Steering your ship!

The analogy of a "Roller Coaster" is often used to describe out-of-control diabetes sugar management.

Here is one I came up with to portray the theory behind properly-controlled glucose management.  The following describes the "feedback mechanism" which a ship's captain uses to steer the ship.  It is the theory behind many control systems and servo mechanisms.

Here's a description of the "feedback mechanism" used in steering a ship:

"When the boat deviates from the present course, say to the right, the steersman assesses the deviation and then countersteers by moving the rudder to the left. This decreases the boat's deviation, perhaps even to the point of moving through the correct position and then deviating to the left. At some time during this movement the steersman makes a new assessment of the boat's deviation, countersteers accordingly, assesses the deviation again, and so on. Thus he relies on continual feedback to keep the boat on course, its actual trajectory oscillating around the present direction. The skill of steering a boat consists in keeping these oscillations as smooth as possible.”

So starting today, instead of thinking of yourself as the helpless Roller Coaster passenger, think of yourself as a ship's captain.  When you're either "high" or "low", assess your deviation and countersteer.  Try NOT to oversteer.  At the same time keep making new assessments of your position.  Rely on "continual feedback" to keep your boat on course and keep your "oscillations as smooth as possible."

Hi Paul,

I came up with a similar analogy a few months ago...  Maybe I should have copyrighted it...?  LOL

But seriously, mine has more to do with the speedometer on a car.  The posted speed limit is the goal (+ a little higher, of course!).  If the number on the speedometer is showing too high, one must ease up on the accelerator.  But not too much, or else the numer will drop too low, in which case one must apply more pressure on the gas pedal.  Finding that perfect balance, that is finding just the right amount of gas to give the engine can be tricky, especially for a new, unexperience driver, but it is achievable.

So, what do you think of my analogy???  Sorry, I don't have a picture to add!  LOL

I didn't know I could steer a ship! I didn't even know I had a ship! lol. That's a really good analogy. I never thought about that. I didn't even know anything about that! I guess it's true you do learn something new everyday!

I owned a 23' Grady-White Power Boat for about 5 years and, I regret to confess, was a very poor captain.  Steering a ship (and probably an airplane as well), is quite different than driving a car, which I am able to do.  Firstly, when you make a steering adjustment, a boat doesn't respond right away.  Secondly, when it begins to respond, it doesn't stop responding right away either.  These aspects are very much like eating food to control lows and taking insulin to control highs. Neither responds right away and both very often continue responding long past the desired point of destination.  When you throw in other factors, such as wind resistance and water currents, you have a very complex "dynamic," just like factoring in exercise and illness to your blood sugar calculations.  I find the image and visualization of a "ship's captain" to be a very positive one of being in control by observing, assessing and acting intelligently and decisively on all the conditions.

Here's a picture of a famous "sailor" who also knew the value of good nutrition:

My analogy has always been driving a car (clunker) that leaks oil.  Before you go anywhere you have to check your dipstick.  If it's low, you have to add oil.  Then take off.  Stop every so often and test dipstick and add oil when needed.  If you put too much in, then it starts blowing out past the pistons and that's bad for the engine.  If you don't put enough in, you're engine will overheat and you'll have to stop and let it cool off an put more oil in.  Sort of like being high or low.

I love it, DDrumminman!!!

Should we extend the ship metaphor?  Large tanker ship captains have to think ahead, they have to respond to a potential obstacle at least 3 miles in advance in order to avoid it.  Researchers found that these captains deviated from the tactics they were supposed to use and tried to wait until the last possible moment to adjust their course.  Sometimes the captains on two different ships would wave as they passed by each other way too close.  They felt that these deviations kept their skills in tip top shape, when all they really did was raise the risk of accidents.  Sort of like how we try to use shortcuts in our control or fail to think ahead and end up complicating what should have been an easy situation.


I always felt there's a "daredevil" in all of us.  How many times I would play "let's see how many more miles I could eek out of that empty gas guage!"  It usually worked, but I'll never forget the the time it didn't with my new wife in the car.  Or how many times I would ride my bicycle downhill through all the lights and through the railroad crossings?  Fortunately, I was always luck and made it;  otherwise, I probably wouldn't be here to tell the story.  I probably shouldn't admit it, especially here on Juvenation, but I've tested my ability to function on extremely low blood sugars on more than one occasion.

Now that's thinking with yer dipstick!

(anyone else see those commercials? i crack up every time)

[quote user="C"]

Now that's thinking with yer dipstick!

(anyone else see those commercials? i crack up every time)



....Jimmy, lol. I like those commercials too C.

[quote user="Nads"]mine has more to do with the speedometer on a car.  The posted speed limit is the goal (+ a little higher, of course!).  If the number on the speedometer is showing too high, one must ease up on the accelerator.  But not too much, or else the numer will drop too low, in which case one must apply more pressure on the gas pedal.[/quote]


Too bad diabetes doesn't have cruise control....haha

well said Heather!

Heather Cole wrote: "Too bad diabetes doesn't have cruise control....haha"


I am hopeful Tom:)  That would be awesome

ya need 2 other things, besides deviation, for cruise control.  One is the derivitive (change in error over time), the other the integral (area of error over time d[error]/dt) , of the distance away from set point.  then it's go time.


to control this


or you get this



the only real thing we are missing is the sensing devices... cause our bg meters and CGM's..... S$$k

and faster insulin

and a braking mechanism


oh yea and HA! who though we would ever actually USE math?


You sound like an engineer (which, doubtless, you are).  I have a deep fondness for engineers, as my grandfather and my husband's grandfather both worked in the field.  If only I could consistently think as beautifully and precisely as they (and you!).


P.S.  You're working on the APP, right?!?  My dearest son needs one of those!

I don't know about a "real" cure, but the artificial pancreas ("cruise control") seems quite possible within the next few years.  The theory and technology for such a device already exists.  A surgically implanted device with ports to the outside for refilling and recharging would almost be a real cure and the pharmaceutical companies would still have a way to make money.  It could be driven by some kind of artificial intelligence software which actually "learns" and adapts to the metabolism of the person into whom it is implanted.  These kinds of devices are still expensive to design but not so expensive to mass manufacture anymore, at least in some third world country.

An interesting thing about sensors is how to determine if they are functioning properly.  Joe may have mentioned this in his formulas but I don't always understand the eloquence of math.  If you are driving in a perfectly straight line in icy conditions, it may be due to your perfect control, or due to sliding on the ice.  To establish if your familiar driving rules still apply you actually might need to shake the wheel (introduce variabliity around perfection to establish perfection).  The same concept happens with space rovers...if they report no deviation from a programmed path you have no idea if they are following the path perfectly or if the sensors are malfunctioning.