Abstract:
The present invention is directed to a system and method which establishes physically fixed charger stations that work in conjunction with a medical cart, such as an ultrasound cart. The medial cart contains a power supply, such as a large battery, with the capacity to keep the system going for a full day&#39;s use. Each docking station provides a fixed location for one or more carts and allows each cart to plug directly into a source of premises power. The docking stations allow the plugged-in cart to recharge while the cart is not in use. In one embodiment, a large Class C battery capable of powering not only the medical device but its associated peripherals as well. Thus, when the cart is removed from the docking station and taken to a patient&#39;s location, the equipment on the cart can be operated without the need for plugging the cart into a wall outlet thereby eliminating the need for a long power cord. The fixed locations of the docking station also eliminates the need for hunting “misplaced” carts.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of co-pending, commonly assigned U.S. patent application Ser. No. 12/392,869 entitled “CHARGING STATION FOR CORDLESS ULTRASOUND CART,” filed Feb. 25, 2009, and this application is related to U.S. patent application Ser. No. 11/590,010 filed Oct. 31, 2006, entitled “DOCKING STATION HAVING AUXILIARY POWER MANAGEMENT FOR USE WITH PORTABLE MEDICAL EQUIPMENT,” the disclosures of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to battery charging systems and more particularly to systems and methods for maintaining the batteries within a portable medical device cart charger. 
     BACKGROUND OF THE INVENTION 
     It is now common practice in a variety of situations to use portable medical devices, such as ultrasound devices, for examination of patients at the location of the patient. Often this location is the patient&#39;s bed in a hospital room. The portable device can be brought to the patient for the examination and in such a situation, the portable device operates from batteries internal to the device. The portable device, in one embodiment, resides on a movable cart and plugs into the cart for recharging. The cart, in turn, plugs into a premises power supply and operates to supply a source of power for both operating the portable device while the device is attached to the cart and for recharging the device&#39;s internal batteries. The cart also provides a source of power for peripheral equipment, such as printers, displays, etc. used with the medical device. Thus the cart requires a power cord long enough to plug into the premises source of power which is a wall outlet. 
     Several problems exist when the cart is moved to a patient&#39;s bedside. Some of these problems revolve around the fact that often there is a myriad of equipment plugged into the wall outlets in a patient&#39;s room and available outlets are scarce. Even when outlets are available, they typically are a large distance from where the cart is to be used thereby necessitating a long power cord attached to the cart. In addition to the problem of simply running this cord from the cart to the wall outlet, there is the problem of containing the cord when the cart is being moved from location to location. Long power cords, as anyone who has used an electric vacuum sweeper well knows, have a disconcerting affinity for becoming tangled, caught on furniture and getting underfoot. In general, power cords on devices, particularly long power cords used in cramped conditions, are a general nuisance and worse, often unsafe. 
     In the medical setting discussed above, when the carts are not in actual use with a patient they are moved off to the side and often the operator forgets to plug in the cart. However, even if the operator remembers to plug in the cart, there is not always an available power outlet in close proximity to the present location of the cart. Thus, the cart operator then must hunt down a suitable location to “park” the cart. Often this suitable location is based on physical space and not on power availability. This then results in the failure to recharge the portable medical equipment residing on the cart. 
     Another problem is that the carts tend to be left available area randomly (usually in a location near where they were last used, with or without being plugged into a power outlet) and thus when the next user desires the use of the cart a search is often required to locate an available cart. This then wastes valuable time of doctors and practitioners either while they look for the cart or while a procedure they wish to be perform is delayed while someone else hunts down the cart. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to systems and methods which establish physically fixed or semi-fixed charger stations that work in conjunction with a mobile cart, such as an ultrasound cart. The cart may comprise a power supply, such as a large battery, with the capacity to keep one or more devices of the system thereof operating, such as to provide operation for a full day&#39;s use. Similarly, devices on or of the cart may additionally or alternatively comprise such a power supply for facilitating their use. Docking stations of embodiments herein provide a fixed or semi-fixed location for one or more carts and allow each cart to plug directly into a source of premises power. 
     Docking stations and carts of embodiments of the invention are correspondingly adapted to facilitate interfacing (also referred to herein as “docking”) a cart with a docking station wherein electrical and/or other connections are completed without further human intervention. That is docking stations and carts of embodiments comprise interface surfaces adapted to guide the relative movement between the docking components such that the desired connections are completed when docked. 
     Docking a cart with a docking station provides power and/or other services (e.g., network communication link, data upload, data download, etc.) for operation of the cart and devices thereof according to embodiments. Additionally or alternatively, docking a cart with a docking station allows the plugged-in cart to recharge while the cart is not in use according to embodiments. For example, in one embodiment, a large Class C battery capable of powering not only a medical device component but also its associated peripheral devices (e.g., printer, external monitor, etc.) may be present on the cart and provided recharging when the cart is docked with a docking station. Thus, when the cart is removed from the docking station and taken to a patient&#39;s location, the equipment on the cart can be operated without the need for plugging the cart into a wall outlet thereby eliminating the need for a long power cord. 
     Embodiments of carts operable with respect to docking stations herein are adapted to accommodate connection of the cart and/or devices thereof to a source of premises power without being docked with a docking station. For example, an auxiliary power connector is provided according to embodiments to facilitate connection to premises power when in an area having no docking stations, in an emergency situation when battery power is depleted, when a docking station is not available, etc. Embodiments implement a power switching mechanism to facilitate switching between such an auxiliary power connector and a docking station connector. For example, an automatic power switching mechanism is utilized to provide selection of a docking station connector as a source of premises power when a cart is docked with a docking station of embodiments herein. Such power switching mechanisms may additionally provide for isolation of a non-selected power connector, such as to provide a safety interrupt preventing an unused such power connector from becoming energized by energy provided by a power connector which is connected to premises power. 
     Docking stations of embodiments herein may be disposed in various locations. For example, fixed locations may be selected, such as in a hospital hallway, nurses&#39; station, surgical suite core, etc., for one or more docking station to eliminate hunting for “misplaced” carts, available/suitable power outlets, etc. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  shows a typical prior art medical cart of the type used for sonography equipment; 
         FIG. 2  shows one embodiment of a cart docking station; 
         FIG. 3  shows one embodiment of a cart base about to be docked into a docking station; 
         FIG. 4  shows one embodiment of an on-cart battery system; 
         FIG. 5  shows one embodiment of multi-cart docking station; 
         FIG. 6  shows one embodiment of a multiple docking system; 
         FIG. 7  shows an embodiment of a docking cart system; 
         FIG. 8  shows an embodiment of a docking station; 
         FIGS. 9A and 9B  show an embodiment of a docking head; 
         FIG. 10  shows a wiring configuration of a docking head of an embodiment; and 
         FIG. 11  shows a striker assembly of an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a typical prior art medical cart  10  of the type used for sonography equipment, such as device  11 . The ultrasound system could have an internal battery (not shown). Note that in this case the ultrasound cart does not have a battery but it does have power outlet  13  connected to long cord  12 . The cord has plug end  14  which is adapted to plug into a wall outlet, such as wall outlet  15  to provide power to the system. Auxiliary equipment  16  is plugged into outlet box  13 . This could be, for example, a printer, a video recorder, a VCR or any other type of equipment, all of which receive power from the cart, via the premises power outlet. As discussed above, when the power plug is removed from the wall outlet none of the auxiliary equipment can operate unless it has internal battery power. 
     In operation, when it is desired to move the cart to a patient location the cord is unplugged and wrapped around the cart, or onto a reel, or most often, held in the hand of the cart operator. When the cart gets to the proper location, the operator locates a convenient (often not so convenient) outlet and plugs the cart into the premises power. If power is not available, only those pieces of equipment on the cart that have internal batteries can function until their batteries run down. In any event, the cart must be plugged in for the peripherals to work since in almost all cases they do not have internal power. 
       FIG. 2  shows one embodiment  20  of a cart docking station. The docking station has at least one power connector  21  for mating with a mobile cart (shown in  FIG. 3 ). Other connectors, such as connector  22 , can be used to connect other connections, such as network connections, to the cart for downloading or uploading data from and to the cart. Openings  23  in this embodiment are designed to accept the wheeled legs of the cart when the cart is mated (docked) with the docking station. The docking station can be hard wired into the premises wiring (not shown) or it can be connected to a wall outlet via cord  24  and plug  25 . If desired, a plurality of docking stations  20  can be positioned at a single location. 
     Note that while not shown, the docking station can have built into it one or more power shaping controls, such as UPS or power converters, so that the carts can have equipment that runs at a different voltage or frequency than the premises power. This, then would reduce the cost of each individual medical service cart. The docking station is designed to be permanently, or at least semi-permanently, positioned at a particular physical location. This positioning can be. for example, by making the docking station not easily movable or positioning the clocking station within a defined space, or even by fastening the docking station to the premises. 
     In operation, when it is desired to dock a medical service cart at the docking station, the operator simply lines up the cart with the docking station and then pushes the cart by its handle into the dock. The power and (if available) the network connections are then made from the docking station to the cart without further human intervention. Cups  23 , in the embodiment shown, serve as an aid to positioning the cart with respect to the docking station. The cups are designed to mate with wheels of the cart. Other positioning aids can be employed including aids not physically attached to the docking station. 
       FIG. 3  shows one embodiment of base  301  of a cart (only cart strut  302  is shown) about to be docked into docking station  20 . The male end of plug  31  is shown about to be mated with connector  21  of docking station  20 . The plug connector is in a fixed position on said cart so that it can mate with a mating connector located on a dock without human intervention. Note that while the male connector is shown on the cart and the female on the dock, the reverse could be used, if desired. If networking connections are included, they also would be in a fixed position (not shown in  FIG. 3 ) about to be mated as the cart comes into docking position with respect to the docking station. The exact shape of the docking station is not critical, providing the attendant can easily move the cart into position with respect to the docking station in order for power and, if applicable, networking or other electrical connections, to be completed. Note that the fixed position of the various connectors on the cart are fixed relative to a docking station and this fixed position would be at the same location on all carts that mate with the docking station, or with similar docking stations. If desired, near-field electrical charging could be accomplished between the docking station and the cart and near-field electronic communications can also occur if hard-wired connections are not desirable. Once the cart is in docked relationship with the docking station, power is supplied to charge the on-cart batteries which, in this embodiment, are shown in device  40 ,  FIG. 4 . 
       FIG. 4  shows one embodiment of on-cart battery system  40  having at least one rechargeable battery section  44  and a power strip section  42 . The power strip is shown having thereon a plurality of power outlets  43 A,  43 B and  43 C, wherein equipment on the cart can plug into outlets  43 A- 43 C or their equivalents. In the embodiment shown in  FIG. 4 , battery system  40  is connectable to a source of external power via cord  45 . As discussed above, cord  45  would plug into a power outlet (such as power outlet  32 ,  FIG. 3 ) on the base of the cart so that device  40  can obtain power for internal charging, etc. when the cart is docked to the docking station. As noted above, the on-cart battery system can be hard wired to the cart if desired and outlets  43 A- 43 C can, if desired, be positioned at various locations on the cart convenient to the device(s) that they serve. In one embodiment, the rechargeable battery would serve to power the sonography equipment, a printer and a recorder when the cart is undocked from the docking station. In addition to or in the alternative to on-cart battery system  40 , one or more devices on the cart may comprise batteries which are provided energy via a docking station. 
     Typically, the power requirement for a cart would be approximately 150 w at 110v. Such power requirement may be met by one or more on-cart battery systems, one or more battery internal to the devices, or combinations thereof. Any or all such batteries may be provided with recharging energy by docking stations of embodiments of the present invention. A battery charging and/or discharging hierarchy may be implemented, such as disclosed in the above referenced patent application entitled “Docking Station Having Auxiliary Power Management For Use With Portable Medical Equipment,” to optimize device battery life. 
     In some embodiments where extensive use of the equipment is not necessary after the cart is disconnected from the docking station, cart batteries may not be desired. In such situations, in place of the battery and battery charging system a power supply can be used, Also if desired, voltages other than 110 can be supplied by the on-cart power supply and/or battery system. If desired, a built-in surge protector could be provided as could alternative energy sources, such as thermal or solar. Also, battery charging circuitry can be positioned on the docking system to charge one or more batteries on the cart. 
       FIG. 5  shows one embodiment of multi-cart docking station configuration having three individual docking stations  20  delineated by permanently affixed flags  501  on either end of the docking station system. Note that the individual docking stations can be connected to power sources individually as shown in  FIG. 5  or they can be daisy-chained with each other, as shown in  FIG. 6 , and connected to the premises power source with a common power connection. 
       FIG. 6  shows one embodiment of a multiple docking station configuration in which individual docking stations  60  physically and electrically inter-connectable to form a multi-cart docking station system. One docking station could be wired to the premises, for example using connection  61 . The interconnection shown in  FIG. 6  is by use of external power cords  601  and  602  between the individual docking stations, but the clocking stations can be designed to mechanically fit together with the mechanical linkage including power distribution without the use of interconnecting external cords. Any number of individual docking stations can be connected provided only that the wiring and premises circuit breakers are sufficiently sized to carry the load occasioned by all docking stations having carts positioned therein and simultaneously charging their respective on-cart batteries. The power load requirement for an individual cart would be expected to be in the range of 150 w according to embodiments. 
     If desired, docking stations can be mounted permanently or semi-permanently in various rooms so that when a cart comes into a room the cart can mate with the docking station and obtain power and be able to communicate information from the sonographic equipment to permanently mounted displays in the room and to a central data collection/monitoring location. This would be especially useful in an operating theatre where big displays are mounted so that the doctors can see the display while they are operating. This would allow the ultrasound system to be plugged in away from the bed in a pre-assigned location but at the same time allow the sonographic equipment to work in conjunction with all the other medical devices being used in that operating theatre. 
     An operating theatre or a room or any other place could have several docking stations available at different locations so that the cart can be positioned as desired from time to time, even being relocated during a procedure without losing communications or power. 
     While the cart is in the docking station the network connections could provide updates to the software of the devices on the cart particularly when they are not being used, such as in the middle of the night. Also, information that had been recorded all day could then be sent to a premises system, or other system, for storage and or further processing and distribution. 
     Directing attention to  FIG. 7 , another embodiment of a docking station system in accordance with the concepts of the present invention is shown as docking station system  700 , Docking station system  700  comprises cart  710  provided docking functionality through docking station  800  and docking head  900 . As can be seen in the illustrated embodiment, docking head  900  interfaces with docking station  800  to provide connectivity, such as electrical connectivity, data connectivity, etc., between cart  710  and/or devices thereon and one or more devices external thereto, such as premise power, central computer systems, etc.  FIG. 8  and  FIGS. 9A and 9B , discussed below, provide additional detail with respect to embodiments of docking station  800  and docking head  900 . 
     Referring now to  FIG. 8 , an embodiment of docking station  800  is shown without corresponding docking head  900  interfaced therewith. Docking station  800  of the illustrated embodiment includes connector  820  for mating with a docking head or other suitably adapted device (e.g., a mobile cart having a corresponding interface). Connector  820  includes one or more conductors  821  to provide electrical connectivity between docking station  800  and a correspondingly mated device. For example, conductors  821  may provide connectivity for premise power delivered to docking station  800  via cord  824  and plug  825 . Additionally or alternatively, conductors  821  may provide connectivity for a network interface, data upload, data download, sensors, state detectors, etc. For example, as will be better understood from the discussion of the exemplary docking station wiring diagram below, one or more conductors  821  may provide connectivity for a docking status indicator, such as indicator  826 . 
     Although the illustrated embodiment includes only one connector, it should be appreciated that embodiments may include a plurality of connectors which may be configured the same or differently. For example, a second connector  820 , perhaps having a different connector configuration that that of the illustrated embodiment of connector  820 , may be provided to make other connections, such as network connections. 
     Connector  820  of the illustrated embodiment is adapted to facilitate docking cart  710  with docking station  800  wherein electrical and/or other connections are completed without further human intervention. For example, connector  820  of embodiments is disposed in a floating or semi-floating mount allowing at least some movement (e.g., side-to-side, up and down, and/or in and out) of conductors  821  when interfacing with a connector and conductors of a corresponding device (e.g., connector  920  and conductors  921  of docking head  900  shown in  FIG. 9A ). Such movement may be relatively limited to facilitate desired interfacing of connectors without resulting in large scale movement causing substantial misalignment of the connectors. As an example, sufficient movement of connectors may be provided to allow for small adjustment of connector  820  during docking of docking station  800  and docking head  900  to accommodate slight mismatch of connectors  820  and  920 , such as due to manufacturing tolerances, uneven surfaces, etc. 
     The illustrated embodiment of connector  820  includes guide holes  822  disposed to accept guide pins to facilitate interfacing of the connectors. Directing attention to  FIG. 9A , wherein an embodiment of docking head  900  is shown without corresponding docking station  800  interfaced therewith is shown, guide pins  922  disposed about connector  920  in positions corresponding to the positions of guide holes  822  disposed about connector  820  are shown. Guide pins  922  of the illustrated embodiment are of sufficient length to engage guide holes  822  prior to conductors  821  and  921  interfacing. Accordingly, guide pins  922  interfacing with guide holes  822  provides alignment of connectors  920  and  820  to facilitate proper mating of conductors  921  and  821 . Embodiments of guide pins  922  and/or guide holes  822  are tapered (e.g., the tips of guide pins  922  and/or the orifice of guide holes  822  present a frustrum of a cone) to accept slight relative displacement between connectors  820  and  920  and provide alignment thereof as the connectors are mated. The aforementioned floating or semi-floating mounting, as may be provided with respect to connector  920  in addition to or in the alternative to connector  820 , may be used in combination with the foregoing guide pin and hole configuration to facilitate connector alignment and mating. 
     The illustrated embodiment of docking station  820  and docking head  920  include adaptations in addition to the foregoing guide holes and pins to facilitate docking and alignment of connectors. For example, docking station  800  includes receiver surfaces  810  which are shaped to guide a corresponding member into a desired docking orientation. Correspondingly, docking head  900  includes boss surfaces  910  to interface with receiver surfaces  810  and guide docking head  920  into a desired docking relationship with docking station  820 . These surfaces provide interface surfaces adapted to guide the relative movement between the docking station components such that the desired connections are completed when docked. For example, in the illustrated embodiment, receiver surfaces  810  provide a sufficiently wide point of entry for docking station  800  that docking head  920  need not be precisely positioned to initiate docking. However, as docking head  900  proceeds to dock with docking station  800 , receiver surfaces  810  narrow towards the width of the docking head boss portion. Thus, the receiver and boss surfaces cooperate to provide suitable relative movement between the docking station components to align connectors  820  and  920  sufficiently for guide holes  822  and guide pins  922  to engage and provide precise alignment of the conductors. 
     Because it is expected that receiver surfaces  810  and/or boss surfaces  910  may be exposed to appreciable impact forces during initial docking positioning of cart  710  and friction forces during subsequent docking mating movement, embodiments of the invention adapt one or more such surfaces to withstand such forces. For example, a leading or “nose” area of the boss portion of docking head  900  comprising boss surfaces  910  may be comprised of a nylon, polytetrafluoroethylene (PTFE) or TEFLON, or other suitable material for absorbing impact forces and minimizing frictional forces. For example, a replaceable “wear” item made of one or more such materials may be provided as the boss nose of docking head  900  having boss surfaces  910 . 
     It should be appreciated that guide holes  822  and guide pins  922  provide fine alignment of connectors  820  and  920  while receiving surfaces  810  and boss surfaces  910  provide more coarse alignment of docking station  800  and docking head  900 . Embodiments of the invention may include additional adaptation to facilitate docking and alignment of connectors. The illustrated embodiment of docking station  800  includes guide surfaces  811  which may additionally or alternatively be utilized to provide docking alignment. For example, surfaces of cart  710 , such as leg surfaces  711  shown in  FIG. 7 , may interface with guide surfaces  811  to provide alignment of the docking components. Guide surfaces  811  may provide a most coarse, general alignment to encourage an orientation of cart  710  for causing a boss portion of docking head  900  to align with a receiver portion of docking station  800 . Thereafter, receiving surfaces  810  and boss surfaces  910  provide less coarse alignment of docking station  800  and docking head  900  to facilitate mating of connectors  820  and  920 , whereupon guide holes  822  and guide pins  922  provide fine alignment of connectors  820  and  920  for mating. 
     Forces applied in docking the components of docking station system  700  may result in forces applied to docking station  800  sufficient to cause its movement, and thus discourage docking, if not adapted to counteract such forces. Accordingly, embodiments of docking station  800  may be rigidly affixed to a premises, such as by fasteners (e.g., screws, nails, bolts, adhesives, etc.) affixing the docking station to a surface such as a floor or wall. Other embodiments of docking station  800  are adapted to discourage undesired movement during docking without such rigid fixation to a premises. For example, embodiments of docking station  800  may comprise bumpers (e.g., bumpers  851  shown in  FIG. 7 ) or other structure to abut a premise wall and prevent movement of docking station  800  away from docking head  900  during docking operations. Additionally or alternatively one or more surface of docking station  800 , such as a bottom surface which faces a floor or other support surface, may be adapted to be non-slip, such as through the use of non-slip feet or a non-slip coating (e.g., rubber feet or rubberized surface coating). 
     Embodiments of docking head  900  are adapted to cooperate with docking station  800  to discourage undesired movement during docking. For example, docking head  900  of the embodiment illustrated in  FIG. 9A  includes ramp surface  912  which is disposed to interface with a corresponding surface of docking station  800  as the components are docked. As ramp surface  912  slides over the corresponding surface of docking station  800 , weight of cart  710  is borne by docking station  800 . Thus additional downward pressure, in addition to that due to the weight of docking station  800  alone, is applied to docking station  800 . Operation of the aforementioned non-slip feature of docking station  800  may be enhanced by this additional downward force applied during the docking process, thereby discouraging movement of docking station  800  during the docking process. 
     Docking station  800  and/or docking head  900  may be adapted to hold the docking station components in a docked relationship, and thus facilitate desired transfer of energy, data, etc. through their mated connectors. For example, the illustrated embodiment of docking station  800  includes spring pins  840  disposed to extend through a surface thereof. Correspondingly, docking head  900  includes detents  940  disposed in an opposing surface thereof. During the docking process, while docking head  900  is not in a full mated relationship with docking station  800 , spring pins  840  are compressed by the opposing surface of detents  940  so as to be substantially flush with the surface of docking station  800 . However, when docking head  900  is fully docked, and in a desired relative position with respect to docking station  800  which provides mating of the connectors thereof, detents  940  are aligned with spring pins  840 . Thus spring pins  840  are biased to extend beyond the surface of docking station  800  and engage detents  940 . Such biased engagement of spring pins  840  with detents  940  encourages docking station  800  and docking head  900  to remain in the desired relative positions. Surface friction of the opposing surfaces, also providing the aforementioned downward force to docking station  800 , may also discourage relative movement between docking station  800  and docking head  900 . The spring bias provided by embodiments of spring pins  840  is selected to discourage undesired relative movement between docking station  800  and docking head  900 , while permitting desired undocking movement when desired. 
     Once in a docked relationship, power, data, signals, and/or the like flow through mated connectors  820  and  920 . Docking head  900  may provide a plug or other connector to which cart  710  and/or one or more devices of cart  710  are connected. For example, plug  926  (shown in  FIG. 9B ) is provided in the illustrated embodiment, such as may comprise a standardized plug to which many devices are readily able to connect, to facilitate completing the connection through docking station  800  and docking head  900  to cart  710 . For example, on-cart battery system  40  of  FIG. 4  may be coupled to plug  926  for providing energy to one or more devices of cart  710 . Additionally or alternatively, devices may plug directly into or be wired directly into docking head  900 , if desired. Similarly, cart  710  may comprise wiring therein, perhaps providing plugs (not shown) adapted to interface with devices thereon, which may plug directly into or wired directly into docking head  900 . Irrespective of the particulars of how connection is made, docking head  900  of embodiments provides connectivity to docking station  800  through connector  920  to cart  710  and/or devices thereof when docked with docking station  800 . 
     Embodiments of docking head  900  facilitate desired connectivity even when not docked with a corresponding docking station. For example, docking head  900  may provide one or more plugs or other connectors for interfacing with premise power, data networks, etc. when separated from docking station  800 . Accordingly, cart  710  and/or the devices thereof may be provided energy, signals, services, etc. when being used, such as at a patient&#39;s bed or in a surgical theatre, or otherwise deployed. 
     The illustrated embodiment of docking head  900  includes auxiliary plug  927  (shown in  FIGS. 7 and 9B ) adapted to provide connectivity to premise power when docking head  900  is not docked with docking station  800 . For example, one end of a standard power cord (not shown) may be plugged into auxiliary plug  927  and the other end of the power cord may be plugged into a premise power outlet, such as in a patient&#39;s room or other location, to provide line power to devices of cart  710 , to recharge batteries of devices of cart  710 , etc. 
     Docking and undocking of docking head  900  provides switched selection between connector  920  and auxiliary plug  927  as the input connector according to embodiments of the invention. For example, to avoid conductors of plug  927  being energized when connector  920  is mated with connector  820  of docking station  800 , and similarly to avoid conductors of connector  920  being energized when plug  927  is connected to premise power, embodiments of the invention implement a switched wiring configuration. 
     Directing attention to  FIG. 10 , an embodiment of a switched wiring configuration as may be utilized with respect to docking head  900  is shown. In the embodiment illustrated in  FIG. 10 , double-pole double-throw (DPDT) switch  1026  provides switchable connection of plug  926  for selective connection to either connector  920  or auxiliary plug  927 . Accordingly, operation of switch  1026  allows for selectively passing signals between either plug  926  and connector  920  or plug  926  and auxiliary plug  927 . 
     The illustrated embodiment includes double-pole single-throw (DPST) switch  1021  to connect/disconnect connector  920  from the internal wiring of docking head  900  and DPST switch  1027  to connect/disconnect auxiliary plug  927  from internal wiring of docking head  900 . Embodiments of docking head  900  include switches  1021  and  1027  in combination with switch  1026  to provide redundancy with respect to isolating an unused plug/connector from energized wiring of docking head  900 . Such redundancy may be desirable with respect to particular applications, such as where cart  710  is used in a hospital or similar environment. Embodiments of the invention may, however, utilize fewer switches e.g., utilize only switch  1026 ) and/or not isolate a plug or connector (e.g., where the plug/connector is disposed to avoid risk of shock due to energized conductors) if desired. 
     Operation of switched selection of connection of plug  926  either connector  920  or auxiliary plug  927  may be done to provide make-before-break connection or break-before-make connection, as desired. For example, in order to provide optimum safety and isolation of an unused plug/connector from energized wiring of docking head  900  a break-before-make configuration may be utilized. However, in order to provide uninterrupted passage of signals when transitioning between use of one plug/connector and the other plug/connector (e.g., during docking or undocking), embodiments of the invention may utilize a make-before-break configuration. 
     As with the mating of connectors  820  and  920  being configured to be accomplished through the docking process without further human intervention, switched selection of an appropriate plug/connector of docking head  900  is also configured to be accomplished through the docking process without further human intervention. Accordingly, switch actuator  1100  ( FIGS. 10 and 11 ) is provided according to embodiments to alter switch settings during docking and undocking operations. 
     Switch actuator  1100  of the embodiment illustrated in  FIG. 11  includes striker  930  (also shown in  FIG. 9A ) which is adapted to interface with a corresponding part of docking station  800  and result in manipulation of switch actuator  1100  during docking/undocking. For example, switch actuator  1100  may be disposed within docking head  900  such that striker  930  is free to move axially (e.g., using tabs  1101  of docking head  900  disposed in slots  1102  of switch actuator  1100 ) when engaged by corresponding pin  830  of docking station  800 . Accordingly, as docking head  900  is docked with docking station  800 , pin  830  engages striker  930  which is displaced axially into docking head  900 , thereby causing switch actuator to alter the states of switches  1021 ,  1026 , and  1027  of embodiments. Likewise, as docking head  900  is undocked from docking station  800 , striker  930  is allowed to move axially in the opposite direction, thereby allowing switch actuator to again alter the states of switches  1021 ,  1026 , and  1027 . Tabs (e.g., tabs  1111 ) or other structure of switch actuator  1100  may interface with switches  1021 ,  1026 , and  1027  to transfer the axial motion of the switching actuator to switch operation motion. 
     As can be seen in the embodiment of  FIG. 11 , connectors  820  and  920  of embodiments may carry signals to and from docking head  900 . For example, one conductor of connector  920  of the illustrated embodiment is tied to another conductor of connection  920  carrying line voltage to thereby provide a loop back of line voltage when connector  920  is mated with connector  820 . This loop back line voltage may be provided to an indicator or sensor, such as power indicator light  826  of  FIG. 8 , to show that docking has resulted in energizing of docking head  900 . 
     Embodiments of the foregoing docking station system are adapted to provide reliable operation, even when deployed in demanding or harsh environments. For example, in addition to providing rugged housing configurations for docking station  800  and docking head  900 , embodiments of the invention adapt moving parts, such as the aforementioned switch actuator, for reliable operation. The embodiment of switch actuator  1100  illustrated in  FIG. 11  includes shock mount  1121 , such as may comprise a rubber grommet mounting configuration for striker  930 , to absorb shocks and undesired loading. For example, side loads (non-axial forces) applied to striker  930  may be accommodated through flexing provided by shock mount  1121 . Moreover, forces which may otherwise cause over-travel of striker  930  may be accommodated through compression of shock mount  1121 . The embodiment illustrated in  FIG. 9A  is adapted to dispose striker  930  within a cylindrical housing which, although allows desired axial travel, protects striker  930  from striking or being stricken by objects other than pin  830 . 
     Further, in providing a reliable configuration, embodiments of switch actuator  1100  utilize spring bias forces of one or more switches (e.g., switches  1021 ,  1026 , and/or  1027 ) to provide axial movement thereof. Such switch spring bias force may be utilized to cause striker  930  to move axially as docking head  900  is undocked from docking station  800 . The use of switch spring bias to provide operation of switch actuator  1100  of embodiments leverages otherwise available structure for this purpose without introducing additional, potentially complicated, structure to the configuration, thereby providing a solution which is relatively simple with fewer points of failure. 
     It should be appreciated that docking head  900  as illustrated in  FIGS. 9A and 9B  provides a modular configuration which may be attached to cart  710  as an optional feature. Accordingly, cart  710  may be retrofitted with docking head  900  or relieved of docking head  900  as desired. Moreover, docking heads such as docking head  900  may be attached to any number of carts and cart configurations. For example, although embodiments herein have been described with reference to cart  710  having surfaces  711  for facilitating docking with docking station  800 , there is no limitation to the use of carts having such a configuration. Accordingly, docking cart  900  may be attached to a cart configuration different than that illustrated in  FIG. 7 , relying upon aforementioned boss portion and guide pins to orient the cart and docking head for docking. 
     There is no requirement that a docking head provided in accordance with the concepts of the present invention be modular. Embodiments of the invention comprise a docking head which is integral with a cart or other structure for which docking is to be provided. 
     Although embodiments have been described herein with reference to ultrasound carts, it should be appreciated that the concepts of the present invention are not limited to applicability with respect to ultrasound devices. Accordingly, docking station systems of the present invention may be utilized with respect to electrocardiogram devices, “crash carts,” fetal monitor devices, drug pump devices, etc. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.