OK, I read the PR piece, nosed around the Yahoo stock board for ADSX, and I've concluded that it's BS.

From the company, quoted on the Yahoo stock bbs:

"The device is waffer thin, about the diameter of a dime..."

From the PR blurb:

"The implantable transceiver sends and receives data and can be continuously tracked by GPS (Global Positioning Satellite) technology."

Let's apply a little common sense here.

First off, NOTHING is "tracked by GPS technology". That's idiot-talk like "your television is watching you".

GPS is a BEACON, and *not* a LISTENING system.

The only -- the ONLY way that GPS could have *anything* to do with a "tracking system" is to have a GPS receiver (tuned to several satellites) that maintained a running "awareness" of where you were, and then have it transmit your location via an RF transmitter.

Now, it strains credulity to the breaking point to accept that a GPS receiver, a powerful radio transmitter (by "powerful", I mean at *least* a sizable portion of a Watt), antennas for GPS *and* the RF transmitter -- AND some sort of battery capable of *running* the contraption -- *and* (pant pant pant), a mechanical battery charger, run by ambient *muscle flexing* (oh, my sides, my sides, I'm choking on laughter here) -- ALL of this stuff is contained in something the size of a DIME?!?!?!?!?!?

Pull the other one.

Wake me up when they have a *working* model, OK?

Now, before someone pipes up with the "doggie implants", I'm fully aware of them, and they are *nothing* like the claims made by the PR flack who wrote that release.

First off, the pet implants are *passive* devices. That means that by *saturating* them with RF, they're able to absorb enough to re-radiate a tiny amount, encoded with a bit pattern.

The most significant limitation is *range*. If you've ever seen a vet scan a dog or cat, you noticed that the scanner had to be *very* close to the pet.

The reason for that is something called "the inverse square law". Every time you double the distance from a transmitter, your power level drops to 1/4. In other words, to maintain the same signal strength at twice the distance, you have to *quadruple* the output power.

So, if the few microwatts of re-radiated RF can be detected at, oh, let's say one foot, you'd need to quadruple it to reach two feet. Then quadruple it again to reach four feet. And again to reach eight feet.

Because of the inefficiencies involved, in order to have any kind of appreciable range (and I'm talking *less* than a mile), you'd need to beam a microwave transmitter at the poor creature, and it would probably be burned to a crisp before you finished reading the serial number!

I don't know what's going on with that company, but I have a feeling I'll find the ultimate resolution to be kind of amusing.

-- Ron Schwarz (rs@clubvb.com.delete.this), December 18, 1999

Answers

GPS technology is already being used by some companies to track the positions of their delivery drivers, etc. I think some auto security systems also use an implanted device that can be tracked by the police. The system works by comparing the difference in the time delays between a ground based station and the signal received from the satellite. Since the signals are sent out in milliseconds, the location of the receiver can be pinpointed to within a few meters, and will be even better soon. The fact that the electronics are now being made into microelectronics isn't suprising when you consider what has happened with computer chips.

-- Hawk (flyin@high.again), December 18, 1999.

United States Patent 5,629,678 Gargano, et. al., May 13, 1997 Personal tracking and recovery system

Apparatus for tracking and recovering humans utilizes an implantable transceiver incorporating a power supply and actuation system allowing the unit to remain implanted and functional for years without maintenance. The implanted transmitter may be remotely actuated, or actuated by the implantee. Power for the remote-activated receiver is generated electromechanically through the movement of body muscle. The device is small enough to be implanted in a child, facilitating use as a safeguard against kidnapping, and has a transmission range which also makes it suitable for wilderness sporting activities. A novel biological monitoring feature allows the device to be used to facilitate prompt medical dispatch in the event of heart attack or similar medical emergency. A novel sensation-feedback feature allows the implantee to control and actuate the device with certainty.

-- Linda (lwmb@psln.com), December 18, 1999.

Hawk: Yes, I know how GPS operates, and I know how it's used as an adjunct to tracking trucks and so forth.

However:

"The fact that the electronics are now being made into microelectronics isn't suprising when you consider what has happened with computer chips."

It's not "surprising", it's "unbelievable".

Some electronic devices -- notably *logic* elements -- can be miniaturized to whatever size the *manufacturing* technology allows.

That's why Moore's Law is still in effect. Each year, chip making technology is able to cram smaller and smaller gates closer and closer together.

So long as each transistor is able to switch between on and off, the device will work. Even if a junction is built of a handful of *atoms*, if it's stable, and they're able to get a tiny bit of power and signal into it, it's usable.

Such is NOT the case with RF devices!

The first consideration is the need for tuned circuits. There are immutable laws that determine the size of coils, IF & RF transformers, and crystal filters.

Next, there's the matter of *antennas*. The "Digital Angel" if taken as-presented (and reading past the nonsense about GPS tracking it) is described as having *three* radio devices: a GPS receiver, an RF receiver (to receive the remote control commands they mention), and an RF transmitter to send its information to a satellite.

Antenna *propagation* characteristics are determined by how well it is tuned to its target frequency.

Let's be charitable, and assume that its using one frequency band for GPS, and another for combined RF transmit/receive.

That's still *two* antennas, each of which would likely *need* to be larger than the entire device.

"Cheat" by making the antenna smaller than it needs to be, and you'll have *significant* losses due to inefficiency.

I'll say it again: a transmitter capable of sending a signal to a satellite -- from *inside* a human body (which creates its own set of signal attenuation issues) -- most assuredly *cannot* meet the physical specifications given for the alleged product.

Then, there's the *power* issue. The claim that a device the size of a dime can contain the necessary tuned components (coils, crystal filters, and antennas) should be sufficiently far fetched as to lay the matter to rest. But, there's still the matter of a *power* source.

The range of a transmitter is determined by a number of factors. The *underlying* factor is the power supply.

No matter how much power your transmitter -- regardless of size -- is capable of transmitting, unless it has sufficient DC power to run, it will be unable to supply its rated output.

To put it another way: you're not going to move a wagon full of rocks very far if you're trying to push it along with a feather.

A semi-microscopic battery, recharged by the *miniscule* amount of kinetic energy transfered by movement of adjacent muscles -- really now, folks. Maybe enough juice there to run an LCD wristwatch. Heck, a couple of wires in an orange will do *that*.

But you're not going to take that barely-detectable galvanic force and use it to run two sensitive receivers *and* a powerful transmitter.

Finally, Linda: This would not be the first time the USPO issued a patent on the basis of *paperwork* alone.

Did you read anything anywhere about a *working model*? I didn't. Please let me know if you run across one!

-- Ron Schwarz (rs@clubvb.com.delete.this), December 18, 1999.

Ron,

Why should I believe anything you say when it's so much more fun to believe that "they're out to get me?".

I mean come on, the next thing you're going to tell me that the television show The X-Files isn't real...

Sheesh, a person is armed with facts and experience and he expects people to actually believe him!!! I guess maybe now "they" are going to try to convince me that the world is round!, when it's obvious that it's flat! Just go to any beach and look at the ocean. See? It's flat I tell ya!!

Flat, flat flat flat flat !!! la la la la la , Ron is talking, but I am not listening to him... la la la la la la la la.

-- (sarcasm@mode.off), December 18, 1999.

BTW, if the lithium battery ruptures, it will great one heck of a grievous boil that will not heal.

-- Hokie (nn@va.com), December 18, 1999.

Look through the actual patent application which is posted on Applied Digital Solution's web site. The device that is described in the patent is a far cry from a trivially implantible dime-sized device that will track you wherever you go.

The patent, by a brief reading, doesn't say how small it is - just that it is small enough to be implanted. As to the power source, one has to suture one end to a muscle and tether the other to a bone! I (I'm an MD) can't immediately think of how you could do this and ensure that the mechanical connection, which would be under varying stress for years, would remain intact. Sutures would either break or erode through their anchor sites under these conditions.

I'm willing to believe that such a device is possible if it's of about the size and complexity of implantation of a cardiac pacemaker. A dime-sized device with no external connections seems out of the question.

-- Ned Taylor (entaylor@cloudnet.com), December 18, 1999.

The dime-sized claim was made by a company official (the CEO, I think) quoted (again, from a radio interview IIRC) on the Yahoo BBS for the company. You might want to check out that forum, I included a link to that particular message in my first post in this thread.

-- Ron Schwarz (rs@clubvb.com.delete.this), December 18, 1999.

This is to the "Dr". The fact that you are an MD did not help you with your biochemistry much, did it. The artical said that the implant was powered electrochemicaly, not by phsical means. The muscles are powered by an action potintial created by proton gradient due to the accumilation of Ca+ cations on one side of a membrain. (You must have skiped the section on ACE inhibitors and Beta Blockers. I hope you don't RX these much to your patients if you don't even know how they work.) It is very possible that this device could be powered in this fassion. No need for a physical connection!!!!! Sheesh.

-- Sean Chamness (biochemisty taken@ACME.com), December 19, 1999.

Sean, if will take the trouble to reread my post, you will see that I am talking about the patent. And if you will take the trouble to read that> you will see that the device "derives power from physical work done by muscle fibers in the body". The patent discusses using a piezoelectric device as a transducer or possibly a "moving magnet generator."

-- Ned Taylor (entaylor@cloudnet.com), December 19, 1999.