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Fig. 1. Smart-home set up that includes control and monitoring of temperature, lighting, entertainment, security, and health. Here we focus on bed-based
monitoring using pressure sensitive mats, as seen in light red.

control, and many other possibilities. In a smart-home, sensors
are placed throughout the home and communicate with a central hub that will then process the information and present it
to the user (Fig. 1).
The following section provides an overview of applications
that have used smart-home pressure monitoring tools applied
to bed-based sensing methods.

Bed Occupancy
Many bed monitors can provide information about whether
a user is in or out of bed. Information about bed occupancy
can provide additional information to healthcare professionals about a person's sleep patterns [4]. For example, if a person
gets up multiple times throughout the night it may be an indication of nocturia, bladder infection, and/or prostate swelling
as they may visit the bathroom many times throughout the
night [18]. For individuals with underlying conditions such as
dementia or Alzheimer's disease, multiple bed exits may indicate wandering patterns, nocturia, or disturbed circadian
rhythms associated with disorientation for time and place [19].
Longer periods in bed may suggest that an individual is more
tired than usual, which may be associated with a person's glucose levels, worsening heart failure, or infection.

Bed Based Mobility
Individuals with reduced mobility or no mobility may remain in the same position for long periods of time. Macknight
and Rockwood developed a system called HABAM to measure bed-based mobility, which considers three categories:
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mobility, transfers, and balance. The HABAM is scored out of
24 points and provides a rapid numerical and visual assessment of an older individual's health [20]. This scale has been
used as a baseline for the evaluation of bed-based mobility assessment using PSM in [21], [22].
When mobility is low, long term pressure in a single position can lead to pressure ulcer development and potentially
infection if not treated. The main method to prevent ulcer development is to have healthcare professionals physically shift
individuals based on a set schedule. Creating tools to make
the timing of this shifting more precise may reduce the pressure ulcer development in the future. When applied to in-bed
monitoring systems, PS have been used to track and evaluate
pressure ulcer development over time [23]. The pressure applied to an individual's skin during bed transfers has also been
investigated using PSM [24], [25].

Sleep Quality
The quality of someone's sleep can have implications on many
other areas of their life. Problems with sleep, referred to as
sleep disruptions, can have impacts in both the short-term
and long-term [26]. Short-term effects include increased stress,
pain, and cognitive, memory and performance deterioration
[26]. Long-term effects include the development of medical
conditions like hypertension, heart disease, weight gain, diabetes, some types of cancer, and even death [26].
Monitoring sleep patterns and breathing (described in the
following section) can provide an indication of sleep quality. In-bed pressure monitoring systems have been used to

IEEE Instrumentation & Measurement Magazine

April 2021

Instrumentation & Measurement Magazine 24-2

Table of Contents for the Digital Edition of Instrumentation & Measurement Magazine 24-2