Medical Design Briefs - June 2023 - 22

Fighting Cancer
pability, and ease of adaptability to hospital
and laboratory environments. "
Negative-stiffness vibration isolation
was developed by Minus K Technology, an
OEM supplier to manufacturers of scanning
probe microscopes, micro-hardness
testers, and other vibration-sensitive instruments
and equipment (see Figure 1).
These vibration isolators are compact and
do not require electricity or compressed
air, which enables sensitive instruments to
Dynamic cell imaging
Breast tissue - Cancerous with 2 subtypes of cancer
be located wherever they are needed.
There are no motors, pumps, or chambers,
and no maintenance because there
is nothing to wear out. They operate purely
in a passive mechanical mode.
What is very advantageous about negative-stiffness
isolators is that they achieve
a high level of isolation in multiple directions.
These isolators have the flexibility
of custom tailoring resonant frequencies
to 0.5 Hz vertically and horizontally (with
Nest of
cancer cells
Isolated
cancer cells
in stroma
some versions at 1.5 Hz horizontally).
(Note that for an isolation system with a
0.5 Hz natural frequency, isolation begins
at 0.7 Hz and improves with increase
in the vibration frequency. The natural
frequency is more commonly used to describe
the system performance.)
Vertical-motion isolation is provided
by a stiff spring that supports a weight
load, combined with a negative-stiffness
mechanism. The net vertical stiffness is
made very low without affecting the static
load-supporting capability of the
spring. Beam-columns connected in series
with the vertical-motion isolator provide
horizontal-motion isolation. A
beam-column behaves as a spring combined
with a negative-stiffness mechanism.
The result is a compact passive isolator
capable of very low vertical and
horizontal natural frequencies and high
internal structural frequencies. "
Negative-stiffness isolators deliver very
high performance, as measured by a
transmissibility curve. Vibration transmissibility
is a measure of the vibrations
that are transmitted through the isolator
relative to the input vibrations. Negativestiffness
isolators, when adjusted to 0.5
Hz, achieve approximately 93 percent
isolation efficiency at 2 Hz; 99 percent at
5 Hz; and 99.7 percent at 10 Hz.
1.2 mm
Dynamic cell imaging of cancerous breast tissue with two subtypes of cancer - nested cancer cells and isolated
cancer cells in stroma. (Credit: Aquyre Biosciences)
Top Plate
Tilt Pad
Upper Column Plate
Vertical
Negative-Stiffness
Flexures
Rigid Support
Beam-Column
Support Tube
(Threaded)
Base
Leveling Screw
Gear
Lower Column PlateSupport Shaft
Fig. 1 - Schematic of a negative-stiffness isolator. (Credit: Minus K Technology)
22
Clamp
Vertical Stiffness
Adjustment Screw
Compression Spring
Support Spring
Flexible Support
Worm
Vertical Load
Adjustment Screw
Better Image Quality
Celtivity's technology is the sole technique
providing axial resolution of 1
µm, which gives the highest quality image
clarity and precision. It enables image
capture on a 1 cm² region of tissue in
one minute, thereby enabling immediate
quality control of biopsies.
Full-field optical coherence tomography
and dynamic cell imaging produce
real-time images showing tissue architecture
and intracellular activity data
without sample processing or staining,
and no need for dyes, contrast agents or
tissue freezing.
This article was written by Jim McMahon,
who writes on industrial, manufacturing,
and technology issues. For more
information on negative-stiffness isolators,
contact Steve Varma, Minus K Technology,
Inc.; Phone 310-348-9656; Fax
310-348-9638; e-mail sales@minusk.
com; www.minusk.com. For more information
about Aquyre Biosciences, contact
Bertrand Le Conte de Poly, CEO;
Phone +33 1 78 96 50 00; e-mail info@
aquyre.com; www.aquyre.com.
www.medicaldesignbriefs.com
Medical Design Briefs, June 2023

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Medical Design Briefs - June 2023

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