Benefits of WSNs in Aged Care

August 18, 2016 jordan 3 comments

Executive Summary

According to the Australian Bureau of Statistics the population of people over the age of 65 is set to jump from 14% of the population in 2012 to between 22.4% and 24.5% of the population in 2061.

This has significate implications to the Australian economy and health services. Aged care will need to become much more efficient to cope with the massive increase in demand.

One way to help reduce the strain on aged care facilities is to use technology to help care for the elderly, enabling nurses to care for more residents. This report looks into the applications and benefits of using wearable electronics that monitor the wear’s vital signs to create a wireless sensor network where the node is an elderly person, creating a network that requires minimum infrastructure and is resilient to down time.

The benefits of wearable electronics that monitor elderly people are the reduced supervision by nurses allowing them to more effectively care for more people.

 

Introduction

My motivation for this leaning experience is that I have been working at an aged care enterprise for the last 12 months in the IT department, so I have a working understanding of the ways staff use technology to help them care for elderly residents. One gap in their use of technology is real time monitoring, meaning nurses need to be constantly monitoring many residents at once in order to care for them. This problem is only going to get worse in the future.

To approach this problem I will use my knowledge of Arduino electronics and Arduino programming concepts to research and build a cheap wearable yet fully functioning vital sign monitor. I may experience problems due to my knowledge of Arduino being limited to 3D printers and Autonomous drones but will work to mitigate these problems by using my knowledge of electronic concepts and adapt them to this particular project. I am yet to discuss this approach with any experts but will use expert knowledge on Arduino from websites and forums I subscribe to.

My approach to research is to find out everything I can on the subject before I design something as to not create a design that is impractical and doesn’t meet the requirements that were set out. Therefore I was not surprised with the information I gathered. As I am currently working on my own on this project I won’t need to spread this knowledge to other people which is in my opinion is a good thing as this research is quite technical and requires knowledge in many concepts that people who don’t have an avid interest in electronics do not possess. This being said once I have a working prototype it will be a lot easier to share this knowledge and lead future team members.

 

The Problem

The problem this project will address is the ratio of nurses to the elderly in both self-care and aged care environments that is set to unsustainably increase in the next 50 years. To the point where nurses will be unable to care for all residents in their care effectively. This problem affects me in my workplace as when a system that nurses rely on breaks down, due to nurses being stretched so thin among so many elderly residents they are unable to effectively care for everyone. This shows a need for new systems that will reduce the strain on staff, because of my IT position in this industry I have an insight from an information technology standpoint that allows me to create a solution that people in the aged care industry could not develop. With this being said I will use my interest in electronics to develop a solution to this increasing problem.

 

Solution Outline and Plan

I plan to address this problem with the use of small wearable electronics that when in a group, forms a resilient wireless sensor networks that sends vital signs of the elderly residents to nurses allowing them to monitor many residents at once. The goals of this vital sign monitor is to monitor heart rate, to be able to detect if a resident has had a fall or has not moved recently, as well as to detect if a resident has left the premises.

Wireless sensor networks consist of interconnected nodes ranging from a few to hundreds which are directly or indirectly connected to a gateway sensor node. These nodes consist of a radio transceiver, antenna, power source, a microcontroller and some form of sensor, which collect data and send it to the gateway directly when in a star topology or forward data between nodes when in a wireless mesh topology.

I plan to achieve my goal by selecting a microcontroller that has inbuilt wifi such as the nodeMCU, selecting the required sensors that meet the set goals and decide on how to power the board.

Possible risks including buying components that aren’t compatible with each other, the finish device doesn’t work correctly due to not enough processing power or problems with code implementation and producing a product that doesn’t meet specified goals. To mitigate these risks I will keep the risks in mind when designing the devices and will be careful to address possible ways these risks could occur.

 

 

 

Implementing the Action Plan

To design the device I set out a list of requirements of the board and components, starting with the sensors and working back to the board.

 

Heart rate sensor

The heart rate sensor I found was the best to use is pulsesensor.com Arduino module which is a compact analogue sensor. During my research I found the heart rate sensor had to be attached to capillary tissue such as earlobes or fingers but not wrists which was a surprise as I assumed you could apply the sensor to a wrist. Therefore I had to change the intended design from a wrist watch shape with the sensor inbuilt to a necklace or wrist watch with the sensor external to the device. Another factor I need to consider is that the microcontroller board I choose will need an analogue input. This sensor costs around $7 on ebay.com which may vary if bought in bulk.

pulse

 

Accelerometer

To detect a resident falling over I have chosen to use a digital accelerometer that can measure the acceleration movement of a fall. It needed to have digital outputs as most microcontrollers don’t have enough analogue inputs for three axis to be measured. I have chosen the ADXL345 3-axis digital accelerometer Arduino module which cost as little as $2 which again may vary if bought in bulk.

3axis

 

Microcontroller

The microcontroller and wifi board I have chosen is the mini NodeMCU with the ESP8266 wifi development board.  It features the smallest possible form factor, 1 analogue input, 11 digital input/outputs and has an operating voltage of 3.3v which makes it perfect to power off a small lithium-polymer battery. This microcontroller costs round $7 making it a very affordable base for this project.

nodemcu

Battery

Ideally I wanted to house the battery with the wifi board but with the power consumption averaging between 50-170mA, I would need a fairly large battery. To mitigate this the battery will be housed in the lanyard which the resident wear’s around there neck. This would allow a single cell lithium-polymer battery of between 450mah and 650mah to be used without being too bulky. The device would have an average power consumption of 50mA which could be further reduced by removing LEDs and reducing data transmission intervals. These batteries cost around $6 making them perfect for powering the device.

 

 

OLED display

A non-essential component is a 64×48 OLED screen to display battery percentage, heartrate and wifi reception but this Is not necessary as this information could be gathered for the current LEDs or a RGB LED. On average these cost $7 which could be an optional extra.

 

 

As shown this device is simple to make that only costs $22 making it very affordable to roll out to many residents. By keeping to the plan I was able to identify risks such as number of analogue inputs and mitigate that by choosing a digital accelerometer. I was surprised by the high power consumption of the wifi development board. Therefore I will investigate and compare the use Low power Bluetooth instead to reduce power consumption. In total I spent around 6 hours researching how I would build this device and what sort of performance and programming to expect in the next step of this project. I would be seeking advice of the form factor of the lanyard and how to best set up the mesh topography.

Outcomes and Benefits

I learnt that this project is in fact a viable business and will seek interest in my workplace to test these devices. I have exceed my learning to the point where I will pursue this project beyond this assignment and have already ordered the parts to commence the next stage of building and programing. With this new knowledge I will research if this technology could apply to enhancing or replacing emergency call buttons. The most important way I will apply this new knowledge is to test the effectiveness and reliability of these low power IoT (internet of things) wifi mesh networks.

Conclusion

In conclusion this report shows the design and first step in a much larger project to produce a reliable way for nurses to care for large groups of elderly people. This possible lifesaving technology will need extensive testing to ensure it is reliable enough for a live environment. I see this an opportunity to make a positive impact on a changing society.

 

 

 

References

3222.0 – Population Projections, Australia, 2012 (base) to 2101. 2016. 3222.0 – Population Projections, Australia, 2012 (base) to 2101. [ONLINE] Available at: http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/3222.0main+features52012%20(base)%20to%202101. [Accessed 01 June 2016].

GitHub. 2016. GitHub – esp8266/Arduino: ESP8266 core for Arduino. [ONLINE] Available at: https://github.com/esp8266/Arduino. [Accessed 01 June 2016].

my2cents. 2016. Comparison of ESP8266 NodeMCU development boards • my2cents. [ONLINE] Available at: http://frightanic.com/iot/comparison-of-esp8266-nodemcu-development-boards/. [Accessed 01 June 2016].

Silicon Labs. 2013. The Evolution of Wireless Sensor Networks. [ONLINE] Available at: http://www.silabs.com/Support%20Documents/TechnicalDocs/evolution-of-wireless-sensor-networks.pdf. [Accessed 1 June 2016].

Banggood.com. 2016. WLtoys V930 V977 RC Helicopter Spare Parts 450mAh Lipo Battery V977-006 – US$7.99. [ONLINE] Available at: http://www.banggood.com/WLtoys-V930-V977-6CH-RC-Helicopter-Parts-Lipo-Battery-V_2_977_006-p-918059.html. [Accessed 01 June 2016].

Banggood.com. 2016. 3Pcs Mini NodeMCU ESP8266 WIFI Development Board Based On ESP-12F Sale – Banggood.com. [ONLINE] Available at: http://www.banggood.com/3Pcs-Mini-NodeMCU-ESP8266-WIFI-Development-Board-Based-On-ESP-12F-p-1058306.html. [Accessed 01 June 2016].

Pulse Sensor – SEN-11574 – SparkFun Electronics. 2016. Pulse Sensor – SEN-11574 – SparkFun Electronics. [ONLINE] Available at: https://www.sparkfun.com/products/11574. [Accessed 01 June 2016].

eBay. 2016. 0 96″ I2C IIC SPI Serial 128×64 Blue Oled LCD LED Display Module FOR Arduino | eBay . [ONLINE] Available at: http://www.ebay.com.au/itm/0-96-I2C-IIC-SPI-Serial-128X64-Blue-OLED-LCD-LED-Display-Module-for-Arduino-/131827067709?_trksid=p2141725.m3641.l6368. [Accessed 01 June 2016].

 

 

eBay. 2016. HOT Sale ADXL345 Digital 3 Axis Acceleration OF Gravity Tilt Module SU DW | eBay . [ONLINE] Available at: http://www.ebay.com.au/itm/Hot-Sale-ADXL345-Digital-3-Axis-Acceleration-of-Gravity-Tilt-Module-SU-DW-/291648809616?hash=item43e79faa90:g:eUMAAOSwJcZWgjAG. [Accessed 01 June 2016].

ADXL345 Quickstart Guide – SparkFun Electronics. 2016. ADXL345 Quickstart Guide – SparkFun Electronics. [ONLINE] Available at: https://www.sparkfun.com/tutorials/240. [Accessed 01 June 2016].

Accelerometer, Gyro and IMU Buying Guide – SparkFun Electronics. 2016. Accelerometer, Gyro and IMU Buying Guide – SparkFun Electronics. [ONLINE] Available at: https://www.sparkfun.com/pages/accel_gyro_guide. [Accessed 01 June 2016].

Arduino – ADXL3xx . 2016. Arduino – ADXL3xx . [ONLINE] Available at: https://www.arduino.cc/en/Tutorial/ADXL3xx. [Accessed 01 June 2016].

ESP8266 Power Consumption – ESP8266 Developer Zone. 2016. ESP8266 Power Consumption – ESP8266 Developer Zone. [ONLINE] Available at: http://bbs.espressif.com/viewtopic.php?t=133. [Accessed 01 June 2016].

3 Comments on “Benefits of WSNs in Aged Care

  1. Nice to read about real-world (i.e. non-hobbyist) applications for the ESP8266. I suggest you also take a look at the ESP8255 which was designed specifically for wearables: http://frightanic.com/iot/nodemcu-esp8285-perfect-match/. The ESP8285 development board I have is very good but it’s fairly expensive because it isn’t produced in bulk yet. I’ve also bought a few https://www.itead.cc/wiki/PSF-A85 which are tiny and cheap. However, I need to practice soldering on such small boards first before I can put it to use (pin width is 1.27mm rather than 1/10 inch).

  2. Thanks for your comment, these ESP boards definitely have a lot of real world potential, wow the ESP8255 could be a game changer. I wish I could say my soldering skills could handle that kind of pin spacing but I struggle with 2.5mm haha

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