Download Personal Health Check – BBC micro:bit Heart Rate Monitor

Personal Health Check – BBC micro:bit Heart Rate
Monitor
Using an accelerometer and programming the system
Subjects: Design & Technology, Computing
Approx. time: 60 - 120 minutes depending on ability and
prior experience of learners
Key words / Topics
> BBC micro:bit
> system and sub-system
> input, process, output
> accelerometer
> programmable components
> embedded intelligence
Suggested Learning Outcomes
> To understand a block systems diagram of the heart monitoring system.
> To understand the use of and apply an accelerometer as a heart monitoring device.
> To successfully program the BBC micro:bit so that the system meets the design criteria.
Introduction
This is one of a series of resources to support the use of the BBC micro:bit in Design and Technology lessons. It can also be
used as a follow up to the IET Faraday Resource ‘Body Centric Antenna’. http://faraday.theiet.org/resources/overview/bodycentric-antenna.cfm
There are many reasons to monitor heart rate. For example:

There are 2.7 million people in the UK currently suffering from heart problems. The quicker these problems can be
found and treated the better the chance of a full recovery.

Athletes measure their heart rate during training to ensure that they are training in their optimum physical range.
In this unit of learning, learners will use the BBC micro:bit to develop a prototype for a personal heart monitoring system.
Purpose of this activity
In this activity, learners will develop their programmable system using the BBC micro:bit’s inbuilt accelerometer to detect
motion created by the pumping of the heart.
This could be used as a main lesson activity with ‘Portable Health Check – Social Effects’ as the starter. It is an ideal exercise
for learners to improve their understanding of basic electronics, develop programming skills, make use of programmable
components and embed intelligence into a product design.
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Activity
Teacher notes
1. Design Brief
The IET TV video – Heart Rate Monitor
https://tv.theiet.org/Index.html?videoid=7298 can be
shown as an introduction or starter for activities in this unit
of work.
Teacher to introduce the situation and design brief to
learners. Use the teacher presentation as a guide for this.
Emphasise that they will be using the BBC micro:bit system,
which is a programmable system, to create their solution.
Situation:
This activity can be attempted by learners as individuals, in
pairs or in small groups.
There are 2.7 million people in the UK currently suffering from
heart problems. The quicker these problems can be found
and treated the better the chance of a full recovery.
If learners have not seen or used a block systems diagram
before it would be necessary to describe this in more detail
(i.e. what is meant by input, process, output etc).
Brief:
It will probably be impractical for learners to attach the
actual system to their actual heart or bodies, so it is fine for
learners to simulate how this would work by manually
moving the BBC micro:bit to trigger the accelerometer.
Using the BBC micro:bit, create a prototype for a personal
heart monitoring system. The system must use an
accelerometer to detect the movement of the heart. It must
also use a suitable sound output and an LED display to give
heart rate information to the user.
2. Systems diagram
Introduce the systems diagram for the heart rate monitoring
system. Discuss this with learners. What do input, process
and output mean? What are the physical parts of the system
and their functions?
3. Design criteria for the system
Go through the design criteria with learners. Question them
as to what each of the criteria might mean in practice in terms
of producing their system. How might they meet each of the
criteria?
4. Use of accelerometer
Describe what is meant by an accelerometer (detects
acceleration), what it does and how it works. Ask learners if
they know of any electronic products that use them and show
examples where possible.
Explain how accelerometers are used in heart monitoring
equipment in hospitals and cardiac care units. They can
detect the tiny body movements made by the heart pumping –
e.g. a smart phone with an inbuilt accelerometer can do this
effectively.
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Programming the BBC micro:bit and example
When writing the program, low ability learners or those
who have not done programming before may benefit from
writing, experimenting with and downloading the example
program shown on the Teacher PowerPoint (also provided
as a PDF handout). They can use this as a base for their
own program. This is presented as Touch Develop code
(search for script ID rurniliqwk at www.microbit.co.uk).
Learners can use Block Editor and Code Kingdom, but due
to the functionality needed, Touch Develop is the most
appropriate editor for this particular activity.
When the accelerometer detects movement, the LED
screen will create a graphical representation of the ‘heart
beat’. A buzzer or beeper can also be added and attached
between pin 1 and ground. A program that achieves the
additional functionality of an audible indication of the heart
rate can be found by searching for script ID vcbjpatqpk.
For ease of testing, Button A can also be used to create
the display images in place of the accelerometer.
5. Sound output and LED display
Introduce a suitable output device to give an audible
indication of the heart rate. This could be a small buzzer or
beeper. Demonstrate how this can be connected to the BBC
micro:bit using either flying leads, block connectors, crocodile
clips or hard wiring. Any external devices used should be
connected between the pin number chosen and ground.
Introduce the BBC micro:bit’s inbuilt LED display and show
how this can display a simple text and/or characters.
6. Writing the program
Learners begin writing their program to meet the design
criteria using the example program as a guide where
necessary.
7. Progress review
Review learner progress part way through the activity and
recap key points as necessary. Refer to the example program
where appropriate to help guide learners.
8. Downloading program and testing
Learners download and test their program, refining and
improving it as necessary.
Differentiation
Basic
Extension
Learners can write the example program directly into the
programming software and download it as a starting point.
They can then develop this further as required. The example
program is included in the accompanying PowerPoint.
Learners could extend the program to provide more
detailed information about the heart rate.
Learners should be able to use the accelerometer as a simple
motion sensor and simulate how this might mimic a device
attached to the heart. Their system should beep each time
the accelerometer detects movement to give an audible
indication of the heart rate. The LED display should also give
some indication of this, such as a simple graphical display
updated with each movement of the accelerometer.
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This could include scrolling graphical information of the
heart rate, a warning if the heart rate drops or rises sharply
or a more complex audible output using a piezo sounder
with a programmed set of tones.
Resources
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Required files
Projector/Whiteboard
BBC micro:bit system and online programming software
(Touch Develop)
Internet (to access programming software)
Crocodile clips or other wiring options (to attach sound
output device)
Personal Health Check – Programming the System
Teacher Presentation
Example BBC micro:bit Block Editor, Touch Develop
and Code Kingdom Programs (also available via
www.microbit.co.uk)
Additional websites
The following websites can be used for additional technical information or to provide a wider context to the development of
the system.
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IET TV – Heart Rate Monitor: Supporting IET TV video - ideal for use as part of a starter or introductory activity to
support this resource. https://tv.theiet.org/Index.html?videoid=7298
BBC micro:bit website: Website containing everything needed to get started with using the micro:bit!
www.microbit.co.uk
IET Faraday – Body Centric Antenna: Existing IET Faraday resource set that can act as an ideal partner to this unit of
learning. http://faraday.theiet.org/resources/overview/body-centric-antenna.cfm
YouTube Video – Normal vs Accelerated Heart Rate: Animated video showing the difference between normal and
abnormal heart rates. https://www.youtube.com/watch?v=BhGwb5hxbX4
YouTube Video – British Heart Foundation: Guide to blood pressure and Holter monitoring tests.
https://www.youtube.com/user/BritishHeartFound?v=N4wi2oiL3BY
Related activities (to build a full lesson)
Starters
> ACTIVITY: Portable Health Check – Social Effects
> IET TV VIDEO – Heart Rate Monitor
https://tv.theiet.org/Index.html?videoid=7298
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www.tomorrowsengineers.org.uk
Plenary
> ACTIVITY: Portable Health Check – Product Integration
> Opportunities within activity for presentations, peer/
self-assessment
> Reflection on Objectives and PLTS skills used
Main
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ACTIVITY: Portable Health Check – Programming the
System
The Engineering Context
Personal health is an ideal topic for teaching about programmable components and embedded intelligence in products.
These are key parts of the 2014 programme of study for Design and Technology at key stage 3.
It is also an ideal vehicle for using the BBC micro:bit in the classroom and developing the programming skills of learners.
Curriculum links
England: National Curriculum
Northern Ireland: Curriculum
Design & Technology
Technology & Design
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KS3 3c, 4c, 4d
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Computing
KS3 Pupils should be taught to:
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design, use and evaluate computational
abstractions that model the state and behaviour
of real-world problems and physical systems
undertake creative projects that involve
selecting, using, and combining multiple
applications, preferably across a range of
devices, to achieve challenging goals, including
collecting and analysing data and meeting the
needs of known users
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KS3 Knowledge and Skills: Control – incorporate
control systems, such as mechanical, electronic or
computer-based, in products and understand how
these can be employed to achieve desired effects.
KS3 Objective 2: Design cost effective and appropriate
solutions to meet the specific needs of diverse local
and global groups.
Learning Outcomes:
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Show deeper understanding by thinking critically and
flexibly, solving problems and making informed
decisions, using Mathematics and ICT where
appropriate.
Demonstrate creativity and initiative when developing
ideas and following them through.
Scotland: Curriculum for Excellence
Wales: National Curriculum
Technologies
Design and Technology
>
TCH 3-01a, TCH 3-03a, TCH 3-04a,TCH 3-13a
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KS3 Skills: Designing 1
KS3 Skills: Systems and Controls 16, 18, 20, 21
Assessment opportunities
Regular questioning throughout the activity, review of progress at key intervals and formal assessment of finished program
and working system.
Personal, learning & thinking skills (PLTS)
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Creative thinker
Independent enquirer
Team worker (if done as a team activity)
Self-manager
Effective participator
Explore engineering careers at
www.tomorrowsengineers.org.uk