Getting a ‘Sense’ of
Monitoring Health at Home
By Sam Brusco, Associate Editor
Monitoring patients is no longer a practice confined to the hospi- tal. Health monitoring technologies designed for the home are
proliferating as a result of the rising costs of healthcare and patient
transportation issues, among others. Due to this, sensor design for
monitoring devices must be tailored specifically for the challenges
of home use. With this in mind, MDT spoke with Jeremy Lug, new
product development manager at Metrigraphics, LLC (
www.metri-graphicsllc.com), and Rick Ercolano, director of medical vertical sales
at Honeywell Sensing and Control ( http://sensing.honeywell.com).
They offered their insights into trends, challenges, and the future of
at-home sensing in patient monitoring.
Sam Brusco: What trends are you noticing regarding sensing in
patient monitoring in the home?
Jeremy Lug: Designers in the patient monitoring sector are
experimenting with novel substrate materials to achieve greater flexibility, thermal management, and general performance advantages. In
our position as process developer and contract circuit manufacturer,
it’s often difficult to differentiate one sensor application from another.
Everyone wants more (and tighter) traces.
Rick Ercolano: There are many options available and at much
lower price points. Many of these options include wireless capabilities
such as Bluetooth or Wi-Fi. Additionally, medical devices are becoming consumer oriented, thus available without a doctor’s prescription.
As hospitals advance to improve their patient care and services and
decrease the duration of a patient’s stay, devices that hospitals use
must become more portable and easy to use at home for a patient.
Brusco: What challenges does miniaturizing sensors for home use
bring? How are you addressing them?
Lug: The need for smaller formats and line sizes requires tighter
tolerances and an increased focus on yield improvements. Better
and more consistent quality is always of chief concern. Smaller line
sizes carry less current, so power consumption must be carefully
calculated to ensure a robust electric circuit. Smaller formats must
accommodate other technologies added to the flex, such as bonding
requirements, chip sizes, or encapsulation. The mechanical aspects of
the sensors play a more integral role in this process; in larger sizes, it
doesn’t need to be considered as much. Line, via, and pad placements
need to be thought out as they will end up being mechanical and
Brusco: What steps need to be taken to move sensing devices from
the hospital to the home?
Lug: Cost and accessibility needs to be considered. The first step
is to focus on everything that impacts the cost of the sensor and the
overall system. Cost is influenced by complete design size, number
of features and layers, size of the smallest feature, and metal selection.
The interface requirements of the design and product goals of the
medical device manufacturer also impacts the system. Ultimately,
ease-of-use and reliability of the sensor system will determine out-of-hospital adoption.
Brusco: How are you going about integrating more functions into
the sensors? What are some challenges with this?
Lug: We optimize yields, improve overall development processes,
and supply preventative maintenance or upgrades to line equipment.
Providing highly detailed documentation to our medical counterpart
allows room for improvements and increased functions.
Increased sensor functionality relies on communication between
the supplier and the customer. They collect and share data with us
to determine improvements or modifications to achieve the desired
results. This communication and transparency fuels control of sensor
production. The more involved we are in the overall system picture,
the better the sensor we can develop.
Ercolano: There are potential tradeoffs when the sensors are made
smaller and less expensive. These may be acceptable to the consumer
space, but the medical space requires the same level of quality and
reliability regardless of use in the home or hospital. Honeywell designs and develops its sensors, so we can design from the ground up.
While Honeywell has made its sensors smaller and lower cost, the
company has added functionality to the sensors such as temperature
compensation, amplification, and digital output.
Brusco: What is the motivation for designing “disposable” sensors?
What are some challenges in designing them?
Ercolano: Single-use or disposable sensors are becoming more
common in the hospital space where sanitation is required when the
device may be used among various patients. Sensor performance may
be affected by various sterilization methods, thus requiring the sensor
within the device to be single-use or disposable.
Brusco: What’s the next step for sensing in patient monitoring in
Ercolano: Allowing for more integration and leveraging multiple
technologies into a single device. Today, you can buy a blood pressure monitoring device, maybe a pulse oximeter, and maybe a CPAP
machine. I expect to see separate devices merge into a single unit and
capture more patient vitals at one time, providing a thorough picture
of the patient’s overall health. MDT