Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laser processes promise better artificial joints, arterial stents

17.09.2009
Researchers are developing technologies that use lasers to create arterial stents and longer-lasting medical implants that could be manufactured 10 times faster and also less expensively than is now possible.

New technologies will be needed to meet the huge global market for artificial hips and knees, said Yung Shin, a professor of mechanical engineering and director of Purdue's Center for Laser-Based Manufacturing.

The worldwide population of people younger than 40 who receive hip implants is expected to be 40 million annually by 2010 and double to 80 million by 2030. In addition to speeding production to meet the anticipated demand, Shin said another goal is to create implants that last longer than today's.

"We have 200,000 total hip replacements in the United States," he said. "They last about 10 years on average. That means if you receive an implant at 40, you may need to have it replaced three or four times in your lifetime."

One of the researchers' techniques works by depositing layers of a powdered mixture of metal and ceramic materials, melting the powder with a laser and then immediately solidifying each layer to form parts. Because the technique enables parts to be formed one layer at a time, it is ideal for coating titanium implants with ceramic materials that mimic the characteristics of natural bone, Shin said.

Findings will be detailed in a presentation this week during the International Medical Device Expo's Advanced Laser Applications Conference in San Jose, Calif.

"Titanium and other metals do not match either the stiffness or the nature of bones, so you have to coat it with something that does," Shin said. "However, if you deposit ceramic on metal, you don't want there to be an abrupt change of materials because that causes differences in thermal expansion and chemical composition, which results in cracks. One way to correct this is to change the composition gradually so you don't have a sharp boundary."

The gradual layering approach is called a "functionally gradient coating."

Researchers used their laser deposition processes to create a porous titanium-based surface and also a calcium phosphate outer surface, both designed to better match the stiffness of bone than conventional implants.

The laser deposition process enables researchers to make parts with complex shapes that are customized for the patient.

"Medical imaging scans could just be sent to the laboratory, where the laser deposition would create the part from the images," Shin said. "Instead of taking 30 days like it does now because you have to make a mold first, we could do it in three days. You reduce both the cost and production time."

The laser deposition technique lends itself to the requirement that each implant be designed specifically for each patient.

"These are not like automotive parts," Shin said. "You can't make a million that are all the same."

The process creates a strong bond between the material being deposited and the underlying titanium, steel or chromium. Tests showed the bond was at least seven times as strong as industry standards require, he said.

The researchers use computational modeling to simulate, study and optimize the processes.

Additional research is needed before the techniques are ready for commercialization. Future work will involve studying "shape-memory" materials that are similar to bone and also have a self-healing capability for longer-lasting implants.

The researchers also are developing a technique that uses an "ultra short pulse laser" to create arterial stents, which are metal scaffolds inserted into arteries to keep them open after surgeries to treat clogs. The laser pulses last only a matter of picoseconds, or quadrillionths of a second.

Because the pulses are so fleeting, the laser does not cause heat damage to the foil-thin stainless steel and titanium material used to make the stents. The laser removes material in precise patterns in a process called "cold ablation," which turns solids into a plasma. The patterns enable the stents to expand properly after being inserted into a blood vessel.

The work is funded by the National Science Foundation.

Writer: Emil Venere, (765) 494-4709, venere@purdue.edu
Source: Yung Shin, (765) 494-9775, shin@purdue.edu
Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Medical Engineering:

nachricht Noninvasive eye scan could detect key signs of Alzheimer's years before patients show symptoms
18.08.2017 | Cedars-Sinai Medical Center

nachricht Water-filtered infrared-A (wIRA) overcomes swallowing disorders and hypersalivation – a case report
10.08.2017 | Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e.V.

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>