These little tiny robots swim through your bloodstream, measuring many different elements in your blood. They then send the information to your doctor (eliminating the need for blood to be drawn at check ups.) The sophisticated robots will also have the ability to read your DNA and decode your entire genome to make predictions about susceptibility to certain diseases. If made affordable and readily available, these little guys will likely be swimming through your body within the next twenty to thirty years. This would greatly improve the predictive and preventative ability of medicine since each doctor would be able to sequence each of their patients' genomes to make predictions about their future health.
The structures of DNA chips are refreshingly simple; they are little wafers of silicon or plastic with strands of DNA embedded in the surface. DNA naturally tends to bind to "complementary partners" in the process of hybridization. These chips can be embedded with the DNA of hundreds of different diseases or genetic disorders then sent into the bloodstream of patient. If one of these chips comes in contact with a matching strand of DNA, the complementary strand will bind to the chip within hours. These chips can then be input directly into an analyzer which confirms the presence of whichever diseases or genetic disorders effecting the patient. The application of DNA chips will greatly increase the accuracy of diagnosis and biopsy analysis.
The future of medicine is all about predicting diseases and preventing them. This will require much more personalization of medicine as doctors will know the genetic sequences of each of their individual patients. While much of this is possible today, the costs of genetic sequencing is a large preventative factor of its widespread application. Many doctors agree that in the next few decades, though, we will see personalization, prediction, and prevention improved dramatically.