Star Trek would have it sorted by now

It's pretty official now... Kirk's developed a condition with a name! Addison's disease.
Besides obviously already having a tumour and having lost all the hormones his pituitary makes, he's also lost cortisol, which is produced by the adrenal gland. Well, at least it has a name, some notoriety, and they make you carry a blue card for emergencies. Kind of cool.

Even cooler would be if the 21st century ever delivered what I've come to expect from the future as presented in the past. Star Trek is just one example. How light they make of those perfectly treatable diseases that were still killing people left and right back in the 20th century. No such luck. No quick diagnosis by tricorder, no immediate treatment with a one-size-fits all hypospray and a short spell in sickbay. Your choice of doctor: grumpy drinker, career mum, genetically engineered genius, or hologram.

Science fiction isn't always far from the truth though. Why recently, for the remake of Tron, they scanned the actors into the computer exactly like they imagined in the original. Back then, they made it up. And within their lifetime, it came true!

Anyway, I've invented the world's first artificial pituitary.

On the one hand, the pituitary gland is a kind of thermostat. It measures the values of certain elements in the blood and reacts accordingly to adjust those levels. It also reacts to certain other bodily states in order to, for example, stimulate more cortisol production in times of stress. As I understand it, fairly simple computers can perform similar tasks, like an electronic blood pressure meter or a fingertip pulse oximeter. Given recent experimental developments like IBM's chip on a molecule (http://www.theregister.co.uk/2006/03/24/ibm_nano_chip/), it should be possible to create a measuring device and processor small enough to be portable or even, ideally, implantable.

Of course, implanting foreign objects in the body can cause rejection, so I would look for a solution by building the processor out of biological materials. There's already been successful experiments of this as well (http://news.bbc.co.uk/1/hi/sci/tech/358822.stm). You could use cells taken from the patient's own body. Perhaps even cells from their own pituitary gland, which, helpfully, actually contains adult stem cells so they would be ideally suited to engineer into a new form.

The other role the pituitary fulfils is that, after having monitored the body's needs, it also produces the necessary hormones or stimulating substances for other glands to produce other hormones. Now, making new cells out of scratch can be a tricky proposition. At the moment, replacement hormones are synthesized in big laboratories and then injected or taken as tablets etc. An intermediate solution could be to do much as the continuous glucose monitoring system for diabetics does. A small device is put just under the skin to measure glucose levels and it then radios to another small device to inject synthetic insulin as required. The artificial insulin comes out of vials and needs to be kept topped up.

However, I'm being ambitious here. I'm designing a completely artificial pituitary, to effectively replace a broken one. It needs to be small, implantable, and virtually maintenance free. I'm willing to put up with it needing replacement every 10 years or so (like an artificial heart valve) and I can allow it to be bigger than the actual pituitary gland, as we'd probably not want to implant it in the brain anyway. I was thinking upper arm, and roughly the size of a contraceptive implant.

The replacement pituitary would, similarly to the original one, have to use building blocks that are present in the body to construct the hormones it needs. As we can synthesize hormones in the lab, I assume we have their 'recipe'. Then, it is merely a question of building a finger-sized lab/hormone factory. This would take some serious nanotechnology, but I'm sure both the molecule microchip and biological processors can provide a solution here.

Come on people! This is the 21st century. Let's stop injecting ourselves with needles and taking tablets. None of those methods even come close to mimicking the intricate machinery of the human body. I want my flying car, my robot housemaid, and some miracle medical breakthroughs.