upon arriving at a fire scene , portable computer or microprocessor 1 is activated . each firefighter , prior to turning on his / her scba , will key in a personal three - digit pin 2 into the scba programmable mechanism , outside the fire scene . then , the command center will individually poll each scba to inquire who is online and whoever is successfully polled is identified on the command center screen . once this is accomplished , the command center is aware of whom is on site . during a fire , the command center will communicate individually with each firefighter &# 39 ; s scba . this communication process is to gather data as to the current status of the firefighter . each communication transmits the pass status , i . e ., body temperature , air pressure , heart rate and blood pressure to the command center which updates the data on the computer monitor . if the firefighter &# 39 ; s pass 3 is caused to alarm , this is indicated on the command center monitor . the individual monitoring the command center knows that the firefighter is in a state of alarm and sends assistance . also monitored is the ambient temperature 4 . if the firefighter enters an area where the temperature exceeds a predetermined level , this results in an alarm and the firefighter &# 39 ; s data is displayed in the screen alarm box . if a firefighter &# 39 ; s cylinder air pressure 5 decreases to a predetermined level , this is considered an alarm and is displayed in the alarm box . also , the time that the firefighter has been on pressurized air is monitored . this is an indication of the amount of time that the firefighter has been actively engaged at the scene and is a relevant parameter for the commander and is used to assure proper rehabilitation procedures . the microprocessor and translates commands issued by the teams software 6 into radio transmissions . the transmissions are received by the addressed scba , which then responds with a radio broadcast which is received by the command center . the command center then sends this scba &# 39 ; s response to microprocessor 1 . the current communication method is a serial port connection . other embodiments are also possible such as usb , ethernet and gpib . wireless communication channels possible are wifi , bluetooth and zigbee protocols . the power supply for the command center is a built - in rechargeable battery pack as well as an interface to power the unit from the line or fire truck power system . the electronic design of the command center consists of a 920 mhz fhss ( frequency hopping spread spectrum ) transceiver that outputs one watt of radio frequency power in the unlicensed ism ( industrial , scientific , medical ) band . this transceiver connects to an embedded microprocessor / microcontroller that contains flash memory that is in - circuit programmable . this embedded microcontroller contains the hardware necessary to connect the transceiver to the computer along with custom software to perform the above actions . in general , an scba contains embedded electronics to monitor various physical parameters and communicate them to the user in a simple and understandable manner . these parameters consist of , but are not limited to , cylinder pressure 5 , pass status 3 , battery voltage and overall unit status . to integrate the scba into the teams network , it is necessary to include an onboard transceiver 7 capable of communicating with the command center . the teams ready scba contains a high performance embedded microcontroller connected to transceiver 8 that is compatible with the command center transceiver , i . e ., the same hopping sequence , channel number , and rf output power . unique features of this system are the ability of the microcontroller to query the transceiver and determine whether or not the scba is within communication range of the command center . in - range transceivers provide a sync pulse at prescribed intervals allowing a lock in the frequency hopping sequence . this allows them to sense whether or not another transceiver is present within its communication envelope . this in - range indication is in the form of an led mounted on the thumbwheel interface that hangs over the user &# 39 ; s shoulder during normal use . when the scba is able to communicate with the command center , the led is illuminated . if the user is not within communication range of the command center , the led is extinguished . this gives the user immediate feedback as to his link status with the command center . in addition to the transceiver interface , the microcontroller is responsible for the implementation of the teams communication protocol . this requires on board storage of various system parameters stored in eeprom and flash memory resident inside the microcontroller . unique to the system is the manner in which each scba user is identified by name . in order to identify the user of a particular scba , the scba contains a thumbwheel interface . this interface is permanently mounted on the unit and allows the firefighter to key in a unique pin . this pin is transmitted to the teams software via the command center during each scba command center event . the teams software contains a database which contains pin assignments . these assignments correlate a pin to a name . this allows the teams software to identify the actual user by name . teams is a software application designed to run on the windows xp platform . the main purpose of the software is to provide the commander with the ability to monitor and recall fire team members either individually or universally . the software is a real - time database application . this differs from a standard application due to the scanning sequence the software performs in order to sample and communicate scba status in a reasonable amount of time . the system operation begins by entering serial numbers into the database via an interface screen provided by a menu selection . the serial numbers of the scbas are entered into the database with this interface . these serial numbers are provided by the manufacturer at the time of sale so that each time the user purchases a new unit the new serial number can be added . a maximum of 32 units can be displayed at any one time so the maximum for one command center is 32 . another embodiment allows this number to be increased without limit . the software sorts the online users based upon the task selected . this allows grouping of firefighters to a particular task . examples might be roof , basement , north quadrant etc . there are four alarm possibilities , including pass ( this alarm is always on so no database interaction is necessary ), low cylinder pressure , high temperature and time - in - fire . if the user clicks on a name in the alarm box , a detailed explanation of any and all alarm causes will appear in a box immediately to the right labeled alarm description . one embodiment of the software design causes a software controlled recall to be issued to the firefighter in alarm status . another embodiment allows the recall to be manual under human supervision . the correlation of the firefighter &# 39 ; s personal information , i . e ., name , address , emergency contact and pin are also stored in a database that can be accessed via a menu selection . when the software is executed by clicking its icon , the startup sequence first asks the user if the event data is to be logged to a database . if the answer is yes , then all runtime data that is gathered from the scbas are logged to the database for later retrieval . the software then loads the serial number database and sequentially communicates via the command center with each one . if a valid response is received , then the data is loaded into the appropriate location on the screen . the software then removes these serial numbers found from the available serial number scan list . this means that only those not online will be scanned the next time resulting in a shorter scan time . polling then transmits a request for data to each scba online , receives the data , and updates the display . each string of requested data is checked against the alarm set points . if a set point has been exceeded , the user &# 39 ; s name is placed in an alarm status . a dynamic link to the alarm cause can be created by clicking on the name in the alarm box . a unique feature of the software is the individual and universal recall capabilities . if the commander on scene determines that a particular firefighter needs to be recalled , he can press that individual &# 39 ; s recall button . that recall button will turn red in color to signify that that firefighter has been issued a recall command . it will continue to transmit a recall command until it receives a response from the user . when a recall command has been received on the user &# 39 ; s scba , the piezo alarm sounds for 10 seconds , during which time the firefighter cannot disable the alarm . at the same time , the heads - up display normally used to display cylinder pressure to the user flashes in a prescribed pattern to visually signal an evacuation command . after the 10 second alarm , the firefighter can locally disable the piezo alarm , but the heads - up display will continue flashing the evacuate sequence for 20 seconds out of every 60 - second interval until the all - clear signal is given . when the command center receives an acknowledgement response from the firefighter &# 39 ; s scba , the recall button will turn yellow . at this point the commander knows that firefighter has received the evacuation command , the piezo is sounding and he should be evacuating . when the firefighter has completed the evacuation , he presses and holds the pass reset buttons on the scba for three seconds . this will cause the scba to transmit an all - clear acknowledgement to the command center . the recall button on the screen will then turn green and the software will remove the firefighter from the scanning sequence . this frees up the system to allow faster scanning for those still online . the green indication of the recall button is an immediate indication to the scene commander that that firefighter is clear of danger . a universal recall is used when the global recall button is pressed . this is equivalent to pressing all the individual recall buttons simultaneously . the process is identical to the individual application with the exception that the software automates the pressing of the individual recall buttons . as each user receives the recall command , the color sequence is red , yellow , green and offline , as with the individual recall . unique to the recall event , either individual or universal , is the acknowledgement by both the scba and the command center that a recall has been received . in addition , the all - clear signal from the scba signals the command center that the firefighter is clear of danger .
a system to monitor the status of a firefighter comprising a self contained breathing apparatus associated with the firefighter and operational with a microprocessor to transmit and receive signals by means of transceivers , a monitor to visually observe the signals , and a personal alert safety system operational with the apparatus to detect firefighter distress signals .