2D Phased Array Ultrasound with Row-Column Electrode Control
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Solution Overview
Problem
Conventional phased array ultrasound devices require complex circuitry and numerous connections to control the delay of transducer elements, leading to high production costs and inefficiencies in creating pressure focus points, particularly for larger arrays.
Innovation Solution
A phased array ultrasound device with a simplified electrode configuration, where each transducer element is connected to a row or column electrode, reducing the number of connections to the array's dimensions, and using PZT ferroelectric piezo material for unipolar actuation to minimize phase jumps and improve pressure focus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional phased array ultrasound devices control delay of each transducer element individually, then pressure focus point can be created, but the number of connections and circuitry complexity increases significantly
Solution Approach 1:
The patent segments the electrode connections into row electrodes and column electrodes, where each row electrode connects to multiple transducer elements along a row, and each column electrode connects to multiple transducer elements along a column. This segmentation reduces the total number of connections from N individual connections to approximately 2√N connections for an N-element array, while still enabling independent delay control of each transducer element through the combination of row and column electrode signals.
Solution Approach 2:
The patent merges the control signals from row electrodes and column electrodes to actuate individual transducer elements. By combining the signals from one row electrode and one column electrode, the system can independently control each transducer element's delay and amplitude, achieving the same functionality as individual connections but with fewer physical connections required.
2Ease of operation
If conventional phased array ultrasound devices use bipolar actuation, then transducer elements can be actuated, but 180-degree phase jumps occur which reduce pressure at focus point
Solution Approach 1:
The patent changes the actuation parameter from bipolar voltage (which can cause 180-degree phase jumps) to unipolar voltage applied to PZT ferroelectric piezo material. The PZT material's hysteresis loop allows it to maintain a consistent polarity relationship between applied voltage and generated mechanical stress, eliminating the 180-degree phase jumps that occur with bipolar actuation of conventional piezoelectric materials. This parameter change ensures that all transducer elements contribute constructively to the pressure focus point.
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 achieves improved pressure focus with reduced connections and eliminates 180-degree phase jumps, enhancing the available pressure at the focus point without additional transistors, thus simplifying production and operation.
Implementation Method 1
each piezoelectric transducer element comprises PZT ferroelectric piezo material located between its associated first electrode and second electrode... when the piezoelectric transducer element is actuated based on a voltage control signal applied to its associated first electrode and second electrode, the PZT ferroelectric piezo material has a deflection actuation curve... the deflection of the PZT ferroelectric piezo material induces a vibration force or an oscillation force onto the piezoelectric transducer element
Implementation Method 2
when a voltage is applied between the two electrodes 73, 74, the piezoelectric layer 72 senses an electric field. Because of its piezoelectric properties, the piezoelectric material, i.e., of the piezoelectric layer (PVDF) 72, expands or contracts when it senses a positive or negative electric field. This vibration of the membrane 71 creates acoustic pressure waves in a fluid above
Implementation Method 3
Creating the pressure focus point can be done by combining the emitted acoustic pressure waves of all individual MUTs in the array... the individual MUTs must have a harmonic vibration, which is more and more delayed as MUTs farther away from the array's center are considered
Data Source
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AI summary
The present invention relates to a phased array ultrasound device. The phased array ultrasound device comprises a plurality of transducer elements arranged in a two dimensional (2D) array; a plurality of first electrodes, each first electrode extending along a first direction; and a plurality of second electrodes, each second electrode extending along a second direction; wherein each transducer element is associated with one first electrode and one second electrode; wherein each transducer element comprises a material located between its associated first electrode and second electrode, and is configured to emit an ultrasonic wave induced by a vibration force or an oscillation force of its material when the transducer element is actuated based on control signals applied to its associated first electrode and second electrode; wherein each transducer element has a unipolar actuation force direction; and wherein the phased array ultrasound device is configured to create a pressure focus point above or below the 2D array by actuating a set of transducer elements to form a combined ultrasonic wave. The pressure focus point may be used to provide a haptic feedback. The present invention also relates to an electronic device comprising a display; and a phased array ultrasound device. The phased array ultrasound device is arranged in or below the display of the electronic device, and is configured to create a pressure focus point above the display.