cMUT Ultrasonic Probe Ground Layer Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultrasonic probes using cMUT technology face insufficient electric safety for subjects due to the upper electrode not being at ground potential, which can lead to electrical hazards.
Innovation Solution
Incorporating a conductive film as a ground layer on the ultrasonic wave radiation side of the cMUT chip, connected to the acoustic lens and housing, ensures the ultrasonic probe operates at ground potential, enhancing electric safety by forming a closed ground potential space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a DC voltage is applied to the lower electrode as bias voltage and AC high frequency voltage is applied to the upper electrode as driving signal, then the ultrasonic transducer can transmit and receive ultrasonic waves, but the upper electrode is not at ground potential which causes insufficient electric safety for the subject
Solution Approach 1:
The patent applies the equipotentiality principle by connecting the upper electrode to ground potential through a ground layer. This ensures that the upper electrode, which was previously at floating potential, is now maintained at ground potential (0V), eliminating the electrical hazard to the subject while preserving the ultrasonic transducer's functionality through proper bias and driving voltage application to the lower electrode
Solution Approach 2:
The patent introduces a ground layer as an intermediary element between the upper electrode and the ground potential. This ground layer serves as a mediator that provides a safe electrical reference potential to the upper electrode without interfering with the ultrasonic wave transmission and reception functions of the cMUT chip
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 implementation of a conductive film as a ground layer significantly improves the electric safety of the ultrasonic probe, preventing electrical shocks and ensuring the ultrasonic probe's electromagnetic waves do not harm external devices or subjects.
Implementation Method 1
The cMUT is a super-minute capacity type ultrasonic wave transducer manufactured using a semiconductor microfabrication process. In the cMUT, an ultrasonic wave transmitting/receiving sensitivity, in other words, electromechanical coupling coefficient changes depending on the magnitude of a bias voltage.
Implementation Method 2
an acoustic lens provided on an ultrasonic wave radiation side of said cMUT chip
Implementation Method 3
a backing layer provided on a back side of said cMUT chip and absorbing a propagation of said ultrasonic wave
Data Source
AI summary
An ultrasonic probe (2) comprises a cMUT chip (20), which has a plurality of vibration elements whose electromechanical coupling coefficient or the sensitivity changes depending on a bias voltage, and transmits/receives an ultrasonic wave; an acoustic lens (26) provided on the ultrasonic wave radiation side of the cMUT chip (20); a backing layer (22) provided on the back side of the cMUT chip (20) for absorbing propagation of the ultrasonic wave; an electric wiring portion (flexible substrate (72)), which is provided from the peripheral portion of the cMUT chip (20) to the side face of the backing layer (22) and has a signal pattern connected with the electrode of the cMUT chip (20) arranged thereon; and a housing (ultrasonic probe cover (25)) for containing the cMUT chip (20), the acoustic lens (26), the backing layer (22) and the electric wiring portion (flexible substrate (72)). A ground layer (conductive film (76)) of ground potential is provided on the ultrasonic wave radiation side of the cMUT chip (20).