Guest guest Posted June 18, 2008 Report Share Posted June 18, 2008 And the tricoder is where? Everything is possible in the future even time travel. LNM from Baku, AZ Sent via BlackBerry by AT & T Chaos >>> . . . " chaos theory " <<< There is a term you do not see on this discussion list very often! Dudley, you are right that elements of the chaos theory apply to the process of deciding where to station EMS vehicles. Very simply, the theory holds that seemingly random events may indeed be predictable if one accounts for a critical number of variables. The accuracy of the prediction improves with discovery and consideration of increasing numbers of variables. Interestingly, the Ivory Tower is applying the theory to resuscitation. It seems the chaotic and random appearance of ventricular fibrillation may not be as random as once believed. It appears to be possible, based on waveform characteristics unperceivable to the naked eye, to accurately predict when a defibrillation attempt will be successful. In the future, it may be possible to avoid interrupting CPR for futile defibrillation attempts until the exact moment the shock will produce a conversion. Stay tuned. . . Kenny Navarro UT Southwestern ------------------------------------ Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 18, 2008 Report Share Posted June 18, 2008 > >>> . . . " chaos theory " <<< > > Very simply, the theory holds that seemingly random events > may indeed > be predictable if one accounts for a critical number of > variables. > The accuracy of the prediction improves with discovery and > consideration of increasing numbers of variables. That's not actually correct. Chaos theory states that given a system, you can predict the limits a system will operate in, but inside the given system you lose the ability to predict at a granuar level how or in what order events will evolve. Take fractals. You can predict the shape of the fractal and describe how it progresses, but you can't predict with any certainty whether a particular element exists or has a given value. The problem with EMS is that the number of variables is much, much too high to be able to compute. You would have to be able to know far too many details about every person and object in your environment, down to the state of rot in tree branches that might fall, or the number of ants chewing on a given electrical wire. You can predict where higher call volumes are likely (population centers, certain communities, etc.) or when higher call volumes are likely - but the actual existence or location of any given call is, for all intents and purposes, random. There's a difference between filling in gaps in coverage through " fill-ins " or " back-ins " (or god forbid SSM) and in attempting to shift coverage based on some deterministic method of predicting the next call. Filling gaps is done to equalize coverage based on available units, reducing the number of points being underserved. You're not doing it because you think that unit will be closer to the next call - you're doing it because you want to equalize your provision of service over a given area. Mike Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 18, 2008 Report Share Posted June 18, 2008 How cool is that...in my TAMU days, I explored this a touch...and it was much more infantile than it is now...as a math nut, it has always intrigued me. Dudley Chaos >>> . . . " chaos theory " <<< There is a term you do not see on this discussion list very often! Dudley, you are right that elements of the chaos theory apply to the process of deciding where to station EMS vehicles. Very simply, the theory holds that seemingly random events may indeed be predictable if one accounts for a critical number of variables. The accuracy of the prediction improves with discovery and consideration of increasing numbers of variables. Interestingly, the Ivory Tower is applying the theory to resuscitation. It seems the chaotic and random appearance of ventricular fibrillation may not be as random as once believed. It appears to be possible, based on waveform characteristics unperceivable to the naked eye, to accurately predict when a defibrillation attempt will be successful. In the future, it may be possible to avoid interrupting CPR for futile defibrillation attempts until the exact moment the shock will produce a conversion. Stay tuned. . . Kenny Navarro UT Southwestern Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 18, 2008 Report Share Posted June 18, 2008 And Mike, the " god forbid SSM " doesn't attempt to say the call will be at 1234 Main St...it says if I have one ambulance available, where would the?best location be at a certain time of day or night to place that one ambulance where it would have the best access to the area of highest probability of a call...or 2?ambulances or 24 ambulances....I have never worked in a system that attempted to predict the actual location of a call.? In the system I worked in, we broke our 300 square mile county into 1mile X 0.5 mile blocks (our map grids) and charted the call volumes in each grid for each hour of the day for each day of the week for a 15 week period.? In this 15 week period, we had approximately 35,000 requests spread across these 600 grids.? With this level of data, we could make some very good assumptions about where calls were going to pattern at certain times of the day and certain days of the week.? We had about 5 posts that always had trucks in them (and sometimes 2)...we had about 5 posts that rarely had any trucks in them (unless we had over 35 available units)...and we had some areas covered by 24 hour stations because the call volume was low enough that posting wouldn't provide adequate coverage.? This is where system design is SO critical in deployment design.? We had 17 communities in our county...and we had a county wide response time requirement and a jurisdiction response time requirement...which forced us to not only respond to the high call volume areas but to also service the low call volume areas so as to not violate the terms of our performance agreement.? Was very efficient, monied well, and provided a tremendous environment for learning and working EMS. As I have always said...rather sitting on a street corner or in a lazy-boy in a station...if the system is not managed and lead well...it will suck...no matter where we park our trucks. Dudley Re: Chaos > >>> . . . " chaos theory " <<< > > Very simply, the theory holds that seemingly random events > may indeed > be predictable if one accounts for a critical number of > variables. > The accuracy of the prediction improves with discovery and > consideration of increasing numbers of variables. That's not actually correct. Chaos theory states that given a system, you can predict the limits a system will operate in, but inside the given system you lose the ability to predict at a granuar level how or in what order events will evolve. Take fractals. You can predict the shape of the fractal and describe how it progresses, but you can't predict with any certainty whether a particular element exists or has a given value. The problem with EMS is that the number of variables is much, much too high to be able to compute. You would have to be able to know far too many details about every person and object in your environment, down to the state of rot in tree branches that might fall, or the number of ants chewing on a given electrical wire. You can predict where higher call volumes are likely (population centers, certain communities, etc.) or when higher call volumes are likely - but the actual existence or location of any given call is, for all intents and purposes, random. There's a difference between filling in gaps in coverage through " fill-ins " or " back-ins " (or god forbid SSM) and in attempting to shift coverage based on some deterministic method of predicting the next call. Filling gaps is done to equalize coverage based on available units, reducing the number of points being underserved. You're not doing it because you think that unit will be closer to the next call - you're doing it because you want to equalize your provision of service over a given area. Mike Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 19, 2008 Report Share Posted June 19, 2008 I have rarely if ever seen Fire Depts. do any real form of SSM other than possibly double coverage or post when another station gets bumped on a protracted call. When SSM the hotest thing I was managing a service and found it to be very un-useful and a huge waste of money and resources. Posting - yes. SSM or anything like it no way. -MH ________________________________ From: texasems-l [texasems-l ] On Behalf Of THEDUDMAN@... [THEDUDMAN@...] Sent: Thursday, June 19, 2008 12:05 AM To: texasems-l Subject: Re: Chaos And Mike, the " god forbid SSM " doesn't attempt to say the call will be at 1234 Main St...it says if I have one ambulance available, where would the?best location be at a certain time of day or night to place that one ambulance where it would have the best access to the area of highest probability of a call...or 2?ambulances or 24 ambulances....I have never worked in a system that attempted to predict the actual location of a call.? In the system I worked in, we broke our 300 square mile county into 1mile X 0.5 mile blocks (our map grids) and charted the call volumes in each grid for each hour of the day for each day of the week for a 15 week period.? In this 15 week period, we had approximately 35,000 requests spread across these 600 grids.? With this level of data, we could make some very good assumptions about where calls were going to pattern at certain times of the day and certain days of the week.? We had about 5 posts that always had trucks in them (and sometimes 2)...we had about 5 posts that rarely had any trucks in them (unless we had over 35 available units)...and we had some areas covered by 24 hour stations because the call volume was low enough that posting wouldn't provide adequate coverage.? This is where system design is SO critical in deployment design.? We had 17 communities in our county...and we had a county wide response time requirement and a jurisdiction response time requirement...which forced us to not only respond to the high call volume areas but to also service the low call volume areas so as to not violate the terms of our performance agreement.? Was very efficient, monied well, and provided a tremendous environment for learning and working EMS. As I have always said...rather sitting on a street corner or in a lazy-boy in a station...if the system is not managed and lead well...it will suck...no matter where we park our trucks. Dudley Re: Chaos > >>> . . . " chaos theory " <<< > > Very simply, the theory holds that seemingly random events > may indeed > be predictable if one accounts for a critical number of > variables. > The accuracy of the prediction improves with discovery and > consideration of increasing numbers of variables. That's not actually correct. Chaos theory states that given a system, you can predict the limits a system will operate in, but inside the given system you lose the ability to predict at a granuar level how or in what order events will evolve. Take fractals. You can predict the shape of the fractal and describe how it progresses, but you can't predict with any certainty whether a particular element exists or has a given value. The problem with EMS is that the number of variables is much, much too high to be able to compute. You would have to be able to know far too many details about every person and object in your environment, down to the state of rot in tree branches that might fall, or the number of ants chewing on a given electrical wire. You can predict where higher call volumes are likely (population centers, certain communities, etc.) or when higher call volumes are likely - but the actual existence or location of any given call is, for all intents and purposes, random. There's a difference between filling in gaps in coverage through " fill-ins " or " back-ins " (or god forbid SSM) and in attempting to shift coverage based on some deterministic method of predicting the next call. Filling gaps is done to equalize coverage based on available units, reducing the number of points being underserved. You're not doing it because you think that unit will be closer to the next call - you're doing it because you want to equalize your provision of service over a given area. Mike Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 20, 2008 Report Share Posted June 20, 2008 Rural/Metro in Pima County, AZ assigns trucks of all sorts to " midpoint 72-73 for coverage " now and then. It generally does not last long. GG > > I have rarely if ever seen Fire Depts. do any real form of SSM other than > possibly double coverage or post when another station gets bumped on a > protracted call. When SSM the hotest thing I was managing a service and found it to > be very un-useful and a huge waste of money and resources. Posting - yes. SSM > or anything like it no way. > > -MH > ____________ ________ ________ _ > From: texasems-l@yahoogrotexasem [texasems-l@yahoogrotexasem] On Behalf Of > THEDUDMAN@... [THEDUDMAN@...] > Sent: Thursday, June 19, 2008 12:05 AM > To: texasems-l@yahoogrotexasem > Subject: Re: Chaos > > And Mike, the " god forbid SSM " doesn't attempt to say the call will be at > 1234 Main St...it says if I have one ambulance available, where would the?best > location be at a certain time of day or night to place that one ambulance > where it would have the best access to the area of highest probability of a > call...or 2?ambulances or 24 ambulances.. And Mike, the " god forbid SSM " doesn't > attempt to say the call will be at 1234 Main St...it says if I have one > ambulance available, where would the?best location be at a certain time of day or > night to place that one ambulance where it would have the best access to the > area of highest probability of a call...or 2?ambulances or 24 ambulances..< > wbr>..I have never worked in a system that attempted to predict the actual > location of a call.? In the system I worked in, we broke our 300 square mile > county into 1mile X 0.5 mile blocks (our map grids) and charted the call v > > We had about 5 posts that always had trucks in them (and sometimes 2)...we > had about 5 posts that rarely had any trucks in them (unless we had over 35 > available units)...and we had some areas covered by 24 hour stations because > the call volume was low enough that posting wouldn't provide adequate > coverage.? This is where system design is SO critical in deployment design.? We had 17 > communities in our county...and we had a county wide response time > requirement and a jurisdiction response time requirement. We had about 5 posts that > always had trucks in them (and sometimes 2)...we had about 5 posts that rarely > had any trucks in them (unless we had over 35 available units)...and > > Was very efficient, monied well, and provided a tremendous environment for > learning and working EMS. > > As I have always said...rather sitting on a street corner or in a lazy-boy > in a station...if the system is not managed and lead well...it will suck...no > matter where we park our trucks. > > Dudley > > Re: Chaos > > > > > >>> . . . " chaos theory " <<< > > > > Very simply, the theory holds that seemingly random events > > may indeed > > be predictable if one accounts for a critical number of > > variables. > > The accuracy of the prediction improves with discovery and > > consideration of increasing numbers of variables. > > That's not actually correct. Chaos theory states that given a system, you > can predict the limits a system will operate in, but inside the given system > you lose the ability to predict at a granuar level how or in what order events > will evolve. Take fractals. You can predict the shape of the fractal and > describe how it progresses, but you can't predict with any certainty whether a > particular element exists or has a given value. > > The problem with EMS is that the number of variables is much, much too high > to be able to compute. You would have to be able to know far too many details > about every person and object in your environment, down to the state of rot > in tree branches that might fall, or the number of ants chewing on a given > electrical wire. > > You can predict where higher call volumes are likely (population centers, > certain communities, etc.) or when higher call volumes are likely - but the > actual existence or location of any given call is, for all intents and purposes, > random. > > There's a difference between filling in gaps in coverage through " fill-ins " > or " back-ins " (or god forbid SSM) and in attempting to shift coverage based > on some deterministic method of predicting the next call. Filling gaps is done > to equalize coverage based on available units, reducing the number of points > being underserved. You're not doing it because you think that unit will be > closer to the next call - you're doing it because you want to equalize your > provision of service over a given area. > > Mike > > Quote Link to comment Share on other sites More sharing options...
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