to a control unit. The control unit processes this force sensor data and adjusts operating parameters or provides user guidance to ensure optimal force application. This feedback mechanism enables the device to adapt to user input and maintain proper operating conditions without requiring complex mechanical guidance structures.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances user experience by ensuring optimal force application, improving efficiency and reducing misuse, while maintaining effectiveness and comfort.

Implementation Method 1

a force sensor that generates force sensor data from which a force value can be determined indicating a force with which a personal care head of the personal care device is pushed against a treatment surface

Methodology Applied
Scientific EffectForce sensing: Force

Data Source

PatentEP4399996B1Personal care device comprising a force sensor
Publication Date: 2025.08.06 BRAUN GMBH
  • EP4399996B1 patent drawingFigure 1
  • EP4399996B1 patent drawingFigure 2A~2B
  • EP4399996B1 patent drawingFigure 3

AI summary

In accordance with the present disclosure, a personal care device has a personal care head, a force sensor structured and/or arranged for acquiring force sensor data indicative of a force value with which the personal care head is pushed against a treatment surface along at least a first force direction, a processor structured and/or arranged for determining the force value from the force sensor data, a drive unit structured and/or arranged for driving the personal care head into a motion that is characterized by at least one motion parameter being one from the list comprising a speed, an amplitude and a frequency, the motion preferably being an oscillatory rotational motion, and a control unit structured and/or arranged for controlling the motion parameter of the personal care head in dependence on the determined force value such that in a first force value range extending from a first lower force value to a first upper force value the motion parameter is gradually increased from a first motion parameter start value to a first motion parameter end value when the force value increases from the first lower force value to the first upper force value.