RF Skin Treatment Control Using Forward and Reverse Voltage

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Solution Overview

Problem

Existing RF treatment devices fail to accurately measure skin impedance in real-time due to the neglect of reverse RF energy reflections, leading to insufficient or excessive energy delivery, which can cause tissue damage.

Innovation Solution

A skin treatment device that measures both forward and reverse RF voltages to calculate skin impedance and RF output power efficiency, using a directional power coupler and digital signal processing to adjust RF energy output based on these measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a method for calculating impedance by measuring current and voltage when RF energy is applied is used, then the measurement process is simple, but the impedance calculation is inaccurate because reverse RF energy reflections are not considered

Engineering Contradiction:
Improvemeasurement process simplicityVSAvoidimpedance calculation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces a feedback mechanism by measuring both forward and reverse RF voltages using a directional coupler. The reverse voltage signal, which represents energy reflected from the skin tissue, is fed back to the controller to calculate reflection coefficient and improve impedance accuracy. This feedback loop enables the system to account for tissue impedance variations in real-time.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs a directional coupler as an intermediary device between the RF generator and the electrode. This coupler separates and measures the forward and reverse voltage components independently, allowing accurate calculation of the reflection coefficient without directly interfering with the RF energy delivery to the tissue.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If RF energy is delivered without considering skin impedance characteristics, then the treatment process is straightforward, but insufficient or excessive energy is delivered causing suboptimal treatment or tissue damage

Engineering Contradiction:
Improvetreatment process simplicityVSAvoidtreatment safety and effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system continuously monitors forward and reverse RF voltages and calculates skin impedance in real-time. Based on the calculated impedance and reflection coefficient, the controller dynamically adjusts RF output parameters (power, frequency, pulse duration) to deliver optimal energy levels tailored to each patient's skin characteristics, preventing both under-treatment and tissue damage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements dynamic adjustment of RF treatment parameters based on real-time impedance measurements. The system adapts treatment conditions during the procedure by modifying power output, frequency, and pulse duration according to the measured skin impedance characteristics, ensuring optimal and safe treatment delivery.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If real-time measurement of forward and reverse RF voltages is implemented, then accurate skin impedance and power efficiency are obtained, but the device complexity increases

Engineering Contradiction:
Improveskin impedance measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The directional coupler serves as an intermediary that passively separates forward and reverse voltage signals without requiring complex active measurement circuits. This passive coupling approach simplifies the overall system architecture while enabling accurate bidirectional voltage measurement for impedance calculation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The controller integrates multiple functions including RF power generation, forward and reverse voltage measurement processing, impedance calculation, reflection coefficient determination, and dynamic parameter adjustment. This multi-functional integration reduces the need for separate dedicated components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables accurate, real-time control of RF energy delivery based on user-specific skin impedance and power efficiency, preventing tissue damage and ensuring optimal treatment.

Implementation Method 1

a measurement unit for measuring a forward RF voltage caused by the RF energy and a reverse RF voltage caused by the RF energy reflected to the RF generator

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

a radio frequency (RF) generator for generating RF energy; an electrode for transmitting the RF energy to a skin tissue of a user

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 3

The RF treatment method uses the principle that when a RF current is supplied to the tissues through an electrode, electrical energy flowing through the tissues is converted into heat energy and the energy is transferred to the tissue

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Data Source

PatentEP4667048A1Skin treatment device and control method therefor
Publication Date: 2025.12.24 VIOL CO LTD
  • EP4667048A1 patent drawingFigure 1
  • EP4667048A1 patent drawingFigure 2
  • EP4667048A1 patent drawingFigure 3

AI summary

A skin treatment device according to the present disclosure includes: a radio frequency (RF) generator for generating RF energy; an electrode for transmitting the RF energy to a skin tissue of a user; a measurement unit for measuring a forward RF voltage caused by the RF energy and a reverse RF voltage caused by the RF energy reflected to the RF generator; and a controller for calculating skin impedance of the user and RF output power efficiency based on the measured forward RF voltage and reverse RF voltage, and controlling outputs of the RF generator based on the calculated skin impedance and RF output power efficiency.