Continuous Body Monitoring - Ambient Intelligence for Scientific Discovery - page 203

All graphics in this chapter are reprinted
with permission from BodyMedia Inc.
Fig. 1. The SenseWear PRO 2 .

devices. The SenseWear Armband is commercially available from BodyMedia,
Inc. based in Pittsburgh PA, as a research tool giving access to “raw” and de-
rived data. Specifically configured SenseWear armbands, together with custom
end-user software applications, are also commercially available from BodyMedia
or their partners, for example the weight management system HealthWear avail-
able from Roche [21].
This chapter describes the armband's functionality and gives an overview
of the technical capabilities of the armband and its construction. A breadth
of applications are presented showing the feasibility and acceptance of a body
worn continuous monitor. This illustrates the SenseWear armband's utility as
an ambient intelligent device.

1.1 Why an Accessory and Not Apparel?

A study of suitable locations on the human body for both sensing physiology
and locating hard components resulted in candidate locations and form factors
for continuous body monitoring [7, 10] (See Fig. 2). The combination of sensors
(discussed later) and the desired small unobtrusive form factor resulted in a
decision to have multiple sensors and data collection inside a single unit worn
on the triceps.
SenseWear occupies a body region that is new for skin-touching wearables -
the upper arm. A custom stretch elastic was employed, the bottom of the unit
and sensors conformed to maximize contact, and thousands of hours of testing
performed to achieve a design that was comfortable and “completely forgettable”
on vastly different arm sizes. A major achievement in this process was developing
a design that was tight enough to keep the sensors in place against the arm
without slipping, but loose enough not to constrict the user's arm and cause
discomfort - a sensitive balance.
Flexible, symmetrical wings were developed to stabilize the device on the arm
(ensuring good sensor contact) and molded to a circumference exactly between