Sensing Prototype
SAPHE
Issue : 1.0
Document Reference: D08
Author: Nigel Barnes
Date: 5 Jan 2009
SAPHE
D08: Sensing Prototype
Table of contents
Introduction ...................................................................................................................................... 2
1
Sensing system architecture .............................................................................................. 3
2
Component Specification.................................................................................................... 4
2.1
2.2
Environmental Sensors .................................................................................................. 4
2.1.1
Sensors ................................................................................................................. 4
2.1.2
Communications .................................................................................................... 5
SAPHE Home hub (aka set-top box) ............................................................................. 5
2.2.1
Hardware ............................................................................................................... 5
2.2.2
Software ................................................................................................................ 6
2.2.3
Communications .................................................................................................... 7
2.3
Home Gateway............................................................................................................... 8
2.4
Interaction devices ......................................................................................................... 8
2.5
Third party point-of-care devices .................................................................................... 8
2.6
Body worn sensors ......................................................................................................... 9
2.7
2.8
2.6.1
Sensors ................................................................................................................. 9
2.6.2
Communications .................................................................................................... 9
SAPHE Mobile hub....................................................................................................... 10
2.7.1
Hardware ............................................................................................................. 10
2.7.2
Software .............................................................................................................. 11
2.7.3
Communications .................................................................................................. 11
2.7.4
Mobile phone connectivity ................................................................................... 11
SAPHE Network platform ............................................................................................. 12
Appendix 1: SAPHE Common Data Protocol ................................................................................ 13
Document history........................................................................................................................... 20
Author: Nigel Barnes
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D08: Sensing Prototype
Introduction
An end-to-end SAPHE system prototype was demonstrated at Imperial College on 10th December
2007 meeting Milestone M4, System Prototype. This document provides an overview of the
system produced and serves as a record of the associated Deliverable D08, SAPHE Sensing
Prototype.
Section 2 of this report follows similar structure to section 5 of D07, SAPHE System Technical
Specification. This is to allow changes from the original specification to be highlighted.
This document serves only to give an overview of the SAPHE Sensing prototype implemented. It
is not intended to give deep technical insight; as such it only highlights key changes from D07
without revised detailed technical description.
Details of the Network Platform and associated applications beyond the recording of sensed data
into the Network Platform database are beyond the scope of the Sensing Prototype and hence
are omitted from this document.
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D08: Sensing Prototype
1 Sensing system architecture
The top level architecture of the sensing prototype is shown in Figure 1 below.
Figure 1: SAPHE Sensing Prototype Top Level Architecture.
The Sensing Prototype has demonstrated the capture of the following sensor data:

Non-invasive activity monitoring from Passive Infra-Red (PIR) sensors

Weight monitoring from personal weight scales

Activity monitoring from a worn e-AR sensor

Heart rate and Sp02 monitoring from a worn e-AR sensor
A common data protocol has been implemented for communications from SAPHE developed
sensors over the following communication links:

ZigBee from PIR sensors to Set-Top Box

Philips Low Power Radio from e-AR sensor to Mobile Hub

Bluetooth from Mobile Hub to Set-Top Box
The SAPHE common data protocol is described in Appendix 1.
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D08: Sensing Prototype
2 Component Specification
This section follows the same structure as Section 5 of the SAPHE System Technical
Specification (D07).
2.1 Environmental Sensors
2.1.1 Sensors
Blob
[Change from D07]
Blob Sensors are no longer part of the initial trial plans. It is hoped prototype devices will be
available for deployment towards the trial end. Communication will be via ZigBee communications
as defined below.
PIR
[Change from D07]
Visonic ‘Discovery W’ or ‘K-980W’ PIRs have now been selected. The two PIRs are physically
identical however the K-980W’s provide pet immunity (up to 36Kg) and have a range of 12m x
12m whereas the range of the Discovery W is 15m x 15m. Further details can be found at
http://www.visonic.com/VisonicHomePage.nsf/webW12BDetTable?OpenView
These devices are able to operate in a continuous (Test) mode of operation without modification
and are powered by a 9v PP3 battery.
The ZigBee module will be housed within the existing PIR casing and will be powered by a
separate 3.6V 2/3AA Lithium battery (1.7Ah) also housed internally. An internal pcb mounted
ceramic antenna will be utilised.
Magnetic Contact
[Change from D07]
Standard low cost magnetic contacts will be utilised, see http://uk.rsonline.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=333192
The ‘active’ component will be suitably housed together with the same ZigBee module as for the
PIR.
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D08: Sensing Prototype
Temperature
[Change from D07]
The ZigBee modules utilised for PIRs and Magnetic contacts provide on board temperature
sensing. It will therefore not be necessary to provide dedicated temperature sensors.
Bed Occupancy
[Updated from D07]
Following the development by Tactex Controls of Quality of Sleep analysis algorithms the
actigraphy version of their bed sensors are to be used. The quality of sleep algorithms will provide
the following sleep measurements:






Sleep efficiency
Sleep Latency
Total sleep time
Number of awakenings
Wake after sleep-onset, and
Bed exits
Algorithms will operate on sensor data collated on the Network Platform.
Communication of the sensor output will be via Bluetooth (utilising a Tactex Bluetooth interface
unit) to the STB.
2.1.2 Communications
ZigBee
[Change from D07]
ZigBee based communication is enabled from environmental sensors using Jennic ZigBee
modules.
Sensors will be battery powered as described in 2.1.1.
2.2 SAPHE Home hub (aka set-top box)
2.2.1 Hardware
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[Confirmation of detail from D07]
The STB is built upon a mini-ITX PC platform utilising an VIA EPIA CN10000EG motherboard
providing a 1GHz processor with fanless operation.
Ancillary components:

512MB RAM
o
Kingston Value Ram 512MB DDR2 533MHz PC4200 DIMM


Secure Digital (SD) card for OS and applications
o

SanDisk 2GB Extreme III
WLAN (IEEE 802.11G)
o
Belkin Wireless PCI card


F5D7001UK
Bluetooth
o

KVR533D2N4/512
Belkin F8T012 Bluetooth USB Class 1
Case
o
Silverstone ML-02-MXR with MCE remote & display

SST-ML02B-MXR
A ZigBee dongle will be externally mounted and will connect to the ITX board via a USB
connection. The ZigBee dongle will utilise an external antenna.
2.2.2 Software
Operating System
[Updated from D07]
Ubuntu Linux 8.1.
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D08: Sensing Prototype
Security and Messaging
[Updated from D07]

IPSEC based VPN connectivity to the network platform.

JMS messaging utilising OpenMQ 4.1.
Applications
[As per D07]
2.2.3 Communications
In home
[As per D07]
The SAPHE Home hub simultaneously supports ZigBee, Bluetooth and WLAN (IEEE 802.11g)
communications within the home.
The SAPHE home hub acts as the coordinator of the ZigBee network for the environmental
sensors.
Bluetooth Class 1 is provided to communicate with the SAPHE mobile hub and off-the-shelf
medical devices utilised within the trial.
WLAN (IEEE 802.11 g) will be used to communicate with the Home Gateway.
Network platform
[Updated from D07]
Communications between the SAPHE home hub and the SAPHE network platform will be via the
Home Gateway (BT home Hub) and will use a VPN connection.
Java Message Service (JMS) is used for data transfer between the STB and the SAPHE network
platform. The chosen implementation is OpenMQ 4.1.
A dedicated hardware device has been implemented on the Network Platform to provide firewall
and VPN capabilities. The device a Cisco ASA 5510 Security Plus Appliance (ASA5510-SECBUN-K9). In addition to IPSEC VPN the device also provides OpenSSL based VPN capability if
required.
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D08: Sensing Prototype
Figure 2: SAPHE End-to-End Prototype Implementation.
Note: OpenMQ 4.1 is utilised in place of ActiveMQ 5.x as shown in Figure 2.
2.3 Home Gateway
[As per D07]
BT Homehub will be specified by default.
An automatic configuration script runs on the SAPHE Home hub.
Where broadband already exists it will be determined if the user’s existing device can be used.
2.4 Interaction devices
[Not yet implemented]
2.5 Third party point-of-care devices
[Confirmation and update from D07]

Weight – Motiva Bluetooth Scales, Model M3813B, Manufactured by T-Systems
These scales are the same as used in the Philips Motiva trials and send weight data to
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the set top box using a Bluetooth connection using a proprietary XML protocol. Weights
can be taken in either lb or kg, there is no option for stones.
The interface presented to the user is via a LCD display and interaction is assisted by
voice instructions so it is clear to the service user when to stand on and off the scales.
Measurement data is encrypted using existing Bluetooth encryption methods.

Blood pressure – A&D UA-767PBT, upper arm cuff device.
This device provides simple single button operation with a clear display.
Communication is via Bluetooth to the STB utilising a proprietary protocol.
2.6 Body worn sensors
2.6.1 Sensors
e-AR
[As per D07]
ECG
[Not part of trial]
ECG – event recorder
[Not yet integrated]
The Cardionetics C.Net5000 ECG recorder will be utilised. This will communicate with the mobile
hub via the Philips Low Power Radio housed within a dongle attached to the recorder’s serial port.
2.6.2 Communications
Body worn sensors communicate wirelessly to the SAPHE mobile hub via the Philips Low Power
Radio.
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D08: Sensing Prototype
2.7 SAPHE Mobile hub
2.7.1 Hardware
The mobile hub is a custom designed and built hardware platform, providing communications and
power management.
Texas Instruments MSP430
I2C
SPI
I2C
RS-232
LegoBrick
MMC Card
Real Time
Bluetooth
Clock
Module
and RTC

MSP430: This 16-bit Texas Instruments microcontroller is specifically designed
for low power applications and forms the heart of the mobile hub. The main tasks
of the MSP430 are to manage connection between the other components and to
oversee the power management of the system.

MMC Card: When the mobile hub is out of range of the home hub, or the power
management algorithms have determined that it is not necessary to keep the
Bluetooth link powered, a MMC card is used to buffer the received sensor
readings.

LegoBrick Radio: The LBR provides the connectivity to the other body sensors
specified in this document and is further described in section 2.7.3.

Real Time Clock: The RTC allows the mobile hub to keep track of the incoming
messages and ensure that they are delivered in the correct order to the backend
system. The time on the Mobile hub is internal and is converted to “real-world”
time on the home hub.

Bluetooth Module: A separate Bluetooth module is used to allow the mobile hub
to synchronise with the home hub. This is connected and controlled by the
MSP430 using a software RS-232 implementation.

Charging Circuit: The mobile hub is operated by a LiIon battery and a charging
circuit is included in the design. The mobile hub is connected to power using a
standardised mini-USB connector.
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D08: Sensing Prototype
2.7.2 Software
The mobile hub software is as follows:

MSP430 software controls the whole operation of the mobile hub. The software is all
custom written and is responsible for communication with the various peripheral devices
described above as well as ensuring optimal power consumption. The components can
be seen in the following system overview:
Saphe Mobile Hub Application
Clock
LegoBrick
MMC
Bluetooth
Interface
Control
Control
Filesystem
Control
Libraries
SPI library
RS-232
Drivers
MMC Card
Bluetooth
I2C Communications
RTC
LegoBrick
Module
Hardware
2.7.3 Communications
Philips Low Power Radio
[As per D07]
Communication with body worn sensors
Bluetooth
[As per D07]
Communication with SAPHE STB.
2.7.4 Mobile phone connectivity
[Not yet implemented, out of scope for trial]
The SAPHE mobile hub will have the ability to communicate with a service user’s mobile phone
via Bluetooth. This will facilitate the following functionality:

Use of the mobile phone as a GUI.

Remote connectivity to the SAPHE system.
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D08: Sensing Prototype
Tracking/location of the service user.
2.8 SAPHE Network platform
[As per D07]
An OpenMQ 4.1 JMS broker has been deployed on the Network Platform to manage
communications with the STB and act as a central point for reception of all raw sensor data.
MySQL Server 5 has been deployed to provide all database functions. The database contains all
raw sensor data, system configuration data, and processed data information.
JMS communication over IPsec (Linux clients) and L2TP/IPsec (Windows clients) have been
demonstrated between partner (Imperial College, Dundee university and Philips) sites and the BT
Network Platform. The master database (hosted by BT) is remotely replicated (as slave
databases) by both Imperial College and Philips.
Further detail is out of scope for this document.
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Appendix 1: SAPHE Common Data
Protocol
These slides have been taken from ‘SAPHE Common Protocol v 0.91.ppt’ which may be found in
the WPB7 download folder on the SAPHE project website. Future revisions of the protocol will be
posted in to this folder.
The protocol refers to the formatting of data contained within the payload of the communications
protocols in use, e.g. ZigBee, Bluetooth, Low Power Radio etc.
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Document history
Issue
Date
Prime author(s)
Comments
Draft 0.1
11/01/2008
Nigel Barnes
Skeletal draft based on D07 Section 5.
Draft 0.2
16/01/2008
Nigel Barnes
Revision to section 2.8 (Network Platform) and
updated Figure 2 (End-to-End Prototype
Implementation) by Tom Mizutani.
Incorporation of SAPHE Common Protocol slides
into Appendix 1.
Draft 0.3
24/01/20008
Nigel Barnes
Minor edits and referencing to D07.
Issue 1.0
05/01/2009
Nigel Barnes
Mobile hub revision to section 2.7 by Rob Blake,
updates to Network Platform implementation in
2.2 and 2.8 including shift from ActiveMQ to Open
MQ and removed reference to MS SQL Server
which is no longer used.
End Of Document
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