Medical implant providers should conduct material verification of all polymers and plastics in pacemakers. Lives could depend on it.
You will see many heart-shaped items this Valentine’s Day. Heart-shaped plastic beads, decorations, cake toppers, and candy bowls can be seen in almost every store window. A heart-related item you may not see while walking down the street, however, is a pacemaker. Pacemakers are medical implant devices that can stimulate the human heart muscle and regulate the heartbeat. Each year, tens of thousands of people get them implanted in an effort to keep their hearts beating at a healthy rate. (You can see an animation of how a pacemaker works on the American Heart Association website.)
Although most of the pacemaker components, including the casing and the leads, are usually made of metals, like Titanium, polymers are also a critical material in the pacemaker. Leads are the wires which run between the pulse generator and the heart and allow the device to increase the heart rate by delivering small bursts of electric energy to make the heart beat faster. The lead itself is insulated by a polymer material such as polyurethane.
Getting the polymer composite correct is critical to the health of the patient. An article in the “How Products are Made” website, explained that the “materials used to construct pacemakers must be pharmacologically inert, nontoxic, sterilizable, and able to function in the environmental conditions of the body.” To ensure the polymer chemistry is correct, before the polymer material reaches the patient’s body, a crucial step in the manufacturing control process is verifying the chemical information of the polymer material.
The production of polyurethanes (PU) starts with polyols — the chemical compounds containing multiple hydroxyl groups. Polyols are based on alkene oxides, generally ethylene oxide (EO) and propylene oxide (PO). The EO content of polyols dictates the characteristics of the final polyurethane products. Nuclear Magnetic Resonance (NMR) spectroscopy is an inherently quantitative technique, and due to the abundance of protons in the repeating structures of polyols, combined with the dispersion of signals, proton NMR spectroscopy is ideally suited for rapid characterization of EO content. Benchtop NMR has been proven to be able to determine EO content in polyols.
According to UC Davis ChemWiki, “Nuclear Magnetic Resonance (NMR) is a nuclei specific spectroscopy that has far reaching applications throughout the physical sciences and industry. NMR uses a large magnet to probe the intrinsic spin properties of atomic nuclei. Like all spectroscopies, NMR uses a component of electromagnetic radiation (radio frequency waves) to promote transitions between nuclear energy levels. Most chemists use NMR for structure determination of small molecules.”
NMR spectroscopy is the method of choice for many organic chemists because of its versatility in elucidating molecular structure, optimizing reaction dynamics, measuring reaction kinetics, monitoring reaction content and controlling product purity.
If you love your customers, and your company brand, add this valuable analytical technique to your production floor for small-batch reaction monitoring and QA/QC in your chemical manufacturing. Lives may depend on it.
Editor’s Note: Take care of your heart this Valentine’s Day. Take two minutes to read the Warning Signs of Heart Failure.
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