May 26, 2012
People With Trypanophobia Need Not Fear, New Research Is Here
A new device may be the cure for those who are afflicted with trypanophobia, someone who has a fear of needles.
MIT researchers have created a device that delivers a tiny, high-pressure jet of medicine through the skin without the use of hypodermic needles.
The researchers say the technology may reduce the potential for needle-stick injuries, which, according to the CDC, happens 385,000 times a year.
A needleless device could help those patients with trypanophobia that refuse healthcare, or those with diabetes that have to constantly prick themselves to get insulin into their body.
“If you are afraid of needles and have to frequently self-inject, compliance can be an issue,” Catherine Hogan, a research scientist in MIT´s Department of Mechanical Engineering and a member of the research team, said in a press release. “We think this kind of technology “¦ gets around some of the phobias that people may have about needles.”
The MIT team, led by Ian Hunter, the George N. Hatsopoulos Professor of Mechanical Engineering, has developed a jet-injection system built around a mechanism called a Lorentz-force actuator.
This actuator is a small, powerful magnet surrounded by a coil of wire that is 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 out through the ampoule's nozzle to an opening as wide as a mosquito's proboscis.
Both the speed of the coil and velocity imparted to the drug can be controlled by the amount of current applied, so the team created pressure profiles that module the current.
The team found, during testing, that various skin types may require different waveforms to deliver adequate volumes of drugs to desired depths.
“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 said. “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, said she sees the group's technology as a promising step beyond jet injection that are currently being used.
“Commercially available jet injectors “¦ provide limited control, which limits their applications to certain drugs or patient populations,” Mitragotri, who was not a part of the research, said. “[This] design provides excellent control over jet parameters, including speed and doses “¦ this will enhance the applicability of needleless drug devices.”
The researchers are developing a version of the device for transdermal delivery of drugs that are typically found in powdered form by programming the device to vibrate, which turns powder into a "fluidized" form that can be delivered through the skin like a liquid.
Hunter said that a device capable of performing these powder-deliveries may help solve a problem known as the "cold-chain" problem.
Under this problem, vaccines delivered to developing countries have to be refrigerated if they are in liquid form, and often coolers can break and spoil the batches of vaccines. Hunter said that a vaccine that can be administered in powder form would require no cooling, ultimately avoiding the cold-chain problem.
The team reports on the development of this technology in the journal Medical Engineering & Physics.
Image 2 (below): MIT-engineered device injects drug without needles, delivering a high-velocity jet of liquid that breaches the skin at the speed of sound. Image courtesy of the MIT BioInstrumentation Lab