Design and Development of In Vivo Sensor Systems: The Long and Tortured Road to a Self-Contained, Implantable Glucose Sensor for Diabetes Management - Designing Receptors for the Next Generation of Biosensors - page 210

1 Diabetes and Blood Glucose Management
Diabetes is one of the most significant global health challenges of the twenty-first
century [ 1 ]. It remains one of the leading causes of death and is a major contributor
to cardiovascular disease and is the leading cause of kidney failure, non-traumatic
lower-limb amputation, and new cases of blindness in the USA [ 2 ]. Worldwide, the
predominance and occurrence of diabetes has reached epidemic proportions and is
expected to grow to 438 million by 2030 [ 3 , 4 ]. Currently, diabetes is not curable
but can be controlled through proper management, which includes accurate moni-
toring of blood glucose levels, in order to improve lifestyle and lifespan. Effective
and consistent measurement of glucose, which is essential for accurate monitoring,
remains a barrier to proper control of this disease due to the invasive and costly nature
of currently available monitoring devices and resulting poor patient compliance.
Currently, the self-monitoring blood glucose test is the cornerstone of self-
management for patients with diabetes. Unfortunately, this test requires that the
patient extract a small drop of blood through an inconvenient and painful finger or
torso pricking method three to four times daily for type I diabetes, according to the
American Diabetes Association. In addition to this motivational barrier, high out-
of-pocket expenditures for device test materials are also cited for noncompliant
testing [ 5 ]. Over time, suboptimal testing frequency leads to out-of-range blood
glucose levels and potential health complications.
Positive societal and economic impact can be achieved with the development of
an easy-to-use, implantable glucose monitoring system. An implantable device is
beneficial to patients because it provides real-time continuous information regard-
ing glucose levels. Early detection of rapidly changing glucose levels is especially
important for patients with type I diabetes when the onset of hypoglycemia can
come without warning and can incur potentially dangerous consequences [ 6 , 7 ]. An
implanted, RFID-enabled device would minimize the continual cost, pain, and
complications of current diagnostic systems. In terms of limiting expense and
increasing comfort and testing compliance, diabetic patients would benefit from
the long operational life of a one-time invasive, implanted device. An implantable
glucose monitoring device is superior to other systems because, although initially
more invasive upon implantation, ultimately and for the long term it is noninvasive
on a daily basis. Ease of use makes patient monitoring and compliance a relative
nonissue compared to the requirements of sampling blood daily or using an
invasive, transdermal cannula. Additionally, glucose fluctuation data can be gath-
ered electronically and stored for observation in real-time with no input from the
patient. This chapter gives an overview of the design and proof-of-concept devel-
opment of a self-contained and closed-cycle, stable glucose sensing system as the
integral component of an implantable device for real-time in vivo glucose measure-
ment and diabetes management.
Since the advent of the first commercial glucose testing devices in the 1970s,
there has been progress toward the development of glucose detection techniques
designed for noninvasive systems [ 8 ]. The three most studied techniques include