Abstract:
The present invention provides a wireless communication device comprising: a wireless communication unit configured to perform wireless communication using radio waves belonging to a predetermined radio wave band between a first external device and a second external device; a proximity communication unit configured to perform proximity communication with a control terminal; and a control unit configured to cause control data, which indicates an instruction for the first external device, received from the control terminal via the proximity communication unit to be transmitted to the first external device via the wireless communication unit, the control unit adjusting a transmission timing of the control data or the data when causing the control data to be transmitted to the first external device while the first external device or the wireless communication unit sequentially transmits data to the second external device.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application based on a PCT Patent Application No. PCT/JP2011/067434, filed Jul. 29, 2011, whose priority is claimed on Japanese Patent Application No. 2010-251969, filed on Nov. 10, 2010, the entire content of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wireless communication device and a wireless communication system that perform wireless communication of control data for remotely controlling an external device. 
     2. Description of the Related Art 
     Generally, when a surgical operation is performed, a surgical operation system including a plurality of medical device groups in which a medical device corresponding to a purpose is mounted on a cart is used. The medical device group is freely arranged according to the kind of a surgical operation. 
     During the surgical operation, some of the medical devices are operated through remote control by a remote controller. Many remote controllers transmit control data to the medical devices through infrared communication. 
     For example, in Japanese Unexamined Patent Application, First Publication No. 2003-245286, a method of increasing an infrared amount through an infrared adapter and transmitting control data to a distant medical device is disclosed. 
     In Published Japanese Translation No. 2008-519501 of the PCT International Publication, the use of a remote controller using wireless technology (radio waves) of which a communication distance is long is shown. 
     Also, in Japanese Unexamined Patent Application, First Publication No. H7-147697, a method of preventing a collision by performing wave detection before transmission in communication between remote controllers is disclosed. 
     With the sophistication of a surgical operation, the number of medical device groups to be simultaneously used is increasing and arrangements of the medical device groups in a wide range are increasing. Further, cases in which image data such as endoscope images is communicated by wireless technology (radio waves) and displayed on monitors of other medical device groups are also increasing. Also, a device such as an electric scalpel, which generates electromagnetic noise in operation, is also frequently used. That is, cases in which the medical device groups are distributed and arranged in a wide range and devices that use radio waves or devices that generate radio waves are used are increasing. 
     SUMMARY 
     The present invention provides a wireless communication device and a wireless communication system capable of successfully performing communication of control data. 
     A wireless communication device may include: a wireless communication unit configured to perform wireless communication using radio waves belonging to a predetermined radio wave band between a first external device and a second external device; a proximity communication unit configured to perform proximity communication with a control terminal; and a control unit configured to cause control data, which indicates an instruction for the first external device, received from the control terminal via the proximity communication unit to be transmitted to the first external device via the wireless communication unit, the control unit adjusting a transmission timing of the control data or the data when causing the control data to be transmitted to the first external device while the first external device or the wireless communication unit sequentially transmits data to the second external device. 
     A wireless communication device may include: a wireless communication unit configured to perform wireless communication using radio waves belonging to a predetermined radio wave band with an external device; a proximity communication unit configured to perform proximity communication with a control terminal; and a control unit configured to cause control data, which indicates an instruction for the external device, received from the control terminal via the proximity communication unit to be transmitted to the external device via the wireless communication unit, the control unit adjusting a transmission timing of the control data based on an operation state of equipment that emits the radio waves belonging to a predetermined frequency band or transmitting an instruction for changing the operation state of the equipment to the equipment. 
     When causing the control data to be transmitted to the first external device while the first external device or the wireless communication unit sequentially transmits image data to the second external device, the control unit may adjust the transmission timing of the control data to a timing different from that of a predetermined wireless transmission period of the image data. 
     The wireless communication unit may have a function of performing wireless communication of image data with the first external device, and transmits the control data to the first external device using the function. 
     The control unit may adjust the transmission timing of the control data to a timing at which generation of electromagnetic noise by the equipment is determined to be small. 
     The external device may have the equipment individually having priority. The control data may include identifier (ID) information allocated to each piece of equipment and instruction information for an instruction for an operation of the equipment. A storage unit configured to store equipment information in which the ID information is associated with the priority may be further included. The control unit may identify the priority of the equipment of an object to be controlled based on the ID information and the equipment information included in the control data, determine equipment of which an operation state is changed based on the identified priority and the priority of each piece of equipment indicated by the equipment information, and transmit an instruction for changing the operation state of the equipment to the equipment. 
     The wireless communication unit may have a function of performing wireless communication of image data with the external device, and transmits the control data to the external device using the function. 
     A wireless communication system may include: a wireless communication device including: a first wireless communication unit configured to perform wireless communication using radio waves belonging to a predetermined radio wave band between a first external device and a second external device; a first proximity communication unit configured to perform proximity communication with a control terminal; and a first control unit, which is a control unit configured to cause control data, which indicates an instruction for the first external device, received from the control terminal via the first proximity communication unit to be transmitted to the first external device via the first wireless communication unit, the first control unit adjusting a transmission timing of the control data or the data when causing the control data to be transmitted to the first external device while the first external device or the wireless communication unit sequentially transmits data to the second external device; the control terminal including: a generation unit configured to generate the control data; and a second proximity communication unit configured to perform proximity communication with the wireless communication device; and the first external device including: a second wireless communication unit configured to perform wireless communication using the radio waves belonging to the predetermined radio wave band between the second external device and the wireless communication device; and a second control unit configured to perform control based on the control data received from the wireless communication device via the second communication unit. 
     A wireless communication system may include: a wireless communication device including: a first wireless communication unit configured to perform wireless communication using radio waves belonging to a predetermined radio wave band with an external device; a first proximity communication unit configured to perform proximity communication with a control terminal; and a first control unit, which is a control unit configured to cause control data, which indicates an instruction for the external device, received from the control terminal via the first proximity communication unit to be transmitted to the external device via the first wireless communication unit, the first control unit adjusting a transmission timing of the control data based on an operation state of equipment to emit the radio waves belonging to a predetermined frequency band or transmitting an instruction to change the operation state of the equipment to the equipment; the control terminal including: a generation unit configured to generate the control data; and a second proximity communication unit configured to perform proximity communication with the wireless communication device; and the external device including: a second wireless communication unit configured to perform wireless communication using the radio waves belonging to the predetermined radio wave band with the wireless communication device; and a second control unit configured to perform control based on the control data received from the wireless communication device via the second communication unit. 
     The control data may include ID information allocated to each piece of equipment of an object to be controlled and instruction information for an instruction for an operation of the equipment. The control terminal may include a reading unit configured to read the ID information from a display screen of an image display device having an information transmission function of optically transmitting the ID information using part of the display screen on which an image is displayed. The generation unit may generate the control data using the ID information read from the display screen. 
     A wireless communication device may include: a wireless communication unit configured to perform wireless communication using radio waves belonging to a predetermined radio wave band between a first external device and a second external device; a proximity communication unit configured to perform proximity communication with a control terminal; and a control unit configured to adjust a transmission timing of the control data to a timing different from that of a predetermined wireless transmission period of image data when causing control data, which indicates an instruction for the first external device, received from the control terminal via the proximity communication unit to be transmitted to the first external device via the wireless communication unit and when causing the control data to be transmitted to the first external device while the first external device or the wireless communication unit sequentially transmits image data to the second external device. 
     The control unit may adjust the transmission timing of the control data to within a blanking period of the wireless communication of the image data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of a remote control system in accordance with a first preferred embodiment of the present invention. 
         FIG. 2  is a block diagram illustrating a connection relationship between medical devices provided in the remote control system in accordance with the first preferred embodiment of the present invention. 
         FIG. 3  is a reference diagram illustrating a structure of control data in the first preferred embodiment of the present invention. 
         FIG. 4  is a block diagram illustrating a configuration of a remote controller provided in the remote control system in accordance with the first preferred embodiment of the present invention. 
         FIG. 5  is a block diagram illustrating a configuration of a relay device provided in the remote control system in accordance with the first preferred embodiment of the present invention. 
         FIG. 6  is a reference diagram illustrating content of a system state table in the first preferred embodiment of the present invention. 
         FIG. 7  is a reference diagram illustrating content of a control data transmission waiting table in the first preferred embodiment of the present invention. 
         FIG. 8  is a timing chart of wireless communication of control data in the first preferred embodiment of the present invention. 
         FIG. 9  is a flowchart illustrating a procedure of an operation of a relay device provided in the remote control system in accordance with the first preferred embodiment of the present invention. 
         FIG. 10  is a flowchart illustrating a procedure of an operation of the relay device provided in the remote control system in accordance with the first preferred embodiment of the present invention. 
         FIG. 11  is a flowchart illustrating a procedure of an operation of the relay device provided in the remote control system in accordance with the first preferred embodiment of the present invention. 
         FIG. 12  is a reference diagram illustrating a display screen for an initial setting process of the remote controller in the first preferred embodiment of the present invention. 
         FIG. 13  is a block diagram illustrating a configuration of a remote control system in accordance with a second preferred embodiment of the present invention. 
         FIG. 14  is a block diagram illustrating a configuration of a relay device provided in the remote control system in accordance with the second preferred embodiment of the present invention. 
         FIG. 15  is a reference diagram illustrating content of a system state table in the second preferred embodiment of the present invention. 
         FIG. 16  is a timing chart of wireless communication of control data in the second preferred embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following preferred embodiments. For example, components of the preferred embodiments may be appropriately combined. 
     First Preferred Embodiment 
     First, the first preferred embodiment of the present invention will be described. In the first preferred embodiment, an example in which the present invention is applied to a remote control system (wireless communication system) having medical device groups (external devices) configured on three carts will be described. 
     Using  FIGS. 1 and 2 , a configuration of the remote control system will be described.  FIG. 1  illustrates the configuration of the remote control system in accordance with the first preferred embodiment. 
     On a cart  10 , an image monitor  1 , which displays an endoscope image or various control screens, a wireless communication device  2 , which performs communication of image data and control data, an endoscope  3 , a pneumoperitoneum device  4 , an ultrasonic treatment device  5 , an electric scalpel  6 , a relay device  7 , a system controller  8 , and a foot switch  9  are mounted. The equipment on the cart  10  constitutes an external device in a wireless communication system of the present invention. 
     On a cart  18 , an image monitor  11 , which displays an endoscope image or various control screens, a wireless communication device  12 , which performs communication of image data or control data, an endoscope  13 , a shaver  14 , a pump  15 , a relay device  16 , and a system controller  17  are mounted. The equipment on the cart  18  constitutes an external device (a first external device) in the wireless communication system of the present invention. 
     A remote controller  19  for remote control of each medical device is in the vicinity of the cart  18 , and is in a state in which a signal from the remote controller  19  is transmitted only to the relay device  16  through infrared communication. Although the remote controller  19  is in the vicinity of the cart  18  in  FIG. 1 , a signal from the remote controller  19  is transmitted only to the relay device  7  on the cart  10  when the remote controller  19  is in the vicinity of the cart  10 . 
     An image monitor  20  and a wireless communication device  21  are mounted on a cart  22 , and the image monitor  20  displays an image received by the wireless communication device  21 . The equipment on the cart  22  constitutes an external device (a second external device) in the wireless communication system of the present invention. 
     A patient  23  is placed on a patient bed  24  and a probe from a medical device such as an endoscope is installed thereon. 
     Because the endoscope, the pneumoperitoneum device, the ultrasonic treatment device, the electric scalpel, the shaver, and the pump in the drawing are known medical devices and will be described as having known functions even in the first preferred embodiment, a further description thereof is omitted here. 
     The foot switch  9  is connected to the system controller  8 , and controls an output of the ultrasonic treatment device  5  or the electric scalpel  6 . By switching an operation state of the foot switch  9 , switching of whether to control the ultrasonic treatment device  5  or the electric scalpel  6  is configured to be performed from the remote controller  19 . 
     The wireless communication device, the relay device, the system controller, and the remote controller will be described later. 
       FIG. 2  is a block diagram illustrating a connection relationship between medical devices provided in the remote control system. As illustrated, each device (equipment) mounted on the cart  10  is connected to the system controller  8  and the system controller  8  recognizes an operation state of each device. Likewise, each device (equipment) mounted on the cart  18  is connected to the system controller  17 , and the system controller  17  recognizes an operation state of each device. 
       FIG. 2  illustrates a state in which a signal output by the remote controller  19  is transmitted only to the relay device  16 . Based on information from the system controller  8 , the relay device  7  recognizes the operation state of each device mounted on the cart  10 , exchanges information with the relay device  16  through wireless communication via the wireless communication device  2  and the wireless communication device  12 , and also recognizes the operation state of each device mounted on the cart  18 . Likewise, based on information from the system controller  17 , the relay device  16  recognizes the operation state of each device mounted on the cart  18 , exchanges information with the relay device  7  through wireless communication via the wireless communication device  2  and the wireless communication device  12 , and also recognizes the operation state of each device mounted on the cart  10 . A method in which the above-described relay devices recognize the operation state of each device will be described in detail using  FIGS. 5 to 11  later. 
     The wireless communication device  2  of the cart  10 , the wireless communication device  12  of the cart  18 , and the wireless communication device  21  of the cart  22  perform wireless communication belonging to a predetermined radio wave band (frequency band). These wireless communication devices have an image communication function. In  FIG. 2 , the wireless communication device  2  of the cart  10  and the wireless communication device  21  of the cart  22  perform wireless communication of image data. Also, the wireless communication device  2  of the cart  10  and the wireless communication device  12  of the cart  18  perform wireless communication of control data for controlling the operation of each device using the image communication function. 
     Next, configurations of the remote controller  19  and the relay devices  7  and  16  will be described using  FIGS. 3 to 5 . In the following description, a state in which a signal from the remote controller  19  is transmitted only to the relay device  16  is assumed as illustrated in  FIGS. 1 and 2 . 
       FIG. 3  illustrates a structure of control data (a control command) transmitted from the remote controller  19 . As illustrated, the control data includes a device identifier (ID) (ID information) indicating an ID of a device of an object to be controlled and instruction information indicating instruction content (control content) for the device of the object to be controlled. 
       FIG. 4  illustrates the configuration of the remote controller  19 . The remote controller  19  includes an infrared light emitting element  27 , a visible light receiving element  28 , a communication interface (I/F) circuit  30 , a control button  26 , a display element  25 , a storage circuit  31 , and a remote controller control circuit  29 . 
     The infrared light emitting element  27  transmits control data through infrared communication. Because infrared light is used, it is difficult for communication of the remote controller  19  and the relay devices  7  and  16  to be affected by electromagnetic noise generated by the electric scalpel  6  or the like. Although an example in which the remote controller  19  performs infrared communication is shown in the preferred embodiment of the present invention, it is only necessary that communication to be performed by the remote controller  19  be proximity communication (near field communication) in which communication is possible only in the vicinity of the relay device, and ultrasonic waves or the like may be used instead of infrared light. 
     The visible light receiving element  28  receives a device ID of each device in optical communication via an image monitor. The reception of the device ID according to the optical communication will be described in detail using  FIG. 12  later. 
     The communication I/F circuit  30  performs communication using the infrared light emitting element  27  and the visible light receiving element  28 . The control button  26  receives an operation input for instructing to operate the remote controller  19 . The display element  25  displays an operation state of the remote controller  19 . The storage circuit  31  stores the device ID received in the optical communication. The remote controller control circuit  29  controls the overall operation of the remote controller  19 . 
     When an operator inputs desired instruction content (control content) by operating the control button  26 , the remote controller control circuit  29  generates instruction information by analyzing the instruction content, displays a result on the display element  25 , and generates control data by adding the device ID stored in the storage circuit  31  to the instruction information. The control data is transmitted by infrared light via the communication I/F circuit  30  and the infrared light emitting element  27 , and received by the relay device in the vicinity thereof. 
       FIG. 5  illustrates the configuration of the relay device  16 . The relay device  16  includes an infrared light receiving element  32 , an infrared I/F circuit  33 , a relay device control circuit  34 , and a storage circuit  35 . 
     The infrared light receiving element  32  receives control data from the remote controller  19  through infrared communication. The infrared I/F circuit  33  processes a signal from the infrared light receiving element  32  and transmits the processed signal to the relay device control circuit  34 . The relay device control circuit  34  controls the entire relay device  16 . The storage circuit  35  stores a system state table in which a list of states of each device (equipment) on the cart  10  and states of each device (equipment) on the cart  18  is shown and a control data transmission waiting table in which a list of control data waiting for transmission to the relay device is shown. Also, the relay device  7  is connected to the system controller  17  via a relay device input/output signal  36  from the relay device control circuit  34 . Furthermore, the configuration of the relay device  7  is also the same as that of the relay device  16 . 
     Upon receiving control data from the remote controller  19 , the relay device  16  notifies the system controller to which a device of an object to be controlled is connected of a control command based on a device ID within the control data. The system controller receiving the control command appropriately controls the device to be controlled based on the control command. 
     For example, when the control command is a command for the shaver  14 , the relay device  16  directly notifies the system controller  17  of the control command based on the received control data because the shaver  14  is connected to the system controller  17  of the same cart  18  as that of the relay device  16 . Also, when the control command is a command for the pneumoperitoneum device  4 , the control data is transmitted to the relay device  7  in wireless communication via the wireless communication devices  2  and  12  and the relay device  7  notifies the system controller  8  of the control command because the pneumoperitoneum device  4  is connected to the system controller  8  of the cart  10  on which the relay device  7  is placed. These procedures will be described using  FIGS. 8 to 11  later. 
     Next, the system state table and the control data transmission waiting table to be used by the relay device will be described using  FIGS. 6 and 7 .  FIG. 6  is an example of the system state table. The system state table is a table to be used for a determination of whether to transmit control data from the remote controller  19  through wireless communication and a decision of a start timing of the wireless communication to be performed by recognizing the operation state of the device on the cart on which the relay device within the remote control system is mounted. 
     As illustrated in  FIG. 6 , the system state table records a type of device mounted on each cart, a device ID, an operation state, and the presence/absence of electromagnetic noise, which is generated when the device is in operation. For example, in  FIG. 6 , for the electric scalpel  6  mounted on the cart  10 , the device ID: SG-001, the operation state: in operation, and the electromagnetic noise generated when the device is in operation: present are registered. This shows that wireless communication of control data from the remote controller  19  is not possible because electromagnetic noise is generated when the electric scalpel  6  is in operation. 
       FIG. 7  is an example of a control data transmission waiting table to be used by the relay device. The control data transmission waiting table is a table in which control data, which should be transmitted to the relay device of another cart through wireless communication, among control data received from the remote controller  19  is summarized. As illustrated in  FIG. 7 , the control data transmission waiting table records an ID of a relay device serving as a transmission destination, a type of device serving as an object to be controlled, a device ID, control content, and a reception time based on reception of control data. In  FIG. 7 , an example in which a command for changing a connection destination of the foot switch from the current electric scalpel  6  to the ultrasonic treatment device  5  and a command for changing a flow rate of the pneumoperitoneum device  4  are registered is illustrated. 
     Next, a procedure of transmitting control data from the remote controller  19  in wireless communication will be described using  FIGS. 8 to 11 . An example in which an image of the endoscope  3  is being communicated to the wireless communication device  21  connected to the image monitor  20  via the wireless communication device  2  and the wireless communication device  21 , control content (a change in a connection destination of the foot switch and a flow rate change in the pneumoperitoneum device) illustrated in  FIG. 7  from the remote controller  19  is indicated to the relay device  16 , and the electric scalpel  6  is in an initial operation and then is stopped is shown in the present invention. 
       FIG. 8  illustrates a state in which control data is wirelessly transmitted in the above-described procedure. In  FIG. 8 , the electric scalpel  6  is operated until a time t 6  and then stopped. The wireless communication device  2  periodically transmits the image of the endoscope  3 . For example, when one frame includes 60 images, a transmission cycle is 16.7 ms. In the drawing, a period between times t 1  and t 5  becomes 16.7 ms. A period of times t 4  to t 5  is a blanking period in which no image data is transmitted, and control data is wirelessly communicated using the above-described period. 
     Because electromagnetic noise is generated when the electric scalpel  6  is in operation, content of wireless communication may not be necessarily accurately transmitted. Although a disturbance is allowed even when the disturbance occurs on a screen under the influence of electromagnetic noise because image data is continuously transmitted, wireless communication of control data is not performed in a period in which electromagnetic noise is generated because an error of control data is likely to cause a serious problem. 
     In  FIG. 8 , control data indicating a control command (a flow rate change in the pneumoperitoneum device) from the remote controller  19  is transmitted to the relay device  16  during a period of times t 2  to t 3 . The control data received by the relay device  16  is added to the control data transmission waiting table. At this time, because wireless transmission is not performed when the electric scalpel  6  is in operation, new control data is added after control data indicating a previously indicated change command of a connection destination of the foot switch as illustrated in  FIG. 7 . 
     In the blanking period of the times t 4  to t 5 , wireless transmission is not performed because the electric scalpel  6  is in operation. In an initial blanking period after the electric scalpel  6  has been stopped, the system state table is transmitted from the relay device  7  to which the electric scalpel  6  is connected to the relay device  16 , and notification of an operation stop of the electric scalpel  6  is provided (times t 7  to t 8 ). According to this notification, the stop of the electric scalpel  6  is checked in the relay device  16 . As a result, the content of the control data transmission waiting table is transmitted in the next blanking period (times t 9  to t 10 ). 
     Although a procedure in which the wireless communication device  2  transmits image data to the wireless communication device  21  has been described above, a procedure in which the wireless communication device  12  transmits image data to the wireless communication device  21  is also the same, and the relay device  16  controls a transmission timing of control data so that the wireless communication device  21  transmits the control data in the blanking period after the stop of the electric scalpel  6 . 
     Next, the operation of the relay device will be described using  FIGS. 9 to 11 . The flowcharts of  FIGS. 9 to 11  are common in the relay device  7  and the relay device  16 . Also, processes illustrated in  FIGS. 9 to 11  are executed by software under operating system (OS) management, and separate software under the OS management is executed after the end of the processes. 
       FIG. 9  illustrates a system state table update process S 1 . The system state table update process S 1  is a process in which the relay device periodically observes a state of each device connected to the system controller via its own connected system controller and updates the system state table. 
     In the system state table update process S 1 , the relay device control circuit  34  initially checks the state of each device via the system controller (S 2 ). Subsequently, the relay device control circuit  34  compares content of the system state table stored in the storage circuit  35  to the state of each device of notification from the system controller (S 3 ). If there is no change in the state of each device, the system state table update process S 1  ends (S 7 ). Also, if there is a change in the state of each device, the relay device control circuit  34  performs the update S 4  of the system state table, a system state table flag is turned ON (S 5 ), a transmission start-up flag is turned ON (S 6 ), and the system state table update process S 1  ends (S 7 ). 
     The system state table flag is a flag indicating that the system state table has been updated, and the transmission start-up flag is a flag for requesting the start-up of a wireless transmission process S 8  as will be described next. When the operation of the electric scalpel  6  has been stopped, the update (S 4 ) of the system state table is performed in the relay device  7  and then the system stable table flag and the transmission start-up flag are turned ON (S 5  and S 6 ). 
       FIG. 10  illustrates the wireless transmission process S 8 . The wireless transmission process S 8  is a process of transmitting content of the system state table and the control data transmission waiting table. When the transmission start-up flag is turned ON, the wireless transmission process S 8  is started up. When the system state table flag is turned ON, the system state table updated in the system state table update process S 1  is transmitted. When the control data transmission waiting table flag is turned ON, content of the control data transmission waiting table is transmitted. 
     In the wireless transmission process S 8 , the relay device control circuit  34  examines the system state table in a transmission environment check S 9 , and determines whether transmission is possible. When the device for which electromagnetic noise: present is registered is in operation, the relay device control circuit  34  iterates the transmission environment check S 9  by determining that the transmission is not possible. When the device for which the electromagnetic noise: present is registered is not in operation, the relay device control circuit  34  checks the system state table flag (S 10 ). When the system state table flag is turned ON, the relay device control circuit  34  executes a system state table transmission process S 11  and a system state table flag OFF process S 12 , and then executes a control data transmission waiting table flag check S 13 . When the system state table flag is turned OFF, the relay device control circuit  34  directly executes the control data transmission waiting table flag check S 13 . 
     In the system state table transmission process S 11 , the system state table updated in the system state table update process S 1  is transmitted. In the system state table transmission process S 11 , the relay device control circuit  34  outputs the system state table to the wireless communication device via the system controller, and the wireless communication device transmits the system state table to another wireless communication device using the next blanking period. The system state table received by another wireless communication device is output to the relay device via the system controller. In the relay device, the relay device control circuit  34  updates the system state table stored in the storage circuit  35 . 
     After the system state table transmission process S 11  the relay device control circuit  34  turns OFF the system state table flag (S 12 ). 
     In the control data transmission waiting table flag check S 13 , the relay device control circuit  34  checks the control data transmission waiting table flag. When the control data transmission waiting table flag is turned ON, the relay device control circuit  34  executes a control data transmission waiting table transmission process S 14  and a control data transmission waiting table flag OFF process S 15 , and then executes a transmission start-up flag OFF process S 16 . 
     In the control data transmission waiting table transmission process S 14 , the relay device control circuit  34  outputs control data to the wireless communication device via the system controller, and transmits the control data to another wireless communication device using the next blanking period. After the control data transmission waiting table transmission process S 14 , the relay device control circuit  34  turns OFF the control data transmission waiting table flag and the transmission start-up flag (S 15  and S 16 ), and ends the wireless transmission process S 8 . 
     When the control data transmission waiting table flag is turned OFF, the relay device control circuit  34  directly executes the transmission start-up flag OFF process S 16 . After the transmission start-up flag OFF process S 16 , the wireless transmission process S 8  ends (S 17 ). 
       FIG. 11  illustrates a remote controller control data reception process S 18 . The remote controller control data reception process S 18  is a process to be performed upon receipt of control data from the remote controller  19 . Upon receipt of the control data from the remote controller  19 , the relay device control circuit  34  starts up the remote controller control data reception process S 18 . In the remote controller control data reception process S 18 , the relay device control circuit  34  initially performs reception S 19  of the control data, and subsequently makes a wireless transmission execution determination S 20 . 
     In the wireless transmission execution determination S 20 , the relay device control circuit  34  makes a device position determination S 24  when a device of an object to be controlled specified from a device ID within control data is mounted on the same cart as its own cart and communication from the remote controller  19  and when communication from the remote controller  19  arrives at both the relay device  7  and the relay device  16 . Otherwise, the update S 21  of the control data transmission waiting table is executed. Furthermore, a determination of a relay device at which communication from the remote controller  19  arrives is made by determining whether operation states of all relay devices of the system state table illustrated in  FIG. 6  are “in remote controller connection.” 
     In the device position determination S 24 , the relay device control circuit  34  determines a device of an object to be controlled from a device ID within the control data. When the device of the object to be controlled is on the same cart as its own cart, the relay device control circuit  34  executes control command notification S 25  to the system controller and ends the remote controller control data reception process S 18  (S 26 ). Otherwise, the relay device control circuit  34  immediately ends the remote controller control data reception process S 18  (S 26 ). 
     In the update S 21  of the control data transmission waiting table, the relay device control circuit  34  adds control data received from the remote controller  19  to the control data transmission waiting table stored in the storage circuit  35 . At this time, only latest control data is placed in the control data transmission waiting table based on a reception time for control data in which control content (for example, a flow rate change in the pneumoperitoneum device or the like) is redundant among control data for the same device. 
     After the update S 21  of the control data transmission waiting table, the relay device control circuit  34  turns ON the control data transmission waiting table flag (S 22 ), turns ON the transmission start-up flag (S 23 ), and ends the remote controller control data reception process S 18  (S 26 ). 
     Next, an example of transmission of control data of the remote controller  19  in the wireless transmission process S 8  will be described. In the case of an example illustrated in  FIG. 8 , in the relay device  16 , the wireless transmission process S 8  is started up through the remote controller control data reception process S 18  performed when the electric scalpel  6  is in operation. However, until the system state table is transmitted from the relay device  7  and notification of the stop of the electric scalpel  6  is provided, communication is determined to be impossible through the transmission environment check S 9  and transmission of the control data is awaited. When the system state table is updated in the notification from the relay device  7 , transmission is determined to be possible in the transmission environment check S 9  and a process from a system state table flag check S 10  is executed. 
     In this case, because the system state table flag is turned OFF and the control data transmission waiting table flag is turned ON, the control data transmission waiting table transmission process S 14  is performed, the control data transmission waiting table flag OFF process S 15  is subsequently performed, and the wireless transmission process S 8  ends (S 17 ) after the transmission start-up flag OFF process S 16 . Through the above-described process, transmission of control data of the remote controller  19  is performed at a timing shown in times t 9  to t 10  of  FIG. 8 . 
     Because both the operation states of the relay device  7  and the relay device  16  of the system state table illustrated in  FIG. 6  are in the remote controller connection when a position of the remote controller  19  is different from positions illustrated in  FIGS. 1 and 2  and communication from the remote controller  19  reaches both the relay device  7  and the relay device  16 , “non-transmission” is determined in a wireless transmission execution determination S 20  in the relay device  16 , “other cart” is determined in a device position determination S 24 , and the remote controller control data reception process S 18  directly ends (S 26 ). On the other hand, in the relay device  7 , “non-transmission” is determined in the wireless transmission execution determination S 20 , “own cart” is determined in the device position determination S 24 , the control command notification S 25  for the system controller  8  is executed, and then the remote controller control data reception process S 18  ends (S 26 ). 
     When the communication from the remote controller  19  reaches both the relay device  7  and the relay device  16  as described above, the system controller to which the device of the object to be controlled is connected is notified of a control command without performing wireless transmission. 
     Next, an initial setting process of the remote controller  19  will be described. In the initial setting process of the remote controller  19 , a process of setting a device ID of each medical device within the remote control system in the remote controller  19  is performed.  FIG. 12  illustrates the case in which a screen for the initial setting process is displayed on the image monitor  20 . 
     As illustrated, a name of a device to be remotely controlled by the remote controller  19  is displayed for each cart on the screen for the initial setting process. On the side of the screen, an ID communication point  37  for transmitting a device ID of each device in visible light communication to the remote controller  19  is arranged. The ID communication point  37  has a function of providing notification of the device ID in a change (blinking) in luminance and notifies the remote controller  19  of the device ID through the visible light receiving element  28  of the remote controller  19 . 
     Each device ID is collected by the relay device of each cart via the system controller and stored as part of the system state table. During initial setting, data of a device ID is extracted from a desired relay device. 
     Although a display of the screen for the initial setting process is possible even in the image monitor  1  and the image monitor  11 , an example in which a screen created by the system controller  8  is displayed on the image monitor  20  will be described in the present invention. In this case, the system controller  8  creates the screen for the initial setting process using the device ID stored in the system state table of the relay device  7 . The created screen is displayed on the image monitor  20  via the wireless communication device  2  and the wireless communication device  21 . Because a method of blinking a part within the monitor and transferring information in visible light communication according to a change in a blinking interval used in the first preferred embodiment is known, a detailed description thereof is omitted here. 
     As described above, according to the first preferred embodiment, communication of control data can be successfully performed by transmitting the control data at a timing at which other wireless communication or electromagnetic noise is not generated and a wireless communication state is good when the relay device wirelessly transmits the control data received from the remote controller  19  through infrared communication using a wireless communication device on its own cart. Also, in a system for wirelessly communicating and displaying image data, it is possible to provide a remote control system that reliably notifies a separated non-control device group of a control command by wirelessly transmitting control data at a timing at which a communication period of the image data is avoided. 
     When a device in which a large amount of electromagnetic noise is generated in operation such as an electric scalpel is in operation, it is difficult to perform wireless communication normally. Thus, normal communication can be performed without being affected by electromagnetic noise by monitoring an operation state of a device, which generates the electromagnetic noise, detecting a time point of an operation state in which the generation of the electromagnetic noise is small such as power OFF or operation interruption, and performing wireless communication of control data at the time point. 
     Also, the setting of the remote controller  19  can be performed by reading a device ID from an image display monitor and convenience is improved. Furthermore, because it is not necessary to newly prepare a wireless communication device for communication of control data by performing wireless communication of the control data using an image communication function, cost reduction is possible when the remote control system in accordance with the first preferred embodiment is configured. 
     Second Preferred Embodiment 
     Next, the second preferred embodiment of the present invention will be described. In the second preferred embodiment, the function of the relay device is mainly different from that of the first preferred embodiment. Specifically, the relay device of the second preferred embodiment has a wireless communication function and wireless communication is performed between relay devices. Also, priority is allocated to each medical device, and processing in the relay device changes according to priority of a medical device in operation upon receipt of control data from the remote controller  19 . 
       FIG. 13  illustrates a configuration of the remote control system in accordance with the second preferred embodiment. Comparing the remote control system in accordance with the second preferred embodiment to the remote control system in accordance with the first preferred embodiment, configurations of the relay device and the cart  18  are different. 
     The configuration of the cart  18  is a configuration in which the image monitor  11 , the wireless communication device  12 , and the endoscope  13  are removed from the configuration illustrated in  FIG. 1 . In the second preferred embodiment, no wireless communication device can be used for transmission of control data between the relay devices as in the first preferred embodiment because the wireless communication device  12  is not on the cart  18 . Thus, the relay device  38  and the relay device  39  of this system are equipped with the wireless communication function, and wireless communication is directly performed between the relay devices. 
       FIG. 14  illustrates a configuration of the relay device  38  mounted on the cart  10 . As illustrated, a wireless communication circuit  44  is connected to a relay device control circuit  42 , and an antenna  46  is connected to the wireless communication circuit  44 . Because an infrared light receiving element  40 , an infrared I/F circuit  41 , a relay device control circuit  42 , and a storage circuit  43  are the same as the configurations described in the first preferred embodiment, description thereof is omitted. Furthermore, the relay device  39  also has the same configuration. Through the above-described configuration, it is possible to perform wireless communication between the relay device  38  and the relay device  39 . 
     In the second preferred embodiment, unlike the first preferred embodiment, priority is allocated to each medical device within the remote control system. Although wireless communication between relay devices is necessary when a control command for a high-priority device is issued from the remote controller  19  during the operation of a low-priority device, a wirelessly communicable state is created and the wireless communication between the relay devices is performed by changing an operation state of the low-priority device when the low-priority device in operation generates noise that interferes with wireless communication. Furthermore, because a previously operated device is prioritized when priority is the same, the operation state is not changed. 
       FIG. 15  illustrates an example of the system state table of the second preferred embodiment. In the second preferred embodiment, priority of each device is added to the system state table described in the first preferred embodiment. As illustrated, priority of the system controller is highest priority 1. Thereafter, the priority is successively given to the electric scalpel: 2 and the ultrasonic treatment device: 3. Also, because the relay device of the second preferred embodiment is not the object to be controlled by the remote controller  19 , no priority is assigned thereto. A command for various urgent processes (urgent stop and the like) is included in a command for the system controller of which priority is 1. 
     Furthermore, in the first preferred embodiment, an item of noise of the system state table is set to “absent” because a radio signal associated with the operation of the wireless communication device does not become noise by transmitting control data using a blanking period of wireless communication of image data. On the other hand, in the second preferred embodiment, the item of noise of the system state table is set to “present” because a radio signal associated with the operation of the wireless communication device becomes noise for wireless communication between the relay devices. 
     Next, the communication timing of control data will be described using  FIG. 16 . In the present invention, an example in which the remote controller  19  transmits control data for the shaver  14  to the relay device  38  will be described using the configuration illustrated in  FIG. 13 . At this time, it is assumed that the wireless communication device  2  is in a state in which image data is transmitted to the wireless communication device  21 , and operation states of the other devices become states illustrated in  FIG. 15 . 
       FIG. 16  is a timing chart of communication of control data in the above-described states. When the relay device  38  has received control data from the remote controller  19 , the relay device control circuit  42  of the relay device  38  compares priority of a control object device corresponding to a device ID within control data to priority of a device that generates noise in operation in the system state table. Because control data is transmitted to the shaver  14  in the present invention, priority “2” of the shaver  14  is compared to priority “7” of the wireless communication device  2  in operation. 
     Because the priority of the shaver  14  is higher than the priority of the wireless communication device  2  when the relay device  38  has received control data from the remote controller  19  at the illustrated timings (times t 12  to t 13 ), the relay device control circuit  42  of the relay device  38  notifies the system controller  8  of an operation stop command of the wireless communication device  2 . An operation of the wireless communication device  2  is stopped through the system controller  8  receiving the notification (a time t 14 ). Thereby, the wireless communication of image data to be originally performed until a time t 17  is stopped at the time t 14 . 
     Subsequently, the relay device control circuit  42  transmits control data to the relay device  39  via the wireless communication circuit  44  and the antenna  46  (times t 15  to t 16 ). The relay device control circuit  42  of the relay device  39  notifies the system controller  17  of a control command based on the received control data. The system controller  17  controls the shaver  14  based on the control command of the notification. Thereafter, the operation of the wireless communication device  2  is resumed (from a time t 18 ). Through the above-described procedure, the control data from the remote controller  19  is transmitted to the shaver  14  via the relay device  38  and the relay device  39 . 
     The initial setting process of the remote controller  19  in the second preferred embodiment is performed using data from a detachable universal serial bus (USB) memory attached to the remote controller  19  differently from the first preferred embodiment. The setting of a device ID of each medical device within the remote control system for the USB memory is performed by attaching the USB memory to the relay device. Because a method of setting information via the USB memory is known, a detailed description thereof is omitted here. 
     As described above, according to the second preferred embodiment, communication of control data can be successfully performed by transmitting the control data at a timing at which other wireless communication or electromagnetic noise is not generated and a wireless communication state is good when the relay device wirelessly transmits the control data received from the remote controller  19  through infrared communication using its own wireless communication device. 
     Also, when control data for a high-priority device is transmitted from the remote controller  19 , a device that generates a large amount of noise according to an operation is in operation in a medical device group to which a relay device receiving control data from the remote controller  19  belongs, and the priority of the device is lower than the priority of a medical device to receive a control command, it is possible to transmit the control data after reducing the noise by stopping the device in operation. Thus, it is possible to transmit control data for a high-priority medical device early and reliably. 
     In accordance with the present invention, when a wireless communication device performs transmission of control data from a control terminal, a transmission timing of data such as control data or image data is adjusted. Alternatively, communication of the control data can be successfully performed because the control data can be transmitted at a timing at which radio waves having an influence on the transmission of the control data are not generated by transmitting an instruction for changing an operation state of equipment, which emits radio waves belonging to a predetermined frequency band, to the equipment. 
     Although the preferred embodiments of the present invention have been described above with reference to the drawings, specific configurations are not limited to the preferred embodiments, and designs can also be made without departing from the scope of the present invention. 
     The present invention can be widely applied to a wireless communication device and a wireless communication system that perform wireless communication of control data for remotely controlling an external device.