Patent Publication Number: US-2019183603-A1

Title: Medical headlamp and camera system

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of application U.S. Ser. No. 14/510,364 filed on Oct. 9, 2014, which claims benefit of provisional application Ser. No. 61/981,695 filed Apr. 18, 2014. 
    
    
     BACKGROUND 
     Medical headlamp assemblies having attached video cameras are old. These assemblies, however, tend to be heavy and are tethered by cables to a base station. This potentially interferes with the wearer&#39;s freedom of movement and may prove to be a distraction during delicate surgical procedures. For medical headlamp assemblies that must be physically tethered, in order to power the headlamp, little benefit could be gained by equipping the assembly with a wireless, as opposed to a wired, camera or vision system. 
     Untethered medical headlamp assemblies, having efficient lamps that permit the use of battery packs on the headband, are currently available. Typically, an adjustable linkage attaches the lamp to a headband. Although it might at first seem possible to simply attach an existing wireless video camera to the lamp, so that the camera images the area that is being illuminated, size, mass and power constraints may make this an undesirable solution. 
     Installing a wireless video camera assembly directly on the lamp adds to the weight of the lamp/camera combination, and results in a requirement for a stiffer linkage, to prevent the lamp/camera from drooping. This is particularly true of the camera includes batteries, for its power. But a stiffer linkage is undesirable as this reduces the ease of adjustment. Also, a bulkier lamp/camera unit may act as a distraction to the wearer, who has some awareness of an element above the lamp, very near his forehead. Finally, a greater mass results in greater inertia when the wearer rotates his head, resulting in an unpleasant sensation during head rotation, and more torque at the location where the linkage holding up the lamp meets the headband. A Wi-FI antenna and a camera battery, at least, are problematic elements to include in the housing with the camera. 
     Moreover, transmitting raw video over a WI-FI link can consume upwards of 2 watts of power. This means that a complete WI-FI camera system would consume more power than the medical headlamp, thereby requiring over frequent battery swap-outs, and appearing impractical. It is therefore desirable to compress the video signal, prior to transmitting this signal. 
     SUMMARY 
     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
     In a first separate aspect, the present invention may take the form of a medical headlamp and camera system having an articulated linkage-and-headlamp assembly, including an articulated linkage supporting a headlamp and a video camera, which produces a first video data signal. A headband assembly, supporting the articulated linkage-and-headlamp assembly, and including at least one battery port, supporting a battery, and further including an electrical network, including a microcontroller, that supplies electrical power to the headlamp, in reliance on computations performed by the microcontroller, from the battery and also delivers electrical power from the battery to the video camera. Also, a data compression network, is electrically connected to the video camera and receives the first video data signal and compresses it into a compressed data signal, Finally, a wireless transceiver supported by the headband assembly and electrically connected to the data compression network wirelessly transmits the compressed data signal. 
     In a second separate aspect, the present invention may take the form of a medical headlamp and camera system having an articulated linkage-and-headlamp assembly, including an articulated linkage supporting a headlamp and a video camera, which produces a first video data signal. A headband assembly, supporting the articulated linkage-and-headlamp assembly, and including at least one battery port, supporting a battery, and further including an electrical network, including a microcontroller, that supplies electrical power to the headlamp, in reliance on computations performed by the microcontroller, from the battery and also delivers electrical power from the battery to the video camera. Also, a data compression network, is electrically connected to the video camera and receives the first video data signal and compresses it into a compressed data signal, Finally, a wireless transceiver supported by the headband assembly and electrically connected to the data compression network wirelessly transmits the compressed data signal. Also, a wireless transceiver is supported by the headband assembly and electrically connected to the data compression network to wirelessly transmit the compressed data signal. The electrical network processes data representative of the first data signal by detecting a region illuminated by the bezel and eliminating from further processing pixels outside of the illuminated region. 
     In a third separate aspect, the present invention may take the form of a medical headlamp and camera system, having a headband assembly, that includes a headband, having at least one battery port, supporting a battery, and further including an electrical network, including an integrated circuit. The headband assembly also has an articulated linkage-and-headlamp assembly supported by the headband, and including an articulated linkage supporting a headlamp and an electrically conductive connection from the electrical network to the headlamp powering the headlamp from the electrical network. Also, an image sensor is supported by the headband assembly such that it can be directed to gather imagery from a region illuminated by the headlamp and electrically and communicatively connected to and powered by the electrical network and producing a first video data signal. Further, a data compression network is electrically connected to the video camera, which receives the first video data signal and compresses it into a compressed data signal. In addition, a wireless transceiver is supported by the headband assembly and electrically connected to the data compression network to wirelessly transmit the compressed data signal. Finally, the electrical network processes data representative of the first data signal and controls the headlamp brightness in response thereto. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments are illustrated in referenced drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
         FIG. 1  is a block diagram of the electrical power and logic of a medical headlamp and video camera headband assembly according a preferred embodiment of the present invention. 
         FIG. 2  is an isometric side-top view of a medical headlamp assembly according to the present invention, configured to be received onto a user&#39;s head. 
         FIG. 3  is an isometric side-top view of the assembly of  FIG. 2 , but without the tightness adjustment elements, and with elements extended outwardly, in a plane. 
         FIG. 4  is a front view of the assembly of  FIG. 3 . 
         FIG. 5  is an isometric side-top view of a rigid-flex circuit element of the assembly of  FIG. 3 . 
         FIG. 6  is a front view of the rigid-flex circuit element of  FIG. 5 . 
         FIG. 7  is a section view of the assembly of  FIG. 4 , taken along view line  7 - 7  of  FIG. 4 . 
         FIG. 8  is a section view of the assembly of  FIG. 4 , taken along view line  8 - 8  of  FIG. 4 . 
         FIG. 9  is an isometric side-top view of a medical headlamp assembly, representing an alternative embodiment of the present invention, configured to be received onto a user&#39;s head. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Definitions: A data signal is any signal that represents a stream of data. Transforming a data signal means changing the representation of a data value, for example changing from a signal in which a “1” is represented by 0.34 volts on a data line, to a signal in which a “1” is represented by 2.3 volts or a signal where a “1” is represented by a value of an electromagnetic signal, present in the air. Transforming a data signal also includes transforming the data represented by the data signal by, for example, compressing it or encrypting it. 
     Referring to  FIGS. 1 and 2 , a preferred embodiment of a medical headlamp and camera system  10  includes a headlamp (also referred to as “light engine bezel”)  12  and an image sensor module (also referred to as “video camera” or simply “camera”)  14 . Image data gathered by module  14  is sent over a multi-conductor cable  16  to a headband assembly  18  that includes a headband structure  20  and internal electrical conductors that lead to a principal video processor  24 , which processes and wirelessly transmits the image data. A tablet computer  26  communicates with system  10 , by way of Wi-Fi Processing and Antenna  60 , and is configured to receive the wireless image data, and to display and record it as commanded by a user. Tablet computer  26  is also configured to wirelessly command micro-controller  48 , through Wi-Fi unit  60 , which is connected to micro-controller  48 , to, for example, command it to command the image sensor module  14  to begin recording. In one preferred embodiment, tablet computer  26  may use the same communications route to adjust the brightness of headlamp  12 . A pair of battery ports  118 , support batteries  32  that power the system, with wire  148  supplying headlamp  12  with electrical power. In one preferred embodiment tablet computer  26  includes a microphone and voice command recognition technology, so that it can be used to relay voice commands to assembly  10 . 
     Image sensor module  14 , includes an image sensor  40 , a lens stack  42  and a front-end video processor  44 . Lens stack  42  sets the field of view and focus distance of module  14 . In one preferred embodiment, lens stack  42  is adjustable to set a precise focus length based on the anticipated distance at which the camera  14  will be viewing a medical procedure, and can be set in place, after adjustment by, for example, set screw  43 . In a variant of this, differing versions of a front end of the lens stack  42  will be made available, each optimized for a different anticipated viewing distance, so that the user may select the front end that best suits his needs. A surgeon may set the focal length of the lens stack  42  of his assembly  10  based on his arm length. 
     Image sensor  40  and video processor  44  may collectively take the form of the Aptina AS0260, which includes a system-on-a-chip and has the capability to perform intra-frame data compression, more specifically in accordance with the JPEG (Joint Photographic Experts Group) standard or MJPEG standard. In an alternative embodiment image sensor  40  may take the form of a sensor with an ultra-low energy change sensing mode, so that the camera  14  can draw as little power as possible for an image that is not undergoing significant change but can be commanded to take much higher resolution and higher frame rate imagery as soon as an image change is detected. Another option for image sensor  40  is the AS01402AT, available from On Semiconductor, which maintains a website at www.onsemi.com. 
     A multi-line data bus  46 , of which multi-connector cable  16  ( FIG. 2 ) forms a part, connects the image sensor module  14  to a principal video processor  24 . A micro-controller  48  controls the system  10 . The principal video processor  24  and the control unit  48 , collectively may take the form of an Ambarella A7LW system on a chip (SoC). This unit includes an ARM processor, which serves as control unit  48  and a video processing unit, which serves as principal video processing unit  24 , which compresses and encrypts the data, according to an interframe scheme of compression. In one preferred embodiment, the H.264/MPEG-4 AVC standard is used for the data compression and encryption. 
     Also, within headband assembly  18 , a power management network  50 , receives power from a battery set  32  and delivers power to the light engine bezel  12 , the image sensor module  14  and the power consuming units of the headband assembly  18 . A brightness control knob  124  permits a user to adjust the brightness of the bezel  12 . In one preferred embodiment, knob  124  also acts as an on/off switch for system  10 , so that as knob  124  is rotated to an extreme position in a first direction, a “click” sound is made and the entire system  10  is turned off. When rotated in the opposite direction a similar click sound is made and the system is turned on, with the WIFI unit  60  placed in listen mode, to receive a command from tablet computer  26 , for image sensor  40  to begin recording, and bezel  12  to illuminate. 
     A WI-FI unit  60 , including an antenna, broadcasts the data received from processing unit  24 . System  10  also includes a USB port, for connection of a dongle or a USB cable. 
     The object of the data processing scheme implemented in both front end processor  44  and principal processor  24  is to determine and send the most important data that can be fit into the limited bandwidth available (about 100 MBPS or less) that can be used without using so much energy as to become burdensome to the operating room crew, which must swap out batteries that have been depleted. One technique that is used is the detection of the region of the frames that is illuminated by the bezel  12  and delivering only information representative of this region to WI-FI unit to be transmitted. A first order detection scheme tests for a border between bright and dim pixels, or otherwise detects the area illuminated by the bezel  12  and eliminates the pixels on the outside of this area. In one embodiment, this processing is not performed every frame, because the relationship between image sensor  14  and bezel  12  will typically not change very quickly. Rather, in one embodiment, after the headlamp and camera are activated, the processor  24  attempts to detect a spot of light. It is possible that there will be none, because the lamp might not be directed at a surface that is close enough to provide a definite light spot. In one methodology, a line of pixels going through or close to the center of the frame is examined, to see if a set in the middle is brighter than those at the ends. For example, if a set of 20 contiguous pixels are found that are twice as bright as five contiguous pixels at either end of the line, then a spot of light may be considered to be tentatively detected. In another preferred embodiment the center pixels must be 10 times as bright for a tentative light spot detection to be noted. Further processing along other lines of pixels running through or close to the center may be used to confirm or disqualify the tentative detection of a light spot. After that initial light spot detection, subsequent frames of pixels may be used to refine the estimate of light spot location. After that, for each frame only the set of pixels found to be in the light spot are processed and transmitted or saved. In one embodiment, a periodic check is performed, for example every second or every two seconds or every five seconds, to verify that the light spot has not moved in the field of view of the image sensor  14 . Further the data compression scheme is optimized for the type of data likely to be encountered during a surgery. In one preferred embodiment the data compression scheme is matched to an expected rate of change of imagery during surgery. In one embodiment, a tablet  26  user can choose a first portion of the camera field of view to be broadcast at a fast data rate, and a second portion of the camera field of view to be broadcast at a slow data rate, slower than the fast data rate. In one embodiment, the user of tablet  26  can superimpose a circle, or other closed form indicator, on the field of view, thereby commanding the imagery within the circle to be broadcast at a faster rate, for example 60 frames per second, 30 frames per second or 24 frames per second, and everything outside of the closed form indicator to be broadcast at a slower data rate, for example 1 frame per second, or 1 frame every 5 seconds. The user direction is sent to WIFI  60 , from tablet computer  26 . 
     In one embodiment, every video data file produced by system  10  is labelled as being patient -sensitive medical information, so that it will be safeguarded from disclosure to anybody other than appropriate medical personnel, to aid in compliance with the Health Insurance Portability and Accountability Act (HIPAA) and any other relevant laws, regulations and procedures. Different systems exist for labelling information for protection, and in one embodiment, a user may select the labelling system. In another embodiment, every frame, in the margin, includes a warning that the imagery is patient-sensitive and subject to HIPAA regulations. In one embodiment, the video produced is password protected, with an automatically generated password being automatically provided to a qualified person, such as the surgeon performing the surgery, by a system that safeguards the information from others. In a preferred embodiment a video library is maintained, and every user of the library can log into an account, using a secret password and a user ID, to see only those videos that are assigned to him or her. Those without a password or user ID are prevented from accessing any of the videos. In one embodiment headlamp assembly  10  includes a biometric sensor, such as a fingerprint sensor, to verify the identity of the user, so that he or she can be given access to the video, without error. 
     In a preferred embodiment, an accelerometer set is placed on the camera  14 , bezel  12  or linkage  114 . Information from this accelerometer set is sent by WIFI and used to deblur imagery from camera  14 , for example if the surgeon shifts his head position and the camera  14  is rapidly moved, the accelerometer yields this information and it is used to deblur the resultant imagery. 
     In another scheme, the rate of wireless transmission is slowed during periods when there is less movement in the field of view. In one embodiment a gravity sensor (plumb bob) is used to detect instances in which the surgeon has straightened himself, from the typical position during surgery of bending over a surgical theater, and can therefore be presumed to be no longer viewing the surgical theater, so that the bezel  12  may be turned off or dimmed, and the video camera may be turned off. In one embodiment, these power saving devices can be left unused at the user&#39;s input to the contrary. In one embodiment an especially low transmit power wireless system is used, to reduce power consumption, take advantage of the nearness of the wireless receiver and avoid interference with other RF equipment in the medical environment. In one embodiment, the device receiving the video signal, such as tablet computer  26 , sends a signal back to WIFI unit  60  and therefore micro-controller  48 , instructing micro-controller  48  to cause data to be broadcast at a lower signal volume, to arrive at the lowest signal volume that avoids unnecessary signal strength, that could disturb other wireless processes in the hospital. In one embodiment a preset signal is sent periodically from WIFI unit  60  to the tablet computer  26 , which determines if the preset signal has arrived correctly. If it has not the tablet computer  26  sends a signal requesting a higher signal intensity. In one embodiment a blue-tooth system is used for transmitting the video signal. In one embodiment a maximum of two watts of power are used to power the bezel  12 , the image sensor  14 , the processor  24  and the wireless transmitter  60 . 
     In one preferred embodiment a user selectable mode is provided in which the control unit adjusts the current delivered to bezel  12 , in response to the brightness of the pixels within the illuminated area, thereby saving electricity when the illuminated circle is brighter than necessary. The user may opt out of this mode, to avoid possible complications. One problem faced by surgeons is reflection from the scalpel and/or other surgical instruments used. Such a reflection may temporarily blind the surgeon and cause a brief interruption in a surgery. Surgical time is extremely valuable, and the surgeon&#39;s full attention necessary to good outcomes, so it is very desirable to reduce or eliminate anything that interferes with the surgical process. In one embodiment, when an image sensor pixel is suddenly illuminated much more brightly than it had been before, and particularly if it becomes illuminated more brightly than other pixels within the light spot, an algorithm detects this condition and reduces the volume of light produced by the bezel, in response. For example, in one embodiment if the volume of light in any 10 contiguous camera pixels triples in less than 0.2 seconds and exceeds a set threshold for light from 10 contiguous pixels, the light output of the bezel  12  is reduced. 
     In another embodiment a user can set a set point, by for example turning the brightness knob, while camera  14  is active, to a place where the amount of light produced appears beneficial, and then give some further indication, for example pressing the knob or another button, to indicate that this level of light return is the desired level. Subsequently, if the light returned from the detected spot exceeds this level, the light output of bezel  12  is reduced by the micro-controller  48 , and if the light returned from the detected spot is less than this level, the light output of bezel  12  is increased by the micro-controller  48 . 
     In another embodiment, the light produced by the bezel is reduced if any pixel is driven into saturation, or returns its maximum value, the level of light produced by the bezel is reduced. In one embodiment, the brightest camera pixel is detected for every frame, and compared to the brightest pixel from the previous frame and the brightest pixel from the frame before that. If there is a sudden increase in brightness, in one embodiment a ten-times increase in the brightest pixel level this is attributed to unwanted reflection and the current delivered to the bezel is reduced. 
     Referring to  FIGS. 2 and 3 , in physical form, a preferred embodiment of the present invention is a medical headlamp assembly  10 , having a light engine bezel  12 , a video camera  14 , an adjustable bezel support linkage  114 , a headband assembly  18 , defining a pair of battery sockets  118 , bearing batteries  32 , each in contact to a rigid-flex circuit insert  130  ( FIG. 5 ). The linkage  114  and light engine bezel  12 , collectively constitute an integrated articulated linkage-headlamp and camera assembly  115 . 
     The charge remaining in batteries  32  is indicated by a set of battery charge indicator lights  121  ( FIG. 4 ). A head-top strap  122  and a head-back strap  123  form a part of headband assembly  18 . As shown in  FIG. 3  straps  122  and  123  are both formed from a pair of arms ( 126 ,  128 ) each having a serrated elongated opening  125 . The two arms of the head-top band are drawn together by tightness adjust  127  which engages the serrations to adjust the length of the coupled arms, and the two arms of the head-back strap  123  are drawn together by tightness adjust  129 . A brightness control knob  124  is also supported by headband assembly  18 . 
     Referring now to  FIG. 4-8  a rigid-flex circuit  130  is embedded into the center portion of headband assembly  18 . Rigid-flex circuit is an industry term that describes a structure having both rigid and flexible portions, constructed by laminating together rigid and flexible layers and then removing the rigid layers in areas where flexibility is desired. In this application, the term “flex circuit” encompasses rigid-flex circuit, so that rigid-flex circuit is a type of flex circuit. Rigid-flex circuit  130  includes right and left-side rigid portions that support a right-hand electrical network  132 , and a left-hand electrical network  134 , respectfully. The electrical components of network  132  and  134  are connected together by a first set of conductive traces (not shown) that are internal to rigid-flex circuit  130 . These traces are configured in a pattern designed to effect a predetermined scheme of connection. Rigid-flex circuit  130  includes an additional rigid portion, right at the location where the linkage  114  connects to headband assembly  18 . 
     The right-hand network  132  is kept in an air pocket, protected by a right-hand top can  135  ( FIG. 7 ) and a right-hand bottom can  137  ( FIG. 7 ), both made of stainless steel that is 0.15 mm thick. The top can  135  is 4.5 mm high, whereas can  137  is 1.5 mm high. During the molding process, these cans  135  and  137  prevent the polymer material from contacting the components of network  132 . Although bottom can  137  does create an area of some rigidity to the outside of strap assembly  18 , it is covered by a 0.3 mm thick covering of relatively soft polymeric material  136 , which greatly ameliorates this condition. A round indent (not shown) in can  137 , which defines a hole (not shown) at its center, provides a seat for the head of a shaft (not shown) for the brightness control knob  124 . On the left-hand side, only a top can  141  ( FIG. 7 ), having similar dimensions to and made of the same material as the top right-hand top can  135 , is required, due to a smaller component set, confined to the top of rigid-flex circuit  130 . In an alternative preferred embodiment (not shown) a type of polymer that permits heat flow is used, thereby eliminating the need cans  135 ,  137  and  141 . In a preferred embodiment ( FIG. 1 ), video processor  24  and microcontroller  46  (in the form of an integrated circuit, in some embodiments capable of substantial data processing) are placed on the right side, as part of network  132 , in can  135  to more directly receive input from the brightness control knob. In an alternative preferred embodiment, these elements are placed on the left side, as part of network  134 , in can  141 . In alternative preferred embodiments, one or more of the cans are larger than described here or are made of a material other than stainless steel, such as titanium. 
     Electrical networks  132  and  134  are electrically connected together, to bezel  12  and to video camera  14 , by a second set of conductive traces  140 , each of which extends either across the center of rigid-flex circuit  130  or from one of the electrical networks  132  and  134  to either a first jack  142  or a second jack  144 . In a preferred embodiment first jack  142  accepts a plug  146  ( FIG. 3 ) that through wire  148 , supplies bezel  12  with electric power. When not in use for this purpose, jack  142  accepts a plug (not shown) from a voltage source, for recharging batteries  32 . Second jack  144  accepts a plug  145  ( FIG. 2 ) for the multi-conductor cable  16 , that forms a portion of data bus  46  from video camera  14  to processing network  132  or  134 . Although plug  145  is shown in the form of an audio plug, which may have several contacts, multi-pin forms are used in alternative preferred embodiments. Plug  146  and the wire attached to it may be considered an electrically conductive system of linkage  114 , whereas first jack  142  may be considered a further electrically conductive element of headband assembly  18 . Bezel  12  could be electrically connected to headband assembly  18  by a simple wire, in which case the portion of the wire in the linkage could still be considered an electrically conductive system and the portion in the headband could be considered a further electrically conductive element. Video camera  14  must be connected by a set of conductors because of the volume of data required to be moved. 
     In an alternative preferred embodiment, rigid-flex circuit  130  is replaced by a longitudinal flex circuit or a longitudinal rigid-flex circuit having a circuit board electrically and physically connected to either end, a right-hand circuit board supporting and electrically connecting network  132  and a left had circuit board supporting and electrically connecting network  134 . In alternative preferred embodiments the pair of circuit boards is connected by a cable harness or a ribbon cable. 
     In a preferred embodiment, rigid-flex circuit  130  (together with jacks  142  and  144  and networks  132  and  134 ) is encased in a sheathing of polymer material  136  that also forms the top arms  126  and side arms  128 . To produce the headband assembly  18 , rigid-flex circuit  130  is suspended in a mold by shafts that extend through apertures for battery charge indicator lights  121 . Polymer material in liquid phase is forced into the mold and after it has been allowed to cure, the shafts are withdrawn and the headband assembly  18  is ejected. 
     In a preferred embodiment sheathing polymer material  136  may be Styrene-Ethylene/Butylene-Styrene Block Copolymer or similar material, preferably having a shore durometer rating of between 50 and 60 in its cured state. In one preferred embodiment, the shore durometer rating is 55. The 100% modulus is preferably between 1800 and 2500 psi. The mold injection temperature is between 180° C. and 240° C. These materials are available from United Soft Plastics of Lawrenceville, Ga. In one preferred embodiment, an antimicrobial agent is added to the polymer material  136 , to prevent fungal and bacterial growth on the surfaces of the material  136 , in use. In a preferred embodiment, MCX 122656 Antimicrobial Masterbatch available from RTP Co., of Winona, Minn., which maintains a website at www.rtpcompany.com, is added to the polymeric substance, in liquid state. 
     In prior art of battery bearing headbands, the battery sockets have been separated from the material contacting the user&#39;s head by a space for circuitry, whereas in the preferred embodiment, the circuitry has been placed in front of the battery, as opposed to a position interposed between the battery and the head. Also, the battery sockets  118  have been moved farther back on the head, relative to prior art headbands, so that the closest portion of the batteries  32  to the linkage is 153 mm from the linkage as measured along the headband as it curves about the head, or stated in a slightly different but equivalent manner, measured as it would be if the headband assembly were laid out flat. For most wearers, this places the forwardmost part of the batteries at a position just above the ears, so that a portion of batteries may extend in backward direction at the place where the head curves inwardly toward the back, thereby avoiding contact between the batteries and the head, and providing a greater balance in weight, yielding greater comfort. 
     There are a number of advantages to the resulting headband. First, as it is constructed as a unitary piece, there are no seams that in other systems provide a foothold for the growth of fungus, and seepage of users&#39; cleaning fluid into interior cavities, which can potentially damage electrical networks  132  and  134 . Also, in one prior art system the two pieces that were joined to form the band for the back of the head also formed the panels separating the batteries from the head. This piece was made of a harder polymer material than other portions of the headband, in part to resist the tendency of the batteries, which extended further from the head because of the interposed electrical network, to torque with the top being pulled by gravity downwardly, which could easily translate to away from the head. The use of a harder polymer, however, can result in discomfort over the hours required to complete some surgeries. In headband  18 , the use over the entire assembly of polymer material  136  which in a preferred embodiment has a shore durometer reading of 55 is more comfortable, even over long periods of time. In addition, the traces  140  that link networks  132  and  134  permit communication that permits these networks to cooperate. In one preferred embodiment, the battery delivering power to the bezel  12  shifts periodically, for example as the voltage of the active battery passes below a threshold, the load of the optical assembly is shifted to the other battery  32 , so that the batteries drain at the same rate, over time. Also, those traces leading from networks  132  and  134  to the jack for supplying bezel  12 , and to the data port of camera  14 , make external wires unnecessary. Such wires can present a snagging hazard. 
     A pair of parallel front-center vertical ridges  150  ( FIGS. 7 and 8 ) are created by the encasement of jacks  142  and  144 . The valley  152  between these ridges form an elongated seat for post  154 , which is part of support linkage  114 . When arms  156  (also part of linkage  114 ) are rotated, post  154  is torqued and in turn torques headband assembly  18 . The structure of post  154  and ridges  150 , however, help to diffuse this torque and material  136  helps to cushion the forehead from the torque, so that the operation of rotating arms  156  is not as uncomfortable to the wearer of headlamp and video camera system  10  as it would otherwise be. Linkage  114  includes a partial collar  157 , which fits onto post  154 . Moreover, partial collar  157  is removable from post  154 , so that assembly  115 , including headlamp  12  and camera  14 , may be quickly removed from headband assembly  18 , with plugs  145  and  146  pulled from jacks  142  and  144 . Accordingly, if an electrical or mechanical problem is detected with either headlamp  12  or camera  14  the entire unit  115  may be quickly replaced with a spare. Alternatively, a first version of unit  115  can be quickly swapped out for a second version of unit  115 , having specialized or more advanced properties. In embodiments, there is an adjust element, such as the threaded bolt shown with camera  14 , for adjusting the angle of the camera  14 , relative to headlamp  12 . 
     Referring to  FIG. 9 , an alternative preferred embodiment of a medical headlamp assembly  210  includes a headlamp and camera unit  211 , which includes a headlamp  212  and an image sensor module  214  joined together. A single cable  216  carries both electric power to unit  211 , where it is divided interior to the housing between headlamp  212  and image sensor  214 , and also carries data to and from sensor  214 . A pair of antennae  260 , driven by wire  262 , are located on top of assembly  210  to have a greater chance of having an unblocked line-of-sight to a receiver, such as tablet computer  26 . An additional pair of batteries are held at the back, in much the same manner as batteries  32 . Assemblies  10  and  210  may be otherwise the same. In the embodiment of  FIG. 9 , special design features draw heat from the headlamp  212 , away from the camera  214 , to avoid overheating camera  214 . 
     An issue encountered when integrating a headlamp  12  and an image sensor  14  is heat from the headlamp  12  interfering with the image sensor  14 , as image sensors tend to be heat sensitive. One approach to addressing this concern is the use of a configuration like that shown in  FIG. 8 , where the image sensor  14  and the headlamp have an air gap in between, over most of their surfaces, with some joining bands, preferably made of a heat resistive substance, such as silicone. In the embodiment of  FIG. 9 , a layer of silicone is interposed between the headlamp  12  and the image sensor  14 , within the housing. In one embodiment, a layer of silicone is interposed with the side on the headlamp covered with heat reflective and conductive material, such as copper, so that heat is drawn away from the camera, along the heat conductive layer. 
     The ability to wirelessly broadcast the video signal of a surgery greatly eases the task of the teaching surgeon, who wishes to bring the student into the operating theater with him, without being tethered by a wire to receiving device or having an additional person actual in the operating room, with him. The greatly facilitated capability of creating a video display of the surgical procedure can be expected to enhance medical education, with the attendant result of better trained junior surgeons, performing their operations in a more expert manner. 
     While a number of exemplary aspects and embodiments have been discussed above, those possessed of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.