Attributes of Wearables (Key Points)

 Sensor Definition: A device that detects, locates, or quantifies energy/matter and signals a
physical/chemical property.

 Not all sensors are wearable, but all wearables must include sensing capability.

 Key Requirements of Wearables:

o Lightweight.

o Variable form factor to suit the wearer.

o Not restrictive (shouldn’t interfere with natural activities, e.g., a gamer’s play).

o Aesthetics matter → improves acceptance and usability.

o Fashion integration → visible devices must look good while being functional.

Functional & Social Aspects

 Wearables are becoming integral to everyday life.

 Sociological acceptance depends on exciting user experiences and aesthetics.

 Ideally, a wearable should:

o Act as a natural extension of clothing/accessories.

o Be invisible (disappears for all intents and purposes).

o Be shape-conformable and behave like human skin.

Technical Capabilities

 Should support measurement and use applications.

 Wearables with single functionality (e.g., only heart rate) are useful but limited.

 In practical use, multiple parameters are needed → multiple sensors must be combined
effectively.

 Risk: Multiple devices may make a person look awkward, reducing acceptance.

 Responsiveness is critical (e.g., real-time acquisition for first responders).

 Device must be “always on” and have low latency.

Information Processing

 Information processing = wearable’s ability to handle multiple data streams (e.g., email
processing on smartwatch).
  Some functions (like communication vs. health monitoring) may be mutually exclusive.

 Wearable can be multifunctional:

o Active.

o Non-invasive.

o Reusable.

o Suitable for health monitoring.

Taxonomy & Benefits

 Helps classify current wearables for:

1. Selecting appropriate devices based on operating constraints.

2. Identifying opportunities for new wearables and performance improvement.

Do you want me to also make a simplified diagram/flowchart of these attributes (like

classification)? That could make it easier for quick revision.

Got it 👍. Here’s the Taxonomy for Wearables explained in clear bullet points from the image:

Taxonomy of Wearables
1. Classification by Functionality

o Single Function → performs only one task.

o Multifunction → performs multiple tasks (e.g., smartwatches).

2. Classification by Invasiveness

o Invasive Wearables

 Enter or penetrate the body (subcutaneous/implantable).

  Examples: pacemakers, implantable glucose monitors.

 Require

 medical procedures to be placed inside the body.

o Non-invasive Wearables

 May or may not be in contact with the body.

 On-body examples: smartwatches, fitness trackers.

 Off-body examples: camera capturing surroundings, gas sensor for harmful

gases.

 Often used for continuous monitoring (don’t require medical intervention).

3. Classification by Power Requirement

o Active Wearables → require power to operate.

o Passive Wearables → do not need external power.

 Example: temperature probe that works without power.

4. Classification by Communication Mode

o Wired Wearables → signals transmitted through physical wired connections.

o Wireless Wearables → signals transmitted wirelessly to monitoring units (e.g., via

Bluetooth, Wi-Fi).

5. Classification by Deployment Mode

o Worn on the Body → smartwatches, bands, glasses, etc.

o Not worn on the Body → environmental monitoring sensors placed around the user.

6. Classification by Usage (Reusability)

o Disposable → used for short duration, then discarded (e.g., medical patches).

o Reusable → long-term usage, recharged/reused (e.g., fitness trackers).

7. Classification by Field of Use

o Health → monitoring vital signs, disease management.

o Public Safety → firefighter sensors, first responder monitoring.

 o Entertainment (Gaming) → VR/AR headsets, motion sensors.

o Information Processing → smartwatches handling messages, emails.

o Military → soldier monitoring, battlefield sensors.

o Sports & Fitness → performance tracking.

o Position Tracking → GPS-based wearable devices.

Components of Wearable Systems

1. Control

 Wearable-specific microcontrollers are:

o Small, comfortable, and discreet.

o Sometimes act as decorative elements (different shapes/colors).

 Many boards are hand-washable (except power source).

 Always check documentation before use.

2. Input/Output

 Instead of pins, these boards have metal eyelets → can loop conductive thread through
them to sew soft circuits.

 Some boards also have snaps or eyelets → large enough to solder snaps for easy removal.
3. Conductive Textiles

 Made from materials containing metals (e.g., silver, stainless steel).

 Allow electrical current to flow.

 Applications:

o Thread for making circuits.

o Fabric for creating capacitive touch sensors.

o Hook-and-loop for switches (like Velcro).

4. Sensors

 Collect data about environment, user, or both.

 Environment Sensors: light, temperature, motion (accelerometer), location (GPS).

 User Sensors:

o Heart rate (ECG).

o Brain waves (EEG).

o Muscle tension (EMG).

 Few wearables already have basic onboard sensors.

 Other manufacturers provide external sensor modules to connect to the main board.

5. Power

 Power supply is a key consideration when designing wearables.

 Example use cases:

o Power for LEDs.

o Power for a servo motor.

 Battery options:

o Boards with integrated lithium coin battery holders → good for small projects.

o Boards with standard JST connectors (with or without charging circuits for LiPo
batteries) → more versatile for larger projects.

6. Actuators

 Used to generate an action in response to an input.

  General rule: In response to X (input), Y (output) happens.

 Examples of actuators:

o LEDs (visual feedback).

o Buzzers or speakers (audio feedback).

o Servomotors (movement).

7. Networking

 To connect with smart devices, the internet, or other wearable systems, connectivity is
essential.

 Wearable-friendly networking options:

o Wi-Fi.

o Bluetooth Low Energy (BLE) → lower power consumption than classic Bluetooth,
range ~50m, data rate ~1 Mbps.

o NFC (Near Field Communication) → range ~20 cm, useful for very short-range
communication.

o RFID (Radio Frequency ID) → range up to ~400 kbps, used for identification and
tracking.

Types of Sensors in Wearable Devices

1.Smartwatches

 These days, watches are tech-enabled.

 They double up as a fitness tracker and sleep monitor, in addition to being the classic time-
keeping device.

 Smartwatches provide many other features including enabling users to make & attend
phone calls and check messages.

 Some watches have the feature of playing FM radio or audio & video files with a Bluetooth
headset.

 They generally connect to the smartphone via an app and act as a supporting device.

 They are often referred to as a “Wearable Computer” on your wrist because of the bundle of
features that can be used through the touchscreen.
2.Fitness Trackers

 Fitness Trackers are among the wearable technology devices wearable on the wrist.

 Primarily launched to perform the function of pedometers (i.e., counting the number of
steps), they have evolved into overall health monitors.

 They perform various functions such as tracking heartbeat, monitoring sleep, calories
burned, and other metrics.

 Data is shared with an app on the smartphone, making them a perfect health tracker.

 Some devices are enabled to regularly share wearer’s health metrics with physicians for
early detection of issues.

3.Smart Jewelry

 Jewelry now acts as smart devices instead of just ornaments.

 Smart Jewelry includes necklaces, wristbands, bracelets, or rings that are tech-enabled.

 They help track steps, heartbeat, sleep, and may notify you of incoming calls.

4. Game Simulators

 The rise of VR in gaming has led to many wearable devices.

 These devices simulate an environment to make the experience more realistic, engrossing,
and adventurous.

 Examples of devices:

 VR Headsets / Head-Mounted Displays (HMDs) → create visual simulations.

 Bands with built-in sensors → detect your movements.

 These bands allow you to control movements using hand gestures.

5. Smart Clothing

 Advancement of technology with IoT has created inventions like Smart Clothes.

 Smart Clothes are also called E-Textile.

 They are integrated with electronic devices to measure health metrics.

  Smart clothes measure health-related aspects such as:

 Heart rate

 Respiration rate

 Sleep

 Body temperature

 They provide you with this information for health improvement.

 Smart clothing also includes smart shoes that:

 Examine your health, steps, fatigue.

 Collect other metrics to help improve health and prevent injury.

6. Smart Glasses

 Range from simple smart glasses with:

 Bluetooth wireless music

 Hands-free calling

 To advanced smart glasses that can:

 Live stream videos

 Take photos

 Are AR-enabled (Augmented Reality) → provide immersive experiences.

 Smart glasses act as eyewear.

 They allow users to:

 Read text messages

 Reply hands-free

 Some companies’ smart glasses also include:

 Internet access

 Browsing through voice commands

7. Heartbeat Trackers & Blood Pressure Monitors
 Fitness trackers exist for specific use cases such as:
o Monitoring heartbeat.
o Regularly measuring blood pressure.
 These devices:
o Help track metrics among people with related diseases.
o Record data and provide measurements to the wearer regularly.
o Some devices also enable data sharing with physicians for medical monitoring.

8. Smart Earbuds
 A new entry in wearable technology.
 Normal Bluetooth earbuds exist but are not considered wearables because they don’t
collect/send data.
 Smart earbuds include advanced features:
o Built-in gyroscope, GPS, and compass.
o Sensors in earbuds relay information to the smartphone.
 Functions:
o Enable smartphone to know user’s direction and movement.
o Provide real-time directions.

9. Smart Contact Lens

 One of the recent inventions enabled by IoT.
 Current smart lenses are mainly for medical purposes, such as monitoring eyes for:
o Diabetes.
o Glaucoma.
o Cataracts.
 They assist in treating farsightedness.
 Beyond medical use, companies are developing:
o Smart lenses that are AR-enabled.
o Lenses powered by solar energy.
o Wireless smart lenses among implantable devices