Exposure management system, dosimeter, and wireless relay device

• US 9,063,233 B2
• Filed: 01/29/2009
• Issued: 06/23/2015
• Est. Priority Date: 02/26/2008
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: Imai, Minoru, Matsumoto, Eiji, Shibata, Tetsuo
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): Mahase, Pameshanand
• Application Number:
  US12/735,878
• Publication Number:
  US 20110063127A1
• Time in Patent Office: 2,336 Days
• Field of Search: 340/573.1
• US Class Current: 1/1
• CPC Class Codes: G01T 7/00 Details of radiation-measuring instruments
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

An exposure management system includes dosimeters, wireless relay devices that wirelessly communicate with the dosimeters, and a monitoring device. The dosimeters are carried by workers for measuring exposure doses in a radiation management facility. The wireless relay devices transmit a monitor indication message that requests the dosimeters to provide respective responses that include information of measured exposure doses. The wireless relay devices receive the responses from the dosimeters by using allocated respective communication channels that are different from each other. Each dosimeter receives the monitoring indication message and generates a designated number of response times for providing a response to the monitor indication message, and determines a communication channel corresponding to each of the generated response times. The monitoring device is connected to the wireless relay devices for monitoring an exposure state of each of the workers through the wireless relay devices and dosimeters.

Claims

1. An exposure management system comprising:

a plurality of dosimeters, which are carried by workers for measuring exposure doses in a radiation management facility, each dosimeter comprising;

means for receiving a monitor indication message transmitted by a relay device, the monitor indication message requesting said each dosimeter to provide a response to the monitor indication message, said response including an amount of a measured exposure dose,

means for generating a designated number of response times based at least on a number of response time slots indicated in the monitor indication message transmitted by the relay device, a response time of the designated number of response times corresponding to a time at which a response is to be transmitted, for providing said response and determining a communication channel, selected from a group of communication channels, corresponding to each of the generated response times, the generated response times being later than a time that reception of the monitor indication message ends, and

means for transmitting said response at each of the generated response times by using the determined communication channel corresponding to said each of the generated response times;

a plurality of wireless relay devices that wirelessly communicate with the dosimeters and are allocated with respective communication channels that are different from each other, the allocated communication channels being selected from among the communication channels of said group on a one-to-one basis, the wireless relay devices being configured to transmit the monitor indication message to the allocated communication channels and receive from the dosimeters respective responses to the monitor indication message; and

a monitoring device connected to the wireless relay devices, for monitoring an exposure state of each of the workers through the wireless relay devices and dosimeters.

2. The exposure management system according to claim 1, wherein each wireless relay device comprises means for designating a number of response times to be generated by the dosimeters by including information designating the number of response times in the monitor indication message.

3. The exposure management system of claim 2, wherein each wireless relay device is configured to collect exposure dose data in a period in which a monitor collection operation from transmission of the monitor indication message to reception of a response to the monitor indication message is repeated a plurality of times, wherein a number of times that the monitor collection operation is repeated corresponds to a number of response time slots.

4. The exposure management system according to claim 1, wherein

each wireless relay device comprises means for transmitting to one of the dosimeters an acknowledgment signal, upon reception of one of the responses from said one of the dosimeters, for providing notification of normal reception of said one of the responses, and

said each dosimeter further comprises means for stopping subsequent transmissions of said response when an acknowledgment signal is received from a wireless relay device.

5. The exposure management system according to claim 1, wherein said each dosimeter further comprises means for retransmitting said response, when a collision occurs between said response and another response that have been transmitted at a same time by using a same communication channel.

6. The exposure management system according to claim 1, wherein the wireless relay devices and the monitor device communicate by radio wave.

7. The exposure management system according to claim 1, wherein the wireless relay devices and the monitor device communicate by cable.

8. The exposure management system according to claim 1, wherein

the monitoring device comprises means for providing to a dosimeter information of abnormality of the dosimeter;

and

said each dosimeter further comprises means for providing notification of an abnormality when abnormality information is provided from the monitoring device to said each dosimeter.

9. The exposure management system according to claim 8, wherein the notification provided by the abnormality notification means is an audio or visual notification.

10. A dosimeter, which is carried by a worker for measuring an exposure dose in a radiation management facility and wirelessly communicates with a plurality of wireless relay devices by using respective communication channels allocated to the wireless relay devices, the allocated communication channels being selected from among a group of communication channels on a one-to-one basis, comprising:

means for receiving a monitor indication message transmitted by a relay device, the monitor indication message requesting the dosimeter to provide a response to a monitor indication message, said response including information of an amount of a measured exposure dose;

means for generating a designated number of response times for providing said response, the designated number of response times based at least on a number of response time slots indicated in the monitor indication message transmitted by the relay device, a response time of the designated number of response times corresponding to a time at which a response is to be transmitted, and determining a communication channel, selected from said group of communication channels, corresponding to each of the generated response times, the generated response times being later than a time that the reception of the monitor indication message ends; and

means for transmitting said response at each of the generated response times by using the determined communication channel corresponding to said each of the generated response times.

11. The dosimeter according to claim 10, further comprising means for stopping subsequent transmissions of said response to the monitor indication message when an acknowledgment signal is received from a wireless relay device.

12. The dosimeter according to claim 10, further comprising means for retransmitting said response when a collision occurs between said response and another response that have been transmitted at a same time by using a same communication channel.