Health care has always been a prevalent theme in sci-fi films and TV shows.

From the original Star Trek to modern films like Elysium, screenwriters and directors have imagined utopian or dystopian worlds where diseases can be instantly cured, severed limbs robotically restored, and new replacement organs artificially created.

In the past, that future seemed fantastic, but in recent years, available technology has steadily caught up to our sci-fi fantasies. Thanks to companies like Qualcomm (QCOM -0.73%), Accuray (ARAY -2.04%), Hanger (NYSE: HGR), and Organovo (ONVO), those past predictions are now coming true.

Let's take a look at three major ways real health care is catching up to its sci-fi counterpart.

1. The real Star Trek medical tricorder
When many people think of health care in science fiction, they think of the Star Trek medical tricorder -- that wondrous handheld omni-tool that diagnoses diseases and collects data from a patient with a simple scan.

At CES 2012, wireless chipmaker Qualcomm, in coordination with the X PRIZE Foundation, launched a $10 million competition to produce the first medical tricorder.

The competition asked participants to create a handheld device to diagnose a set of 15 diseases and measure health metrics such as blood pressure, respiratory rate, and body temperature. The proposed device is also expected to accumulate and store data wirelessly over the cloud.

Silicon Valley company Scanadu is in the clear lead. The company unveiled a prototype of its tricorder device, known as the Scout, in November 2012.

The Scout can instantly scan a wide variety of health parameters, including pulse transit time, heart rate and variability, electrical heart activity, and blood oxygenation. It can also help a doctor diagnose a wide variety of diseases ranging from abdominal cramps to shingles.

At this week's CES 2014, Scanadu finally unveiled its final hardware design for the Scout, which runs on the same operating system used by NASA in the Mars Rover.

The Star Trek tricorder (L) and the Scanadu Scout (R). Sources: Wired.com, Engadget.

The Scout just needs to be held up to a patient's temple for 10 seconds to obtain a complete reading. Scanadu hopes that the Scout will hit the market by the end of 2014 after FDA approval.

2. Curing cancer with machines
Neill Blomkamp's 2013 film Elysium featured a magical medical pod that could cure cancer in less than a minute. While that device is an obvious Hollywood fantasy, it has roots in real medical technology that is available today.

Over the past decade, cancer treatments have improved dramatically on the pharmaceutical level, with immunotherapy and targeted therapies, and on the mechanical level, with advanced oncology machines.

Accuray's flagship product, the CyberKnife Stereotactic Radiosurgery System, is one of these machines. The CyberKnife uses tiny lasers to deliver highly concentrated doses of radiation into the body to kill cancerous cells. The process, unlike chemotherapy, spares healthy cells and requires no physical incisions -- making it a pain-free, minimally invasive option for patients with inoperable or surgically complex tumors.

Elysium's medical pod (L) and Accuray's CyberKnife System. Source: Technolife360.com, Pitt.edu.

Accuray also manufactures the TomoTherapy system, which uses 3-D CT imaging to accurately locate the position of the tumor before initiating radiation therapy. The machine calibrates the intensity of the radiation beam to the size and shape of the patient's tumor and delivers the radiation in "layers" to prevent any excess radiation.

3. We can rebuild you
We should also mention how much prosthetic limbs have improved over the past few years. In the past, amputees were given plastic prosthetics that could not be controlled beyond the most basic movements.

Fully functioning prosthetic limbs, such as those seen in The Six Million Dollar Man, Star Wars, or Almost Human were long thought to be a sci-fi fantasy.

However, prosthetic limb maker Hanger has turned those dreams into reality. The company's C-Leg uses feedback from multiple sensors that report back the processor 50 times per second to make real-time adjustments to the position of the prosthetic knee and leg. The result is a cybernetic leg that allows amputees to run and ride bicycles.

An even more impressive device is Hanger's i-LIMB prosthetic hand, which uses the electrical signals from a patient's remaining limb to control the movement in the hand. This process, known as myoelectric technology, could previously only generate a single grip pattern.

The i-LIMB dramatically improves that technology by allowing patients to freely move all five fingers. Patients with the i-LIMB can dial the phone and type -- tasks that would have seemed impossible a mere decade ago.

Hanger's C-Leg (L) and i-LIMB (R). Source: Company website.

Meanwhile, 3-D bioprinting company Organovo has tickled the fancy of scientists across the world with the possibilities of 3-D printed organs and limbs. Organovo's first product, a 3-D-printed liver assay for pharmaceutical testing, hasn't been approved yet, but that hasn't stopped scientists from exploring the possibilities.

A team of scientists from the University of Nottingham in England recently demonstrated that artificial bones can be printed from a polymer and a gel-like substance known as alginate. After printing this "bone," the 3-D printer coats the surface with adult stem cells, which can grow into various tissues and muscles.

That experiment indicates that we could be advancing beyond the realm of sci-fi altogether -- as impressive as Hanger's prosthetic limbs are, imagine if limbs could be bioprinted as perfect replacements.

The Foolish takeaway
The medical tricorder, cancer treatment machines, and prosthetic limbs -- these are just three incredible new technologies that are changing how doctors treat patients.

As computers get even smaller and more powerful (as Intel recently demonstrated at CES 2014), patients' lives will be significantly improved by innovative new technologies.

What other innovative new medical technologies will shake up the health-care world over the next few decades? Share your ideas in the comments section below.