Linear Amplifier Console for Multi-Handpiece Ultrasonic Drive

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ultrasonic surgical tool systems face limitations in generating drive signals over a wide range of frequencies and voltages, leading to reduced efficiency and the need for multiple consoles, which increases costs and administrative burdens, especially when dealing with handpieces requiring different signal characteristics.

Innovation Solution

A console with a linear amplifier, power supply, and transformer that can rapidly ramp up signal potential, minimizing energy loss and allowing for drive signals to be sourced over a wide frequency and voltage range, using a processor to regulate the signals and maintain optimal transistor operation, ensuring efficient energy transfer to handpieces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional amplifiers are used in ultrasonic consoles, then the console can operate handpieces within a limited frequency and voltage range, but multiple consoles are required to support handpieces with different signal characteristics, increasing costs and administrative burdens

Engineering Contradiction:
Improvecompatibility with different handpiecesVSAvoidnumber of consoles required
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal console design with a linear amplifier that can output drive signals across a wide frequency range (20 kHz to 100 kHz) and voltage range (50 to 1000 volts), allowing a single console to support multiple handpiece types with different signal requirements, eliminating the need for multiple specialized consoles

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

Solution Approach 2:

The linear amplifier dynamically adjusts output signal parameters including frequency, voltage amplitude, and phase to match the specific resonant characteristics of different handpieces, enabling one console to adapt to various handpiece requirements through real-time parameter modification

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If conventional amplifiers with limited bandwidth are used, then the console structure can be simpler, but the ability to provide drive signals over a wide range of frequencies and voltages is restricted

Engineering Contradiction:
Improvedrive signal rangeVSAvoidamplifier structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces conventional switched-mode amplifier electronics with a linear amplifier architecture that uses continuous analog signal processing, providing superior frequency response and voltage control without the bandwidth limitations and switching artifacts of digital or switched-mode approaches

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a feedback control system with sensors that monitor handpiece impedance and resonant frequency, using this information to automatically adjust amplifier output parameters, thereby simplifying the user interface while enabling wide signal range capability

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the console ramps up signal potential slowly, then energy loss is higher and time lag increases, but rapid ramping requires more complex circuitry

Engineering Contradiction:
Improveresponse timeVSAvoidcircuit complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The linear amplifier implements dynamic voltage ramping control that adjusts the rate of signal potential increase based on real-time handpiece impedance measurements, enabling rapid response when needed while maintaining circuit simplicity through adaptive rather than fixed behavior

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent incorporates feedback control where sensors monitor the handpiece operating state and the amplifier adjusts its output ramp rate accordingly, allowing rapid signal buildup when the handpiece is ready while preventing excessive complexity through intelligent control rather than hardware complexity

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

The solution enables efficient operation of ultrasonic handpieces by providing drive signals that match the specific requirements of different handpieces, reducing energy loss and time lag, and allowing for precise tissue removal with minimal administrative and financial burdens.

Implementation Method 1

an ultrasonic surgical tool includes a handpiece that contains at least one piezoelectric driver. A tip is mechanically coupled to the driver and extends forward from the housing or shell in which the driver is disposed. Upon the application of the drive signal to the driver, the driver cyclically expands and contracts. The expansion/contraction of the driver induces a like movement in the tip

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

Other ultrasonic tips remove tissue by inducing cavitation in the tissue and surrounding fluid. Cavitation occurs as a result of the tip head moving back and forth. Specifically, as a result of these vibrations, small cavities form in the fluid located immediately adjacent the tissue. These cavities are very small zones of extremely low pressure. A pressure differential develops between contents of the cells forming the tissue and these cavities. Owing to the magnitude of this pressure differential, the cell walls burst.

Methodology Applied
Scientific EffectCavitation: Cavitation

Implementation Method 3

The power supply applies a DC signal to a center tap of a primary winding of the transformer. The linear amplifier selectively pulls the opposed ends of the transformer primary winding to ground or essentially an open circuit state. This causes an AC signal to develop across the windings. This causes induces an AC signal to appear across the transformer secondary winding.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3294467B1System and method for driving an ultrasonic handpiece with a linear amplifier
Publication Date: 2024.04.10 STRYKER CORP
  • EP3294467B1 patent drawingFigure 1
  • EP3294467B1 patent drawingFigure 2
  • EP3294467B1 patent drawingFigure 3

AI summary

A control console (50) for a powered surgical tool (330). The console includes a transformer (250) that supplies the drive signal to the surgical tool. A linear amplifier (115) with active resistors (162, 184), selectively ties the ends of the transformer primary winding between ground and the open circuit state. Feedback voltages from the transformer windings regulate the resistances of the active resistors.