The Future of Point
of Care Diagnostics
By Nick Rollings, a principal engineer
in the Medical Technology Division
at Cambridge Consultants
From central lab to physician office
Over the past 25 years, there has been a steady transition of diag- nostics from the central hospital
lab to the Point of Care (PoC). This
broad term covers a number of scenarios. Initially, PoC diagnostics were used
in the hospital ward. Now, they’re being
applied in places of primary care, such
as the physician’s office. This expanded
use is being made possible by several
For example, the Alere i platform1
exploits a new generation of isothermal chemistry. It requires a consistent
temperature to carry out the reaction as
opposed to thermal cycles required for
traditional molecular techniques such as
Polymerase Chain Reaction (PCR). This
innovative integration of chemistry, instrument and workflow, has resulted in the
Alere i platform being the first molecular
diagnostic platform to satisfy the mandatory regulations2. This allows for tests to be
simple while presenting a low risk of erroneous results. Satisfying these regulations
enables tests to be taken out of the lab and
placed in the hands of non-expert users
such as physicians and practice nurses.
The PoC transition has occurred in a
number of waves, each enabled by technological innovations. Past and current
innovations like this are what will allow
the PoC to be taken beyond clinical
The current wave of PoC technological
development represents an exciting and
disruptive approach to the PoC sector.
It has introduced new technologies that
enable radically different and innovative
products compared to those of the past.
In addition, these developments are not
just focused on traditional diagnostic
techniques. The developments exploit
more advanced techniques such as highly specific DNA sequencing. They also
provide a richer and deeper picture of
a pathogen at a genomic level. This genomic approach holds great promise for
areas such as oncology, where tumours
and underlying causes of cancers differ
significantly between patients.
Examples of these systems include
DNA Electronics Ltd (DNAe), which
has developed a method to read DNA &
RNA on a standard semiconductor chip3.
DNAe is initially focused on bloodstream infections such as sepsis, where
rapidly determining the underlying cause
of the infection is vital and yet, existing
blood culture methods take days.
Another platform that holds great
promise for the PoC sector is the platform developed by Oxford Nanopore
Technologies. Originally developed
at Oxford University, this technology
passes DNA through a very small opening (a ‘pore’). Each DNA base (A, T,
G or C) uniquely modifies an electrical
current across the pore resulting in a
readout unique to the DNA sequence.
The company has developed a miniature
USB-powered device called the MinION4 that has created large interest in
the DNA sequencing community. There
has been particular interest in using the
device for real-time, portable genome
sequencing for Ebola surveillance5. It was
successfully used last summer on board
at the International Space Station6.
The emergence of smart devices
Looking beyond current developments,
it is possible to identify the foundations of yet another disruptive wave
of development in PoC diagnostics.
Today’s smart device-enabled diagnostic
platforms will give way to a new era of
diagnostics that will increasingly become
an extension of the smart devices, rather
than serve as standalone diagnostic
systems. These systems will be able to
exploit the increasingly powerful data
processing and graphical user interfaces
of smart devices.
An example of such a device under
development is Oxford Nanopore Technology’s smart phone powered DNA sequencing device called the SmidgeION,
based on the same core technology as
their MinION product7.
New applications for PoC diagnostics
The prevalence of PoC systems now
means that emerging medical approaches are targeted at PoC environments
where they can bring the largest benefit.
The MinION- 3 DNA sequencing device
turns any laptop computer into a powerful
bio-analysis tool. Some upcoming models
will use a Smartphone as their host system. Image courtesy of Oxford Nanopore