Authors: C.-Y. Huang, K.-W. Chang, C.-Y. Tai, W.-T. Chen,
Y.-L. Hsu (2017-06-12); recommended Yeh-Liang Hsu (2017-08-14).
Note: This paper was published in 2017 IEEE International Conference
on Consumer Electronics - Taiwan (ICCE-TW).
Development of a smart living platform based on a motion
mobility monitoring are fundamental functions for constructing a smart living
space. This paper presents a smart living platform based on motion sensing
carpets. It is developed in the form of 50×50cm ‘puzzle floor mat’ units, which
allows the users to assemble by themselves according to their desired shape and
area. From the pressure data collected by motion sensing carpets, functions
such as location tracking, mobility monitoring and fall detection can be
achieved. This platform has been installed in Zhulun Apartment for field trial.
mobility level for older adults are highly related to the transition from
relatively independent living to ill and declined functional health status
. In addition, wandering behavior is significantly more prevalent in
patients with dementia. It is important to provide objective and accurate
approaches for localization, walking trajectory and long-term mobility level
assessment in the elderly care environment. Considering user acceptance, the
technology in elderly care environment has to be unobtrusive, easy to use, low
cost, considerate for privacy and be a natural part of the home environment .
As a result, the floor sensor is a more suitable approach than cameras and
wearable devices. This paper presents the development and implementation of WhizCarpet,
a motion sensing carpet for tele-monitoring of indoor locations, walking
trajectory, mobility level and fall events in an unobtrusive way for older
adults in the elderly care environment.
The motion sensing
carpet WhizCarpet is developed in the form of 50×50cm ‘puzzle floor mat’
units, which allows the users to assemble by themselves according to their
desired shape and area (Figure 1). The auto mapping firmware identifies
relative positions of all units after assembly. The working principle is
similar to that of a membrane switch. Once a WhizCarpet unit is under
pressure, the top and bottom layers make contact with each other. Different
pressure will create different contact quality and therefore generates
different resistance (Figure 2).
I2C bus is used for data transmission between units. The
WhizCarpet is designed as an Internet of Thing (IoT) device and follows the Message
Queuing Telemetry Transport (MQTT) protocol. It collects data from sensor units, perform the analysis and publish
events to the ‘‘broker’’. Other IoT devices such as
mobile devices of the caregivers can receive events by subscribing specific
topic, and displays the location and fall events on the
Fig.1 WhizCarpet allows the users to
assemble the units by themselves according to their desired shape and area
Fig.2 Different pressure will create different
contact quality and therefore generates different resistance
WhizCarpet is designed as an IoT device. There are two possible
information structures, depending on the environments. Figure 3 shows the
information structure for household environment. ESP8266 is used as the
controller for WhizCarpet, which collects data from sensor units and
perform fundamental analysis. It is also a “publisher” in the IoT structure,
which publishes “events” such as location and fall events to the Raspberry pi.
Raspberry pi is
the IoT “broker” which receives events published by ESP8266, stores them and
performs further analysis. In the home environment, Raspberry pi also works as
a publisher, which publishes events to a cloud broker. Mobile devices subscribing
the specific topic will receive notification of the events.
In hospitals and
nursing homes, data is often not allowed to transmitted outside. As shown in
Figure 4, in this case only mobile devices in the same intranet can subscribe
specific topic and receive events notifications. Figure 5 shows the App
receives and displays a possible fall event.
Fig.3 Information structure for household
Fig.4 Information architecture for Hospital and
Nursing home environment
Fig.5 App receives and displays a possible fall
Results & Discussion
The smart living
platform based on motion sensing WhizCarpet has been developed and
implemented in Zhulun Apartment for healthy older adults (Figure 6).
Reliability of the information structure, user acceptance, as well as other
practical design issues were observed and verified in this field trial. In
general, older adults seemed to like the WhizCarpet and requested to
install in more rooms. Issues observed in this field trial include as follows:
The indicator LED light is too bright for older adults
High friction between the chair and the WhizCarpet
cause difficulties when the older adult pulls out the chair.
How WhizCarpet can be cleaned.
The pins of the connector are too easy to bend
when user assembles WhizCarpet.
Wi-Fi signal is sometimes unstable.
Some data packages were lost when a large amount
of data is sent at the same time, resulting in incorrect display of current
Some adjustments were made to solve these
problems encountered in the field trial:
The color of controller box was changed to black.
Sponge foam caps were added to the chair legs to
designed as water repellent. The surface also receives antifouling treatment
for easy maintenance.
The connector has been redesigned into pogo pin
for easier assembly. Plastic clasp is added to make it more stable.
ESP8266 PCB has been redesigned to add an auto
restart mode, and a stronger antenna was added.
ESP8266 was set to refresh the current status of
WhizCarpet sensor every 20 second.
Fig.6 WhizCarepet has been developed and
implemented in Zhulun apartment
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