Its vision of romantic encounters with aliens and plagues of tribbles may not have come to pass just yet, but Star Trek has proved surprisingly accurate in predicting the future in other ways.
When it comes to technology, the show's gadgets have already become reality in several cases: its communicator predicted the clamshell mobile phone, the food replicator was made real with 3D food printing, and Captain Kirk was using voice input long before Alexa became a household name.
But of all Star Trek's technological imaginings, it's the Tricorder that continues to capture the popular and scientfic imagination: a handheld medical device that could be used to analyse a patient, helping doctors diagnose and treat the crew on the bridge and beyond.
No blood tests, no X-rays, no genetic sequencing: Star Trek's doctors could just point their tricorders at the patient and seconds later work out if they'd succumbed to a cold or the Quazulu VIII virus.
The Tricorder continues to fascinate because it magically solves some of the problems about medicine we still have today: it takes too long, it's expensive, it's uncertain, and the times you need it most -- when you're far from home -- is often when it's unavailable.
People have been trying to make replicate elements of the Tricorder since the 1990s. But it's only in the last few years that the dream of creating a genuine Tricorder-type device has seemed within reach.
The first signs that a medical Tricorder could be more than a sci-fi fantasy coincided with the emergence of the first serious smartphones and tablets. Back in 2007, MIT researchers used a Nokia 770 as the basis for a Tricorder, displaying information from sensor networks, while a few years later, a rash of medical peripherals released for the iPhone offered the hope that Apple's mobile could be turned into a real-life Tricorder.
Such early discussions focused on customising existing mobile hardware to a medical diagnostic device; the first standalone device would be a few years further on.
SEE MORE ON OUR NHS REPORT: VR, AR and the NHS: How virtual and augmented reality will change healthcare
One of the first companies to make a serious attempt at creating a Tricorder was Scanadu, which released a device called the Scout in 2015.The Scout could measure a handful of vital signs -- blood pressure, heart rate, blood oxygen saturation, and temperature -- by being held up to a patient's forehead. It's not quite the Tricorder's no-touch technique, and had no diagnostic capabilities, but it was arguably further towards such a device than any hardware before it. After raising $1.7m on Indiegogo, and several million dollars more from investors, the Scout eventually went on sale. However, the company had released it under the banner of a "research device for investigational use". When it subsequently failed to win FDA approval -- for unspecified reasons -- the research effectively came to an end, and devices were bricked, leaving buyers furious.
Despite the Scout's difficulties, there was no shortage of companies that were looking to succeed were Scanadu had failed.
As befits a potentially game-changing and technologically-complex device, the Tricorder concept had caught Google's eye. Back in 2014, the head of life sciences at what was then Google X, the company's moonshot division, announced a cancer-detection system that would lay the foundations for the creation of a Tricorder. The system that Dr Andrew Conrad announced aimed to use magnetic nanoparticles that would attach themselves to cancer particles; a separate wrist-worn device would measure the particles to detect cancer. The system would over time form part of a real-life Tricorder, Conrad said.
"Instead [of] going to the doctor who says, 'Let me draw blood and in three days I'll call you if there's anything wrong,' the doctor can look and say, 'Oh, I just checked all your blood over this last year, and it looks like your kidneys are good, your liver is good, I don't see any indication of oncologic cells, pretty good, thanks.' ... We want to have a Tricorder where Dr. McCoy will wave this thing and say, 'Oh, you're suffering from Valerian death fever.' And he'd then give some shot in a person's neck and they'd immediately get better. We won't do the shots -- our partners will do the shots. But we're hoping to build the Tricorder," he told Medium at the time.
Since then, Google and its X division have been reorganised: Google's life sciences arm has become Verily, now overseen -- along with Google and other Google spinouts, including Calico -- by a new parent company Alphabet. Conrad remains head of Verily, but his dream of a Star Trek-grade medical device has not come to pass: Verily has yet to showcase any progress on building either the cancer-detection system or the Tricorder itself.
A spokesperson for Verily says its nanoparticles research is still active, but added it had experienced difficulties in the past: "Our nanoparticle research is focused on developing nanoparticles that demonstrate consistent properties. We found that nanoparticles we purchased from third-party manufacturers have been unreliable in research due to inconsistencies."
The $10m prize
Arguably one of the biggest stimulants for building a Tricorder came when chipmaker Qualcomm sponsored the Tricorder XPRIZE, a competition intended to help foster the creation of innovative medical hardware.
Rather than asking for a machine that can read vitals to help diagnose any number of illnesses, the XPRIZE asked for hardware that could diagnose a set list of 13 medical condition, including anaemia and diabetes, as well as monitor a handful of vital signs.
The prize, launched in 2011, was won last year by Basil Leaf Technologies with a device called DxtER, a small unit with a range of specific medical peripherals, including a sensor for heart and lung sounds, an ECG monitor for measuring heart rate and rhythm, and a device for analysing blood glucose and white cell count, a sign of infection and inflammation when raised.
By winning the prize, the inventors -- a group of siblings and others led by Philadelphia-based emergency room physician Basil Harris -- received a $2.6m grant to help take the DxtER from concept to commercialisation.
However, the first publicly available device based on this technology is likely to have a far smaller scope than Bones' Tricorder. Basil Leaf Technologies is working on creating a monitoring device for a single disease state, congestive cardiac failure (CCF), that a patient could keep with them at home to help monitor the progress of their condition. The aim is for a person with CCF, a chronic condition, to interact with the device a couple of times a day, and that information to be sent back to a medical professional to review. With such longitudinal monitoring, a doctor can monitor the patient's progress regularly without having to ask them to take time out of their days to come in for regular check-ups.
"A diagnostic device that can diagnose one of 13 medical conditions is not really that viable -- a first year medical resident can diagnose 75 to 100 medical conditions. We just designed something to win a prize, but it's not something that's useful out in the marketplace yet. And if you think about how the FDA in the United States approves medical devices, if we sought an approval for a medical device that did a large collection of medical conditions, it would take aeons to be approved. From a strategic point of view, we changed our strategy and said let's focus on one disease state," Phil Charron, head of user experience at Basil Leaf Technologies, tells ZDNet.
SEE MORE ON OUR NHS REPORT: Why the NHS is killing paper records to save lives
Nonetheless, Basil Leaf Technologies is still working towards creating a Tricorder in the way that most people think of it: a single device that can diagnose a range of conditions. For a real-life Tricorder to serve as a universal diagnostic tool in the way that Star Trek envisioned, it would need to be able to analyse far more biomarkers than the DxtER currently does.
Handily, scientists are also working on expanding the capabilities of Tricorder-like devices. Earlier this year, researchers from the University of Glasgow created a handheld sensor device based on a CMOS chip that can analyse a number of metabolites in blood or urine, analysing them to diagnose conditions including heart attacks.
Elsewhere, companies are working on creating Tricorder type hardware with a focus on infectious disease: the Q-POC, made by QuantumDx, is expected to launch next year, and brings handheld diagnostics for bacterial and viral infections. The idea of the Q-POC is putting short-read genetic sequencing into a device the size of a smartphone: with a sample of bodily fluid, the reader could pick up not only the nature of an infection, like TB, but also its resistance to particular drugs. The technology already exists and is in common use, but shrinking it down to a device that can fit in a pocket is QuantumDx's real challenge.
The fact that the company has had to put back the Q-POC's launch date from 2016 to 2019 shows that miniaturisation is no small task. In fact, it's one of the key challenges that exists for building a Tricorder: the technology that doctors use to diagnose illnesses already exists, but it often exists in large, discrete machines, often spread around different parts of a hospital. Tricorders have to bring all of those capabilities into a single device that can be carried by one person.
"Most of the technologies that exist out there we can turn into something we can put into the patient's hands, I think that [the challenge] is more about shrinking the technologies that exist. A lot of the things that a physician can do in a regular exam room we put in a Tricorder. Labs and radiology -- that's the difficult thing to shrink down into a Tricorder," Basil Leaf Technologies' Charron says.
As well as difficulties with hardware, creating the right software for Tricorders is likely a number of years away. Creating algorithms that can diagnose certain conditions from a tight set of physical biomarkers is one thing, but there's an old adage in medicine that 'if you listen hard enough, the patient will tell you the diagnosis'. To be a universal diagnostic device, Tricorders will not only have to interpret test results, they'll also need software that knows the right questions to ask and unpick the answers they get back: a patient saying they have a tight chest pain and a sharp chest pain might sound similar, but could be the difference between a full blown heart attack or pericarditis -- a painful, but relatively benign, infection of the heart's covering.
"Our expectations about the medical tricorder stem from Star Trek and it's never a good decision to base expectations on science fiction, even though many technologies have become real from science fiction in the 21st century," says Dr Bertalan Meskó, director of The Medical Futurist Institute. And it doesn't mean we won't need doctors, Meskó says.
"There is a reason why we train medical professionals for decades and artificial intelligence-based algorithms, tricorders and many other advanced technologies are designed to upgrade their capabilities so they can use their unique vision, expertise and experience while focusing on the patients. The tricorder should make this possible instead of replacing what physicians do today."
Though the challenges to a medical Tricorder remain substantial, technology companies show no signs of waning enthusiasm for the device. That's because the potential applications for such hardware are huge. Many of the companies working on the tech today envision their machines being used by healthcare staff that aren't doctors to go do some of the run-of-the-mill diagnostic legwork, calling in doctors only for the trickiest of cases.
And, aside from managing consultants' workloads better, Tricorders could potentially make a much more significant contribution to medicine. Imagine an area -- be it in rural Europe or rural Africa -- where population density is lower, and the provision of medical care is even more sparse. Instead of having to drive for hours or even days to find a doctor the next time you take sick, a Tricorder in the home or local clinic could help you to decide whether you need to get to the nearest A&E or take a couple of aspirin and sleep off the fever.
"A working tricorder could bring about a new era in medicine," says Meskó.
Instead of expensive machines and long waiting times, information would be available immediately. Physicians could scan a patient, or patients could scan themselves and receive a list of diagnostic options and suggestions. "Imagine the influence it could have on underdeveloped regions. It should not substitute for medical supervision, but when there is none it comes in handy. Also, it would make the biggest promise of digital health real: making patients the point-of-care. Technologically, it's absolutely viable," says Meskó.
Perhaps the most interesting use of the Tricorder takes us right back to the device's sci-fi conception. Should humans ever attempt more long-distance space travel, a Tricorder would be a must: a manned mission to Mars could see astronauts travel for weeks or months without access to the full repertoire of medical support.
A sufficiently advanced Tricorder could help astronauts keep in good health during the journey. Without it, it's hard to imagine how the next generation of astronauts will be able to boldly go where no one has gone before.
PREVIOUS AND RELATED COVERAGE
Smart watches, fitness trackers and the NHS: Are wearables just what the doctor ordered?
While more and more of us are wearing fitness trackers, the real benefits of wearables may come from another quarter.
Why the NHS is killing paper records to save lives
The NHS still relies on paper for many patient records. Getting rid of it could free up time, and money.
Robots and the NHS: How automation will change surgery and patient care
The rise of robots is inevitable in healthcare, but for now, keeping it simple is just what the doctor ordered.
VR, AR and the NHS: How virtual and augmented reality will change healthcare
Against a background of growing enterprise adoption of virtual reality, mixed reality and similar technologies are beginning to gain a foothold in the NHS.
AI and the NHS: How artificial intelligence will change everything for patients and doctors
The rise of artificial intelligence is set to reshape the health sector as we know it, from back office to doctor's office.
IoT and the NHS: Why the Internet of Things will create a healthcare revolution
The Internet of Things must be one of the most high-profile technology trends of the last five years. Could IoT be the backbone of the NHS of the future?
NHS and technology: Making the case for innovation
Physician, reboot thyself! The health service is caught between its creaky past and a shiny future. But change is needed, and fast.
Healthcare security nightmare: UK's NHS lost nearly 10K patient records last year (TechRepublic)
Despite having electronic record systems in place, 94% of NHS Trusts still use handwritten notes for patient record keeping, according to a report from Parliament Street.
Omron Healthcare Blood Pressure Monitor (CNET)
This gadget from Omron Healthcare is worn around your wrist, displays the time, tracks your steps -- and monitors your blood pressure, too.