Systems, apparatuses, and methods for electromagnetic interference mitigation

Abstract

An electromagnetic interference mitigation device can be provided, including a power supply; a power supply line; a power supply enclosure; a low value resistor; and a capacitor. The power supply enclosure encapsulates at least the power supply, the power supply being physically isolated from the power supply line; the low value resistor being in electrical communication with at least the power supply line and the power supply; the capacitor being disposed between the power supply enclosure and a device enclosure, wherein the device enclosure encapsulates the power supply enclosure, wherein the device enclosure is disposed at a distance from the power supply enclosure, and wherein the capacitor is formed by the device enclosure and the power supply enclosure.

Description

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 111,134, filed November 9, 2020, the contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to medical devices. More specifically, this disclosure relates to systems, apparatus, and methods for mitigating electromagnetic interference associated with medical and laboratory equipment. Background Technology

[0003] Leading technology analysts believe that technology is evolving at a near-exponential pace. Many industries that once relied on hand tools and primitive processes have been revolutionized by the integration of microcomputers, sensors, and other modern components. Consequently, there is more computer hardware and circuitry in homes and workplaces than ever before. This proliferation of electronics has led to two problems related to electromagnetic interference (EMI). First, a vast number of devices are now susceptible to errors caused by EMI. Second, there are more devices that contribute to EMI.

[0004] EMI can have a catastrophic impact on the performance of electronic devices, causing malfunctions and leading to overall failure. The increasing prevalence of EMI-emitting devices each year further amplifies these problems. In particular, wireless technologies such as mobile phones, laptops, Bluetooth, GPS, and Wi-Fi are exacerbating electromagnetic interference issues.

[0005] EMI can be divided into two categories: conducted EMI and radiated EMI. Conducted EMI arises from the physical contact of conductors, while radiated EMI arises from induction and is therefore non-contact. Typically, conducted EMI results from lower frequencies, while radiated EMI results from higher frequencies. EMI is also commonly generated by less complex components such as generators and motors. These components often include switching power supplies that radiate and conduct EMI due to high switching speeds.

[0006] Specifically, hospital equipment can be adversely affected by electromagnetic interference. Equipment such as life support systems, life monitoring devices, and ventilators are vulnerable and must be shielded against EMI. EMI issues in hospitals are particularly complex because EMI sources are often another extremely important part of medical equipment.

[0007] To mitigate EMI issues, "x-capacitors" can be installed at the power line input to divert current from the chassis and wiring back to the power source, rather than conducting it along the power line. While these "x-capacitors" work well in many cases, they can increase grounding current flowing into the ground. However, medical equipment is unique in that grounding current must be minimized to ensure that the patient's electrical equipment does not malfunction. While reducing the size of the "x-capacitor" might decrease grounding current, EMI mitigation will be much more difficult.

[0008] Therefore, it is desirable to provide systems and methods to address the issue of reducing EMI in an environment with poor grounding. Commonly, in the lower frequency range, devices may fail to meet safety guidelines regarding EMI. To reduce low-frequency emissions without affecting high-frequency emissions, it would be desirable if the power supply enclosure were electrically isolated from grounding.

[0009] Further efforts are needed to address the shortcomings of current EMI mitigation technologies by creating capacitors, where capacitor plates serve as the walls of power supply enclosures and equipment chassis. Summary of the Invention

[0010] In one embodiment, the invention disclosed herein may be an electromagnetic interference mitigation device, comprising: a power supply; a power line; a power supply chassis; a low-value resistor; and a capacitor. The power supply chassis at least encapsulates the power supply, which is physically isolated from the power line; the low-value resistor is at least electrically connected to the power line and the power supply; the capacitor is disposed between the power supply chassis and a device chassis, wherein the device chassis encapsulates the power supply chassis, wherein the device chassis is disposed at a distance from the power supply chassis, and wherein the capacitor is formed by the device chassis and the power supply chassis.

[0011] Furthermore, low-value resistors can be placed in series with the power supply and power lines. The device may also include a first x capacitor and a second x capacitor, wherein the first x capacitor and the second x capacitor can be disposed within the power supply chassis. In one embodiment, the capacitors can act as high-pass filters configured to reduce low-frequency emissions from the power supply.

[0012] In one embodiment, the power supply chassis forms the first plate of the capacitor, and the equipment chassis forms the second plate. Furthermore, a dielectric material may be disposed between the first and second plates. In one embodiment, the distance between the plates is between 0.14 cm and 0.178 cm (i.e., between 0.055 inches and 0.070 inches). Low-value resistors may have a resistance of less than 100 ohms. In one embodiment, the power supply line supplies a power input of 90-264 volts AC voltage, and the power supply outputs 48 volts DC voltage at a maximum of 15.6 amps. Attached Figure Description

[0013] The accompanying drawings, which are incorporated in and form part of this specification, illustrate various aspects of the invention and, together with the specification, explain and illustrate the principles of this disclosure.

[0014] Figure 1A An embodiment of the desired electromagnetic interference mitigation is shown.

[0015] Figure 1B An example of unwanted electromagnetic interference is shown.

[0016] Figure 1C An embodiment of a device configured to mitigate electromagnetic interference is shown.

[0017] Figure 2 A graph of the frequency response is shown.

[0018] Figure 3 An example of a conductive electromagnetic compatibility test setup is shown. Detailed Implementation

[0019] This article discloses devices, systems, and methods for mitigating electromagnetic interference in electronic devices.

[0020] For the purposes of this disclosure, unless otherwise expressly stated, singular terms should be interpreted to include their plural meaning. Furthermore, the term "comprising" is not restrictive. Additionally, unless otherwise expressly stated, "or" is equivalent to "and / or". Although a scope may be declared as a preferred scope, embodiments operating outside the preferred scope may exist unless expressly stated otherwise.

[0021] Figure 1A Examples of ideal electromagnetic interference mitigation are shown. For example, Figure 1 shows functional components of a hospital device without EMI. For the purposes of this disclosure, Figure 1A This can represent the expected result of EMI mitigation methods.

[0022] Figure 1B An example of a device is shown that allows low-frequency transmission through the device's ground wire. Therefore, for the purposes of this disclosure, Figure 1B This can represent a system with an undesirable number of EMIs.

[0023] refer to Figure 1C The device 100 may include a device chassis 102, a power supply chassis 104, a power supply 106, a power cord 108, a first x capacitor 110 (X1), a second x capacitor 112 (X2), a low-value series resistor 116, and a capacitor / high-pass filter 114.

[0024] A capacitor 114 can be formed when the device chassis 102 and the power supply chassis 104 are positioned at a distance from each other (e.g., 0.055-0.070 inches) or any other suitable distance. In one embodiment, the capacitor distance is measured between the walls of the device chassis 102 and the power supply chassis 104, where the two chassis 102 / 104 are physically closest to each other. However, in other embodiments, the capacitor distance can be measured in other ways, such as at the location where one of the chassis holds the most charge. In one embodiment, each chassis 102 / 104 may have four enclosure walls, a top wall, and a bottom wall. In this embodiment, the capacitor 114 can be formed along two corresponding walls of the chassis 102 / 104. Furthermore, in this embodiment, the distance between two corresponding walls (the walls forming the capacitor 114) can be shorter than the distance between other corresponding walls (e.g., the distance between the left wall of the device chassis 102 and the left wall of the power supply chassis 104). Therefore, the wall of the chassis 102 / 104 forming the capacitor 114 can be the closest corresponding wall. However, in other embodiments, capacitor 114 may be formed by any number of walls or combinations of walls at any distance.

[0025] In one embodiment, the capacitor distance can be adjusted by a user, manually, automatically, or via an attached computer. In one embodiment, a servo motor or other similar component is disposed between housings 102 / 104, allowing the capacitor distance to be varied. In one embodiment, the variable distance is fixed and therefore not adjustable. In one embodiment, a winch, wedge, or screw is disposed between power supply housing 104 and equipment housing 102, enabling fine-tuning of the capacitor distance. Such embodiments and similar alternative embodiments are provided by Figure 1C express.

[0026] Device 100 may include device chassis 102 and power supply chassis 104. In many embodiments, power supply chassis 104 surrounds power supply 106. In one example, power supply 106 may include electrical inputs / outputs, such as an input of 90-264 volts AC voltage and / or an output of 48 volts DC voltage at a maximum of 15.6 amps. However, power supply 106 may have any suitable electrical inputs or outputs. Power supply 106 may be an alternating current (AC) power supply, a direct current (DC) power supply, or any other commonly used type of power supply. In alternative embodiments, power supply chassis 104 surrounds multiple power supplies 106. In another embodiment, device chassis 102 surrounds multiple power supply chassis 104.

[0027] In one embodiment, both device chassis 102 and power supply chassis 104 are made of metal and act as electrical conductors. However, alternative embodiments exist in which device chassis 102 and power supply chassis 104 are made of various suitable materials. For example, in another embodiment, device chassis 102 and / or power supply chassis 104 may be composed of or include a thin film, foil, or electrolyte. In an alternative embodiment, one of the two chassis is constructed of a material designed to have lower conductivity than the other chassis. In this alternative embodiment, the lower conductivity chassis can reduce the overall effectiveness of the capacitor generated by the two chassis. This alternative embodiment can reduce the effectiveness of the high-pass filter 114, which can benefit users seeking to reduce the percentage of high-frequency signals passing through capacitor 114.

[0028] In one embodiment, a dielectric material is disposed between the device chassis 102 and the power supply chassis 104. For example, in various embodiments, glass, polytetrafluoroethylene, polystyrene, titanium dioxide, barium titanate, or other dielectric materials may be placed between the two chassis 102 / 104. In one embodiment, the power supply chassis 104, the device chassis 102, and any other chassis or components are insulated. In one embodiment, the power supply chassis 104, the device chassis 102, and any other chassis or components may be insulated from electricity, heat, vibration, or sound.

[0029] There are also embodiments in which the device chassis 102 and power supply chassis 104 do not form capacitor 114. In these alternative embodiments, a separate capacitor may be disposed between the two chassis 102 / 104. Alternatively, power supply chassis 104 may not surround power supply 106. In this embodiment, another component, such as a metal plate, may be electrically connected to power supply 106 such that this other component forms one half of capacitor 114, while device chassis 102 forms the other half. In one embodiment, power supply 106 is connected to a separate ground wire or other cable configured to carry low frequencies.

[0030] Although in some embodiments capacitor 114 can act as a high-pass filter, capacitor 114 can also be configured as a low-pass filter. (See reference...) Figure 2 The embodiment of the electromagnetic interference mitigation device 100 reduces low-frequency emissions. This is from... Figure 2 It is obvious that Figure 2 This illustration shows how embodiments of the invention can reduce transmission amplitude in the low-frequency range. (Reference) Figure 2 Although embodiments of the electromagnetic interference mitigation device 100 are configured to reduce low-frequency emissions, the invention is not limited to... Figure 2 The slope and characteristics. Several embodiments exist that allow users of device 100 to customize the effect intensity of device 100 for specific applications. In such embodiments, the impact of the invention disclosed herein on emissions can be greater than... Figure 2 The larger or smaller shown.

[0031] In some embodiments, the power supply chassis 104 and / or the device chassis 102 are constructed from a single continuous sheet. For example, in these continuous sheet embodiments, the entire chassis 102 / 104 may be manufactured by milling, three-dimensional (3D) printing, molding, or otherwise, such that the chassis 102 / 104 is a single unit. Alternatively, there are embodiments where one or both of the power supply chassis 104 and the device chassis 102 are constructed from multiple parts. For example, in these alternative embodiments, the chassis 102 / 104 may include a top side, bottom side, left side, right side, front side, and rear side. Furthermore, the top side, bottom side, left side, right side, front side, and rear side may be separate components, each fastened to form the device chassis 102 or the power supply chassis 104.

[0032] Alternative embodiments exist in which either of the enclosures 102 / 104 is not uniformly composed of the same material. For example, 90% of the enclosure may be composed of a metal known in the art to act as a good conductor, and 10% may be composed of a material known to be a weak conductor or an insulator. Such embodiments can be advantageous in applications where there are sensitive components that must be located within the enclosure but not necessarily in a specific vicinity of a conductive material.

[0033] Alternatively, in one embodiment, the device enclosure 102 and / or power enclosure 104 may be a mesh, links, foil, or other stretchable material arranged around components within the enclosure. For example, in conventional, fixed, geometrically or physically impermeable enclosures used in non-conductive applications, the stretchable material may "cover" components typically located within the enclosure. In this alternative embodiment, the stretchable material constituting the enclosure may have many of the same properties as conventional enclosures previously disclosed (e.g., conductivity, material properties, dielectric properties, etc.).

[0034] In one embodiment of the electromagnetic interference mitigation device, the device further includes a low-value resistor 116. The low-value resistor 116 may be less than 100 ohms. In some embodiments, a lower resistance may be associated with a higher low-frequency conductance amplitude, and / or a higher resistance may be associated with a larger radiated emission. In one embodiment, the resistance may be approximately 56 ohms. However, there are alternative embodiments where the low-value resistor 116 may be greater than 100 ohms. In one embodiment, the low-value resistor 116 is connected in series at least with the power supply 106 and the ground and / or power line 108. However, there are other embodiments in which the low-value resistor 116 is connected in parallel at least with the power supply 106 and the ground and / or power line 108.

[0035] The electromagnetic interference mitigation device 100 includes additional embodiments that include more than one low-value resistor 116. In these alternative embodiments, multiple low-value resistors 116 may be connected in at least series or parallel to the power supply 106 and the ground and / or power line 108. In one embodiment, the low-value resistor 116 is a variable resistor. In such embodiments, the low-value resistor 116 is easily adjustable by the user.

[0036] Electromagnetic interference mitigation device 100 can be configured to prevent conducted electromagnetic interference frequencies in the range of 100 kHz to 30 MHz along the AC power line 108 of the device under test. (Reference) Figure 3 Electromagnetic interference emissions can be measured by connecting the AC power line 108 of the device under test 100 to a line impedance stabilization network 304, wherein the spectrum analyzer 302 further communicates with the line impedance stabilization network 304. The line impedance stabilization network 304 can then be connected to the main power supply 306. However, there are embodiments that use other methods and / or components to measure conducted electromagnetic interference emissions.

[0037] In alternative embodiments, the invention seeks to prevent conducted electromagnetic interference outside the 100 kHz to 30 MHz range. In further embodiments, device 100 prevents conducted electromagnetic interference emissions propagating along components other than AC power line 108. For example, in these further embodiments, electromagnetic interference mitigation device 100 may be configured to reduce emissions along (but not limited to) cables attaching peripheral devices to the device under test, frames or structures supporting the device under test, or other electronic devices very close to the device under test.

[0038] In one embodiment, an electromagnetic interference mitigation device may include a power supply, a power line, and a power supply enclosure that at least encapsulates the power supply. In such an embodiment, the power supply may be physically isolated from the power line. However, the power supply may be electrically in communication with the power line (e.g., via additional circuitry, wires, etc.). The device may also include a low-value resistor and a capacitor. The low-value resistor may be electrically in communication with at least the power line and the power supply, and the capacitor may be disposed between the power supply enclosure and the device enclosure. In one embodiment, the device enclosure encapsulates the power supply enclosure, and the device enclosure is disposed at a distance from the power supply enclosure; the capacitor is formed by the device enclosure and the power supply enclosure. The low-value resistor may be connected in series with the power supply and the power line.

[0039] In another embodiment, the device includes a first x capacitor and a second x capacitor, wherein the first x capacitor and the second x capacitor are disposed within a power supply chassis. The capacitors may be configured as high-pass filters, and the capacitors are also configured to reduce low-frequency emissions from the power supply. The power supply chassis may form the first plate of the capacitors, and the device chassis may form the second plate of the capacitors. In another embodiment, a dielectric material is disposed between the first plate and the second plate. Furthermore, a distance may exist between the two plates, wherein the distance may be between 0.055 inches and 0.070 inches. However, this distance can be any suitable size. In one embodiment, the low-value resistor includes a resistor with a resistance of less than 100 ohms. In another embodiment, the power line inputs a 90-264 volt AC voltage to the power supply, and the power supply outputs a 48 volt DC voltage at a maximum of 15.6 amps.

[0040] Although the present invention has been described in conjunction with the foregoing embodiments, many alternatives, modifications, and variations will be apparent to those skilled in the art upon reading the foregoing disclosure. Therefore, as stated above, the embodiments of the present invention are intended to be illustrative, not limiting. Various changes can be made without departing from the spirit and scope of the invention.

Claims

1. An electromagnetic interference mitigation device, comprising: power supply; Power cord; A power supply enclosure, wherein the power supply enclosure at least encloses the power supply, and the power supply is physically isolated from the power cord; A low-value resistor, which is at least electrically connected to the power line and the power source; as well as A capacitor is disposed between the power supply chassis and the equipment chassis. The equipment chassis encapsulates the power supply chassis. The equipment chassis is positioned at a certain distance from the power supply chassis. The capacitor is formed by the equipment chassis and the power supply chassis, and The distance adjustment component is disposed between the equipment chassis and the power supply chassis, and the distance adjustment component is configured to change the distance between the equipment chassis and the power supply chassis.

2. The electromagnetic interference mitigation device according to claim 1, wherein, The low-value resistor is placed in series with the power supply and the power line.

3. The electromagnetic interference mitigation device according to claim 1 further includes a first x capacitor and a second x capacitor, wherein, The first x capacitor and the second x capacitor are disposed inside the power supply chassis.

4. The electromagnetic interference mitigation device according to claim 1, wherein, The capacitor acts as a high-pass filter, which is configured to reduce low frequencies emitted from the power source.

5. The electromagnetic interference mitigation device according to claim 1, wherein, The power supply chassis forms the first plate of the capacitor, and the equipment chassis forms the second plate of the capacitor.

6. The electromagnetic interference mitigation device according to claim 5, wherein, The dielectric material is disposed between the first plate and the second plate.

7. The electromagnetic interference mitigation device according to claim 6, wherein, The distance is between 0.14 cm and 0.178 cm.

8. The electromagnetic interference mitigation device according to claim 7, wherein, The low-value resistors include resistors with a strength of less than 100 ohms.

9. The electromagnetic interference mitigation device according to claim 8, wherein, The power line inputs an AC voltage of 90-264 volts to the power source, and the power source outputs a DC voltage of 48 volts at a maximum of 15.6 amps.

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