Monthly Archives: March 2006

ICDs, wandless telemetry, and encryption

Here’s something nobody has ever been able to tell me:

Do wandless ICDs (implantable cardioverter-defibrillators) employ any kind of encryption?

As far as I can tell, the answer is no.

Let me give you a little background. At the last Heart Rhythm Scientific Sessions (2005, in New Orleans) most of the big ICD companies were showing off their wonderful new “wandless telemetry” systems. Historically, ICDs have been programmed (after implantation) and interrogated with some variety of inductive communication. This was done by placing a “wand” over the part of the patient’s body where the device was implanted and then initiating communication. It has a short range, around a few inches. Device companies have begun to use radio-frequency (RF) communication instead, which has a longer range, something on the order of feet or meters.

This is a big problem.

Not one person I’ve asked (admittedly, sales people for the most part) has been able to tell me if the new RF (a.k.a wandless) telemetry communication is encrypted. I did some patent searching at, and found that no patents have been granted on anything like this yet. However, Medtronic did apply for a patent in September 2005. As the patent application says in its background, “With the advent of long range telemetry of messages, and the associated increase in communication range, the risk that a message can be compromised is increased. For example, a replay attack can be launched in which a message, or a piece of a message, can be captured and then maliciously used at a later time.”

So it does appear that someone is thinking about this. Most people don’t really think about or understand encryption, even technically-inclined people like medical device engineers.

Do you know anything about this? Do you know someone who might?

Demolition of flooded homes in New Orleans has begun

A lot of those homes, including my former apartment, might be turned into parks since they’re not in a good place should another hurricane hit.

City starts to raze homes hit by Katrina – Americas – International Herald Tribune

It was a moment of fearful anticipation for New Orleans, the first demolitions of flooded homes in the six months since Hurricane Katrina. Three were razed Monday in a process that was long delayed by legal challenges, physical obstacles, and the difficulty in getting money to search for bodies that almost certainly remain in some of the houses.

Army Corps of Engineers officials estimate millions of cubic yards of debris from demolished houses will have been removed in Orleans Parish when the process ends, roughly a year from now, representing perhaps as many as 25,000 houses. About 120 houses, nearly all in the Lower 9th Ward, are set for immediate demolition.

Science, Buddhism, and GTD

When I realized that I was essentially a Buddhist (without even deciding to be, mind you) and a scientist something snapped and it all came together.

In my view, Buddhism and scientific inquiry are two sides of the same coin. While scientific observation and testing deals with the outside world, Buddhism deals with the world within. Both approaches seek to understand what is through careful attention and observation. An often-suggested approach in Buddhism is to seek to have a mind like a child.

What is a child’s mind like? Do you know any two or three-year-olds? What word is so often on the tip of their tongue?

It is: why?

When you let go of something and it drops — why?
When the sun comes up in the morning — why?
When someone sees a wobbling star way out there in space — why?
When we shock the heart and it stops fibrillation — why?
When I’m in a bad mood and I want to lash out — why?
When I’m happy and I feel on top of the world — why?
When I’m impatient and I get that twisty feeling in my stomach — why?
When I’m obsessed with figuring something out — why?

You probably get the picture, but there’s more. There’s a twist. Neither one works if we ignore what we find because it’s not what we think is true when we seek the answer. We have to make a completely earnest effort to get as close to the truth as we can, and if there’s no objective truth to an issue or no clear-cut answer, to find out as much as we can about it and act accordingly.

The bad mood thing is a particularly good example of the power of Buddhism (for me in particular, Zen) and the harm of clinging to what we think we know. I’m sometimes in a bad mood, but I don’t know why. I may attribute it to anything that annoys me at the moment, but addressing those annoyances doesn’t eliminate the problem. It becomes clear after a few attempts to fix things that even though I think I’ve found the problem and fixed it, I have not. To rage on that the problem is unfixable when I’m fixing the wrong problem is folly, and it’s oh-so common. This is when two things have to happen:

  1. Recognize the state of off-centeredness
  2. Take a moment to sit and observe one’s thoughts

The first bit requires some practice beforehand. If you’re not used to having a quiet mind, it’s hard to notice when you’ve deviated from that state. (click — just remembered where Getting Things Done fits here) With regard to the second bit, it seems impossible, in the arena of one’s own mind, to make objective observations. However, after a little practice by meditation, it becomes possible to do just that. Depending on the type of meditation you practice, the approach may be different, but the results are similar. If you can arrest the active part of the mind, the part that is in the thoughts, and just let thoughts arise from the subconscious or wherever, then you can observe. The mind is pretty good at finding patterns, and if you sit back and just pay attention to the thoughts that arise for a few minutes, usually a pattern emerges. Once you know what the problem is, it’s a lot easier to fix it.

Back to the Getting Things Done bit. I had meant to post about how Buddhism, Science and GTD are interrelated months ago, and couldn’t figure out how to write about it. I lost the epiphany I’d had about it. I gave up and decided to just write this post on science and Buddhism, but then it clicked as noted above while writing. An underlying principle in GTD is that if your mind is clear, you can properly recognize and deal with new input. Really Science and GTD are linked by Buddhism, as such:

Science <— Buddhism —> Getting Things Done

What Buddhism and Getting Things Done have in common is their ‘rest’ state. There’s a saying in the GTD community that, “If it’s on your mind, it’s not Getting Done.” In GTD, everything that you need to do or be concerned with should be out of your head. When it enters your head, you dump it to a capture device, and process it later. Then you make sure it’s in your system in such a way that you will see it again when you need to. I won’t get into the details just now. In Buddhism, all of the “other stuff” of your life should be out of your mind. Your only concern should be what’s often referred to as “The Now” (as compared to the past and the future).

The neat thing is, GTD actually facilitates living in The Now. By removing all of those thoughts that bounce around in the head, reminding you of things when you don’t need to be reminded and so on, the mind is cleared.

It is then possible to (a) be in the moment and (b) focus with full intent, clarity, and creativity on what you’re doing. In fact, that sentence is nearly redundant, because (a) and (b) are practically the same thing.

I think there’s a particular synergy in these three things, and now that I’ve finally laid it out in words I hope to have more observations about this synergy to share in the near future. Questions? Comments?

The (formal) logic behind science

This is an interesting post about the formal basis of scientific inquiry, in which it’s proven that for a sufficiently large universe of observable things, the probability of a scientific law being true is zero!

Conjectures and Refutations » Blog Archive » Falsificationism In One Lesson

Even in such situations where the range of x is thus restricted, a high degree of falsifiability is a desirable trait in a hypothesis. It allows the hypothesis to be tested more readily and eliminated quickly if false, and a higher degree of falsifiability in a theory is isomorphic with a greater simplicity — there are more ways for a data point to lie off a straight line than off a quartic curve. Given any collection of data points there’s always a more probable function you can draw that runs through all of them — even if it’s hideously convoluted (think Ptolemaic epicycles). In the limiting case, we can always plead persistant delusion to avoid the need to accomodate recalcitrant data, or answer “god did it” to everything, or make up all manner of new assumptions on an ad hoc basis. But what ultimately distinguishes the scientific mindset from the unscientific one is a willingness to put a theory up against critical tests, a desire for elegance and an strong aversion to ad hockery. The other counterintuitive upshot to this conclusion is that it’s improbability rather than probability which is a virtue in a theory. A priori, it’s more logically probable that your data will be scattered all over the place than that they’ll all line up along a perfectly straight linear function. We should strive for explanations which are both true and simple, but we should also consider it something of an improbable miracle if we manage to find both together in one theory.

Helping the body fight cancer

There’s a nice overview (with links to abstracts) on Biosingularity about this discovery:

Biosingularity » Blog Archive » Newly discovered killer cell fights cancer

A mouse immune cell that plays dual roles as both assassin and messenger, normally the job of two separate cells, has been discovered by an international team of researchers. The discovery has triggered a race among scientists to find a human equivalent of the multitasking cell, which could one day be a target for therapies that seek out and destroy cancer.

“In the same way that intelligence and law enforcement agencies can face deadly threats together instead of separately, this one cell combines the ability to kill foreign pathogens and distribute information about that experience,” says Drew Pardoll, M.D., Ph.D., the Seraph Professor of Oncology at the Johns Hopkins Kimmel Cancer Center.