Wavefield finite time focusing with reduced spatial exposure.

Area of Science:

• Acoustics
• Wave propagation
• Computational physics

Background:

• Wavefield focusing is crucial for applications like medical imaging and non-destructive testing.
• Traditional time-reversal mirrors (TRM) require infinite signals and lead to extensive wave propagation.
• Existing single-sided methods, while using finite input signals, still produce infinite output signals.

Purpose of the Study:

• To develop an alternative double-sided wavefield focusing method.
• To achieve wavefield focusing with finite input and output signals.
• To reduce the energy of propagating waves compared to TRM.

Main Methods:

• Derivation of a new integral representation for double-sided wavefield focusing.
• Utilizing finite time signals for both input and output.
• Numerical simulations using a heterogeneous head model (skull and brain).

Main Results:

• The proposed method successfully achieves double-sided wavefield focusing.
• Both input and output signals are finite in time.
• Wave energy propagation within the focal region is significantly reduced compared to TRM.

Conclusions:

• The novel double-sided focusing method offers an efficient alternative to TRM.
• Finite signal requirements and reduced wave energy propagation enhance practical applicability.
• Demonstrated potential in complex heterogeneous media, such as biological tissues.