The discovery of penicillin, the first organ transplant, laparoscopic surgery.

These are just a few of the landmark innovations that defined medicine in the 20th century. While humankind has come a long way in its treatment of diseases, there remain a plethora of problems that have yet to be solved -- but which technologies hold the most promise for the future of medicine?

We asked our top health care contributors to weigh in on the debate with one area of research they think investors should be watching today. Let's see what they said.

Ailmentary, Dr. Watson
Keith Speights: IBM (IBM 1.48%) caused a buzz in 2011 when its Watson computer system beat two of the best contestants to ever play the TV game show Jeopardy!. I think that victory will pale in significance compared to the company's application of the artificial intelligence technology to health care.

Watson's natural language processing, hypothesis generation and evaluation, and evidence-based learning capabilities will be put to the test at New York's Memorial Sloan-Kettering Cancer Center sometime in the near future. The plan is for the computer to serve essentially as a physician's assistant, helping the doctor diagnose and treat patients. Considering that the amount of medical information is reported to be doubling every five years, the use of artificial intelligence in health care could be a game-changer by improving treatment and reducing medical errors. 

Computing in general, not just of the artificial intelligence variety, is already slowly revolutionizing the industry. Physicians started adopting technology at greater levels a few years ago when financial incentives kicked in for "meaningful use" of electronic health record, or EHR, systems. One innovative company helping to further that revolution is athenahealth. Its cloud-based clinical systems not only improve workflow but also incorporate quality management protocols to ensure best practices are followed.

We're really still only in the infancy of applying computer technology to health care. One day, people could view the first 20 years of the 21st century as the health care equivalent of the Industrial Revolution.

Yet another application for 3-D printing?
Maxx Chatsko: No discussion about the future is complete without mentioning 3-D printing. 3D Systems wants to transform the way the health care industry develops and creates medical devices, but a number of other companies are also making strides in this area. Early last year, an institute in Belgium in collaboration with private company LayerWise brought that dream closer to fruition by successfully transplanting a 3-D printed jawbone into a patient with a chronic bone infection. While the development will force us to rethink the possibilities of both additive manufacturing and health care, it pales in comparison to another application: 3-D printed organs.

Earlier this year, a team from Heriot-Watt University in the United Kingdom and Roslin Cellab, a Scotland-based stem cell company, made the first step (link opens PDF) toward home-grown human tissues. The team created a rough prototype of a biological 3-D printer that was "gentle enough to maintain stem cell viability, accurate enough to produce spheroids of uniform size" and demonstrated that "printed cells maintain their pluripotency [the ability to become various types of tissue]."

Why does this technology matter? According to the Department of Health and Human Services, someone in the U.S. is added to an organ transplant waiting list every 10 minutes. Although 79 people receive an organ transplant each day, another 18 die waiting for organs. The technology is still many years -- if not many decades -- out of reach and is restricted by our current lack of knowledge in regenerative medicine. Nonetheless, the potential to save lives and de-risk organ transplantation procedures is enormous.  

Genome sequencing
Sean Williams: Researchers began sequencing the human genome as early as 1990, but only recently has the turnaround time and cost of human genome sequencing made the technology both revolutionary and immediately feasible.

Life Technologies (NASDAQ: LIFE), a leader in genome sequencing, introduced the Benchtop Ion Proton Sequencer in January 2012. Unlike previous models that cost upward of $500,000 and took weeks if not months to sequence the human genome, Life Technologies' sequencer costs just $149,000 and can sequence a human genome in just one day!

When uncovering 50 amazing health-care statistics recently, no statistic stuck out more than the cost of sequencing the human genome, which has fallen from approximately $95 million in 2001 to less than $7,700 as recently as January 2012. The implications of cheaper, yet dramatically faster, technology are immeasurable in a laboratory setting. It will allow researchers to conduct multiple studies at a rapid pace in the lab with the end result being significantly more compounds reaching the clinical study stage. It's no coincidence that the number of clinical studies currently under way has ballooned from just 6,998 in 2001 to more than 140,000 as of this very moment as sequencing costs have dropped.

Life Technologies' continued genome sequencing innovation should continue to drive down sequencing costs and could, by my estimation, spur an explosion in individualized personal care with regard to cancer research, as well as a hose of other diseases. It's a revolutionary technology capable of changing the pace of the drug development process.

Making sense of antisense
Brian Orelli: After a long road to development, a new broad class of drugs that target mRNA is starting to make a splash. mRNA leads to the production of proteins that cause disease symptoms, so the RNA therapeutics can have the same effects as current drugs that attack proteins directly.

The most advanced RNA therapeutics are antisense drugs, which target the mRNA for destruction. Since they're upstream, less mRNA means less of the protein that facilitates the disease. In January, Sanofi and Isis Pharmaceuticals gained FDA approval for their cholesterol-lowering drug Kynamro. The drug may not be a commercial success because it'll have to compete with Aegerion Pharmaceuticals' Juxtapid, but it proves that second-generation antisense drugs can gain approval. Isis has more than 20 antisense drugs -- many partnered out -- behind it in the clinic.

RNAi therapeutics also bind to mRNA and target them for destruction. RNAi drugs use a special pathway, which is more efficient than antisense in theory, but researchers have had trouble getting enough of the drugs to the cells that need to be treated. New targeting mechanisms developed by Alnylam Pharmaceuticals seem to be overcoming that obstacle. Its lead program is in phase 2 development at the moment.

Regulus Therapeutics, a joint venture of Isis and Alnylam, targets microRNAs, which regulate multiple mRNAs that code for proteins that carry out similar functions. The biotech has signed up quite a few big pharma partners, but doesn't have any drugs in the clinic yet. MicroRNAs look promising and learning from the issues that antisense and RNAi have run into should help their development, but we're still many years away from seeing a microRNA targeted drug on the market.

Finally, there are drugs like Sarepta Therapeutics' (SRPT 1.26%) eteplirsen that affect mRNAs by skipping the part of the gene that contain mutations. It's a specialized solution for genetic diseases such as Duchenne muscular dystrophy where certain parts of the mutated gene are causing the disease.

Investors should keep an eye on RNA therapeutics given their potential to revolutionize medicine.

What's the point of syringes, anyway?
Max Macaluso: I hate needles, and -- as much as the "macho" side of my brain hates to hear me say this -- that's why I didn't get a flu shot this year. However, people suffering from chronic diseases, like type 1 diabetes, don't have the luxury of opting out of their treatment. Daily injections are essential to survival, and they can be both painful and inconvenient.

That's where needle-free injectors come in. These devices force medicine through an opening that is only a fraction of a millimeter in diameter, and the resulting stream is actually able to enter the body like it would with a normal syringe. Antares Pharmaceuticals (ATRS), a long-standing player in this market, has struggled to gain traction in the diabetes space and currently lacks a commercial partner for its insulin delivery device. However, it has licensed its product to Teva Pharmaceuticals for the delivery of human growth hormone and is partnered with Pfizer on an "undisclosed Consumer Healthcare product." The adoption of this technology has been slow to date, but with better models on the way – including a prototype from a MIT lab that can deliver a medicine "at almost the speed of sound" -- it's an exciting technology to keep tabs on.

If this technology doesn't impress you, then take a deep breath. Biotech company MannKind (MNKD 1.95%) has developed a unique formulation of insulin, which is normally injected, that can be delivered through a small inhaler. The company should complete its phase 3 clinical trials this year for its product, called Afrezza, and if the FDA gives it the green light, it could open the door for drugs that would normally be injected to instead be inhaled.

What will the future look like?
All of these innovations are remarkable from a scientific standpoint, but it's important for investors to realize that just because a technology has the potential to revolutionize medicine does not mean that it actually will. Many of these technologies may never be approved by regulatory bodies, and even those that are given the stamp of approval may never be widely applied in mainstream medicine.