afrinl
04-13-2003, 12:28 AM
Hello --
I have been looking for a particular 802.11b device that seems like it ought to exist, yet I can't find one despite extensive searching of the net.
This is the simplest of all possible 802.11b devices, so it seems odd that nobody would have thought of this, so I'm guessing I just haven't found it yet and would appreciate anyone pointing me in the right direction.
The problem I'm trying to solve is tracking patients and mobile equipment in a hospital environment. It may sound silly, but patients often are not where they're expected to be, and a lot of hospital personnel spend a lot of time going to where they expect the patient to be, only to find the patient isn't there, and then they spend more time trying to track down where the patient actually is. It sure would be helpful if we could "press a button" and identify the current vicinity of the patient's location.
There's a similar problem with mobile equipment such as IV pumps, wheelchairs, etc.
Our hospital is about to get outfitted with an 802.11b-compatible wireless infrastructure for purposes of supporting mobile access to our clinical information systems, and it struck me that I ought to be able to use the same infrastructure to solve our patient- and equipment-tracking problems.
Since 802.11b devices are, at their heart, Ethernet devices with their own MAC addresses, you can identify a patient to whom you give an 802.11b device by the device's MAC address. And since you can trace (at least I'm pretty sure you can trace) what wireless access point (which has its own IP address and MAC address) a given wireless client device is using to gain access to the wired network, you therefore can identify the vicinity of any given wireless client device.
So I'm looking for an 802.11b device which would have a tiny footprint (maybe could be packaged in an ID badge you could clip to the patient's gown, or a band you could strap around the patient's wrist, or something like that) and basically would be nothing more than an 802.11b transceiver and a battery (or maybe would work off of a solar cell via ambient light) and would do absolutely nothing more than ping a given server once a minute.
The server therefore ought to be able to know the IP addresses of the devices that are pinging it, and for any given device you want to locate, the server could do a traceroute to the device's IP address, then translate the penultimate IP address in the traceroute (that is, the IP address of the wireless access point nearest the client device at the moment) into the known location of that particular wireless access point.
Ta-da! An 802.11b-based locator device. And given how simple the device is, it oughta be ultra-cheap, too. It wouldn't have to be the most rugged thing in the world, but it would either have to be cheap enough to throw away if it got soiled, or it would have to be autoclavable (i.e., sterilizable). And however it gets attached to the patient, you'd have to be able to detach it fairly easily (with intentions of soon reattaching it) when the patient goes to get an MRI scan.
The same approach ought to work for a mobile equipment locator, except that batteries would become an issue, which is why I raise the possibility of working off of ambient light via a solar cell. Sure, if the piece of equipment (let's hope not the patient!) gets stuffed in a dark closet, the locator device would go dead for lack of power and the server won't be able to contact the equipment, but the server *will* be able to review its logs and see the *last place* the equipment was at before it "disappeared," and the odds would be pretty good that the present location of the equipment is pretty close to the last place registered in the server's logs.
So, has anybody seen or heard of such a patient or equipment tracking device, or does it not exist? Does it not exist because it's so simple and nobody has thought of this application? If so, is there anybody in this forum who's with a company that could build, and would like to build, such a device and use my institution as a testbed?
BTW, I thought of a Bluetooth solution, but our wireless infrastructure probably won't have dense enough coverage (at least, not to begin with) to support reliable Bluetooth access.
Thanks for listening as well as any insights, ideas, advice, etc. you can offer. I would appreciate your copying your response to my e-mail address.
Sincerely,
Larry Afrin, M.D.
Assistant Professor of Medicine, MUSC Division of
Hematology/Oncology
Director of Information Technology, MUSC Hollings Cancer Center
Chairman, MUSC Clinical Information Systems Steering
Committee
Medical University of South Carolina
afrinl@musc.edu
I have been looking for a particular 802.11b device that seems like it ought to exist, yet I can't find one despite extensive searching of the net.
This is the simplest of all possible 802.11b devices, so it seems odd that nobody would have thought of this, so I'm guessing I just haven't found it yet and would appreciate anyone pointing me in the right direction.
The problem I'm trying to solve is tracking patients and mobile equipment in a hospital environment. It may sound silly, but patients often are not where they're expected to be, and a lot of hospital personnel spend a lot of time going to where they expect the patient to be, only to find the patient isn't there, and then they spend more time trying to track down where the patient actually is. It sure would be helpful if we could "press a button" and identify the current vicinity of the patient's location.
There's a similar problem with mobile equipment such as IV pumps, wheelchairs, etc.
Our hospital is about to get outfitted with an 802.11b-compatible wireless infrastructure for purposes of supporting mobile access to our clinical information systems, and it struck me that I ought to be able to use the same infrastructure to solve our patient- and equipment-tracking problems.
Since 802.11b devices are, at their heart, Ethernet devices with their own MAC addresses, you can identify a patient to whom you give an 802.11b device by the device's MAC address. And since you can trace (at least I'm pretty sure you can trace) what wireless access point (which has its own IP address and MAC address) a given wireless client device is using to gain access to the wired network, you therefore can identify the vicinity of any given wireless client device.
So I'm looking for an 802.11b device which would have a tiny footprint (maybe could be packaged in an ID badge you could clip to the patient's gown, or a band you could strap around the patient's wrist, or something like that) and basically would be nothing more than an 802.11b transceiver and a battery (or maybe would work off of a solar cell via ambient light) and would do absolutely nothing more than ping a given server once a minute.
The server therefore ought to be able to know the IP addresses of the devices that are pinging it, and for any given device you want to locate, the server could do a traceroute to the device's IP address, then translate the penultimate IP address in the traceroute (that is, the IP address of the wireless access point nearest the client device at the moment) into the known location of that particular wireless access point.
Ta-da! An 802.11b-based locator device. And given how simple the device is, it oughta be ultra-cheap, too. It wouldn't have to be the most rugged thing in the world, but it would either have to be cheap enough to throw away if it got soiled, or it would have to be autoclavable (i.e., sterilizable). And however it gets attached to the patient, you'd have to be able to detach it fairly easily (with intentions of soon reattaching it) when the patient goes to get an MRI scan.
The same approach ought to work for a mobile equipment locator, except that batteries would become an issue, which is why I raise the possibility of working off of ambient light via a solar cell. Sure, if the piece of equipment (let's hope not the patient!) gets stuffed in a dark closet, the locator device would go dead for lack of power and the server won't be able to contact the equipment, but the server *will* be able to review its logs and see the *last place* the equipment was at before it "disappeared," and the odds would be pretty good that the present location of the equipment is pretty close to the last place registered in the server's logs.
So, has anybody seen or heard of such a patient or equipment tracking device, or does it not exist? Does it not exist because it's so simple and nobody has thought of this application? If so, is there anybody in this forum who's with a company that could build, and would like to build, such a device and use my institution as a testbed?
BTW, I thought of a Bluetooth solution, but our wireless infrastructure probably won't have dense enough coverage (at least, not to begin with) to support reliable Bluetooth access.
Thanks for listening as well as any insights, ideas, advice, etc. you can offer. I would appreciate your copying your response to my e-mail address.
Sincerely,
Larry Afrin, M.D.
Assistant Professor of Medicine, MUSC Division of
Hematology/Oncology
Director of Information Technology, MUSC Hollings Cancer Center
Chairman, MUSC Clinical Information Systems Steering
Committee
Medical University of South Carolina
afrinl@musc.edu