Medical Design Briefs - January 2023 - 15

Medtronic Insulin Pump
Linda ran her first half marathon in
1996 in Vancouver, BC, and was in her late
thirties when she first acquired a Medtronic
insulin pump. With the pump, Linda fills
the reservoir with insulin every three or
four days and can adjust the insulin pump
depending on how she feels and what she's
doing if she chooses to. Before receiving
the pump, she had to be more aware and
cautious when she ran a marathon because
her blood sugar levels need to be fairly consistent
throughout the entire race.
The Medtronic pump is designed to automatically
adjust background insulin,
which could be important during training
and running a marathon. During a run, if
Linda senses a change in her body, she
can quickly check her glucose measurement
and, if needed, make an adjustment
by increasing her sugar intake through
candy or drinking some Gatorade. After a
marathon, she would often not feel good
for about 24 hours. She'd adjust the settings
on her pump to balance herself out
so that she'd feel better. Since Linda
would be traveling in extreme weather
and to remote areas, Medtronic provided
a loaner pump to her in case she needed a
backup during her World Marathon Challenge
that she could use if her Medtronic
pump failed during her runs.
Linda currently uses Medtronic's MiniMed™
670G system insulin pump with
the Guardian™ 3 continuous glucose meter
(CGM) that automatically reads her
blood sugar levels and adjusts background
insulin every five minutes based on sensor
glucose changes (see Figure 1). Medtronic
insulin pump systems include the insulin
pump, reservoirs, infusion sets, sensors,
and transmitters.
Medtronic's most advanced insulin
pump available today in the United States
is the MiniMed770G system. Through
real- time glucose readings, the system is
able to calculate a personalized amount of
insulin to deliver based on each individual's
needs. These insulin pump systems
connect with compatible smartphones via
software that allows users to view sugar
trends and insulin delivery whenever they
choose. When first training for her running
career, Linda tweaked her insulin
pump system to her specific needs. Now
that she has nailed down the settings, she
doesn't have to adjust them very often.
The MiniMed systems come with an
IPX8 rating, which means that they are
water resistant to a depth of up to 12 ft
Medical Design Briefs, January 2023
Imagine starting your first marathon out of seven in Antarctica with a temperature of -15 °F. When
Linda Carrier ran the World Marathon Challenge in 2019, that's where she started.
for up to 24 hours. The sensor and transmitter
are water resistant at 8 ft for up to
30 minutes, although CGM readings
cannot be transmitted from the CGM to
the pump while in water. The pumps
also operate at altitude (from 10.2 to
15.4 psia). Present and historical data
can be read on the system's color screen,
which offers auto-brightness for ease of
use. These design specifications are important
when it comes to Linda being
able to run under extreme conditions
without concern about the operation of
the insulin pump system.
The Medtronic series of insulin pumps
must offer high performance and long
life. The core to the pumping action of
the product is the pump motor system,
which is designed and manufactured by
maxon (see Figure 2). The motors used
are brushless DC (BLDC) motors that incorporate
high-energy neodymium magnets
to provide a very responsive mechanical
time constant.
The motors include built-in Hall effect
sensors to provide closed loop feedback
to the control electronics, ensuring
that the pump delivers a precise amount
of insulin. Electronic commutation allows
for minimum electrical noise, as
well. Maxon motors are available with a
wide range of speeds and torques for a
variety of applications across a wide
range of industries.
Fig. 1 - Linda Carrier typically wears her Medtronic MiniMed 670G insulin pump to help keep her
blood sugar levels balanced.
www.medicaldesignbriefs.com
15

http://www.medicaldesignbriefs.com

Medical Design Briefs - January 2023

Table of Contents for the Digital Edition of Medical Design Briefs - January 2023