Patent Application
20240204462
This description relates to protecting electronic circuitry from electrostatic discharges and electromagnetic interference.
External electrical phenomena (e.g., electrostatic discharge (ESD), electromagnetic interference (EMI), etc.) can have a deleterious effect on the functioning of electrical and electronic circuits. ESD can ignite flammable mixtures and cause malfunctions and damages to industrial equipment and consumer electronics. In the health care field, electronic medical equipment and data processing equipment often have electrical or electronic circuits that are susceptible to ESD. ESD in the electronic medical equipment can be hazardous both to health care workers and to patients. ESD in an electronic medical equipment may occur, for example, when external I/O connection cables are connected to, or disconnected from communication ports (e.g., Ethernet ports, USB ports, etc.) in the equipment by an operator. Similarly, electromagnetic interference (EMI) from radiofrequency sources may cause an electronic medical equipment to malfunction, compromising patient safety.
In a general aspect, an apparatus includes a circuit board disposed in a frame. The circuit board includes at least one signal input parts/signal output parts (SIP/SOP) port. A fascia cover is disposed over the at least one SIP/SOP port. The fascia cover has an opening aligned with, and providing an external cable connector access to, the at least one SIP/SOP port. The fascia cover includes a door movable from an open position to a closed position across the opening. The fascia cover further includes an insulating material layer and a conductive material layer coupled to the insulating material layer. The conductive material layer is disposed on an area of the fascia cover at a distance from edges of the opening. Further, the door includes an insulating material layer and a conductive material layer coupled to a portion of the insulating material layer of the door. The conductive material layer is disposed on an area of the door at a distance from an edge of the door.
In an aspect, the at least one SIP/SOP port is isolated (e.g., galvanically, or optically isolated) from a ground of the circuit board and a ground of the frame.
In a general aspect, an apparatus includes a circuit board disposed in a frame. The circuit board includes at least one signal input parts/signal output parts (SIP/SOP) port. The at least one SIP/SOP port is electrically isolated from the frame. A fascia cover including an insulating material layer is disposed on the frame to cover the at least one SIP/SOP port. The fascia cover has an opening aligned with the at least one SIP/SOP port. The opening provides an access to attach an external cable connector through the opening to the at least one SIP/SOP port. Further, a conductive layer is disposed in the fascia cover. The conductive layer is connected to a ground of the circuit board and forms a Faraday shield preventing electromagnetic radiation from crossing the fascia cover.
In an aspect, the insulating material layer in the fascia cover blocks external electrostatic discharge (ESD) from crossing the fascia cover to reach the at least one SIP/SOP port.
In an aspect, the fascia cover includes a spring-loaded door movable from a closed position to an open position across the opening, the door being biased by a spring to automatically close. The spring-loaded door is movable from the closed position to the open position by an operator's finger pressure without using a tool (e.g., a screwdriver or other tool).
In a general aspect, a method includes disposing a fascia plate to cover an SIP/SOP port in an electronics equipment. The fascia plate includes at least one layer of insulating material and a layer of conductive material. Further, the fascia plate includes an opening with a door that can be moved from a closed position to an open position and vice versa across the opening. The door also includes the at least one layer of insulating material and the layer of conductive material.
In an aspect, disposing the fascia plate to cover the SIP/SOP port in the electronics equipment can include aligning the opening with the SIP/SOP port to provide access through the opening, for example, to an operator, to attach a cable connector to the SIP/SOP port.
In an aspect, disposing the fascia plate to cover the SIP/SOP port in the electronics equipment may further include configuring the at least one layer of insulating material to intercept and block external electrostatic discharge (ESD) events from propagating across the fascia plate to the SIP/SOP port, and configuring the at least one layer of conductive material to intercept and block electromagnetic (EM) radiation from propagating across the fascia plate.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
In the drawings, which are not necessarily drawn to scale, like reference symbols or alpha-numeral identifiers may indicate like and/or similar components (elements, structures, etc.) in different views. The drawings illustrate generally, by way of example, but not by way of limitation, various implementations discussed in the present disclosure. Reference symbols or alpha-numeral identifiers shown in one drawing may not be repeated for the same, and/or similar elements in related drawings. Reference symbols or alpha-numeral identifiers that are repeated in multiple drawings may not be specifically discussed with respect to each of those drawings but are provided for context and cross-reference between related views. Also, not all like elements in the drawings are specifically referenced with a reference symbol or alpha-numeral identifier when multiple instances of an element are illustrated in various drawings.
Systems and methods for reducing occurrences of, or mitigating the effect of, electrostatic discharge (ESD) and electromagnetic interference (EMI) in electrical or electronics equipment are described herein. The disclosed systems and methods, which may be collectively referred to herein as the ESD/EMI reduction solution, ensure compliance with at least the basic industry-standard safety requirements for isolated SIP/SOP ports.
The ESD/EMI reduction solution can prevent ESD from damaging the electrical or electronic equipment (e.g., damaging system boards or other static-sensitive devices in the equipment). The ESD/EMI reduction solution can ensure electromagnetic compatibility (EMC) of the electrical or electronic equipment to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as EMI or even physical damage to the equipment.
The ESD/EMI reduction solution can be designed so that the electrical or electronic equipment meets or exceeds common industry standards for ESD safety and EMC. The ESD/EMI reduction solution may be applied to electrical or electronics equipment (hereinafter “electronics equipment”) that includes at least one isolated communications port (e.g., a signal input parts/signal output parts (SIP/SOP) port). The SIP/SOP port can be an interface or a point of connection between the electronics equipment and its peripheral devices (e.g., electronic or electrical subsystems, monitors, keyboards, display units, other medical devices, etc.) or between the electronics equipment and a network (e.g., Internet or intranet, local area network (LAN), etc.). A main function of the SIP/SOP port can be to act, for example, as a point of attachment, where a cable connector from a peripheral device or network can be plugged in or connected to allow, for example, data to flow from and to the peripheral device or network.
In example implementations, the SIP/SOP port may be a communications port of any type (e.g., a PS/2 port, a Serial Port, a S/PDIF/TOSLINK port, a Video Port, Digital Video Interface (DVI), a Display Port, a RCA Connector, a Component Video port, a S-Video port, an HDMI, an USB port, a RJ-45 connector, a RJ-11 connector, or an e-SAT port, etc.).
The ESD may, for example, be a static voltage discharge that is accumulated by a human operator attaching the cable connector to a connection port on the electronics equipment. The connection port may, for example, be an isolated SIP/SOP port or another port (e.g., a non-isolated port). The ESD can occur, for example, preceding or during the process of attaching the cable connector to the connection port (e.g., the isolated SIP/SOP port) as the human operator approaches the electronics equipment.
Electrical and electronic products (including medical equipment) are subject to safety requirements for electromagnetic compatibility (EMC) (including for ESD, EMI) under industry safety standards (e.g., International Electrotechnical Commission (IEC) standard—IEC 60601-1-1 Ed. 2.0 b:2000, Medical Electrical Equipment—Part 1-1: General Requirements for Safety—Collateral Standard: Safety Requirements for Medical Electrical System, etc.). The industry safety standards may be standards that are published by trade, regulatory, or government organizations (such as the National Institute of Standards and Technology).
The industry safety standards lay out test procedures for determining if an electrical or electronics product (electronics equipment) is compliant with the safety requirements. For example, the IEC 61000-4-2: ESD Standard for System Level Testing, prescribes a system level test that replicates a charged person discharging to a system in a system end user environment. The IEC 61000-4-2 standard defines four standard levels of ESD protection using two different testing methodologies—contact discharge testing and air discharge testing. Contact discharge testing involves discharging an ESD pulse directly from an ESD test gun that is touching the electronics equipment under test. In the air discharge testing, the ESD test gun is brought close to (but not touching) the electronics equipment under test until an air discharge occurs. The ESD testing standards are defined so that at each of the four standard levels the two different testing methodologies are considered equivalent (e.g., a Level 4 contact discharge of 8 kV is considered equivalent to an air discharge of 15 kV).
The ESD/EMI reduction solutions described herein are designed to ensure that electronics equipment with isolated SIP/SOP ports is compliant with at least the ESD and EMI safety testing standards (e.g., IEC 61000-4-2).
In example implementations, an ESD/EMI reduction solution involves covering the SIP/SOP ports in the electronics equipment with a fascia plate attached to a frame of the electronics equipment. The fascia plate includes at least one layer of insulating material and a layer of conductive material. The at least one layer of insulating material (e.g., a plastic material layer) may be disposed on a front side (operator side) of the fascia plate. This plastic material layer blocks ESD strikes on the operator side of the fascia plate from propagating to the SIP/SOP ports on the equipment side of the fascia plate. The layer of conductive material (e.g., a metal layer, conductive paint etc.) may be disposed on a back side (machine side) of the fascia plate on top of the plastic material layer or between two plastic material layers. This layer of conductive material (e.g., a metal layer) can intercept or block external EMI radiation incident from the operator side of the fascia plate from propagating to the SIP/SOP ports on the equipment side of the fascia plate and may also block outbound electromagnetic radiation emissions from the electronics equipment.
In example implementations, the fascia plate includes door openings or apertures aligned with the SIP/SOP ports on the electronics equipment. The SIP/SOP ports can be accessed by an operator across the fascia plate through the door openings. An operator may, for example, plug (or unplug) cable connectors in the SIP/SOP ports on the electronics equipment through the door openings.
Fascia plate 100 includes door openings (e.g., opening 110, opening 112, etc.) that are aligned with the SIP/SOP ports in the electronics equipment when fascia plate 100 is disposed on the electronics equipment. Fascia plate 100 may include a door assembly (e.g., sliding door assembly 400,
With the door in the open position, the operator can physically access the corresponding SIP/SOP port (e.g., SIP/SOP port 201) through the opening (e.g., opening 110), for example, to plug in a cable connector in the SIP/SOP port.
Fascia plate 100 including the doors (e.g., door 130) may include a layer of insulating material (e.g., a plastic material layer) and a layer of conductive material (e.g., a metal layer) (not visible in
In example implementations for ESD safety compliance testing (e.g., under the safety testing standards of IEC 61000-4-2), the insulating properties of the insulating material layer 102 (e.g., plastic material) may be selected so that an ESD contact discharge of 8 kV or an ESD air discharge of 15 kV (caused by ESD gun 10 on the front side of fascia plate) does not propagate through the fascia plate (or cause arcing or sparking at the SIP/SOP ports (e.g., SIP/SOP port 201)).
The layer of conductive material (e.g., a metal layer) (not visible in
The ESD/EMI reduction solution may be implemented on any medical device or equipment that has isolated SIP/SOP ports. An example medical equipment may, for example, be an anesthesia machine.
In accordance with the principles of the present disclosure, a fascia plate (e.g., fascia plate 100 including an insulating material layer and a conductive material layer) can be installed on area 210 (including the isolated SIP/SOP ports) of anesthesia machine 200 to block occurrences of external ESD and EMI from reaching the SIP/SOP ports. In example implementations, fascia plate 100 of
As shown in
In example implementations, disposing the conductive material layer only in areas at a distance from the edges of the openings in the insulating material layer may be accomplished by making corresponding openings in the conductive material layer larger than the openings in the insulating material layer.
As noted previously, in some implementations, door 130 may, for example, be a sliding door (with a protrusion or handle 132) that can be moved (e.g., by an operator using their finger) from a closed position to an open position. Door 130 like fascia plate 100 includes insulating material layer 102 and a conductive material layer portion 103D. The conductive material layer portion 103D in door 130 (like conductive material layer 103 disposed on other portions of fascia plate 100) may be disposed only in areas that are at a distance (e.g., distance d2,
Sliding door assembly 400 may include a space or cavity 430 formed, for example, between a wall 420 and insulating layer 102 of fascia plate 100. Wall 420 may be made of insulating material (e.g., plastic) like that of insulating material layer 102. A spring 410 is disposed in cavity 430. Spring 410 may be made, for example of a metal, a metal alloy, or a conductive elastomer. Sliding door 130 (with handle 132) may be biased by spring 410 to slide in cavity 430 (e.g., along the y direction) across opening 110 in the fascia plate 100. In example implementations, sliding door 130 may be resiliently biased by spring 410 to automatically close across opening 110 in the fascia plate 100.
Spring 410 (e.g., a metal or metallic alloy spring) may be connected to conductive material layer 103 disposed on the back side of fascia plate 100. In example implementations, conductive spring 410 may be grounded to the frame of the electronics equipment by attaching fascia plate 100 to the frame of the electronics equipment (e.g., using bolts or screws through screw holes 104,
Further, as shown in
In the example shown in
Further, for purposes of illustration, a creepage or clearance distance between edge E′ of conductive material layer portion 103F of the fascia plate and edge E″ of conductive material layer portion 103D of door 130 in closed position (measured along the surface of insulating material layer) may be given by a distance D=d1+d2.
In some example implementations, the fascia plates (e.g., fascia plate 100) described in the foregoing (e.g., in
In some other example implementations, the fascia plates (e.g., fascia plate 100) may be fabricated using overmolding processes to dispose insulating material (e.g., insulating material layer 102) on both the front side and the back side of fascia plate 100. In example implementations, the insulating material (e.g., insulating material layer 102) may be disposed on all sides (including the edges) of conducting material layer 103 (e.g., a metal layer).
Method 600 includes disposing a fascia plate to cover a SIP/SOP port in an electronics equipment (610). The fascia plate includes at least one layer of insulating material and a layer of conductive material. Further, the fascia plate includes an opening with a door that can be moved (e.g., by finger pressure or touch) from a closed position to an open position and vice versa across the opening. The door may be a spring-loaded door that can be opened without access to a tool. The spring-loaded door may close automatically. The door also includes the at least one layer of insulating material and the layer of conductive material. Disposing the fascia plate to cover the SIP/SOP port in the electronics equipment 610 may include aligning the opening with the SIP/SOP port to provide access through the opening, for example, to an operator, to attach a cable connector to the SIP/SOP port (612). Disposing the fascia plate to cover the SIP/SOP port in the electronics equipment 610 may further include configuring the at least one layer of insulating material to intercept and block external electrostatic discharge (ESD) events from propagating across the fascia plate to the SIP/SOP port (614). Disposing the fascia plate to cover the SIP/SOP port in the electronics equipment 610 may further include configuring the layer of conductive material to intercept and block electromagnetic (EM) radiation from propagating across the fascia plate (616).
Method 600 may further include connecting the layer of conductive material to a ground of the electronics equipment.
In method 600, disposing the fascia plate to cover the SIP/SOP port in the electronics equipment 610 can include disposing a first portion of the layer of conductive material in an area of the fascia plate at a distance from an edge of the opening. Further, disposing the fascia plate to cover the SIP/SOP port in the electronics equipment 610 can include maintaining a gap between the first portion of the layer of conductive material disposed in the fascia plate and a second portion of the layer of conductive material disposed on an area of door at a distance from an edge of the opening. In some example implementations, method 600 can include filling the gap between the first portion of the layer of conductive material and the second portion of the layer of conductive material with insulator material.
While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the scope of the implementations. It will be understood that they have been presented by way of example only, not limitation, and various changes in form and details may be made. Any portion of the apparatus and/or methods described herein may be combined in any combination, except mutually exclusive combinations. The implementations described herein can include various combinations and/or sub-combinations of the functions, components and/or features of the different implementations described.
It will be understood that, in the foregoing description, when an element is referred to as being on, connected to, electrically connected to, coupled to, or electrically coupled to another element, it may be directly on, connected or coupled to the other element, or one or more intervening elements may be present. In contrast, when an element is referred to as being directly on, directly connected to or directly coupled to another element, there are no intervening elements present. Although the terms directly on, directly connected to, or directly coupled to may not be used throughout the detailed description, elements that are shown as being directly on, directly connected or directly coupled can be referred to as such. The claims of the application, if any, may be amended to recite exemplary relationships described in the specification or shown in the figures.
As used in this specification, a singular form may, unless indicating a particular case in terms of the context, include a plural form. Spatially relative terms (e.g., over, above, upper, under, beneath, below, lower, and so forth) are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. In some implementations, the relative terms above and below can, respectively, include vertically above and vertically below. In some implementations, the term adjacent can include laterally adjacent to or horizontally adjacent to.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure. As used in the specification, and in the appended claims, the singular forms “a,” “an,” “the” include plural referents unless the context clearly dictates otherwise. The term “comprising,” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. The terms “optional” or “optionally” used herein mean that the subsequently described feature, event or circumstance may or may not occur, and that the description includes instances where said feature, event or circumstance occurs and instances where it does not. Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, an aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
