Variable-Focus Lens Assembly for Deep Brain Imaging

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Solution Overview

Problem

Current multiphoton and confocal fiber-coupled imaging devices face challenges such as large optical scanning footprints, limited collection efficiency, and resolution, which restrict their ability to perform high-resolution deep brain imaging beyond 2 mm from the brain surface.

Innovation Solution

The development of an optical imaging device featuring a flexible lightguide with a variable-focus lens assembly, enabling high-speed axial focusing without mechanically moving parts. This device includes a photodetector for detecting radiation and uses electrowetting technology to tune the focal length of the lens element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If mechanical actuators are used for axial scanning, then focusing capability is achieved, but device size and complexity increase

Engineering Contradiction:

Improveaxial focusing speedVSAvoidmechanical actuator complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent replaces mechanical actuators with an electrowetting-based optical system. The electrowetting lens element uses electrical signals to change the curvature of a liquid-liquid interface, thereby adjusting focal length without any mechanical moving parts. This substitution eliminates mechanical complexity while achieving high-speed axial focusing through electrical control of the liquid lens curvature.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the optical parameters of the lens system by using an electrowetting lens element whose focal length can be dynamically adjusted through electrical voltage application. By changing the electrical parameters (voltage) applied to the electrowetting lens, the focal length is modified, enabling axial scanning without mechanical movement. This parameter change approach allows rapid focusing while keeping the device compact.

Inventive Principle:

Principle #35Parameter changes

2Volume of moving object

If miniaturized scanners are used, then device size is reduced, but collection efficiency and resolution are limited

Engineering Contradiction:

Improvedevice volumeVSAvoidimaging resolution

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent replaces miniaturized mechanical scanners with an electrowetting-based optical scanning system. The electrowetting lens element, controlled by electrical signals, achieves axial scanning without mechanical components. This substitution maintains a compact device volume while preserving high imaging resolution through precise electrical control of the liquid lens curvature, avoiding the resolution limitations inherent in miniaturized mechanical systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If fixed focal depth imaging is used, then device simplicity is maintained, but imaging flexibility is reduced

Engineering Contradiction:

Improveimaging depth flexibilityVSAvoidoptical system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements variable focal depth imaging by using an electrowetting lens element whose focal length can be dynamically changed through electrical voltage application. This allows the system to adapt to different imaging depths and targets without mechanical adjustment mechanisms. The electrical control of the liquid lens parameters provides imaging flexibility while keeping the overall optical system relatively simple and compact.

Inventive Principle:

Principle #35Parameter changes

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 high-resolution imaging with a sub-cellular resolution laterally and axially, and an axial scan range of up to 80 μm, allowing for detailed visualization of neural networks deep within the brain without the need for mechanical actuators.

Implementation Method 1

the lens assembly includes an electrowetting lens element, the electrowetting lens element having a tunable focal length

Methodology Applied

Scientific EffectElectrowetting: Electrowetting

Implementation Method 2

focusing the radiation on or in the sample

Methodology Applied

Scientific EffectFocusing: Focusing

Data Source

PatentUS20250102789A1Optical imaging devices and variable-focus lens elements, and methods for using them

Publication Date: 2025.03.27 THE REGENTS OF THE UNIV OF CO A BODY CORP

AI summary

The present disclosure relates optical imaging devices and methods useful in biological and medical imaging applications. In one embodiment, an optical imaging device includes a flexible lightguide having a first end and a second end, the output of the source of pulsed infrared radiation being optically coupled to the first end of the flexible lightguide; a lens assembly attached to and optically coupled to the second end of the flexible lightguide, the lens assembly comprising a variable-focus lens element, the a variable-focus lens element having a tunable focal length; and a photodetector coupled to the flexible lightguide to detect radiation propagating from the second end toward the first end of the flexible lightguide. The optical imaging devices and methods can be used in both confocal and multi-photon techniques.