hWatch - A femtech based wearable IoT development platform

Overview

hWatch is an ESP8266 based wearable IoT development platform for supporting women. Women are undergoing through many physical, mental and social challenges in her day to day life. hWatch wearable IoT platform is concentrated in monitoring these challenges and supports her in facing these challenges. The physical and mental challenges are more over genetical to an extent. Here hWatch is meant for fetching data from the feminine body and automatically supports her in the needy situations. As it is mentioned as "development platform", hWatch is like to a be a prototyping or a real-time validating platform for the emerging femtech technology, rather than be like to an end product.

Features

• Wearable.
• Rapid prototypable and real time-validatable.
• IoT Device.
• High sensitive temperature sensor for fetching body temperature.
• High precision pulse oximetry and heart-rate monitor module.
• Three different touch controllable operations, which can be customized by the user.
• On board USB for programming, charging and validation.
• 0.91" OLED Display.
• 3.7V rechargable Lipo-Battery.
• Open Source.

How it works...?

hWatch is basically a health monitoring watch which is designed as it shows the current time as soon as it is connected to a Wi-Fi Hotspot. In Addition to this basic feature there are two sensors and touch switch for giving inputs to the device. The two integrated sensors includes a high precision temperature sensor and a pulse oximetry heart-rate monitoring sensor. The onboard extended touch switch turns on the LCD Display on touching it and other than that, it offers three more different modes of operation, which can be customized according to the need of the person. Thus this device is used for giving inputs from the body, which are further stored and processed in cloud network platform.

Hardware

• The Key component of this project is ESP8266 Module which consists of on board Wi-Fi Microchip and Microcontroller for processing I/Os and thus making the device an IoT capable.
• SI7021 is a high precision temperature-humidity sensor for giving periodic body temperature inputs to the ESP8266 module. The sensor consists of an onchip ADC and communicates via I2C Interface.
• MAX30101 is an integrated pulse oximetry and heart-rate monitor module for giving periodic heart rate report inputs to ESP8266 module. This sensor module also communicates via I2C Interface.
• The onboard touch switch and the touch controller IC (TTP223-BA6) is used as an alternative for a push button or a switch. The touch switch is extended to the inner frame around the OLED Display. The touch switch is used for waking up or turning the display ON. The touch switch's On and Off time are controlled accordingly, for the customization feature of this device.
• An on board Type-A USB along with a battery controller (TP4056) made it possible for direct plug able USB charging. UART to USB Converter (CP2102) along with on board USB is used for rapid programming and real time validation of the device.
• OLED Display board 0.91" is an I2C controlled device for displaying the received and processed inputs from the sensors and time.
• The power to the whole setup is delivered by a 3.7V rechargeable lipo battery in associated with different voltage regulators and discrete components.

How to build...?

• Block diagram of the project.

• Now it's time to turn the block diagram to schematics. Build the schematics using Autodesk Eagle CAD Software (eagle schematic file attached).

• Switch to board file and draw the board layout.

• Place all the component footprints in the top and bottom sides of the board and finish the routing.

• Generate and finish the board file.
• Now select Manufacturing button and view the Bare PCB image that can be obtained with your board file. Check for errors and rectify that errors if any there.

• For creating a 3d Model of the board, initially, combining of all the libraries used in the project to a single library has to be done
• Now, create Managed libraries Version 1 (in which 3d Packages are not mapped with eagle libraries) from the combined library.
• After that, open Library editor and create 3d Packages for all the component libraries using libraries.io (either create the 3d Packages for the eagle libraries or import 3d Packages if already there). And map the 3d Packages for appropriate libraries. Once the mapping of the 3d Packages for all the eagle libraries has done, then save the Managed Libraries Version 2 (in which 3d Packages are mapped).
• Now after giving library > update all, check in the library manager weather the mapped 3d Packages appears along the with the foot print and symbol.

• Once everything is set, Now it's the time to push the board into Autodesk Fusion 360.
• For that Switch to board file and select Fusion 360 from side blocks and select the project location.
• Then it will shows for the 3d Package mapped libraries with a green tick mark. Check weather all required libraries are mapped with 3d packages and finally push the board into fusion 360.
• Now it's time to close Autodesk Eagle and open Autodesk Fusion 360.
• Now open the pushed project file from Eagle and check for any errors.

• Now, as per the design, the rechargeable lipo-battery has to be connected as a power source. So a 3D Design of the battery has to be created.

• Now the lipo-battery has to be placed above the ESP8266 Module.

• The 3D file for 0.91" SSD 1306 OLED Display can be obtained from here.
• In this 3D file, the display image is blank which is added by inserting a canvas image (Select Insert > Canvas and select the image).

• Now, the OLED Display has to be placed above the battery-board setup as per our design.

• Next the on-board touch pad has to be extended to the top near the OLED Display.

• Then, the whole setup has to be cased.

• Now the strap or band has to be attached along with case.

• This is how the hWatch has built.

ESP8266 (ESP-12E WiFi Module)

ESP8266 (ESP-12E WiFi Module) is the core component of the project to which all the I/Os are connected.

ESP8266 Arduino Library can be obtained from here

Datasheet of ESP-12-E WiFi Module can be obtained from here.

Charging

For charging, hWatch can be directly plugged to a 5V USB Adapter or PC or a Power Bank. For giving charge indication or notification, one can program by referring the outputs of CHRG & STDBY signals from battery controller. These signals are connected to the GPIO 12 & GPIO 13 of ESP8266 module respectively. please refer the below table for more information.

SI7021 & MAX30101

SI7021 (high precision temperature humidity sensor) and MAX30101 (pulse oximetry and heart-rate monitor module) are connected to the I2C Pins (SCL and SDA) of ESP8266 module.

Arduino Library for SI7021 sensor can be obtained from here.

Arduino Library for MAX30101 sensor can be obtained from here.

Datasheet of SI7021 sensor can be obtained from here.

Datasheet of MAX30101 sensor can be obtained from here.

Programmable Touch Switch

Touch switch is used in hWatch for an alternative for push button. The touch switch can be used for the customization feature according to one's need. The single switch can be programmed for executing multiple tasks by controlling On-Time, Off-Time & Number of switchingoperation.

Touch Switch is connected to four GPIOs in total, three for customization feature and one for controlling OLED Display wake up.

OLED Display

The primary use of 0.91" OLED Display is to show time, periodic body temperature and heart rate. Every IO operations can be included to show in display according to the need. The OLED Display communicates using I2C. The Display can be waked up using Touch Switch interface. The Arduino Library for 0.91" SSD 1306 OLED Display can be obtained from here.

CP2102

CP2102 is a USB to UART bridge. This is used for data transfer between USB and UART. Which means, it's used for programming the ESP8266 module and for real-time validation. RX and TX pins in the ESP8266 module are used for this purpose, were RX and TX of CP2102 and ESP8266 are interconnected. The drivers of CP2102 can be obtained from here.

Programming hWatch

• Arduino IDE.
• After opening, we have to make IDE compatible of programming our board.
• For that copy the below URL in File > Preference>Additional Board Manager URLs and then Click OKURL : http://arduino.esp8266.com/stable/package_esp8266com_index.json

• After that, select Tool > Boards > Boards Manager. In that search the keyword ESP8266. Then install ESP8266 boards. After complete installation, you will see the INSTALLED label on ESP8266 boards.

• Now select Tools > Boards > Nodemcu 1.0 (ESP-12E Module).

• Now type the code for hWatch and check for any error by compiling the code by clicking the verify button beneath the menu bar.
• Connect the hWatch to PC for programming using the on-board USB.

• Now select the Tools > Ports > select the port to which the board is connected.

• Once everything is selected, then upload the program to the board by clicking the upload button (aside the verify button) in the Arduino IDE.

What's Next...?

Why Temperature & Heart Rate Sensor....?

Temperature sensor & Heart rate sensor has became the common features of the latest Smart Watches and Smart Bands. Then what is the importance of these in this project......? And why adding customization features to this device...?The researches found that resting heart rates (RHRs) show distinct values for the four phases of menstrual cycle and which opens a wide world for the wearable sensor technology. In simple, we can say that heart rate of women varies during the different stages of menstrual cycles. Researches also founds that the body temperature of a women rises and falls minutely at various stages of menstrual cycles due to the changes in the hormone levels.

So with the help of a wearable sensor technology it's possible to make women aware of the very minute changes in their body prior to different phases of Menstrual cycle. And same technology can be used for supporting her to overcome the impact of physical symptoms of menstruation (or PMS-Premenstrual Syndrome) such as low energy, fatigue, sleeping troubles, back pain, headaches, joint pain, muscles pain, bone loss etc. Both the things can be achieved with the help of a typical mobile application.

HackingMenopause

Apart from the above, the result of the case study is completely different for Menopause. Because while entering from a proper menstrual cycle to perimenopause stage and from there to menopause stage, the impact of the physical symptoms on the women body will be drastically increasing. For examples, during menstrual cycle, the resting heart rates and body temperature of a women shows very minute variations, But during menopause women are experiencing hot flashes and heart palpitations. Hot flashes are sudden feelings of warmth, which will not raise the core body temperature rapidly, instead it will raise the inner body temperature. So treating hot flashes like normal temperature variation is impossible. Studies and researches also founds that heart palpitations (heart racing or missing beats) also occur in middle of hot flashes. But that too a common symptom of stress during menopause. Thus accurate heart rate and minute body temperature variation should be the main inputs for treating menopause. As mentioned before, Depending on the values of the received inputs from the body, the mobile application should be capable of distinguishing women undergoing through different stages of menstruation and should notify them with proper tips and suggestions to overcome the impact of the physical symptoms.

Touch-SwitchCustomization

Touch-Switch customization will be a very useful feature for every women since they are undergoing through impact of mental stress and mood swings due to menses. The physical and mental impact of the menstrual and menopause symptoms can create mood swings, dizziness, fatigue, stress, etc. During these time, it's very hard for them to be active in their daily routines. So the touch switch option can be used to control or automate any three of their needs which can be fulfilled with a touch. It can be like, sharing of their live location with a single touch in case of any emergencies (widening the application level to support women for facing social challenges too) or be like controlling any device remotely or like automation of any device and will be better if all such features can be include in a single software application platform.

What's Next....? Coming into this question, the answer is that a very powerful Mobile Companion Application for hWatch (If hWatch can satisfy the requirements of fetching data from body) incorporating the above mentioned, from aspects to reality with practical validation and researches for making feminine life better and better.

Current Drawbacks and Next Revision

• The current design is more bulkier, So the next Revision should be like more lighter.
• Should exploit the NC GPIOs (not connected GPIOs) too and make the device features more better.
• Alternate sensor parts if the current sensors can't met the requirement of fetching data from the body.