Abstract:
A surgical light system ( 10 ) includes a lighthead ( 44 ) coupled to a suspension arm ( 41 ′) adapted for mounting to a surface ( 14 ) of a surgical room. A bulb ( 130 ) is disposed in the lighthead. A processor ( 120 ) in the lighthead is operatively coupled with the bulb for controlling an intensity of light of the bulb and is adapted to generate a lighthead status signal representative of a first status of the lighthead. A control apparatus ( 32, 34 ) is in operative communication with the processor ( 120 ) in the lighthead. The control apparatus receives the lighthead status signal and selects a set of control algorithms from among a group of algorithms based on the lighthead status signal for controlling the lighthead. The lighthead status signal includes information regarding a size of the lighthead, an intensity of light from the bulb, a condition of the bulb, a level of current applied to the bulb, a level of current applied to the bulb, a level of voltage applied to the bulb, an internal temperature of the lighthead, and the presence of one or more of a video camera, a surgical task light, and a controllable ambient light. A human-readable display device ( 160 ) is provided for displaying information relating to the lighthead status signal. Several levels of redundancy are provided in the control system to minimize the potential loss of control due to failures. In that regard, the lightheads are operable when the control apparatus ( 32, 34 ) fails.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. provisional application Ser. No. 60/348,999, filed Jan. 15, 2002. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to the surgical lighting, table, and accessory arts, and, more particularly, to a surgical lighting control system providing multiple user interfaces, centralized graphical control for various functions, advanced camera detection/signal routing, and closed loop control of lamp intensity. It finds particular application in conjunction with providing a comprehensive control system for a surgical operating room (OR) theater and will be described with particular reference thereto. It is to be appreciated, however, that the invention also finds application in other multi-task control applications and is not limited to the aforementioned operating room environment. 
   Typically, in an operating room setting, large, high lumen output lightheads are used to illuminate the surgical site. Often, video cameras, are attached to the lightheads for documenting the surgery, and to assist the surgeon in achieving more optimal views. Some systems offer no control of the camera to personnel in the OR. Without physically moving the camera/lighthead, such systems only offer a single camera orientation and zoom factor. Other systems offer control of the camera and lightheads to personnel in the OR, but not to the surgeon. The surgeon must request that a non-sterile circulating nurse adjust the lighting controls or the camera controls when needed. 
   Existing systems do not monitor power delivered to the bulbs within the lighthead. This results in light intensity fluctuations due to bulb deviations, voltage fluctuations, and line resistences. Variances in the lamp power can reduce light intensity with potential adverse effects on the surgical procedure or increase light intensity causing a reduced lamp life. 
   Additionally, most existing systems do not offer centralized control. Accordingly, the circulating nurse staff must move first to one panel to operate light intensity controls, then to another location to rotate the camera, etc. This leads to confusion when operating the systems, and clutter in the OR due to additional user interface locations. 
   In systems using a centralized control, hardware updates/upgrades are difficult because the software of the control often cannot be adapted to recognize and operate with the new equipment. It would be desirable to provide a surgical lighting and video control system with software adapted to interact with new equipment through simple software parameter updates or settings. 
   The present invention provides new and improved methods and apparatus that overcome the above referenced problems and others to provide better, more comprehensive control of lighting and video systems in surgical operating room applications. 
   BRIEF SUMMARY OF THE INVENTION 
   The preferred embodiments of the present invention provide a plug and play control interface that gives a user access to multiple devices at one station, gives the surgeon control of more devices within the sterile field, and makes control of the system simpler and more intuitive. 
   The present invention improves user access to the system by providing a graphical LCD display for use to control a plurality of devices, such as overhead lighting, ambient lighting, cameras, and other operating room accessories. The surgeon&#39;s control is improved by a voice interface system, allowing the surgeon to adjust lighting and other aspects by simply speaking. A foot pedal interface and an infra-red remote control interface grant the surgeon control of the cameras, enabling direct control of rotate and zoom functions of the camera. 
   The preferred embodiments of the present invention provide plug and play compatibility, so that devices such as cameras, entire lightheads, task lights, and other surgical accessories can be switched in and out of the system as needed, without the need to update system software or control protocol. This may occur as additional lightheads or other devices are added to the system or when devices are replaced as by way of an upgrade or the like. 
   A wall control unit of the subject system provides a graphical LCD display that enables centralized user input/output for all controls. The wall control also provides input/output connections for system options such as a video, recording device, voice control, a fiber-optic task light, and camera foot control. The LCD interface provides high-level user control of the video camera fiber optic task light, ambient light, and multiple lightheads. 
   All medium and large sized lightheads are preferably camera ready. A camera module can be placed into any of these lightheads as desired. The control system is adapted to automatically detect the particular lighthead in which the camera is located and direct the signal to the wall control through electronic means in a “plug and play” fashion. 
   Further, service function is incorporated into the system that allows service or maintenance personnel to disconnect entire lightheads for replacement with new lightheads. The control system detects a new lighthead and downloads compatible software to the lighthead (plug and play) as necessary. This decreases product down time due to service calls. Each lighthead includes a micro-controller adapted to send and receive control information from the wall control and further adapted to respond to the switches on the light handle bezel. 
   The micro-controller also provides closed loop control for tight control over lamp power. The controller measures lamp voltage and current and sets a duty cycle for a pulse width modulation (PWM) circuit. This effectively gives consistent light by compensating for most all sources of variation. 
   The advanced control allows all lightheads in the system to be turned on/off from the switch bezel input on any light in the system. Pushing and holding the ‘−’ intensity down button at the bezel of the lighthead handle for a selected period, preferably four (4) seconds turns all lightheads off and preferably simultaneously turns an ambient light on. Pushing and holding the ‘+’ intensity up button a selected period preferably for two (2) seconds turns all the lightheads on and preferably simultaneously turns the ambient light off. 
   The wall control provides a simple, centralized user interface saving time for the circulating nurse. The advanced control of the switches on the light handle bezel gives control of the lights to the surgeon as well. This saves time for the entire staff. 
   The control system provides several levels of redundancy in order to minimize the potential loss of control of the lighting system during surgical procedures. Either one of the two power supplies in the control center is sufficient to maintain operation of the microcontroller. If the microcontroller or switches in the wall control unit fail, then ON/OFF and intensity control functionality can be performed using just the lighthead-based microcontroller and switches. 
   Video camera features are accessible through the user interface, including at least power and zoom, rotate, brightness and focus controls. Advanced camera controls are also accessible through the user interface including white balance, picture freeze, time and date display as examples. The camera module is adapted for connection with any medium or large lighthead. The control system of the subject system automatically detects camera module presence and directs the video signal(s) to the wall control. 
   Many control features are provided in the surgical lighting system according to the invention. A graphical user interface, preferably, a LCD display provides for centralized control of all components in the system. ON/OFF control of all lightheads is provided in the system from a single point of intensity control at the light handle switch bezel while maintaining sterile technique. Advanced camera control features are provided including white balance, picture freeze, time and date display. The control system detects the camera module and directs the video signal to the wall control. This coincides with the system&#39;s ability to accept a camera module at multiple locations. A closed-loop lamp power control scheme maintains consistent intensity levels over time and over differing installation conditions. The wall control senses new lightheads and automatically download software to make the lighthead compatible in the system. 
   The above list is not exhaustive of the control features provided in the surgical lighting systems according to the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take form in certain methods, parts, and arrangements of parts, the preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: 
       FIG. 1  is a perspective view of a surgical light system in accordance with the present invention showing a first set of surgical lighting equipment suspended from a primary spindle and a second set of lighting equipment suspended from a secondary spindle, and a system control apparatus; 
       FIG. 2  is a block diagram illustrating components of the subject lighting control apparatus; 
       FIG. 3  is a block diagram illustrating functional blocks of an electronic module of the subject surgical lighting system; 
       FIG. 4  is a functional block diagram illustrating a lamp controller board of the subject surgical lighting system; 
       FIG. 5  is a flow chart illustrating a component auto-detect function executed by the subject control system; 
       FIG. 6  is a view of a user&#39;s screen displayed by the lighting control apparatus of the subject surgical lighting; and 
       FIG. 7  is a view of the user&#39;s screen displaying a sub-menu provided by the lighting control apparatus of the subject system. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference now to the drawing figures wherein the showings are purposes of illustrating the preferred embodiments of the invention only and not for purposes of limiting same,  FIG. 1  shows a surgical lighting system  10  including a first set of lighting devices  12  supported from the ceiling  14  of an operating room by a primary spindle hub  16  and a second set of lighting devices  18  supported at the ceiling  14  by a secondary spindle hub  20 . A lighting control apparatus  30  includes a master control unit  32  for operating the first set of lighting devices  12  and a second control unit  34  for controlling operation of the second set of lighting devices  18 . A set of communication and power lines  36  connect the lighting control apparatus  30  with the first and second set of lighting devices  12 ,  18  for control thereof in a manner to be described in greater detail below. 
   The first set of lighting devices  12  supported by the primary spindle hub  16  includes three (3) overhead lightheads  40 - 44 , a surgical task light  46  and an operating room ambient light  48 . Each of the surgical lightheads  40 - 44  are carried on a corresponding suspension system  40 ′- 44 ′. Similarly, the surgical task light is carried on a suspension arm  46 ′. Each of the suspension arms  40 ′- 46 ′ carry appropriate power and communication cables which will be described below and further enable movement of the lightheads  40 - 44  and of the task light  46  into selected positions relative to the operating room application. Each lighthead is provided with a set of manually operable light intensity control buttons  124 , preferably located adjacent the lighthead handle of each device. The ambient light  48  is mounted in a fixed location relative to the primary spindle hub  16 . A single auxiliary lighthead  50  together with an auxiliary ambient light  52  is supported on the secondary spindle hub  20  by a suitable suspension arm  50 ′. It is to be appreciated that although several lighting devices are provided in the first set  12  and only a single lighting device is found in the second set  18 , more or less lighting devices can be used as desired. Additionally, more or less spindle hubs  16 ,  20  can be included in the system as desired. 
   With reference next to  FIG. 2 , the subject lighting system  10  is shown in functional block diagram form. It is to be appreciated that the system is partitioned to provide a high level of redundancy to prevent single point failures from causing a “black out” or no light condition. To that end, each surgical lighthead includes a separate AC/DC power supply and further includes the capability to switch to a 24 VDC battery backup supply. Each surgical lighthead is also provided with its own electronics controller and resident operational firmware which is executable in the lighthead. 
   The lightheads  40 - 44  and  50  each respectively include an electronics module  60 - 66  for executing programs in accordance with predetermined algorithms. Each of the lightheads in the subject system are adapted to communicate with the lighting control apparatus  30  for controlling various lighting functions and to provide for plug and play capability. The communication and power lines  36  include separate lighthead power cables  70 - 76  for delivering power from the lighting control apparatus  30  to the individual lightheads. In addition, the communication and power lines  36  include a pair of communication cables  80 ,  82  for carrying command and status data between the lighting devices  12 ,  18  and the lighting control apparatus  30 . To that end, the master control unit  32  includes an electronic controller board  90  for generating signals to be carried on the communication cables  80 ,  82  between the control unit and the lightheads  40 - 44 ,  50  and task light  46 . 
   With continued reference to  FIG. 2 , it is to be noted that the embodiment of the subject surgical lighting system  10  includes a video camera  100 . The video camera  100  is carried by the large lighthead  44  as illustrated. The video signals from the camera  100  pass through the suspension arm  44 ′ of the large lighthead  44  and into a common hub electronics board  104  and into a video card component  106  of the electronic controller board  90  of the master control unit  32 . The video card component  106  is adapted to generate a composite video signal  108  and an S-video signal  110 . 
     FIGS. 3 and 4  show, in block diagram form, the functional components of the electronics module  64  of the large lighthead  44 . As shown in  FIG. 3 , the electronics module  64  includes a lamp controller board  120 , a camera module  122 , a set of manually operable bulb intensity switches  124 , a visual output lamp  126 , preferably an LED, a bulb change mechanism  128  holding a primary  130  and a secondary  132  bulb, and a bulb change solenoid  134  for effecting bulb changes upon failure of the primary bulb  130 . All of these components are in operative local communication with the lamp controller board  120 . Operative communication with the lighting control apparatus  30  ( FIGS. 1 and 2 ) is provided by the set of communication and power lines  36  including a differential video signal line  140 , a lamp serial port signal line  142  and a system power signal line  144 . The differential video signal line  140  delivers video signals from the camera module  122  to the lighting control apparatus  30 . The lamp serial communication lines  142 , however, are bi-directional and carry commands and data between the electronics module  64  and the lighting control apparatus  30 . The system power lines  144  communicate electrical power to the lighthead. 
   Closed loop control is provided for lamp power. To that end, a bulb intensity controller  152  detects the current delivered to the bulb  130  and the voltage signal at the bulb terminal. A bulb feedback signal  154  is generated by the controller  152  and delivered to the microcontroller  150  or use in calculating a desired duty cycle for a PWM circuit  156 . In this way, a consistent lighting effort is realized. 
   Further details of the lamp controller board  120  of the electronics module  64  is provided in  FIG. 4 . As shown, a microcontroller  150  is in operative communication with all of the components previously identified above. The microcontroller  150  is adapted to communicate with the lighting control apparatus in accordance with program code stored on a memory portion of the microcontroller. More particularly, the microcontroller  150  is adapted to execute program code to carry out the plug and play capabilities of the subject surgical lighting system. 
   The control system provides several levels of redundancy in order to minimize the potential loss of control of the lighting system during surgical procedures. Either one of the two power supplies in the control center is sufficient to maintain operation of the microcontroller. If the microcontroller or switches in the wall control unit fail, then ON/OFF and intensity control functionality can be performed using just the lighthead-based microcontroller and switches. 
     FIG. 5  is a flowchart illustrating a device auto-detect sequence executed by the controller of the preferred embodiment. At power on S 10 , the lighting control apparatus  30  interrogates each of the microcontrollers  150  and each of the lightheads in order to determine a software revision level S 12  and the quantity of lightheads in the system S 16 , their size and style, and any other information that can be derived at power up. One such determination is provided by a camera detect signal line  136  ( FIG. 3 ) which is read by the microcontroller  150  of the lamp controller board  120  at power up. When a camera module  122  is installed in the electronics module  64 , the camera detect signal line  136  is tied to a logical ground. In the absence of a camera module, the camera detect signal line  136  is permitted to float and represents a logical high value. 
   The microcontroller  150  includes program code to report the status of the presence of a camera module  122  within the electronics module  64  of the lighthead  44 . Other information is also reported by the microcontroller  150  to the lighting control apparatus  30 . This information includes data regarding the software version executed by the microcontroller  150 . The subject surgical lighting system  10  uses this information beneficially to download new executable code to the microcontroller S 14  when update software versions become available. To that end, the new software is downloaded S 14  from the lighting control apparatus  30  to the separate electronics modules  60 - 66  using the communication and power lines  36 . 
   Based upon a determination of the installed components S 16 , the controller selects an algorithm from among a group of algorithms for performing a control function. When a video camera is detected, a camera control algorithm is selected S 18 , a task light control algorithm and an ambient light control algorithm is selected at steps S 20  and S 22  when those devices are detected by the controller within the system. With regard to the surgical lightheads, as noted above, a variety of sizes are supported by the system, each preferably controlled according to separately distinct and tuned algorithms. To that end, the lighthead type is determined at step S 24  and a small lighthead control algorithm is selected S 26 , a medium lighthead control algorithm is selected S 28 , and/or a large lighthead control algorithm is selected S 30 , based upon the lighthead type determination step S 24 . 
     FIG. 6  shows a user&#39;s display  160  presented on the master control unit  32  of the lighting control apparatus  30  of the subject surgical lighting system  10 . Preferably, the master control unit includes a monochrome graphics LCD with backlight and a set of membrane contact switches  162 . The contact switches  162  are used to obtain manual user input for controlling the subject surgical lighting system. An ON pushbutton  164  and an OFF push button  166  are provided together with a set of other control buttons  168  positioned adjacent a display area  170  which is programmed to solicit input from the user. The display area  170  essentially provides visual information to the human user regarding the function of the adjacent buttons  168 . The visual information is generated by the software in the control and is useful to redefine the function of the physical buttons as needed. 
   As shown in  FIG. 6 , the display area  170  includes a “select light” indicia or label area, an “intensity” area, an “ambient light ON/OFF” area, a “camera” area, and a “system” area. An up arrow  172  and a down arrow  174  are provided among the other input buttons to select a lighthead from among the group. Actuation of either the up or down input buttons  172 ,  174  causes an arrow  176  displayed on the user display  160  to transition between one of three selectable fields  178 . In addition, an intensity decrease arrow  180  and an intensity increase arrow  182  are provided for enabling the user at the lighting control apparatus  30  to control the intensity of the particular lighthead selected by the position of the arrow  176 . As shown in  FIG. 6 , lighthead number 3 is selected by the arrow  176  and the intensity is set to level 3. 
   An ambient light power button  190  is also provided on the contact switches  162  together with an ambient light icon in the display area so that users can turn the ambient light  48  on or off as desired. A camera input button  192  is also provided adjacent a camera icon in the display area  170  for toggling camera operation. Lastly, a system inquiry button  194  is included for users to query the surgical lighting system for information. 
   A lighthead is selected using the UP/DOWN buttons  172 ,  174  under the SELECT LIGHT display, the intensity is adjusted with the LEFT/RIGHT buttons  180 ,  182  under the INTENSITY display. Seven (7) predefined power levels are hard coded into a non-volatile memory in the lighthead for each of the seven light intensity levels. The power level definitions for various wattage lamp types are stored in a set of power level tables in the lightheads. The intensity indicators  200 - 208  shown in  FIG. 6 , consist of a lamp head number  210  followed by a progressive, seven bar segment display  212 . When the lamp is off, no segments are displayed. When the lamp is at a maximum intensity level, all seven segments are displayed. As shown in the FIGURE, lamp  1  is at full power, lamp  2  is off, lamp  3  is at a low power setting, and lamp  4  is slightly brighter than lamp  3 . As the user increases lamp intensity, successive segments are displayed from left to right with all preceding segments remaining on. 
   When two or more lightheads are detected in the system, the ALL LIGHTS indicator  214 , shown in the FIGURE are displayed on the light control screen. When the ALL LIGHTS indicator is selected using the UP/DOWN buttons  172 ,  174  under the SELECT LIGHT display, the control and intensity of all detected lightheads follows a predefined operational sequence. Essentially, when the ALL LIGHTS indicator is selected and the intensity right  182  or up button is selected, all lamps immediately increase to the next higher level of intensity. Conversely, when the left  180  or down arrow is pressed, all lamps in the system immediately decrease in intensity to the next lower level. 
   Primary and secondary lamps for the lighthead are designated as “A” and “B” with the “A” being understood as the primary lamp location. In the system of the preferred embodiment as noted above, the lamps are continuously monitored regardless of whether they are turned ON or OFF. When a lamp is missing or burned out, a lamp fault indicator  220  is displayed and flashes on and off at a preselected rate, preferably a two second rate with a fifty percent duty cycle. 
   With continued reference to the drawing figures, the system automatically detects the installation of a manual task light as described above. To that end, a task light intensity display  208  is provided together with a lamp life indicator  230 . The intensity indicator consists of a seven segment display  212  in the form of a bar graph similar to the display provided for the lightheads. As the user increases lamp intensity, successive segments are displayed from left to right with all preceding segments remaining on. 
   In addition, a task light lamp life indicator  230  is presented to the operator to indicate the remaining life on the lamp used in the manual task light. A progress bar meter  232  moves to the right as shown in the drawing figure as lamp light diminishes. The bar is calibrated preferably for 0 hours on the left and 500 hours full scale on the right. After the bar graph reaches 400 hours of bulb life, the progress bar begins to flash at a predetermined rate, preferably a two second rate with a fifty percent duty cycle. After 500 hours are reached, a graphical display of a lamp with a cross therethrough is indicated and begins flashing to attract the attention of the operator. At 500 hours, a fault log entry is made which indicates that the number of lamp hours used in the manual task light has exceeded a predetermined operational limit. 
   In addition, a backup battery display icon is presented to display the remaining life of the backup battery. 
     FIG. 7  shows a sub-menu  250  presented by the subject control system when the button below the “camera” icon  234  ( FIG. 6 ) is operated. As shown, select function keys  172 ,  174  are used to change the position of an arrow  176  to select various camera control options including power  252 , zoom  254 , rotate  256 , a brightness adjustment  258 , and a camera focus  260 .