BREAKTHROUGHS
Microscale Technology Reshapes
Electronics Protection in Implants
The burst of the dot-com bubble earlier this laser-welded titanium can, out of which wires are
decade was devastating to many people. But for fed to a lead.
Proteus Biomedical Inc. it was the catalyst By applying a thin and durable protective
for an unlikely meeting of minds that ultimately layer over the electronic components, Proteus
yielded an unprecedented approach to electronics discovered that electronics could be protected
integration in implantable devices. via a different design approach. “We figured out
“Starting seven years ago, how to deposit the can on the
[the founders of Proteus] chip,” explains Savage. “So
decided to try to really push instead of chips-on-board-in-the technology envelope and can, we can put the can on
address some applications the chip and not increase the
that had always been thought size at all.” Furthermore, this
of as impossible, like putting method enables the chip to be
electronics in leads,” recounts integrated inside the lead.
George Savage, Proteus cofounder Although it has potential
and chief medical officer. applications in neurostimulation,
Upon the burst of the dot- spinal cord stimulation, and
com bubble, Proteus pounced on gastroenterology, ChipSkin
the opportunity to hire suddenly- technology is first being
out-of-work experts with fresh employed in implants engineered
eyes and diverse backgrounds for cardiac resynchronization
in such areas as fiber-optic therapy, which are currently
communications and MEMS in clinical trials. Its use in this
Proteus Biomedical’s tiny ChipSkin
protected electronics add ‘intelligence’ to
technology. “By getting their type of device opens the door to
medical device leads.
skills into the medical context, better patient care, according
we were able to work out the to Savage. He suggests that the
problem, which is how to deposit a biocompatible technology provides added flexibility in terms of how
‘can’ on an otherwise standard chip,” Savage therapies are deployed and the number of electrodes
says. that can be attached to a lead, for example.
The company’s ChipSkin technology is “It really expands the therapy options for
designed to offer an alternative to conventional these patients,” Savage says. “[A physician] can
methods of protecting an implant’s vital electronic change the parameters of therapy without having
components—a crucial design element. Shielding to reoperate on a patient and have to move a lead
an implant’s electronic components from exposure by hand. Also, there’s potential to provide real-to the body’s fluids is essential; failure to do time or near-real-time feedback on how the heart
so can result in corrosion and, ultimately, device is doing.”—Shana Leonard
failure. Protection methods traditionally consist of an implantable device’s integrated circuits being ■ Proteus Biomedical Inc.
REDWOOD CITY, CA
placed on circuit boards and encased in a
www.proteusbiomed.com
Bioresorbable
Polymers Perform
Localized Drug
Delivery
Not only can implants disappear within the
body on schedule, they can now also deliver
drugs at a predetermined rate, thanks to
advances in combination products. Increased
availability of biocompatible materials has
played a significant role in the progress of
these products. Taking these technologies to
the next level is Foster Pharma, part of Foster
Corp., a contract process development and
manufacturing company, that offers custom
Resorbable Delivery formulations.
Foster’s formulations are polymers blended
with pharmaceuticals that are used to create
implantable devices that feature drug-delivery
capabilities. Using advanced melt extrusion
technologies, the polymers are manufactured in
a Class 7 pharmaceutical cleanroom. The melt
extrusion processes ensure dispersion of the
active pharmaceutical ingredient throughout
the polymer matrix. As the materials resorb
into the body, they release the drug.
Polymers blended with active pharmaceuticals offer
localized drug delivery in the form of resorbable implants.
Ultrasonic System Performs
Nondestructive Nitinol Measurements
Nitinol is playing an increasingly prominent
role in the manufacture of medical-grade tubing.
However, because of its unique crystalline
structure, the material has been difficult to measure
accurately. With its UltraGauge+ ultrasonic system,
LaserLinc Inc. hopes to remedy this problem. The
company claims that its system is the first practical
in-process method for performing nondestructive
ultrasonic measurements on nitinol tubing.
The traditional method for measuring material
thickness involves measuring the time that elapses
between a signal reflected from the outer wall of
a material and a signal reflected from the inner
wall. But nitinol’s crystalline structure “causes it
to yield inconsistent and unreliable results [when
it is measured] using traditional ultrasonic wall-thickness measurement techniques,” notes Robert
Wexler, LaserLinc’s communications director.
To overcome this obstacle, LaserLinc discovered
a measurable characteristic that directly correlates
with nitinol thickness and produces repeatable
results. Based on a previous-generation ultrasonic
measurement tool pioneered by Hudson, MA–based
On Line Controls, the UltraGauge+ is equipped with
a digital signal processor that can accommodate up
to eight ultrasonic transducers, enabling continuous
in-process inspection of tubes, hoses, and other
products. In conjunction with a laser scanning
micrometer, UltraGauge+ provides data on the
inside diameter (ID), outside diameter (OD), and
wall thickness of medical-grade tubing.
Medical products are manufactured under
In conjunction with a laser
scanning micrometer, UltraGauge+
provides data on the ID, OD,
and wall thickness of
medical-grade tubing.
tight specifications,
remarks Wexler.
“Slight variations in any of these aspects can
cause the entire production run to be scrapped.
Measuring the ID, OD, and wall thickness [of
tubing] during production enables manufacturers
to monitor as they go and identify problems as they
occur, which minimizes scrap and downtime.”
Along with UltraGauge+, the company offers the
UltraLock wave-analysis procedure, which simplifies
ultrasonic measurement system setup. A component
feature of the company’s Total Vu software,
UltraLock reduces ultrasonic measurements to one
step, automatically sets software parameters to
ensure accurate measurements even if the size of
the product changes during a production run, and
configures the system to measure all the layers of
multilayer products.
Manufacturers of medical-grade tubing made
from plastic, glass, or metals such as nitinol may
benefit from the ultrasonic measurement technique,
according to Wexler. Applications include
guidewires, stents, and catheters. —Bob Michaels
■ LaserLinc Inc.
FAIRBORN, OH
www.laserlinc.com
“Combination products that simultaneously
serve short-term mechanical functions as
biocompatible implants and function as long-term drug-delivery devices is an expansion
on the bioresorbable material technology
that has gained traction in recent years,”
Foster Pharma president Dan Lazas explains.
“Bioresorbable materials are becoming more
acceptable for device designs, and use of them
is crossing over into more segments of the
industry than ever before.”
In addition to producing the blended
polymers in pellets suitable for injection
molding implants, the company can produce
resorbable drug-eluting fibers, rods, and films.
And because they resorb, the need for implant
removal surgery is eliminated. This is a great
benefit to patients, Lazas says.
Benefits of creating these products can also
be seen from both the pharmaceutical and
manufacturing sides. “Localized drug delivery
offered in the form of a drug-eluting implant
can reduce potential adverse events associated
with systemic treatments that can affect areas
of the body that do not require treatment,”
Lazas says. The controlled-release properties
are part of the custom formulation process
along with tailoring the implant degradation
time, tensile strength, and other application-specific characteristics. And because the active
pharmaceutical ingredient is blended within
the polymer, no extra coating processes are
required. —Stephanie Steward
■ Foster Pharma
PUTNAM, CT
www.fostercorporation.com
For more information
and articles on the latest
technologies, go to devicelink.com/mpmn/emergingtech
