COVID-19 Coronavirus Ventilator Magnets / ECMO Magnets
Exhalation valve is a necessary component of the ventilator. The positive end expiration pressure (PEEP) function of the ventilator can help patients to preserve some gas in their lungs and hence enhance oxygenation time. Most of current exhalation valves are utilizes voice coil motor to drive the diaphragm to do linear displacement and this displacement will change the throttle area of fluid channel to dominate the on-off and flow rate, thus inhale and exhale can be controlled. Ventilator magnet is essentially a voice coil motor magnet. The voice coil motor in the exhalation of ventilator is composed of a ventilator magnet situated within a moving coil and all of two are inside of a ferromagnetic cylinder. Coil will be magnetized when current run through the coil and repels against the magnets, thus producing an in and out motion.
COVID-19 is caused by a coronavirus. Coronaviruses are a large family of viruses that are common in people and many different species of animals, including camels, cattle, cats, and bats. Rarely, animal coronaviruses can infect people and then spread between people such as with MERS-CoV, SARS-CoV, and now with this new virus (named SARS-CoV-2).
The SARS-CoV-2 virus is a betacoronavirus, like MERS-CoV and SARS-CoV. All three of these viruses have their origins in bats. The sequences from U.S. patients are similar to the one that China initially posted, suggesting a likely single, recent emergence of this virus from an animal reservoir.
Ventilator machine / Ventilator is a crucial medical equipment which enables to treat respiratory failure, reduce complication and prolong patient‘s life. In the absence of specific drug, ventilator and extracorporeal membrane oxygenation (ECMO) is extremely critical to the treatment of novel coronavirus pneumonia. According to the relevant medical reports, novel coronavirus pneumonia will cause obvious damage to the lung function of patients. Severe case must rely on the ventilator to achieve assistant ventilation once confusion, respiratory failure or shock, thus enhances blood oxygen saturation and decrease the mortality rate. In fact, neodymium magnet has also served as the ventilator magnet in the exhalation valve.
Moving Magnet – Another common type of actuator would be the moving magnet design, where the coil is fixed and magnet assembly moves. This construction change would prevent moving leads during operation. The package operates similarly, but instead of an exposed coil that moves in and out of the magnet assembly, the moving magnet style utilizes a permanent magnetic field assembly “piston” moving inside a cylindrical coil tube. This style often comes with the permanent field assembly attached to a shaft, and end caps containing bearings so that this style is most commonly supplied with an integrated bearing system.
Voice Coil Motors (VCM), also called Voice Coil Actuators (VCA), are a very mature design that utilizes a magnet and yoke in conjunction with a coil. The coil and magnet are concentric about a common axis and there exists an engineered magnetic return path.
Ceramic Voice Coil Motor Magnet The coil is typically connected to a mechanism which translates the coil’s linear motion into a beneficial action. For example, a conventional loud-speaker uses a voice coil motor to drive a cone which converts the coil’s oscillating motion into sound energy.
The typical characteristics of a voice coil motor are a round coil, concentric with and located in a gap where a radial magnetic field is present. This field is generally developed by a permanent magnet located within the structure. The interaction between the coil’s magnetic field and the magnetic field in the gap is what gives rise to the linear force acting on the coil. (The coil’s magnetic field is due to the current flowing in coil.) The magnet’s position within the unit, the type of magnet, the surrounding structure, etc., can influence the nomenclature of the unit.
Originally, most VCMs were similar to a loud-speaker’s design. This design uses a gap whose axial length is short and the magnetic field density in the gap is very high. Because of the short gap length, this style required a longer axial length coil to create any reasonable “stroke” or axial travel. Newer designs utilized longer axial length gaps, lower magnetic field densities, and shorter coils using fewer turns of wire. This means that more of the coil operated in the gap, resulting in a mass and resistance reduction. Lower mass equals better acceleration and “settling” and lower resistance translates into greater linearity.