Low Triboelectric Noise Wire and Cable
AAMI Compliant Cable, Medical Instruments Wire and Cable
Cable and wire used in low-level signal measurements such as in medical applications have very stringent requirements in terms of low-noise performance. In a medical cable when noise gets mixed in with the actual
medical signal it can obscure the medical signal and make accurate diagnosis difficult, if not impossible. According to AAMI/ANSI EC53 requirements, the maximum peak-to-peak noise level must be less than 50 micro-volts (µV).
A particularly challenging source of noise in medical cables and other very low-voltage signal applications is the triboelectric noise originating in the cable itself.
What is Triboelectric Noise?
When two materials are rubbed together, an electrical charge is generated between them and this electrical phenomenon is known as the triboelectric effect. Triboelectric noise is the
internal noise generated by the flexing or vibrating of the cable. Such cable movements result in friction between the cable's various conductors, insulation, and fillers. In turn, this
friction generates the surface charge which translates into the triboelectric noise.
AAMI Certified Low-Noise Wire and Cable
Systems Wire & Cable is a large provider to the medical industry and one of the very few qualified
manufacturers for low Triboelectric Noise cables and lead wires that are certified to AAMI standards. Meeting the AAMI (Association for the Advancement of Medical Instrumentation) EC53 noise
requirements for medical wire and cable is a reflection of our engineering excellence, advanced manufacturing, expert material selection, and our unwavering commitment to the medical industry.
This allows us to support our customers in the industry with medical grade cable and wire that not only meets but exceeds AAMI EC53 noise requirements.
Low Triboelectric Noise Technology
Simply flexing or twisting a traditional cable can generate voltage spikes with magnitudes in the tens
of millivolts. The noise is due to triboelectric charging of the insulator materials, which act as capacitors and store the charge. Adding noise filters to cable assemblies has only a limited
potential in dealing with triboelectric noise. The real answers for controlling the triboelectric effect lie in the design and manufacturing of the raw cable and wire. The size of the triboelectric voltage
spikes in the cable is very much a function of the materials selected by the cable designers. Copper and foamed polyethylene, for instance, are two of the lowest triboelectric generators available today.
Adding conductive low-noise layers can also reduce the noise levels from tens of milivolts to the microvolt range. The cable noise reduction noise occurs as a result of draining the triboelectric
induced charge away from the wire insulation.
Furthermore, low noise cables are built such that the dielectric is bonded to both the center conductor and the shield. Thus, there can be no relative movement of cable layers, no "flex induced"
layer friction and, as a result, no triboelectric noise. We are very proud to know that medical diagnostic devices using our AAMI Certified Low-Noise Wire and Cable can greatly contribute to
making more accurate diagnosis throughout the medical field.
In small-signal applications, noise-free transmission lines are necessary to maintain signal integrity.
At Systems Wire & Cable, we are dedicated to manufacturing very low-noise cable and wire not only for the medical instrumentation field but also for potential applications in the military and aerospace
industries.
|
