Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MEDTEC Europe 2012: Implant to replace defective venous valve

01.03.2012
If heart valves don’t close properly, they are replaced. Conventional treatment of venous valve failure, however, has up to now always and exclusively been via medication. In future, an implant will assume the function of damaged valves – and a new dispensing tool means these prostheses can be made using an automated process.

It’s one of the most commonly occurring medical conditions – chronic venous in-sufficiency (CVI). Almost ten million German citizens suffer from weak veins that require treatment, with twice as many women being affected as men. The cause of this widespread condition is restricted functioning of the venous valves in the legs.


The finished venous valve is highly durable. © Helmholtz-Institute of Biomedical Engineering of RWTH Aachen

If the venous valve is no longer able to close properly, blood will observe the laws of gravity in between heartbeats and flow down to collect in the legs. This leads to edemas, and can cause open ulcers in particularly severe cases. CVI is usually treated with anti-inflammatory drugs and diuretics; as yet there is no globally available venous valve implant that can be used to treat the illness.

This is something that researchers from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart are setting out to change: In close collaboration with four industrial partners and Helmholtz-Institute for Biomedical Engineering of RWTH Aachen University, they have developed an automated production facility that can make venous valve prostheses from polycarbonate-urethane (PCU), a plastic. The project was sponsored by the German Federal Ministry of Economics and Technology BMWI.

The centerpiece of the facility is a 3D droplet dispensing tool which enables the researchers to precisely apply a particular polymer onto freeform surfaces and at the same time combine various grades of polymer hardness, called Shore hardnesses. “3D droplet dispensing technology is an additive procedure that allows three-dimensional geometries to be created layer by layer using a polymer”, explains Dr. Oliver Schwarz, group manager at the IPA. The scientists use PCU because it is particularly strong and flexible, while another useful property of the material is that it is easy to sew into surrounding tissue. PCU structures can be made in very thin layers, which is ideal when replacing wafer-thin atrioventricular valves. “By using PCU in combination with our 3D dispensing kinematics, we can achieve seamless transitions within the material between six different grades of elasticity and hardness – without any breaking points whatsoever. This technique mirrors the design of highly stressed structures in nature. It can’t be done using injection molding”, says Schwarz.

But how does the PCU become a venous valve prosthesis? Initially, the polymers are dissolved in a solvent and deposited onto a venous valve prosthetic mold one droplet at a time, using the dispensing tool. The system is accurate to within 25 micrometers, and can deliver up to 100 droplets per second, each with a volume of 2 to 60 nanoliters. A six-axis kinematic system positions the piezo feeder precisely above the mold. Once it is fully coated with droplets, the mold is bathed in a warm stream of nitrogen. This causes the solvent to evaporate, leaving the polymer behind. Further layers are applied by repeating the dispensing process, and in the end the polymer prosthesis can simply be peeled from the mold. Doctors can take the finished replacement valves and implant them into the veins of the leg via a catheter passed through the skin.

The production facility comprises numerous other components besides the dispenser. The IPA experts are responsible for, amongst other things, the filling and monitoring system, the drying facilities, the entire clean-room box and the control mechanism for the six-axis kinematic system. “We have successfully managed to re-program the Beckhoff control system normally used with milling machines in such a way that it can now be used with additive processes,” Schwarz is happy to report. The solution they have come up with will soon see the researcher and his team in a position to produce thin-walled, highly durable implants such as heart valves or intervertebral disks. The IPA scientists will be presenting a prototype of their 3D droplet dispenser at the MEDTEC Europe 2012 trade fair from March 13 – 15 in Stuttgart (Hall 6, Booth 6211).

Dr. rer. nat. Oliver Schwarz | Fraunhofer Research News
Further information:
http://www.fraunhofer.de/en/press/research-news/2012/march/implant-to-replace-defective-venous-valve.html

More articles from Medical Engineering:

nachricht New technique makes brain scans better
22.06.2017 | Massachusetts Institute of Technology

nachricht New technology enables effective simultaneous testing for multiple blood-borne pathogens
13.06.2017 | Elsevier

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>