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Newsletter Jun 2026 | Menu of
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Minus K
Educational Vibration Isolator Giveaway
2022 Winner Research
Project
Optical
Coherence Elastography - Pushing the Boundaries
of Real-Time Strain and
Elasticity Imaging of Biological Tissue
Optical coherence
elastography (OCE) holds great promise for detecting and monitoring the altered
mechanical properties of strain and elasticity with biological tissue that
accompanies many clinical conditions and pathologies, particularly in cancer,
cardiovascular disease and eye disease. Researchers at UC Irvine's Beckman
Laser Institute are pushing the research envelope with OCE application, with
the assistance of Negative-Stiffness vibration isolation.
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Tissue exhibits
varying degrees of viscoelasticity (time-dependent response to a load),
poroelasticity (presence of fluid-filled pores or channels), and anisotropy (a
physical property that has a different value when measured in different
directions), as well as a nonlinear relationship between elasticity and the
applied load.
In establishing the link between elasticity and
displacement, simplifying assumptions are usually made about tissue behavior
and structure. Most commonly, that tissue is approximated as a linear elastic
solid having mechanical properties which have the same value when measured in
different directions (isotropic). Optical coherence elastography (OCE),
however, has permitted a broader understanding regarding strain and elasticity
in biological tissue.
OCE is a non-invasive imaging method for
biological tissue, characterized by its niche in intermediate spatial
resolution of tens to hundreds of micrometers, about one millimeter of depth
penetration, and its high sensitivity to small mechanical changes at the
microstrain level.
Optical Coherence Elastography
Elastography
is a medical imaging technique used to measure tissue deformation under
mechanical loads, enabling the mapping of local mechanical properties. The
resulting images are known as elastograms. The term "elastography" has been in
use since 1979, and significant advancements have been made in the field,
primarily through ultrasound imaging, magnetic resonance imaging, and optical
elasticity imaging.
Optical coherence elasticity imaging, one of the
earliest optical elasticity methods, utilizes optical coherence tomography
(OCT) to detect depth-resolved deformations in samples subjected to
compression.
Displacement measurement plays a crucial role in OCE
techniques, as tissue deformation often reveals essential mechanical
properties. Although traditional OCT provides important diagnostic information,
it is often inadequate for early diagnosis when structural deformations are
minor.
Phase-sensitive detection is a primary method for detecting
tissue deformation, similar to phase-based displacement detection in ultrasound
imaging. This involves processing the phase-sensitive OCT signal to determine
tissue displacement, followed by strain measurement. Compressional OCE
integrates strain data from phase shift with stress applied through compression
loading to calculate the elastic modulus, which characterizes the tissue's
mechanical properties.
OCE presents new possibilities for various
biomedical applications due to its superior resolution and mechanical
sensitivity compared to ultrasound and magnetic resonance elastography. One
particularly promising application lies in the differentiation between
malignant and normal tissues, wherein OCE demonstrates superior contrast
compared to conventional structural OCT imaging. There is a strong interest in
accelerating OCE visualization for intraoperative use. By leveraging
differences in the Young's modulus* of tumor components, OCE can produce images
that closely resemble histological images. Unlike traditional histological
techniques, which are invasive, time-consuming, and labor-intensive, OCE can be
conducted on freshly resected tissue samples and even performed in
vivo.
(*Young's modulus is a measure of
the ability of a material to withstand changes in length when under lengthwise
tension or compression).
OCE Research at UC Irvine's Beckman
Laser Institute
Researchers at UC Irvine's Beckman Laser Institute have
considerable experience with OCE/OCT possibilities.
According to Fengyi
Zhang, Ph.D Graduate Student with the Beckman Laser Institute, "We have focused
on two destinations of OCE: a) Visualization of local movement and strains in
biological tissue; and b) Visualization of elasticity of the tissue with
mechanically produced deformations"
"The OCE technique is operable for a
broad class of sufficiently soft biological tissues, even such tissues as
cartilage," continued Dr. Zhang. "Previously, obtained strain and elasticity
maps for such materials were obtained using mechanical testing. In contrast,
OCE enables imaging in real-time."
In ophthalmology, OCE could be
utilized to characterize the mechanical properties of the cornea to diagnose
related ocular disease. With Dermatology, the elasticity of skin could indicate
related pathologies. OCE technology could detect differences in stiffness of
human skin layers in vivo. Oncological imaging ex vivo of excised tissues from
different sample regions with different stiffness could be highlighted in a 2D
depth-resolved elastogram. To improve management of atherosclerosis, OCE could
be utilized to monitor the stability of plaque by mechanical characterization
of the arterial wall.
Vibration Isolation
Maintaining the
micron-level precision needed for the OCE technique at the Beckman Laser
Institute was compromised due to low-frequency vibrations originating from the
building's air conditioning system, elevator movement and other facility
operations.
"We were using an air table to help reduce these
low-frequency vibrations, but with little success," explained Dr. Zhang. "Our
data sets were being compromised."
"The problem was resolved however,
when our laboratory was awarded a complementary Negative-Stiffness vibration
isolation platform," said Dr. Zhang, in reference to being a winner of Minus
K's Educational Vibration Isolator Giveaway.
Full
article...
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LC-4
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See Weight &
Pricing Details... | |
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Helium-Free Magnetic Refrigeration
Supports Continuous
Milli-Kelvin Temperatures for Quantum
Research
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Cryogenic
characterization is a must to accelerate and enable breakthrough science and
quantum technologies. Quantum sensors, quantum communication devices and future
quantum computers will rely on scalable and efficient cooling for their
operation.
Quantum computers rely on qubits, which can exist in
multiple states simultaneously. These quantum states are extremely fragile and
susceptible to disruption from environmental noise, especially thermal energy.
Many quantum computing approaches, especially those utilizing superconducting
qubits, rely on superconductivity, which occurs at extremely low
temperatures. Cryogenic temperatures, near absolute zero, minimize thermal
fluctuations, allowing qubits to maintain their coherence for longer, enabling
complex quantum computations.
Magnetic refrigeration is emerging as a
promising technology for achieving these conditions. Traditional cryogenic
cooling using liquid helium is expensive and complex, while magnetic
refrigeration offers a potentially simpler, more scalable, and cost-effective
solution.
Magnetic Refrigeration
Magnetic refrigeration aids
in producing extremely low temperatures at almost absolute zero temperature
(called sub-Kelvin temperatures, below -273°C) by using the relationship
between a magnetic field and entropy in certain materials.
Entropy
refers to the disorder or randomness in a material. In magnetic materials, the
entropy is composed of essentially two parts: a) the entropy of the crystalline
structure, where greater entropy means higher temperature due to vibrations of
the crystal lattice; and b) the entropy of the magnetic moments of the
crystalline material. Magnetic moments are a vector quantity that represents
the magnetic strength and orientation of the magnetic object. A collection of
magnetic moments is called a spin system. The way the entropy of this spin
system responds to a magnetic field is at the very core of magnetic
refrigeration.
Here is the process:
Full
article...
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Standard
and Custom Vibration Isolation with Better Performance than Active Systems
Cutting Edge Vibration Isolation for use in...
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