Replaceable Callus Abrasion Rotor for Safer Hygienic Use

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Solution Overview

Problem

Existing callus removal methods using conventional scalpels or handheld devices with fixed blades pose a high risk of injury, require complex construction, are difficult to maintain, and compromise hygiene due to blade contamination and replacement complexity.

Innovation Solution

A handheld device with a replaceable rotor and stator design, featuring a motor-driven shaft, allows for easy blade replacement without direct contact, and includes a detachable stator for improved hygiene and reduced risk of injury, with motor speeds up to 10,000 RPM for efficient callus removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a reduction gear is used to reduce motor speed from 40,000 RPM to 10,000 RPM, then overheating of the rotor is prevented, but the device complexity increases and reliability decreases due to additional transmission mechanism components

Engineering Contradiction:
Improverotor temperatureVSAvoidtransmission mechanism complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The invention extracts and removes the reduction gear from the system. Instead of using a motor that operates at 40,000 RPM with a reduction gear to achieve 10,000 RPM, the patent directly uses a motor designed to operate at 10,000 RPM, eliminating the transmission mechanism entirely while maintaining the desired rotor speed and preventing overheating.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the motor speed parameter from 40,000 RPM (with reduction gear) to 10,000 RPM (direct drive). This parameter change eliminates the need for speed reduction while maintaining the optimal operating temperature of the rotor, thereby simplifying the device structure and improving reliability.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If blades are attached to the rotor using screw connections, then blade replacement is possible, but the ease of operation deteriorates due to time-consuming screw loosening and increased injury risk during blade changes

Engineering Contradiction:
Improveblade replaceabilityVSAvoidblade replacement ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The invention adopts a disposable rotor design where the entire rotor assembly (including blades) is replaced as a single unit. This eliminates the need for screw connections and individual blade replacement, making the process simple and safe. The low cost of the disposable rotor makes this economically viable.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention merges the blades and rotor into a single integrated assembly that is replaced together. This combination eliminates the intermediate fastening components (screws) and simplifies the replacement process to a single insertion/removal action, significantly improving ease of operation and reducing injury risk.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the rotor is cleaned when changing blades, then hygiene requirements are met, but the loss of time increases due to additional cleaning steps required for multiple patient use

Engineering Contradiction:
Improvehygiene complianceVSAvoidblade replacement time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention uses a disposable rotor that is discarded after a single use or single patient treatment. This eliminates the need for cleaning and sterilization steps, as each new patient receives a fresh, sterile rotor. The low cost of the disposable rotor makes this time-saving approach economically viable while maintaining high hygiene standards.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Device complexity

If conventional scalpels or fixed blade devices are used for callus removal, then the device complexity is reduced, but the object-affected harmful factors increase due to high risk of injury and cuts

Engineering Contradiction:
Improvedevice structure simplicityVSAvoidinjury risk
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The invention transitions from static fixed blades to dynamic rotating blades. The rotor spins at 10,000 RPM, creating a controlled cutting action that reduces the risk of injury compared to manual scalpel use. The rotation provides consistent cutting pressure and reduces the likelihood of slips or accidental cuts.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention uses a standardized rotor design with precisely engineered blades that replicate optimal cutting geometry. This standardized design ensures consistent, safe performance across multiple units while maintaining simplicity in the overall device structure.

Inventive Principle:
Principle #26Copying

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

The device ensures safe, hygienic, and efficient callus removal with reduced risk of injury and enhanced flexibility, as the rotor can be easily replaced and cleaned, minimizing the need for complex maintenance and reducing contamination risks.

Implementation Method 1

handheld device for abrasion of callus

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 2

layers of the callus are scraped away

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4696188A1Hand-held device for abrasion of callus
Publication Date: 2026.02.18 NWT MANAGEMENT GMBH
  • EP4696188A1 patent drawingFigure 1A~1B
  • EP4696188A1 patent drawingFigure 2A~2B
  • EP4696188A1 patent drawingFigure 3

AI summary

The invention relates to a handheld device for removing calluses, comprising a housing, a rotor, and a stator. A motor with a drive shaft is arranged in the housing of the handheld device. The rotor also has two blades and can be attached to the drive shaft of the motor. According to the invention, the rotor is attached to the drive shaft of the housing, and the stator is attached to the rotor. The stator is then secured to the housing. Advantageously, the rotor of the handheld device is replaceable. The invention further includes a rotor for use in a handheld device for removing calluses. The rotor has a cylindrical body and two blades. The cylindrical body has an axial bore for receiving a drive shaft and two receiving devices, each of which can hold a blade.