Fitness Trackers

Fitness trackers have created a huge buzz in the last couple of years and have been quickly adopted by those who are looking to add personal style to tracking their health. Data that was once only measurable by a doctor or specialist can now be sent to your phone and then analyzed and explained to you in a custom daily report. The power to improve your health and track your progress on a daily or even hourly scale has never been easier. An estimated 25 million people purchased fitness trackers in 2015; however, the number of people who use their new gadget for more than 6 months is up for debate.

Several focus studies have shown that fitness trackers are the ultimate motivational tools , rather than the ultimate health-monitoring tools. They very successfully encourage users to rethink their daily habits, like taking a longer route when walking, eating less, and generally paying more attention to their sleep cycles. This is most likely because of the user interaction they foster. Every time you look at your phone, check your email, or glance at the touchscreen on your device, you are reminded of your daily progress. Not only that, but many of them have the ability to network to other fitness trackers so you can compare your activity to that of your friends and family.

An important question that many people have about fitness trackers is, what happens to all the collected data ? Currently, the information is private and only accessible to the devices you connect to your tracker. However, several other industries would love to have access to this information. Some obvious groups include doctors, who would be able to analyze what may be the largest data pool ever, and advertisement agencies that could target you when you are most alert. This issue is discussed in greater detail in the last chapter. This may not be a huge concern right now, though, because studies show that none of these fitness trackers are particularly accurate. When tested simultaneously, each one overcompensated in some areas and undercompensated activity in other areas. Figure 11-1 shows three different fitness trackers that were tested simultaneously by one user, who found that the results varies tremendously from device to device.

Figure 11-1. A reviewer testing three fitness trackers simultaneously: from top-left to bottom, Fitbit Flex, Jawbone UP MOVE, Fitbit Zip

Today, the three most highly reviewed fitness trackers are the Fitbit, Jawbone, and Garmin Vivosmart. There are hundreds of others on the market, not to mention smartwatches like the Apple Watch that have integrated fitness trackers. Following are some distinguishing aspects of the top three:

• Fitbit HR: A thin wristband with a small digital display that can show your statistics as well as caller ID for a paired smartphone. Its strongest feature is the heart-rate-monitoring sensor, which appears to be more accurate than other brands.

• Garmin Vivosmart: Has been praised for offering measurements that are equally accurate to those of the Fitbit and Jawbone, but features a larger screen and has a more user-friendly integrated notification system. It is waterproof, whereas most are only splash proof, and performs better when tested by runners. It is also said to have a very comfortable band.

• Jawbone UP MOVE: Designed a bit differently and does not feature a display on the device, encouraging the use of other devices with the wristband. It has a very strong sleep-monitoring system.

Smart Clothing

Smart clothing refers to e-textiles or clothing embedded with electronics. Smart clothing is being researched and developed in several different areas, primarily focusing on fitness, fashion, and health.

Bracing Yourself

DIY braces and casts are popular projects among hackers and medical experts. By taking advantage of the lower cost of digital-fabrication machines, they can make custom-fit prosthetics, splints, and more at much lower costs than ever before. One example is the e-Nable Community, an incredible global organization of doctors, makers, and hobbyists who have come together to create prosthetic 3D-printed hands for children in need. The community began as a husband and wife maker team who posted a video on the Internet of a metal puppet hand they had designed for a steampunk convention in 2011. The video went viral, and they discovered they had a much larger fan base outside of the steampunk community. Their project gave hope of restoring limbs with affordable DIY methods to thousands of people around the world with upper limb differences. Today, this online platform provides resources for designing mechanical hands, getting started with 3D printers, support for families, and more. Other prosthetic initiatives are discussed in Chapter 13.

Quell is a knee brace that uses wearable intensive nerve stimulation (WINS) to treat chronic pain. The brace stimulates sensory nerve fibers in the upper calf, which activates descending pain-inhibition systems in the brainstem. Then, high-frequency nerve stimulation triggers a cascade of processes that block pain signal transmission and result in widespread pain relief. The brace is embedded with sensors such as accelerometers to transition between therapy levels based on the wearer’s activity. User studies show that 81% of people who use Quell reported an improvement in their chronic pain, and 67% reported a reduction in their use of pain medication. The product is FDA approved, and the starter kit can be purchased for $250.

Kinetic is another company that is rethinking medical braces . Its smart back brace can detect when you are lifting an object and which muscles you are using during the act. It pairs with a wristband that receives information from the brace. The brace uses this data to determine whether you have put your back at risk and are lifting the object safely. If it seems you are performing an unsafe action, the brace signals the wristband to vibrate. The device was invented to help reduce the number of work-related injuries that result from unsafe lifting and bending, and help employers save on workers compensation claims. The brace also sends collective data to an app that a manager can use to see how their team is performing at any given moment and provide suggestions for redesigning the workspace to optimize workflow.

For Better Posture

“Stop hunching”—words my mother and grandmother have said to me more times than I can count. Although the reminder helps, it’s often not enough to keep me standing straight for the whole day. So, what is? A range of products that aim to help correct posture have come to market in the past few years. They typically involve a sensor that detects when you are slouching and sends you a friendly reminder to straighten up via a buzz from a small pager motor in the device. Following are some wearable posture sensors that take different approaches to form and style. The one thing they all have in common is that they pair with an app:

• Lumo Lift: A small plastic sensor that is worn like a pin just below your collarbone. It is held in place using a magnetic clasp, as shown in Figure 11-3. Once you have attached the sensor to your shirt, you double-tap to calibrate the patented angle-displacement sensor and set a training program through the app. Depending on the coaching settings you have selected, the sensor vibrates to remind you to correct your posture. The app also keeps track of your progress over the long term to show how you have improved. Lumo can measure additional metrics like the number of steps you take and the calories you have burned. I tried a Lumo Lift for several months and found that it was indeed quite helpful, but it did not work with looser tops. The company is working on ways to attach the sensor to wearables that give more reliable feedback, such as bra straps, but it largely depends on how the clothing fits on the user.

  

  Figure 11-3. Lumo Lift worn on a blouse, with a diagram of the entire system (© Lumo Body Tech)

• UPRIGHT Posture Trainer: A small, curved device that attaches to your lower back and vibrates when you slouch. It is not the most discrete tool, but it is easily hidden by a shirt or jacket. It uses built-in sensors that automatically calibrate to your body and then detect changes to your posture and send an activity log to the app.

• JINS MEME : A product that stands out for taking a different approach to measuring posture than you may expect. It is a pair of glasses that measure your eye movements and ear and nose position to determine whether you are tired and have poor posture. The smart glasses frames have embedded electrooculography sensors near the bridge of the nose to monitor changes in your eye movements, gyroscopes to detect changes in your body, and two six-axis acceleration sensors in the earpieces to check for posture and general body state. This data is sent to an app, which analyzes your state and can help you optimize your form and function. For example, if the glasses detect that you are drowsy while driving, they send you an alert. The glasses come in a few different styles including a Darth Vader model.

• Prana : A bit different from the others on this list in that it is not specifically for improving your posture; it is designed to improve your breathing. However, good posture facilitates good breathing, so the Prana can also be used to keep track of your posture. It is a circular disc, about one inch in diameter, that clips to your waist. Prana measures your breath with its patented sensors and sends this data to an app that passively notifies you of your status. It is popular among meditation and yoga communities.

The last part of this chapter provides a recipe for creating your own DIY pair of posture-sensing suspenders!

Concept Products

Here’s a futuristic wearable that takes things to another level: smart contact lenses. The project was originally announced in 2014 as a collaboration between American tech company Google and Swiss pharmaceutical company Novartis and is expected to be on the market by 2018. The lenses are embedded with a tiny circuit that measures the blood glucose levels of diabetics and wirelessly sends this data to a device.

The team has filed for a patent on the technology, which suggests that they are already planning to use it in other areas. The lenses could be adapted to improve vision loss due to age by autofocusing on distant objects like a camera lens or to detect and report your blood alcohol content. It could even be used to sense environmental conditions like allergens and dust and to verify the wearer’s identity.

Posture Suspenders Project

This project was developed by Tobias Sonne during his research at Carnegie Mellon University and can be seen at http://tobiassonne.com/?p=272 . Although the sensors are quite low tech compared to the technology in the products mentioned earlier in this chapter, you will gain an understanding of how posture sensing works.

Begin by collecting the following materials :

• 1 pair of suspenders

• 2 DIY bend sensors (tutorial in Chapter 7)

• 1 microcontroller (preferably sewable like the LilyPad or Flora)

• Conductive thread

• LiPo battery (rated for the microcontroller you are using)

• Desired output: sewable vibration motor or LED

• Alligator clips (for prototyping)

• 2 10k ohm resistors

Follow these steps:

1. Prototype your circuit as shown in the diagram in Figure 11-4 (colored lines represent alligator clips).

   

   Figure 11-4. Circuit diagram for posture suspenders

2. Loosely attach the bend sensors to the suspenders with safety pins or double-sided tape. Make sure to place them on your upper back in an area that changes shape dramatically if you start to slouch.

3. Connect your microcontroller to the computer, and upload the following program to measure the values coming in from the sensor:

   int sensorleft = A0;       // left bend sensor                    
   int sensorRight = A1;      // right bend sensor                    
   int Right = 0;             // variable to store the value coming from the right bend sensor                    
   int Left = 0;              // variable to store the value coming from the left bend sensor                    
   
   void setup() {
   Serial.begin(9600);
   }
   
   void loop() {
     Right= analogRead(sensorRight);
     Left= analogRead(sensorLeft);
     Serial.println("right:" + Right);
     Serial.println("left:" + Left);
     delay(200);
   }

4. Analyze the data to find the threshold value : that is, the point at which the value changes dramatically when you begin to slouch. Values on one end of this threshold value mean you are standing upright, whereas values on the other end signify that you have started to slouch.

5. Connect the output to your circuit—either an LED or a vibration motor—and upload the following code to your microcontroller. Now, when the bend sensor detects that you have started slouching, it should trigger the output to turn on:

   int sensorleft = A0;       // left bend sensor                    
   int sensorRight = A1;      // right bend sensor                    
   int Right = 0;             // variable to store the value coming from the right bend sensor                    
   int Left = 0;              // variable to store the value coming from the left bend sensor                    
   
   int threshold= 500;        // change to your observed threshold value
   int vibe = 9;
   
   void setup() {
   Serial.begin(9600);
   pinMode(vibe, OUTPUT);
   }
   
   void loop() {
   Right= analogRead(sensorRight);
   Left= analogRead(sensorLeft);
   digitalWrite(vibe, HIGH);
   if (Right >=threshold){
   digitalWrite(vibe, LOW);
   delay(2000);
   }  
   else if(Left >=threshold){
   vibe= HIGH;
   delay(2000);
   }  
   
   }

6. If you are happy with your circuit, you can replace the alligator clips with conductive thread! Before you start, you may want to refer to Chapter 5 for a refresher on how to sew with electronics. Here are some tips:

   • Curl the legs of the resistors with pliers to make loops to sew through, as shown in Figure 11-5.

     

     Figure 11-5. Resistor with curled legs for sewing through

   • When sewing to a pad on the microcontroller, be sure to loop through the pad a few times, until the connection feels secure.

   • If there is not enough room to attach the microcontroller to the suspenders, you can sew on a patch of fabric to create a larger surface.

   • You may want to sew a pocket for the battery to sit in on the back of the suspenders so that it stays in place.

   • Be careful when placing the components. Make sure all the negative rails go along the same side of the suspenders, and the positives on the other side—remember not to cross the paths.

7. Try out your suspenders! Do they help you improve your posture? Try different outputs and output patterns on the suspenders to see what works the best, as shown in Figure 11-6. You could make a light fade in and out or a buzzer increase in intensity depending on the angle of slouch—be creative!

   

   Figure 11-6. Completedposture suspenders

Summary

The technologies and products describes in this chapter are just a small percentage of the amazing wearables being developed for medical and wellness applications. Ultimately, these technologies can only become as successful as we allow them to be, so the design and interface of these gadgets is extremely important and, arguably, has much room for improvement. As more people adopt these gadgets for help with monitoring their infants’ conditions, tracking their daily calorie intake, or checking their posture, manufacturers will get more feedback about which features work best. Calibrating sensors to adapt to the physically and environmentally dynamic conditions of our bodies is another challenge that requires much research and development. These technologies show great promise and will likely improve exponentially in the next few decades. The next chapter examines techniques and projects that offer less visible alternatives for wearables.