100% Positive Material Identification

From the Wire (continued)
SMALLER, SMARTER AND EFFECTIVE
Miniaturising growth is the way we work at Valtronic. The
size, weight and volume are considered when developing and
manufacturing active implants and other medical devices.
When it comes to making implantable medical devices, size
begins to get smaller and smarter, bringing challenges to advanced
circuitry and encapsulation.
Both titanium and titanium alloys have been the materials of
choice for cardiac pacemakers and defibrillators. However, glass
encapsulation is providing smaller active implants the ability to be
used throughout the body.
These include neurostimulators for the treatment of epilepsy,
implantable drug pumps, cochlear implants and physiological
sensors.
The cold sealing process of glass encapsulation is why encapsulation
can be used in smaller implants.
Sealing titanium implants against moisture requires a hightemperature
laser welding technique, so active implants must be
substantially larger or they would otherwise minimise the risk of
damaging circuitry during the welding process.
That is not the circumstance with cold welding used in glass
encapsulation. This procedure does not require high temperatures
for sealing, enabling smaller, less invasive implants.
Glass encapsulation also offers effective transmission of radio
frequency (RF) signals used to send bio data to an external reader or
for recharging of an onboard battery.
The reason for its effectiveness is that glass encapsulation is largely
transparent to radio signals allowing for smaller antennas, less
power and smaller implants.
Smart implants have researches continuously looking for ways to
extend the life of an implant’s power supply. In many cases such
as the pacemaker, its average lifespan is 15 years and has to be
surgically replaced.
The next generation of implants aims to find ways of remotely
recharging from outside the body with an external RF link.
Other options include working from various body energyharvesting
techniques, taking from the heartbeat or blood flow,
body temperature for converting electrical energy and more.
SELENIUM MEDICAL HAS DEVELOPED ITS OWN TYPE II ANODISING PROCESS FOLLOWING
RECOMMENDATIONS OF THE SE AMS 2488D STANDARD.
This type of anodising results in the
formation of an oxide layer with a
single colour, gray anthracite. It is
applied to titanium alloy implants
and instruments when the surface is
subjected to friction, or mechanically
stressed during use.
Process advantages include:
• Improved mechanical and surface
properties of medical devices,
resulting in reduced wear, scratch resistance, increased fatigue,
corrosion resistance, and greater hardness than colour anodising
• Improved biological properties
of medical devices such as
improved grip of the bone, good
biocompatibility and ease of
removal after recovery
• The treatment causes no
dimensional change to medical
devices
Selenium Medical R&D project
manager Boussad Sebih said: “This
process, not very developed in France, comes from our expertise
and has been developed with all co-workers of the research and
development division of Selenium Medical.”
78 TITANIUMTODAY