A wearable computer on your wrist may allow you to check the time, send emails and texts, and even predict medical emergencies like a heart attack. Currently, Apple is developing software and sensors to monitor the user's heart with optoelectronic sensor technology, which measures heart rate and blood oxygen levels.  The smartwatch, “iWatch,” may increase the chances of survival for heart attack patients and reduce the annual death rate of 600,000 people who die of heart disease.

"It could be part of a larger portfolio of solutions aimed at the broader ecosystem of health care," said Bill Kreher, an analyst with Edward Jones Investments in St. Louis, to the SF Gate. "That would be fascinating to watch." The iWatch is expected to come with several health and fitness-related features that will provide more personalized information about the health of the person.

The new technology, featuring medical sensors, aims to predict heart attacks by identifying the sound blood makes when it tries to pass through a blocked artery. During a heart attack, the coronary artery — one of two blood vessels, branching off from the aorta, that feeds oxygen-rich blood to the heart muscle — suddenly becomes blocked, stops the flow of blood to the heart muscle, and damages it. The Cleveland Clinic says all or part of the heart muscle becomes cut off from its oxygen supply, which therefore leads the heart muscle to be injured.

The iWatch, an optoelectronic — electronic devices that source, detect, and control light — measures changes in light reflected by the body as it detects the amount and color of the light that bounces back. The changes shown in light levels are monitored and used to measure a person’s heart rate and blood oxygen levels.

According to Apple Insider, the smartwatch tracks blood oxygen levels in a process known as pulse oximetry. Pulse oximeters use visible red and infrared LEDs to detect how much oxygen is being carried in the blood’s hemoglobin — a red protein responsible for carrying oxygen from the lungs to all other tissues of the body. In this process, the oxygenated hemoglobin absorbs more infrared light, while the deoxygenated hemoglobin absorbs more visible red light. In other words, when the body pumps more blood, more light is absorbed.

The company chose the light-based technology over electrocardiography because it is considered to be a more accurate method to measure electrical impulses. Most electrocardiogram (EKG or ECG) products require users to attach several diodes to their body or to touch the product with both hands in order to get a reading. However, the light-based technology will monitor the user’s heart rate with the user just simply wearing the wristwatch.

The smartwatch will take measurements of respiratory rate, blood oxygen levels, and pulse rate throughout the day so the user can get a view of their overall health and physical condition. Talk of the iWatch comes at a time where the climate for “wearable” computers is high with Google introducing “Google Glass,” Nike the “FuelBand,” and Samsung’s release of the "Galaxy Gear." The question remains whether Apple can make the body-monitoring, health-improving smartwatch marketable to a wide audience, especially those under 30. The release date for the iWatch has yet to be announced, but Apple’s iWatch patent in 2011 can be viewed here.

Aside from the forthcoming iWatch, several medical technologies in recent years have made it feasible for people to assess their risk for diseases. The following three may you keep your health in check:

1.  Alzheimer’s Take-Home Test

The Self-Administered Gerocognitive Examination (SAGE) has developed a 15-minute evaluation test that is able to spot cognitive decline in patients who are unable to identify them on their own. The SAGE self-administered test can assess six separate aspects of cognition: orientation, language, reasoning/computation, visuospatial comprehension, problem solving, and memorization. This medical advancement may help physicians identify patients with mild cognitive impairments that would fail to meet the criteria for Alzheimer’s otherwise.

2. Blood Test Predicts Possibility of Heart Attack

Researchers developed a procedure called the High-Definition Circulating Endothelial Cell (HD-CEC) assay to detect and characterize the CECs in blood samples. The test determines whether a patient is at very high risk for a heart attack by recognizing these specific cells in the bloodstream. In a study, the researchers found the assay correctly identified CECs by their morphological features, along with their reactions with specific antibodies.

3. Blood Test Predicts Breast Cancer Relapse Risk

Canadian researchers discovered a “genetic marker” method to accurately profile women who are more likely to have their breast return years later. The new blood test assess a patient’s risk of getting luminal A breast cancer. It may help physicians and ocologists to design a more aggressive therapy for these patients in order to prevent the cancer from coming back.