Lensfree method for imaging biological samples in three dimensions

A device for three-dimensional imaging of a sample, said device comprising:

• at least one light source configured to illuminate a sample from a plurality of different angles;
• at least one image sensor, each comprising an array of light-detecting elements for detecting incident light, wherein the at least one image sensor is configured to acquire a plurality of interference patterns, wherein each interference pattern is formed by scattered light scattered from the sample in three dimensions and non-scattered light from the light source and each interference pattern is acquired for a different angle between the sample and the light source, wherein the plurality of interference patterns includes at least four interference patterns;
• a processing unit configured to determine a scattering potential of the sample measured in each of three dimensions based on the received interference patterns and apply an iterative algorithm to change the three-dimensional scattering potential of the sample by calculating a data fidelity term representing a difference between the acquired interference patterns represented by a measured amplitude of an optical field forming the interference patterns and predicted interference patterns based on the determined three-dimensional scattering potential formed by a light propagation model that maps the three-dimensional scattering potential of the sample to a scattered optical field in a sensor plane of the light-detecting elements and an incident optical field from the light source which is superposed with the scattered optical field to form the predicted interference patterns, wherein the iterative algorithm reduces a sum of the data fidelity term and a non-differentiable regularization term and wherein the iterative algorithm includes a forward-backward splitting method alternating between forward gradient descent on the data fidelity term and backward gradient descent on the regularization term;
• a processing unit configured to perform digital holographic reconstruction on the acquired interference patterns based on the application of the iterative algorithm;
• and
• a reconstructing unit configured to reconstruct a three-dimensional image representation of the sample based on the digital holographic reconstruction.

A method for three-dimensional imaging of a sample, said method comprising:

• receiving a plurality of interference patterns acquired using light-detecting elements for detecting incident light, wherein each interference pattern is formed by scattered light scattered from the sample in three dimensions and non-scattered light from a light source interfering at the light-detecting elements for acquisition by the light-detecting elements, and wherein the interference patterns are acquired using different angles between the sample and the light source, wherein the plurality of interference patterns includes at least four interference patterns;
• determining a scattering potential of the sample measured in each of three dimensions based on the received interference patterns;
• applying an iterative algorithm to change the three-dimensional scattering potential of the sample by calculating a data fidelity term representing a difference between the received interference patterns represented by a measured amplitude of an optical field forming the interference patterns and predicted interference patterns based on the determined three-dimensional scattering potential formed by a light propagation model that maps the three-dimensional scattering potential of the sample to a scattered optical field in a sensor plane of the light-detecting elements and an incident optical field from the light source which is superposed with the scattered optical field to form the predicted interference patterns, wherein the iterative algorithm reduces a sum of the data fidelity term and a non-differentiable regularization term and wherein the iterative algorithm includes a forward-backward splitting method alternating between forward gradient descent on the data fidelity term and backward gradient descent on the regularization term;
• and
• performing digital holographic reconstruction on the received interference patterns based on applying the iterative algorithm.

A device for three-dimensional imaging of a sample, said device comprising:

• at least one light source configured to illuminate a sample from a plurality of different angles;
• at least one image sensor, each comprising an array of light-detecting elements for detecting incident light, wherein the at least one image sensor is configured to acquire a plurality of interference patterns formed at the at least one image sensor, wherein each interference pattern is formed by scattered light scattered from the sample in three dimensions and non-scattered light from a light source interfering at the light-detecting elements for acquisition by the at least one image sensor, wherein the plurality of interference patterns includes at least four interference patterns;
• and
• a processing unit configured to determine a scattering potential of the sample measured in at least three dimensions based on the received interference patterns and apply an iterative algorithm to change the three-dimensional scattering potential of the sample by calculating a data fidelity term representing a difference between the acquired interference patterns represented by a measured amplitude of an optical field forming the interference patterns and predicted interference patterns based on the determined three-dimensional scattering potential formed by a light propagation model that maps the three-dimensional scattering potential of the sample to a scattered optical field in a sensor plane of the light-detecting elements and an incident optical field from the light source which is superposed with the scattered optical field to form the predicted interference patterns, wherein the iterative algorithm reduces a sum of the data fidelity term and a non-differentiable regularization term and wherein the iterative algorithm includes a forward-backward splitting method alternating between forward gradient descent on the data fidelity term and backward gradient descent on the regularization term;
• and
• a processing unit configured to perform digital holographic reconstruction on the acquired interference patterns based on the application of the iterative algorithm.