To advance medical technology, we need to understand the body. By developing nanotechnology devices which can explore and analyse the body, we are able to achieve a detailed knowledge, allowing the technology to advance.

Nanotechnology devices could monitor levels within the body, their location and the time and store that on an internal memory. This could then be gathered by filtering them out of the blood and a picture developed on what's affecting the body, where and at what times. These findings could also be reinforced by taking small tissue samples with the devices.

What Could Medicine Achieve?
A lot of diseases and illnesses are caused by damage at the cell level. For these to be worked on it requires small fine tools, making the surgical tools currently used appear to large and unsuitable for the task and possibly cause more damage than good.

Using nanotechnology, small machines could be created which are smaller than human cells, allowing for intervention at a cell level.

What could they be used for?
There are many tasks the nanobots could be used for including:

• Removing obstructions in the circulatory system
• Killing Cancer cells
• Artificially fulfilling a task within the cell, such as that of a mitochondria
• Examining tissue in high detail

These machines could also be designed to be self replicating, achieving low manufacturing costs. Although many people fear that this could make nanotechnology dangerous it will take many years to reach that stage and eventually will become unavoidable.

The Size of Devices
The size of the machines is obviously required to be very small, with the volume of each element being less than 100 cubic nanometres. Meaning overall, the device should be less than 100 nanometres long on each side of a cube. This device would hold the equivalent of a small computer today.

Within this volume, a 'robotic' arm would be included at less than 100 nanometres long and binding sites and 10 nanometres long or less.

In comparison a red blood cell is over 80 times larger than this.

Applications

Killing Cancer Cells
A device could be designed with the ability to identify and kill cancer cells. To achieve this, the device would have to have some binding sites to attach itself to cells to test them, a computer on board with information to compare the findings to see if the cell is cancerous and some poison which could be released on the cell in order to kill it.

The device would be able to go around the body in the circulatory system and using the binding sites check the different molecules surrounding it until a cancerous cell was detected.

By using acoustic signals the device would be able to send and receive instructions as well as determine where it is in the body, in a similar way to GPS in a car.

Providing Oxygen - Artificial Red Blood Cells
Using items such as bucky balls oxygen could be delivered to parts in the body where it is required, creating an artificial blood cell. This would help prevent tissue damage as it could detect when oxygen levels fell below a certain point and release the oxygen.

To completely become an artificial red blood cell, the device would also have to absorb oxygen when levels were higher than the threshold.

Artificial Mitochondria
The mitochondria within cells often fail after tissue injury cause by loss of blood flow, therefore increasing oxygen would not restore the tissue. However designing a device to be artificial mitochondria could help restore the functions of the cell, even if the original mitochondria are no longer active, thus restoring the metabolite levels in the body.

Taking Snapshots of the System
The devices could take tissue samples which they could then analyse at a molecular level. These samples could also be frozen to halt chemical process and allow the tissue samples to be analysed at a later date.

If these devices are able to self replicate, a lot of these devices could be going around the body, raking and analysing samples and eventually building up a picture of the whole body.

How long until it happens?
An exact time can't be put on this, however looking at the development of technology in the previous 50 years; it could be feasible to see it within 20 years. The medical applications of this technology would only need slightly longer than this to develop.

The exact timescale largely depends on public demand. If the public is very negative on the advancements, then these developments will slow down, if they happen at all, however, if the public like the idea and money into research is increased, it could happen sooner.

It is quite possible, to our advantage, that the technology could be developed and begin helping within our lifetimes, and it is clear to see some ideas slowly coming through.