Author Topic: Forget the pain from needle of syringe, Right now the era syringe witout needle  (Read 1526 times)

Offline daimond

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 Device May Inject a Variety of Drugs
Without Using Needles
ScienceDaily (May 24, 2012) — MIT
researchers have engineered a device
that delivers a tiny, high-pressure jet
of medicine through the skin without
the use of a hypodermic needle. The
device can be programmed to deliver
a range of doses to various depths --
an improvement over similar jet-
injection systems that are now
commercially available.
The researchers say that among other
benefits, the technology may help
reduce the potential for needle-stick
injuries; the Centers for Disease
Control and Prevention estimates that
hospital-based health care workers
accidentally prick themselves with
needles 385,000 times each year. A
needleless device may also help
improve compliance among patients
who might otherwise avoid the
discomfort of regularly injecting
themselves with drugs such as insulin.
"If you are afraid of needles and have
to frequently self-inject, compliance
can be an issue," says Catherine
Hogan, a research scientist in MIT's
Department of Mechanical
Engineering and a member of the
research team. "We think this kind of
technology … gets around some of
the phobias that people may have
about needles."
The team reports on the development
of this technology in the journal
Medical Engineering & Physics.
Pushing past the needle
In the past few decades, scientists
have developed various alternatives to
hypodermic needles. For example,
nicotine patches slowly release drugs
through the skin. But these patches
can only release drug molecules small
enough to pass through the skin's
pores, limiting the type of medicine
that can be delivered.
With the delivery of larger protein-
based drugs on the rise, researchers
have been developing new
technologies capable of delivering
them -- including jet injectors, which
produce a high-velocity jet of drugs
that penetrate the skin. While there
are several jet-based devices on the
market today, Hogan notes that there
are drawbacks to these commercially
available devices. The mechanisms
they use, particularly in spring-loaded
designs, are essentially "bang or
nothing," releasing a coil that ejects
the same amount of drug to the same
depth every time.
Breaching the skin
Now the MIT team, led by Ian Hunter,
the George N. Hatsopoulos Professor
of Mechanical Engineering, has
engineered a jet-injection system that
delivers a range of doses to variable
depths in a highly controlled manner.
The design is built around a
mechanism called a Lorentz-force
actuator -- a small, powerful magnet
surrounded by a coil of wire that's
attached to a piston inside a drug
ampoule. When current is applied, it
interacts with the magnetic field to
produce a force that pushes the
piston forward, ejecting the drug at
very high pressure and velocity
(almost the speed of sound in air) out
through the ampoule's nozzle -- an
opening as wide as a mosquito's
proboscis.
The speed of the coil and the velocity
imparted to the drug can be
controlled by the amount of current
applied; the MIT team generated
pressure profiles that modulate the
current. The resulting waveforms
generally consist of two distinct
phases: an initial high-pressure phase
in which the device ejects drug at a
high-enough velocity to "breach" the
skin and reach the desired depth, then
a lower-pressure phase where drug is
delivered in a slower stream that can
easily be absorbed by the
surrounding tissue.
Through testing, the group found that
various skin types may require
different waveforms to deliver
adequate volumes of drugs to the
desired depth.
"If I'm breaching a baby's skin to
deliver vaccine, I won't need as much
pressure as I would need to breach
my skin," Hogan says. "We can tailor
the pressure profile to be able to do
that, and that's the beauty of this
device."
Samir Mitragotri, a professor of
chemical engineering at the University
of California at Santa Barbara, is
developing new ways to deliver drugs,
including via jet injection. Mitragotri,
who was not involved with the
research, sees the group's technology
as a promising step beyond jet
injection designs currently on the
market.
"Commercially available jet injectors …
provide limited control, which limits
their applications to certain drugs or
patient populations," Mitragotri says.
"[This] design provides excellent
control over jet parameters, including
speed and doses … this will enhance
the applicability of needleless drug
devices."
The team is also developing a version
of the device for transdermal delivery
of drugs ordinarily found in powdered
form by programming the device to
vibrate, turning powder into a
"fluidized" form that can be delivered
through the skin much like a liquid.
Hunter says that such a powder-
delivery vehicle may help solve what's
known as the "cold-chain" problem:
Vaccines delivered to developing
countries need to be refrigerated if
they are in liquid form. Often, coolers
break down, spoiling whole batches of
vaccines. Instead, Hunter says a
vaccine that can be administered in
powder form requires no cooling,
avoiding the cold-chain problem.

http://www.sciencedaily.com/releases/2012/05/120524134703.htm
« Last Edit: May 27, 2012, 10:27:33 am by daimond »

Offline moonbeam

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That's pretty cool. It'll kinda like "Star Trek".

 


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