A fundamental design flaw in the current human organism is a lack of sufficient protection for our most crucial organs, the cradles of intelligence and personality — the brain and spinal cord. Thanks to improvements in workplace safety, enforcement of drunk driving laws, and buckle-up campaigns, death due to injuries of the head and spinal cord have decreased throughout the last few decades, but many of us can name friends or family who were killed or permanently disabled by a traumatic head injury. The 5th leading cause of death, unintentional injuries, often involves fatal injuries to the head or spinal cord.
As the recent death of the actress Natasha Richardson demonstrates, “minor” head injuries can be fatal too.
According to the Franklin Institute:
Every 15 seconds, someone in the United States suffers a traumatic brain injury. Of the 1,000,000 people treated in hospital emergency rooms each year, 50,000 die and 80,000 become permanently disabled because of traumatic brain injury (TBI). This is higher than the combined incidence of Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis.
Brain injuries occur more frequently than breast cancer or AIDS. One out of every fifty Americans is currently living with disabilities from TBI. There’s even an association between head injury and Alzheimer’s disease later in life.
Therefore, a call to develop implants to protect the brain and spinal cord from injury seems justified, even if the present technology is not perfect. Our present protection, which consists primarily of calcium hydroxylapatite, is just 6.5 mm thick in men (on average) and 7.1 mm thick in women. While it has some flexibility due to embedded collagen, the skull is essentially brittle, which, while enhancing its strength, makes it susceptible to catastrophic failure in an accident. If our skulls were just slightly thicker or stronger, how many lives would be saved? No one knows.
The most obvious proposal would be to try to find out some way (even if it takes decades) to replace the skull with a fullerene composite, which would be lightweight, over 100 times stronger than bone, and could probably be made biocompatible. What is the current state of the art in the field?
Hydroxylapatite ceramic skull plates have already been used by brain surgeons to patch holes in the brain caused by traumatic injury. These can be precisely shaped to fit the hole in the skull. These ceramic skull plates are entirely artificial, but “are characterized by an excellent biocompatibility and biostability resulting in bony fusion”, because they’re made of pretty much the same molecules as the bone itself. It is important to note that the fine-grained structure of these ceramic plates is entirely different than that of true bone, but they still are completely biocompatible. This indicates the (possibly obvious) fact that chemical composition for these implants is the crucial aspect for biocompatibility, not physical structure.
Present-day neurosurgery is at a primitive stage, so the risk of paralysis, brain damage, infection, psychosis, or death is ever-present. Looking around, it seems like the overall complication rate is between 3% and 5%, but some new techniques for minimally invasive neurosurgery have complication rates as low as 1%. This is still unacceptably high for the purposes of enhancement, but the point is that the technology is improving. Handing the surgical tasks from human to robotic hands, as is becoming the standard in surgical removal of the prostate with the Da Vinci Surgical System, will help vastly lower complication rates. While complications rates for direct surgery by human hands can only be brought so low, the use of surgical precision machines potentially offers an almost unlimited domain for improvement.
I would argue that a complication rate of 1/3000 (0.033%) ought to be considered acceptable for approval of this technology. 1/3000 is roughly the annual probability that you will suffer a traumatic brain injury if you live in the United States. So, you’d be taking roughly the same chance you otherwise would in a typical year, except a successful operation would vastly lower the probability of traumatic head injury in all subsequent years. If we have such advanced surgical technology, it would be a good bet that we’d also have the technology to entirely prevent formation of scars, though that is just speculation.
Ultimately, many individuals would want to replace their entire skull with a stronger composite material, but conventional surgery might not work in this instance. More futuristically and speculatively, we might use biocompatible microbots (not nanobots!) to incrementally drill through bone, ship out the debris, and replace it with a matrix of a stronger material. This is less crazy than it sounds, as MEMS have already been in use within the body for over a decade and the area of implantable MEMS is a huge field. Swarm and cooperative robotics are also areas that have received substantial attention over the last couple decades — these fields will merge with bioMEMS to produce useful physiological sculptors at the cell-sized scale.
I also point out this area of enhancement because it seems unequivocably beneficial — as long as the complications rate is very low, who would protest against having a better-protected cranium? You might argue that we’re hard-headed enough as it is, but in my vision of the future, we’ll take that tendency to a new level.
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