WO2016192789A1

WO2016192789A1 - Power over ethernet management for power devices

Info

Publication number: WO2016192789A1
Application number: PCT/EP2015/062424
Authority: WO
Inventors: Stefan Hager; Lisa ABELE
Original assignee: Brainlab SE
Current assignee: Brainlab SE
Priority date: 2015-06-03
Filing date: 2015-06-03
Publication date: 2016-12-08
Anticipated expiration: 2017-12-03

Abstract

Power control system for use in a power-over-Ethernet system, the power control system comprising: at least one first connection port (P1) capable of receiving power as a power signal from an Ethernet connection; at least one second connection port (P2; P2'; P2'') capable of delivering power to at least one device (PD; PD1, … PDn); a power quality monitoring unit (1) being connected to the first connection port (P1) and being capable to monitor the quality of the power signal received from the Ethernet connection; and a power management unit (2) being connected to the power quality monitoring unit (1) and the at least one second connection port (P2; P2'; P2'') and being capable of being connected to at least one additional power source (5, 5'), wherein the power management unit (2) is capable of receiving a power quality signal from the power quality monitoring unit (1) representative of the quality of the power received at the at least one first connection port (P1) from the Ethernet connection, wherein the power management unit (2) is capable of receiving the power from the first connection port (P1) and from the at least one additional power source (5, 5') and delivering power to the at least one second connection port (P2; P2'; P2''), and wherein, at least when the power quality signal indicates that the power signal is of insufficient quality or permanently, the power management unit (2) is capable of improving the quality of the power signal and is capable of adding power from the at least one additional power source (5, 5') to such an amount to deliver a combined power signal to at least one of the second connection port(s) (P2; P2'; P2''), the combined power signal consisting in part of the power received from the first connection port (P1) and in part of the power received from the at least one additional power source (5, 5') and meeting predetermined quality requirements.

Description

Power over Ethernet management for power devices

The present invention relates to a power control system for use in a power-over-Ethernet (PoE) system, and to a method for providing power to at least one device, the method being performed for example by a computer. The invention can be used in a medical environment, for example to power a medical or sensitive device over the Ethernet.

It is noted that in the context of this invention, reference is made to the Ethernet and the possibility to provide power-over-Ethernet, wherein the invention also may encompass other known data connections being able to provide power and data at the same time, such as Universal Serial Bus (USB) or IEEE 1394 (Fire Wire). Thus, the term "Ethernet" as used herein can also be replaced by "USB" or "Fire Wire", although the Ethernet is the herein described exemplary embodiment which provides for long cable length. Each of the mentioned data connections can encompass a number of individual ports or pins, wherein a single pin or a pair of pins (or individual ports) can be used to provide a functionality, such as two pins (or individual ports) transmitting a first set of data in a specific direction and another pair of pins (or individual ports) transmitting other data or electrical power. In a standard IT environment, there are various PoE standards available, providing various power levels with different quality intransparent to the user. Moreover, standard IT environments are not stable, but are changing continuously due to additional devices being added or removed (powered or switched off). The present invention provides a stable and reliable power quality to one or more connected devices being independent of these changes.

An additional power source may add power to insufficient power delivered by the Ethernet connection to a first connection port, and the combined power of the Ethernet connection and the additional power source(s) can be provided at the second connection port serving to deliver power to at least one connected device. The additional power is provided to such an extent, if needed, to provide an overall power signal meeting a predefined quality, such as specified or demanded by connected powered devices. A stable or good power signal may become instable or be of inferior quality if too much power is drawn. It may become again a power signal of a required quality if either the power consumption is reduced (e.g. by removing a device or restricting its functionality), or additional power is added.

The system, the method and the program are defined by the appended independent claims. Advantages, advantageous features, advantageous embodiments and advantageous aspects of the present invention are disclosed in the following and contained in the subject-matter of the dependent claims. Different advantageous features can be combined in accordance with the invention wherever technically expedient and feasible. Specifically, a feature of one embodiment which has the same or a similar function to another feature of another embodiment can be exchanged with said other feature, and a feature of one embodiment which adds an additional function to another embodiment can in particular be added to said other embodiment.

BACKGROUND

US 7,941,677 B2 discloses a network apparatus and method for managing power supplied to a network device. A plurality of power inputs to the network device are scanned to ascertain if a power signal is present and to identify an active power source. Available power is determined from the active power source and required power for the network device and any operatively connected auxiliary devices is also determined. The required power is compared to available power to determine if available power is sufficient to power the network device. An operation of the network device is controlled based upon the active power source and/or if available power is insufficient to power the network device. US 2011/0133551 Al discloses a power control system arranged for use in a power-over- Ethernet system comprising a battery, a battery charging unit connected to, and for charging, the battery and a processor arranged to monitor the charge level of the battery and, in response, to direct current to, or away from, the battery. A power-over-Ethernet (PoE) system for delivering power to a load comprises a powered device and an Ethernet power sourcing device configured to supply DC power to the powered device. The powered device has a battery, a battery charge unit, and a processor. The processor is arranged to monitor the current requirement of the load, and to control the charging of the battery and the supply of current from the battery to the load in response to said monitoring. A method of providing current to a load in a power-over-Ethernet system which includes a power sourcing device, a battery and a processor, comprises the steps of monitoring the current requirement of and the current supplied to, the load, monitoring the charge level of the battery; monitoring the current supplied to the power load, the current supplied by the power sourcing device and charge level of the battery in response to said monitoring.

US 8,479,043 B2 discloses a power over Ethernet (PoE) powered device with power fallback states. A powered device can be powered using a primary local power source and a secondary PoE power source. To enable consistent behaviour by the powered device, a controlled power fallback state can be defined that would ensure limited functionality in the powered device upon a failure of the primary local power source. For example, the limited functionality could include a communication channel to the switch, diagnostic circuitry, etc. US 8,873,370 B2 discloses in one embodiment, that a connection is maintained between a pair of ethernet ports that have circuitry connected in series with the ports and receiving power-over-ethernet (PoE) from one of the ports, by providing a controllable bypass circuit coupled to the pair of Ethernet ports in parallel with the circuitry receiving power-over- ethernet, sensing a preselected condition, and opening and closing the bypass circuit in response to the presence or absence of the preselected condition. Power sourcing equipment may supply the one of the ports with power over Ethernet, and the circuitry may transport data between the pair of ethernet ports. The circuitry may also supply the switch with a control signal in response to the detection of the preselected condition. US 8,898,446 B2 discloses a power over Ethernet extender arranged to detect if power is received over 2 pairs of wires or over 4 pairs of wires. If power is received over 4 pairs of wires, power is output over only 2 pairs of wires. Preferably, the power signature of the received power is further detected. If the incoming power over a first 2 pairs of wires supports in excess of 13 watts of power consumption, and power is received over 4 pairs, then the output power supports in excess of 13 watts of power consumption; and if the incoming power over a first 2 pairs of wires supports in excess of 13 watts of power consumption, and power is not received over 4 pairs, then the output power does not support in excess of 13 watts of power consumption.

DEFINITIONS

Terms to describe the invention are defined as follows: Power signal A power signal is a signal or voltage or electric potential, e.g. relative to another reference signal, which can be for example ground, and may consist of one, two or more than two individual signals. Data connections or cable pairs of an Ethernet connection may carry or transport the power signal. One or more of the individual power signals can be considered to determine the quality of the power signal, such as e.g. the (overall) stability or fluctuation. The power signal is transmitted via a conductive cable, such as a cable made from copper.

Navigation system

The invention can be used to power a navigation system or at least one part thereof, such as a camera. A navigation system can include:

a computer for processing absolute point data and relative point data;

a detection device for detecting the position of main and auxiliary points in order to generate absolute point data and to supply absolute point data to the computer;

a data interface for receiving relative point data and for supplying relative point data to the computer; and

a user interface for receiving data from the computer in order to provide information to the user, wherein the received data are generated by the computer on the basis of the results of the processing performed by the computer.

Computer

The method in accordance with the invention is preferably at least partly executed by a computer, i.e. all the steps or merely some of the steps (i.e. less than the total number of steps) of the method in accordance with the invention can be executed by a computer. Data processing method

The method in accordance with the invention is for example a data processing method. The data processing method is preferably performed using technical means, for example a computer. The data processing method is preferably constituted to be executed by or on a computer and for example is executed by or on the computer. For example, all the steps or merely some of the steps (i.e. less than the total number of steps) of the method in accordance with the invention can be executed by a computer. An embodiment of the data processing method is a use of the computer for performing the data processing method. The computer for example comprises at least one processor and for example at least one memory in order to (technically) process the data, for example electronically and/or optically. The processor being for example made of a substance or composition which is a semiconductor, for example at least partly n- and/or p-doped semiconductor, for example at least one of II-, III-, IV-, V-, Vl-semiconductor material, for example (doped) silicon and/or gallium arsenide. An embodiment is directed to the use of such a substance or composition in the data processing method. The calculating steps described are for example performed by a computer. Determining steps or calculating steps are for example steps of determining data within the framework of the technical data processing method, for example within the framework of a program. A computer is for example any kind of data processing device, for example electronic data processing device. A computer can be a device which is generally thought of as such, for example desktop PCs, notebooks, netbooks, etc., but can also be any programmable apparatus, such as for example a mobile phone or an embedded processor. A computer can for example comprise a system (network) of "sub-computers", wherein each sub-computer represents a computer in its own right. The term "computer" includes a cloud computer, for example a cloud server. The term "cloud computer" includes a cloud computer system which for example comprises a system of at least one cloud computer and for example a plurality of operatively interconnected cloud computers such as a server farm. Such a cloud computer is preferably connected to a wide area network such as the world wide web (WWW) and located in a so-called cloud of computers which are all connected to the world wide web. Such an infrastructure is used for "cloud computing", which describes computation, software, data access and storage services which do not require the end user to know the physical location and/or configuration of the computer delivering a specific service. For example, the term "cloud" is used in this respect as a metaphor for the Internet (world wide web). For example, the cloud provides computing infrastructure as a service (IaaS). The cloud computer can function as a virtual host for an operating system and/or data processing application which is used to execute the method of the invention. The cloud computer is for example an elastic compute cloud (EC2) as provided by Amazon Web Services™. A computer for example comprises interfaces in order to receive or output data and/or perform an analogue- to-digital conversion. The data are for example data which represent physical properties and/or which are generated from technical signals. The technical signals are for example generated by means of (technical) detection devices (such as for example devices for detecting marker devices) and/or (technical) analytical devices (such as for example devices for performing imaging methods), wherein the technical signals are for example electrical or optical signals. The technical signals for example represent the data received or outputted by the computer. The computer is preferably operatively coupled to a display device which allows information outputted by the computer to be displayed, for example to a user. One example of a display device is an augmented reality device (also referred to as augmented reality glasses) which can be used as "goggles" for navigating. A specific example of such augmented reality glasses is Google Glass (a trademark of Google, Inc.). An augmented reality device can be used both to input information into the computer by user interaction and to display information outputted by the computer. Another example of a display device would be a standard computer monitor comprising for example a liquid crystal display operatively coupled to the computer for receiving display control data from the computer for generating signals used to display image information content on the display device. A specific embodiment of such a computer monitor is a digital lightbox. The monitor may also be the monitor of a portable, for example handheld, device such as a smart phone or personal digital assistant or digital media player.

Computer program product; signal wave

The invention also relates to a program which, when running on a computer, causes the computer to perform one or more or all of the method steps described herein and/or to a program storage medium on which the program is stored (in particular in a non-transitory form) and/or to a computer comprising said program storage medium and/or to a (physical, for example electrical, for example technically generated) signal wave, for example a digital signal wave, carrying information which represents the program, for example the aforementioned program, which for example comprises code means which are adapted to perform any or all of the method steps described herein. Within the framework of the invention, computer program elements can be embodied by hardware and/or software (this includes firmware, resident software, micro-code, etc.). Within the framework of the invention, computer program elements can take the form of a computer program product which can be embodied by a computer-usable, for example computer- readable data storage medium comprising computer-usable, for example computer-readable program instructions, "code" or a "computer program" embodied in said data storage medium for use on or in connection with the instruction-executing system. Such a system can be a computer; a computer can be a data processing device comprising means for executing the computer program elements and/or the program in accordance with the invention, for example a data processing device comprising a digital processor (central processing unit or CPU) which executes the computer program elements, and optionally a volatile memory (for example a random access memory or RAM) for storing data used for and/or produced by executing the computer program elements. Within the framework of the present invention, a computer-usable, for example computer-readable data storage medium can be any data storage medium which can include, store, communicate, propagate or transport the program for use on or in connection with the instruction-executing system, apparatus or device. The computer-usable, for example computer-readable data storage medium can for example be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, apparatus or device or a medium of propagation such as for example the Internet. The computer-usable or computer-readable data storage medium could even for example be paper or another suitable medium onto which the program is printed, since the program could be electronically captured, for example by optically scanning the paper or other suitable medium, and then compiled, interpreted or otherwise processed in a suitable manner. The data storage medium is preferably a non- volatile data storage medium. The computer program product and any software and/or hardware described here form the various means for performing the functions of the invention in the example embodiments. The computer and/or data processing device can for example include a guidance information device which includes means for outputting guidance information. The guidance information can be outputted, for example to a user, visually by a visual indicating means (for example, a monitor and/or a lamp) and/or acoustically by an acoustic indicating means (for example, a loudspeaker and/or a digital speech output device) and/or tactilely by a tactile indicating means (for example, a vibrating element or a vibration element incorporated into an instrument). For the purpose of this document, a computer is a technical computer which for example comprises technical, for example tangible components, for example mechanical and/or electronic components. Any device mentioned as such in this document is a technical and for example tangible device. SUMMARY

According to an aspect, the invention is directed to a power control system for use in a power- over-Ethernet (PoE) system. The power control system can be independent from the data transmission or data connection but can, however, also be included or combined with the data transmission or data connection.

The power control system comprises one or more first connection ports (hereinafter simply: first connection port) capable of receiving power as a power signal from an Ethernet connection. The first connection port and/or the Ethernet connection can have an arbitrary number of individual connection ports, wherein the Ethernet connection can meet an IEEE standard, such as the IEEE 802.3af-2003 PoE standard or the IEEE 802.3at-2009 PoE standard, but may also deviate therefrom. The first connection port can use all of the pins or individual ports provided by the Ethernet connection or may only use a subset of pins or individual ports, such as one, two or more connections or individual ports being part of the Ethernet connection.

The power signal received via the first connection port can have a varying quality or varying stability resulting from numerous influences, such as length of the cable of the Ethernet connection or stability of the power source providing power to the Ethernet.

The power control system comprises at least one second connection port capable of delivering power to a least one device, such as a medical device, e.g. a camera or medical instrument used in a medical environment or operating room. It is possible to provide only a single second connection port or more, such as two or three or any arbitrary number of second connection ports, if more than a single device are to be connected or are to be powered using the power control system. For example, all second connection ports can be of the same type or meet the same standard as the first connection port, e.g. all connection ports being Ethernet connection ports.

A power quality monitoring unit is connected to the first connection port and is capable to monitor the quality of the power signal received from the Ethernet connection. It is noted that not only a missing PoE signal leads to activation of one or more additional power sources, but any deterioration of the power signal or power supply (PoE) leading to a power signal no longer meeting e.g. "high" quality standards. Other than simply replacing a missing PoE signal, the invention ensures an output power signal of a predetermined quality at the second connection port, even if the input PoE signal is still present, but does not meet the predefined quality demands .

The quality of the power signal can be judged using one or more of the following parameters: Availability of source power (within specified ranges)

It can be determined according to which power standard the provided source is (e.g. the IEEE 802.3af-2003 standard PoE is different from IEEE 802.3at-2009, often referred to as PoE plus). Moreover it can be checked whether the provided source power is within a predetermined range or above or below a predetermined limit, such as being a too high (e.g. being above 50 V or 57 V and/or above 400 mA, 450 niA, 500 mA or 530 mA) or too low (e.g. being below 44 V or 50 V and/or below 350 mA or 400 mA and/or below 12,8 W, 13 W or 21 W, 24 W) source power.

In case the source power is determined to be too high, the power control system can for example reduce the power input received at the first connection port or can limit the maximum provided voltage using for example a Zener diode. In case the provided source power is determined to be too low considering the specified power requirements of for example one or more (medical) devices connected to the power control system, the power requirement of the (medical) devices being known to the power control system, it is possible to add an additional power source which can be part of the power control system, such as a battery or a capacitor, and/or by providing power through an additional power connection separate from the Ethernet.

In addition or alternatively, the functionality of one or more of the connected (medical) device(s) may be reduced in order to reduce the power demand which has to be provided by the power control system resulting from the Ethernet and optionally one or more additional power sources.

Stability of source power The stability of the source power can for example be judged by considering current and/or voltage fluctuations or oscillations. In case an instable source power is observed (e.g. voltage, current and/or power deviate or fluctuate more than +- 5%, +- 10 % or+-15 % from a given operating state or operating point, such as a steady state operating point), the power control system can either smooth these observed oscillations using for example an inductor or a capacitor, or a switched-mode power supply circuitry which may be provided within the power control system.

Alternatively or in addition, an additional power source can be added, as described above. This can e.g. reduce undesired fluctuations or oscillations of the PoE signal.

Strength of initial current

In case the initial current required by the powered device is too high (e.g. above 1.000 mA, 5.000 mA), it can be limited using passive means, such as a diode or active means, such as a switched-mode power supply. In case the initial current provided by the power sourcing equipment is too low (e.g. below 350 mA or 400 mA), an additional power source can be added as described above. Alternatively or in addition, the connected (medical) device(s) can be stepwise powered to for example increase the functionality stepwise, so that the stepwise powering-up of the connected devices may reduce a possible too high inrush current.

Amount of ground leakage current

In case the ground leakage current is above a predefined value, such as being above 100 mA or 500 mA, the power control system can switch off one or more or all of the connected devices.

In most cases a high ground leakage current is an indication of a problem in the overall setup and should be indicated to a user who then should check whether or not the setup is in good order.

Electrical impedance of ground connection

In case the electrical impedance of the ground connection is above a predefined value (e.g. above 3 Ω, 5 Ω or 10 Ω), resulting for example from a too long wire connection, this should be indicated to a user and/or the power control system can switch off one or more of the connected devices for security reasons.

The power control system comprises further a power management unit which may also be considered as being a switching device, the power management unit being connected to the power quality monitoring unit and being capable to receive a power quality signal from the power quality monitoring unit representative of the quality of the power received at the first connection port from an Ethernet connection. The power management unit being further connected to the first connection port, either directly or indirectly, e.g. via the power quality monitoring unit, to receive power from the first connection port. The power management unit is capable of being connected to or is connected to an additional power source, such as a battery, a capacitor or an external power source, to receive additional power therefrom. The power management unit is further connected to the at least second connection port and is capable of delivering power to the at least one second connection port, the delivered power stemming from the power received via the Ethernet connection and optionally stemming from one or more additional power source(s).

The power quality monitoring unit thus monitors the quality of the power delivered by the Ethernet connection and issues a power quality signal to the power management unit, which is capable of either improving the quality without adding additional power or by adding power from an additional power source to such an amount to deliver a combined power signal to the at least one second connection port, the combined power signal consisting in part of the power received from the first connection port and in part of the power received from the additional power source. The resulting power signal meeting predetermined quality requirements, such as being capable of providing sufficient power and/or at a sufficient stability, such as having no or only an allowable amount of fluctuation.

Alternatively to adding power from an additional power source or in addition thereto, the power management unit can interact with one or more of the devices being connected at the at least on second connection port in order to control one or more of the connected devices to for example stepwise reduce or increase the functionality of the respective device. In many cases, the amount of functionality provided by a connected device can vary, which in turn influences the required power or power consumption, so that for example in case not sufficient (or at the required amount instable) power is available, the functionality of such a device can be reduced, so that the power demanded by the at least one connected device can be adapted to an actual provided power in order to achieve a power signal meeting a predetermined quality criterion.

The additional power source may always be present and can optionally be also scanned, for example by the power quality monitoring unit. Alternatively, no scan of the additional power source is performed, since for example the properties or quality of the additional power source is known. Preferably the available power from the Ethernet power source (PoE) is determined and in addition, the suitability of the power for the attached device is determined. The information concerning the current power demand of a connected device can be transmitted to the power control system, for example the power management unit, which information can be a basis for the decision of the power management unit to for example add an additional power source or communicate to one or more of the connected devices that the functionality of the respective device(s) should be reduced. Thus, the power management unit can optionally exchange information with one or more of the connected devices to control these devices or at least the power demand of the connected devices.

The required power of the connected device(s) is in most cases already known and this information can be provided to the power management unit either as a permanent information resident within the power control system or as an information being provided from the connected device or a measurement unit associated with the connected device giving as a feedback information to the power management unit the actual or current power demand.

The information regarding the power consumption of a connected device having different levels of functionality, especially the power consumption associated to each level of functionality, can be either an information being input to the power control system, for example by a user, or being stored in the power management unit, before operating the device. Alternatively or in addition, this information can be provided during operation of the respective device to the power control system or power management unit.

Optionally, a battery charging unit can be provided in order to charge a battery being an additional power source, in case more power is delivered by the Ethernet connection than needed by the connected device(s). The power control system, for example the power management unit or the power quality monitoring unit, can monitor the charging level of the battery and depending on the current demands of the connected devices and the power delivered by the Ethernet, current can be directed to or away from the battery. The power delivered through the Ethernet connection can be distributed via as many pairs of wire as necessary for the available PoE standard (e.g. 2 pairs of wire for IEEE 802.3at) that are connected to the first connection port (input port). The additional power source can be directly connected to the power management unit, i.e. not via an Ethernet connection, or can be connected thereto via an Ethernet connection. The additional power source may be present at any time or may be added as needed.

The power quality monitoring unit can evaluate the presence and quality of the power signal received from the Ethernet connection irrespective of the presence of an additional power source.

The second connection port can be a port meeting the Ethernet specification or can alternatively be a different connection port suitable for connection with an external (medical) device.

The power consumed by the power control system itself, such as by the power quality monitoring unit, the power management unit and optional switching systems, can be provided by the external Ethernet power signal and/or an additional power source, such as a battery being e.g. an internal part of the power control system.

According to an embodiment, the external PoE can be cut or closed in case the additional power source is required, so that for example in the case of a poor power signal received via the Ethernet being below a repairable or improvable level (the improvement being done e.g. by using an additional power source and/or by other means as described herein), this power connection is cut off and the device(s) connected to the at least one second connection port are exclusively powered by the additional power source(s).

The power control system can, according to an embodiment, automatically switch on and off the power of the Ethernet connection, the additional power source(s) and/or one or more devices connected to the at least one second connection port, or switch the functionality of one or more of these connected devices to a higher or lower level of functionality depending on the available total power provided by the Ethernet and optionally provided additionally by at least one additional power source.

Thus, the present invention can secure and control a constant power source quality provided via the at least one second connection port to one or more connected (medical) devices. A connected powered device can thus be protected to secure a possible critical function of the respective device by maintaining a constant power source quality being independent of the quality of the power signal provided by the Ethernet. According to an embodiment, the power control system comprises a data/power separation unit being connected between the first connection port and the power quality monitoring unit and being capable of separating a data signal from a power signal. According to this embodiment, a data/power combination unit is connected between the power management unit and the at least one second connection port, being capable of combining the separated data signal with a (possibly improved) power signal. Thus, data is not manipulated by the power control system but only led through. This provides the benefit that no or only a negligible latency is added to the data signal. No security of data is violated using the described power control system. Of course, the power control system can also be used for non-PoE devices, since the data signal is always present.

According to an embodiment, an additional power source can be manually selected by user interaction e.g. overriding a possible automatic selection of the additional power source(s) being for example made by the power quality monitoring unit and/or the power management unit in dependence of for example the quality of the power signal provided by the Ethernet. According to an embodiment, there is a (medical) grade insulation of data and power consisting of an insulation device in each path offering one (or two) means of protection. According to an embodiment, an indicator, such as an optical and/or acoustical indicator, is provided at the power control system for outputting to a user whether or not a power signal received from an Ethernet connection or Ethernet port meets a predetermined quality requirement. The indicator can thus provide information to a user on the status of a power source and optionally on the status of an additional power source (e.g. "battery charging", "battery discharging", "battery being connected to second connection port or connected devices").

According to a further aspect, the invention relates to a medical system comprising the above described power control system and at least one powered or non-powered medical device, such as a camera or a medical instrument, being connected to the at least one second connection port of the power control system.

In the case of a camera, the levels of functionality can be defined e.g. by the viewing range or field of view of the camera. It can for example be determined that the camera be automatically switched off in case the field of view is below a predetermined level, such as below 3 m or 2,5 m, due to insufficient power supply. Alternatively, this reduced functionality can actively be controlled by the power control system and can again be switched to a higher functionality or larger field of view when sufficient power can be provided by the power control system.

According to a further aspect, the invention is directed to a method for providing power to at least one (medical) device, comprising one or more of the following steps: power is received as a power signal from an Ethernet connection and power is delivered to the at least one (medical) device. The quality of the power signal received from the Ethernet connection is monitored, which monitoring can be constant or permanent or can be at predefined intervals. When the quality of the power signal does not meet predetermined quality requirements as set forth above, an additional power signal or additional power source can be added to such an amount to deliver a combined power signal to the at least one (medical) device, the combined power signal consisting in part of the power received from the Ethernet and in part of the power received from the additional power signal. Thus, the combined power signal can again meet predetermined quality requirements even if the Ethernet power signal is below these quality requirements.

According to an embodiment, the functionality of at least one of the (medical) devices can be reduced to reduce the power consumption of the device, when the quality of the power signal does not meet predetermined quality requirements. Preferably, the reduced functionality goes along with reduced power consumption, so that the quality of the power signal at the reduced power consumption is improved. The functionality of the at least one (medical) device can be enriched, if it is determined that sufficient power can be provided. Optionally, a step-up procedure can be performed for one or more of the connected devices to power these devices, for example in order to avoid a high inrush current. BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is described with reference to the enclosed figures which represent embodiments. The scope of the invention is not limited to the specific features disclosed in the figures, which show:

Figure 1 a first embodiment of the power control system;

Figure 2 a flow chart illustrating the operating principle of the power control system;

and

Figure 3 a second embodiment of a power control system.

DESCRIPTION OF EMBODIMENTS

Figure 1 shows a first embodiment of a power control system which is connected at a first connection port PI to a cable providing data and power, such as the Ethernet. The power provided by the Ethernet is input by the shown power sourcing equipment. The data and power received at the first connection port PI is transmitted internally of the power control system to a data/power separation device 3 which can also be designated as being a splitter. The data/power separation device 3 separates the data from the power. The power is led to a power quality monitoring unit 1 able to perform a power quality detection. The power itself is further transmitted to a power management unit or switching device 2. In addition, the power quality monitoring unit 1 provides a power quality signal to the power management unit 2, which is connected to an additional power source 5, such as a rechargeable battery. Depending on the quality information provided to the power management unit (switching device) 2, the additional power source 5 is switched on or off, which can be done step-wise to only add a required amount of energy to achieve a suitable power signal meeting a set quality, to optionally provide additional dosed power in case the power received from the Ethernet does not meet the predefined quality requirements. The power management units 2 is further connected to a data/power combination device 4 and provides suitable power of good quality to the data/power combination device 4. The power provided by the power management unit 2 may thus be power being received solely from the Ethernet or solely from the additional power source 5 or may be a combination thereof. For example, the additional power source 5 adds as much power to the power provided over the Ethernet as required by the connected powered device PD being connected to the second connection port P2. The second connection port P2 is connected to the data/power combination device 4 and receives power having sufficient quality in addition with the data signal transmitted from the data/power separation device 3 to the data/power combination device 4 and therefrom to the second connection port P2.

Figure 2 is a flow chart according to an embodiment illustrating an operating principle of the power control system.

Power and data are provided by a source, such as an Ethernet connection. The power control system provides an intermediate circuit, such as the data/power separation device 3, power quality monitoring unit 1 and/or power management unit 2 to negotiate the suitable PoE protocol between the power sourcing equipment and the powered device. Depending on a determined quality of the provided power, an additional power source 5 is activated.

Power and data are separated, for example by a data/power separation device 3. The data itself is not manipulated and is transmitted for instant combination with a probably improved power signal, for example at a data/power combination device 4.

The separated power is checked for specific quality requirements as shown, such as whether or not the source power is too high or too low, the occurrence of current or voltage oscillations, the amount of the initial current, the amount of the leakage current (not shown) and/or the electrical impedance of the ground connection (also not shown).

Although a number of quality requirements are shown, it is noted that only one or a subset of the shown quality requirements may be used or the shown quality requirements may be individually or in total be combined with other quality requirements described in this application.

In case one or more of predefined required quality requirements are not met, an additional power source 5 is activated. In case all quality requirements are met, no activation of the additional power source 5 takes place. In case a rechargeable battery is provided as additional power source, this battery can be charged, if excess power is available, i.e. provided by the Ethernet and not consumed by the connected devices. After combination of the power and data signals, an intermediate circuit negotiates the suitable PoE protocol and activates the power for drain to the at least one powered device PD.

The connected powered device PD is powered with adequate power and receives and/or transmits data.

It is noted that the data connection is bidirectional, i.e. data can be transmitted both ways through all mentioned and shown data connections.

Figure 3 shows a further embodiment of a power control system, wherein data and power is provided to the power control system via an Ethernet connection being connected to a power sourcing equipment and optionally an external data system or data nets, such as for example the Internet.

Compared to the embodiments shown in Figure 1, additional optional features are shown, such as an Ethernet insulation and a power insulation For this insulation a suitable insulation device offering one or more means of protection is present in each path. The degree of protection offered is depending on the possibility of patient contact of the powered device. As can be seen from Figure 3, more than a single additional power sources can be provided and can be connected to the switching device (power management unit) 2 to provide power thereto.

As described above, more than a single powered device PD can be connected to one of the provided two or more second connection ports P2.

The switching device or power management unit 2 can provide a signal to a user indication, such as a LED or display, indicating the current internal state of the power control system.

Further, a manual selection can be made a user, for example via a switch or a touch screen, to control the switching device 2 or power management unit to enter desired settings.

Claims

1. Power control system for use in a power-over-Ethernet system, the power control system comprising:

- at least one first connection port (PI) capable of receiving power as a power signal from an Ethernet connection;

- at least one second connection port (P2; P2'; P2") capable of delivering power to at least one device (PD; PD1, ... PDn);

- a power quality monitoring unit (1) being connected to the first connection port (PI) and being capable to monitor the quality of the power signal received from the Ethernet connection; and

- a power management unit (2) being connected to the power quality monitoring unit (1) and the at least one second connection port (P2; P2'; P2") and being capable of being connected to at least one additional power source (5, 5'),

wherein the power management unit (2) is capable of receiving a power quality signal from the power quality monitoring unit (1) representative of the quality of the power received at the at least one first connection port (PI) from the Ethernet connection,

wherein the power management unit (2) is capable of receiving the power from the first connection port (PI) and from the at least one additional power source (5, 5') and delivering power to the at least one second connection port (P2; P2'; P2"), and

wherein, at least when the power quality signal indicates that the power signal is of insufficient quality or permanently, the power management unit (2) is capable of improving the quality of the power signal and is capable of adding power from the at least one additional power source (5, 5') to such an amount to deliver a combined power signal to at least one of the second connection port(s) (P2; P2'; P2"), the combined power signal consisting in part of the power received from the first connection port (PI) and in part of the power received from the at least one additional power source (5, 5') and meeting predetermined quality requirements.

2. The power control system of claim 1 , wherein the power quality monitoring unit (1) is capable to monitor the following parameter determining the sufficient quality of the power signal: stability of source power or provided power and/or voltage and/or current fluctuation being less than +- 5 %, +- 10 % or +- 15 % from a given operating point or steady state operating point.

3. The power control system of one of the preceding claims, wherein the power quality monitoring unit (1) is capable to monitor the following parameter determining the sufficient quality of the power signal:

strength of initial current or initial current required by one or more powered devices (PD; PD1, ... PDn) being below a first predefined value and/or initial current provided by the power signal being above a second predefined value.

4. The power control system of one of the preceding claims, wherein the power quality monitoring unit (1) is capable to monitor the following parameter determining the sufficient quality of the power signal:

amount of ground leakage current being below a predefined value.

5. The power control system of one of the preceding claims, wherein the power quality monitoring unit (1) is capable to monitor the following parameter determining the sufficient quality of the power signal:

electrical impedance of ground connection being below a predefined value.

6. The power control system of one of the preceding claims, wherein the power quality monitoring unit (1) is capable to monitor the following parameter determining the sufficient quality of the power signal:

availability of the power source or provided power and/or voltage and/or current being above or below defined values or within defined ranges.

7. The power control system of one of the preceding claims, further comprising at least one additional power source (5, 5').

8. The power control system of one of the preceding claims, further comprising: a data/power separation unit (3) being connected between the at least one first connection port (PI) and the power quality monitoring unit (1), capable of separating a data signal from a power signal; and

a data/power combination unit (4) being connected between the power management unit (2) and the at least one second connection port (P2; P2', P2") capable of combining a data signal with a power signal or combined power signal.

9. The power control system of one of the preceding claims, further comprising an indicator for outputting to a user whether or not a power signal received from an Ethernet port meets a predetermined quality requirement.

10. Medical system comprising the power control system of one of the preceding claims and at least one medical device (PD; PD1, ... PDn) being connected to the at least one second connection port (P2; P2', P2") of the power control system.

11. Method for providing power to at least one device (PD; PD I, ... PDn), comprising the steps:

receiving power as a power signal from an Ethernet connection and delivering power to the at least one device (PD; PD1, ... PDn);

monitoring the quality of a power quality signal received from the Ethernet connection, and

when the quality of the power signal does not meet predetermined quality requirements, such as defined in one of claims 2 to 6, adding an additional power signal to such an amount to deliver a combined power signal to the at least one device (PD; PD1, ... PDn), the combined power signal consisting in part of the power received from the Ethernet and in part of the power received as the additional power signal and meeting predetermined quality requirements.

12. The method of the preceding claim, wherein the functionality of at least one of the devices (PD; PD1, ... PDn) is reduced to reduce the power consumption of the device when the quality of the power signal does not meet predetermined quality requirements.