With the emergence of more complex and demanding products, plastics are increasingly at the forefront of medical solutions in a wide range of needs.
\"External liver\" VitaGen, Inc.
, Is using plastic materials as an integral part of a unique medical therapy that combines living cells with plastic.
Chief Operating Officer Robert Johnson said
In vitro Liver Assist Device)
System is a hybrid device that uses a human liver cell line packed in a plastic box to provide temporary liver support for patients with liver failure.
Cells are placed in separation.
Type cartridge with polycarbonate housing.
The hollow fibers of cellulose acetate in the box pass the patient\'s plasma through the liver cells, and the toxins spread from the plasma to the liver cells, where they are metabolized.
Rubber tubes made of PVC are configured to separate plasma from the patient\'s blood through a set of four boxes containing human cell lines and then return the purified plasma to the patient.
TheELAD is currently undergoing clinical trials to test the safety and effectiveness of the system.
Cardiac Support Cardia Technologies is currently developing a system called cardiac support (CSS).
Initially, its use will be studied in patients suffering from cardiac shock.
A polyurethane sleeve with an internal inflatable element attached to a computer
Console, short function for one time
When pressurized, the cuff simultaneously compresses the left and right ventricle of the heart with the heartbeat.
In fact, the system is a \"mechanized\" of the heart hand massage, which can usually only be carried out in a limited period of time.
In contrast, the initial version of the system is designed to support patients for seven days.
The implantable cuff is intended to be introduced through a cut between the ribs and fixed to the heart through a vacuum/shrink film made of polyurethane, rather than using stitches or adhesives.
John Tovey, vice president of R & D at heart Technology, said cuff technology is not at all
Invasive vascular system, unlike the very invasive chamber currently used-assist devices.
The non-disposable part of CSS is a console that receives signals from patients and manages synchronous pressure pulses required to assist the heart.
The doctor can control the intensity of these pulses to adjust the patient\'s parameters.
In the cuff design specifications, the performance requirements for an average of 3 million cycles meet 7-
Daily running parameters. (
The cycle includes expanding the element from zero to maximum pressure. )
Several plates, thickness and mechanical structures have been studied.
The pressure element was originally a ring chamber made of compliant segmented polyurethane, and in pre-clinical studies it provided the necessary efficacy relative to the heart displacement, but its durability was not well redesigned,
Facing the flap that does not meet the requirements, heat to the maximum volume of the pressure.
When the pressure is allowed to return to zero, the brain leaves collapse because the ventricle expands to replenish the blood.
The aromatic polyurethane was finally selected to handle the changing material deformation involved.
Taking into account the need to minimize folding and creases and provide the ability to withstand fatigue cracks, optimized thickness and durometer materials are selected.
The human heart of Tanabata
A day of use has been carried out and the survey data will be submitted to the research equipment exemption for the United StatesS.
In the near future, the feasibility study and the European clinical survey.
For more than 40 years, Baxter Healthcare\'s position on diverse materials for medical containers has been based on a pragmatic philosophy of flexibility to meet special requirements.
In this case, Baxterbelieves believes that in clinical use over the past 40 years,PVC)
Medical products including intravenous injection (IV)
Bags, blood bags and catheter have proven to be safe and effective, and abelief has also been supported by a lot of data and strict regulatory review.
However, PVC is not a panacea for all clinical needs, said david bacehoski, vice president of advanced technology development, corporate research and technical services.
In order to better meet specific needs, Baxter continuously evaluates a variety of alternative materials.
Based on the history of research and development of alternative materials, the company plans to gradually provide new non-
Pvc products with superior properties for special clinical applications.
The company has provided many of these medical products, using a variety of materials that, as bacehoski pointed out, do not negate pvc but \"go beyond\" in special circumstances
Study possible alternatives to PVC include materials tailored to olefin, including polyethylene and polypropylene, to contain specific solutions;
Mixed with thermoplastic rubber (TPEs); metallocene-
In the alternative
The PVC material that Baxter has incorporated into its portfolio is a heatSealed, more
The layered laminated structural film of the Galaxy premix product line is compatible with the aseptic process. Another non-
PVC developed a multi-layer co-extrusion of isBaxter through the olefin/TPE membrane of the final sterilized solution container.
One of the drivers of this stationfrequency-
A sealable material needs to improve compatibility with a specific composite solution and change sterilization from a sub-Alpha oxide to a gamma;
The company also hopes to continue using its vast-
Container manufacturing base of scale.
Another addition to Baxter\'s film and container portfolio was 1997, when Baxter purchased Bieffe, a European company that had already put Clear-Flex, a multi-layer non-
PVC film and flexiblecontainer system for intravenous and renal solution containers.
Baxter recently expanded the product line with a second one.
The fourth generation container design called ViaFlo.
These products are made in Europe using aseal. fill-
Sealing heat sealing technology with manufacturing efficiency is very suitable for smaller markets.
Baxter will continue to look for alternative materials for PVC, continuing efforts to \"improve clinical performance\" as new requirements emerge \".
Nevertheless, bacehoski said that Baxter supports PVC as the cornerstone of the \"foundation of the company\'s materials, and that no other single material is universal and effective for the company\'s various medical products.
\"Although there have been a lot of research and reports on the efficacy of PVC in countless applications in recent years, another study ---
Features, production and cost-effectiveness-
The search for alternative materials continues.
So far, there are no commercial products that match PVC in all evaluation areas.
Recently, Daland Juberg of the International Centre for toxicology and medicine provided an \"internal observation\" of a group of 17 scientists and doctors, led by formerU. S.
Everett science, at the Medical plastics 2000 conference sponsored by the Chicago branch of the American Institute of Professional Technology and the medical plastics division, discussed the safety of PVC.
Held under the auspices of the American Committee on Science and Health (ACSH)
Scientific evidence to assess potential health risks associated with DEHP [di(2-ethylhexyl)phthalate}and DINP [
Diester of neighboring benzene]
The team concluded that \"DEHP, such as for medical devices, will not be harmful to humans even in chronic and higher settings --than-
Average condition of exposure.
\"In addition, the panel concludes that DEHP gives a variety of important physical features that are critical to the functioning of medical devices.
The World Health Organization\'s national cancer research agency has strengthened this finding in determining that \"based on existing scientific evidence, DEHP cannot be classified as human carcinogens.
\"There is less scientific literature on DINP than there is on dehp, and although the results of animal trials suggest a thorough assessment is required, the panel concluded that the evidence is nothing for humans
In addition, the panel concluded that the DINP in the toy was harmless in normal use.
Nevertheless, the panel recommends further studies to more fully document the exposure time and speaking behaviour of children with toys;
And other objects and rates released by DTNP under realistic conditions. A long-
The Vinyl Institute has once again responded to a long debate over the past 20 years.
Greenpeace and healthcare have long arguedHCWH). Fred E.
Krausecom commented that the allegations were mainly concentrated on the generation of dioxin during ethylene production and disposal;
In addition, phthal salts for the production of soft, flexible medical products such as blood bags and intravenous bags were added.
\"Science believes vinyl is a secondary source of dioxin,\" Krause said . \".
Supporting scientific institutions on the safe use of non-medical products of neighboring benzene ester are growing.
He cited the report of ACSH Koop;
Decision of the World Health Organization\'s International Agency for Cancer Research on DEHP;
And the report of the National Toxicology project center on human reproductive risk assessment (CERHR)
Most of the neighboring benzene Ester caused concern.
However, some concerns were raised about the impact of blood replacement for pregnant women and newborns.
Nevertheless, the CERHR team recognizes that \"the benefits of these medical procedures can outweigh the risks.
Krause added that the ongoing research is in place to answer some of these questions, and it is expected that an ongoing review of neighboring benzene Ester will confirm their safety.
He concluded that sound science is slowly replacing emotion and speech when communication is good and supports the use of vinyl as a safe and ongoing choice for medical professionals.
Dow Chemical recently launched a new medical product in the RF weldable olefin.
It is a solderable olefin film that can be sealed by RF Welding. As \"drop-
Alternatives in \"PVC and EVAheat-sealed and HF (RF)
Weldable film for medical collection bags, bed covers, medical packaging and support devices such as braces and stop bleeding, new film, which can be processed on existing RF machines.
These films have excellent versatility in making, says Dowsays;
Tear, puncture, chemical resistance;
Soft and flexible;
They also allow measurements without sacrificing performance.
These movies are EtO and gamma-sterilizable.
Polyurethane Applications \"polyurethane polymers are continuing to enter the medical field of the market,\" said Len Czuba, director of medical department at combrest Lazar Bell.
\"Their extensiveness makes them a material substitute for common materials such as natural rubber latex, flexible PVC and other rigid, transparent medical polymers.
\"A range of properties in the polyurethane polymer family make these materials suitable for products such as insurance gloves, sheaths, and balloons,\" he said.
\"A slightly different formula can be used as a plasticizer --
Free soft flexible film, can be reSealed, solvent-
Bonding and steam-sterilized.
However, in the case of up to the cost of flexible PVC, the new application of this material must be specifically required not to meet the functional requirements of byPVC, such as low temperature performance.
\"Czuba notes, for example, that the css of aerobic technology relies on the re-sealing capability of the polyurethane film to form an inflated airbag in the final product to help the weak heart continue to pump blood;
The bending fatigue resistance of this material makes it an ideal choice for application.
He added that in other products the polyurethane material was squeezed in mm
The wall tube forms a highly specialized cardiac catheter.
Whether it\'s for cardiac imaging or delivery and deployment of acardiac brackets, these materials are used in many of these lives-
Similar materials can be molded into chemistry-
At the other end of the spectrum, polyurethane foam (
From soft to hard, from small to large cells, in the opencell or closed-cell variety)
Covers a range of applications and continues to improve resistance to discoloration, hydrolysis, and/or oxidation degradation.
The new use of foam materials is to better treat sore, improve toothpicks and wound coverage.
Czuba also anticipates that the improved coating technology can carry out specific engineering on the surface of medical devices.
The combination of biochemistry and polymer science further improves the biological compatibility of the surface.
The surface-to-protein binding of slow-release drugs is only diagnostic chemistry and the new treatment method depends on two techniques that cause biological effects.
Finally, the development of gel technology, with its variable viscosity properties, stimulated the development of several new products, from a simple examination pad to a pressure point dispersion agent for pressure sore, prevent repetitive stress diseases such as wrist tunnel syndrome. Cyclo-
The potential of o\'lefins\' Topas TiVo in Tikona-
Olefin polymer (COC)
Find applications in the medical field.
Marketing manager Donnell McNally said that ethylene/norbonene polymers have increased potential for use in insulin and heparin, glass substitutes for laboratory and diagnostic equipment, and drug delivery systems due to their biological inertia
Tikona brought it recently.
Flow 000 30,000-ton-
The Topas factory in Oberhausen, Germany, is expected to supply Europe and North America.
Some manufacturers have commercialized microtiter or multiwell plates containing a range of small wells as reaction sites
Test Procedure for Volume Analysis.
Results are determined by spectral scanning, requiring high transparency and chemical resistance.
Topas is also used to produce one-time-
Use tools to make contact lenses.
Over time, dimensional stability and resistance to reagents used to produce lenses are required, and the tool is first an injection mold and then used as a mold for the production of lenses in combination with acrylic acid and other reagents.
McNally said that due to late-stage reasons, the polypropylene commonly used has a strict time limit on the length of production
Molding size change.
The COC tool maintains its molding size for a few months, thus liberating the molding process of time constraints.
Reaction Injection Molding \"use of polyurethane reaction injection molding (RIM)
Richard Messi, technical marketing representative for the special RIM group of Bayer polyurethane division, said: \"The medical market has been growing at a rate of 8% to 11% per year . \"
\"In today\'s medical equipment and instrument industry, aesthetics and styling are rapidly becoming important requirements.
In addition, the medical housing must meet demanding parameters, including resilience and dimensional stability at high temperatures, while achieving cost targets at relatively low production volumes.
\"The BD Bioscience of the company, the Picton Dickinson, uses Bayer\'s low
726 structure foam polyurethane edge system and prism CM-
200 solid polyurethane system with its new advanced battery
Analysis equipment. Both low-
The viscosity system allows the elimination of expensive steel tools for large enterprisespart, low-volume six-
Color desktop flow analyzer, which uses UV laser to easily quantify the composition of cells.
Many of the challenges facing medical plastics continue to emerge.
On the one hand, the reuse of medical devices in hospitals and other health fields is growing --
The care facility raises significant questions about the materials used and the provisions of standards for post-treatment/sterilization, functional and safety monitoring.
Another challenge is the latest progress in molecular biology and gene therapy, for example, the role of plastics will be extended to the efficient application of genetic engineering drugs.
All in all, scientists and doctors and their patients are increasingly dependent on plastic.