3D Imaging via Iterative Slice Wavefield Propagation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating three-dimensional images of objects, such as those described in WO 2008/142360, are compromised by Fresnel-type fringes and do not account for multiple scattering effects, leading to incomplete or distorted image reconstructions.
Innovation Solution
The method involves determining illumination wave fields at multiple slices of an object, propagating exit waves through these slices, and using a summation plane to combine and correct diffraction patterns, allowing for iterative updates of object estimates that account for interactions and scattering between planes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If iterative phase-retrieval methods are used to determine object estimates from diffraction patterns, then three-dimensional image data can be obtained, but Fresnel-type fringes from adjacent planes complicate the images and multiple scattering effects are not accounted for
Solution Approach 1:
The object is divided into multiple discrete planes or slices along the propagation direction. Each plane is processed independently to determine its transmission function, allowing the complex three-dimensional reconstruction problem to be broken down into manageable two-dimensional problems that can be solved iteratively without interference from adjacent planes
Solution Approach 2:
An iterative feedback mechanism is implemented where the estimated transmission functions of multiple planes are used to calculate expected diffraction patterns, which are then compared with measured patterns. The discrepancy information feeds back to update the transmission function estimates, progressively improving accuracy while accounting for multiple scattering effects between planes
2Device complexity
If simple iterative processes are used to construct object estimates at each plane, then computational complexity is reduced, but multiple scattering effects and interactions between planes are not considered
Solution Approach 1:
The object volume is segmented into multiple discrete planes, allowing the complex three-dimensional multiple scattering problem to be decomposed into a series of coupled two-dimensional problems. This segmentation enables manageable computational complexity while preserving the physical interactions between different depth layers through the propagation of wavefields between planes
Solution Approach 2:
The method maintains continuous updating of transmission function estimates across all planes through an iterative process that propagates wavefields sequentially through each plane. This continuous action ensures that multiple scattering effects are progressively accounted for without requiring prohibitively complex single-step calculations
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 approach enables the generation of accurate three-dimensional image data by considering interactions between planes and multiple scattering effects, resulting in improved image quality and accuracy.
Implementation Method 1
incident radiation falls upon a target object and scatters as it transmits through the object
Implementation Method 2
an exit wave from each of the slices is propagated to a subsequent slice of the object and/or to a plane of a detector
Implementation Method 3
an estimate of a diffraction pattern is determined at a plane of a detector
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of providing image data for constructing an image of a region of a three dimensional target object, comprising providing, from a radiation source, incident radiation directed at a target object, detecting an intensity of radiation scattered by the target object, and determining image data for each of a respective plurality of slices within the target object each indicating one or more characteristics of the target object at a respective depth within the target object, wherein the image data is determined based on the detected intensity of radiation via an iterative process wherein running estimates of the image data for each of the plurality of slices are updated step by step.