Piezoelectric Pump Driving Circuit for Negative Pressure Therapy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current negative pressure wound therapy (NPWT) systems consume excessive power and lack efficient control mechanisms for generating and managing negative pressure, which can lead to suboptimal wound healing outcomes.
Innovation Solution
The development of a NPWT apparatus that utilizes a piezoelectric pump or micropump as a negative pressure source, integrated with a coupling circuit and driving circuit, including an inductive reactance to limit the rate of change of the driving signal, allowing for the conversion of electrical energy to mechanical energy without magnetic energy conversion, and a controller for pulse width modulation of the driving signal, optimizing power consumption and pressure application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional negative pressure wound therapy systems use traditional motors or pumps to generate negative pressure, then negative pressure can be generated, but power consumption is excessive
Solution Approach 1:
The patent replaces traditional motor-driven pumps with a piezoelectric pump that converts electrical energy directly to mechanical motion through piezoelectric actuation. This substitution eliminates the need for magnetic field conversion and intermediate mechanical components, significantly reducing power consumption while maintaining negative pressure generation capability
Solution Approach 2:
The patent changes the operating parameters by using high-frequency low-power electrical signals to drive the piezoelectric pump instead of traditional low-frequency high-power motor signals. The piezoelectric actuator responds to voltage changes by expanding and contracting, creating the pumping action needed for negative pressure generation with minimal energy consumption
2Speed
If traditional driving circuits supply electrical signals directly to piezoelectric actuators, then the actuators can respond quickly, but the rate of change of the driving signal causes excessive power consumption and potential damage
Solution Approach 1:
The patent employs periodic square wave signals with controlled duty cycles to drive the piezoelectric actuator. By using periodic action with optimized timing, the system achieves reliable actuator response while allowing the piezoelectric material to complete its expansion and contraction cycles efficiently, reducing overall power consumption
Solution Approach 2:
The patent implements a coupling circuit with inductive reactance that acts as a buffer between the driving circuit and the piezoelectric actuator. This circuit limits the rate of change (dV/dt) of the driving signal, preventing excessive current spikes and reducing power consumption while still enabling the actuator to respond quickly enough for effective negative pressure generation
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
This solution reduces power consumption and enhances the efficiency of negative pressure generation, promoting faster wound healing by optimizing pressure application and minimizing tissue edema, bacterial load, and promoting granulation tissue formation.
Implementation Method 1
The actuator can generate negative pressure by converting the electrical energy to the mechanical energy without converting the electrical energy to a magnetic energy. The source of negative pressure can include a piezoelectric pump, and the actuator can include a piezoelectric transducer.
Implementation Method 2
The coupling circuit limits a rate of change over time of the driving signal supplied from the driving circuit to the actuator. The inductive reactance can be greater than 5 mΩ at an operating frequency of 1 kHz. The coupling circuit includes an inductor electrically coupled in series between an output of the driving circuit and an input of the actuator.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Embodiments of negative pressure wound therapy systems and methods are disclosed. In one embodiment, an apparatus includes a source of negative pressure, a coupling circuit, a driving circuit, and a controller. The driving circuit supplies a driving signal to the source of negative pressure via the coupling circuit to cause the source of negative pressure to provide negative pressure to a wound dressing. The coupling circuit includes an inductive reactance that limits a rate of change over time of the driving signal. The controller controls the driving signal supplied by the driving circuit.