IEEE Circuits and Systems Magazine - Q3 2021 - 85

Lacewing, a nucleic acid amplification test which offers
the best of both worlds: high accuracy, high speed
and low cost, without a lab and in the palm of your
hand. Lacewing is a handheld test which connects to
a smartphone to provide results from a swab in under
20 minutes and synchronize the results with electronic
health records (see Fig. 2). This article describes our
state-of-the-art approach to diagnostics and our entrepreneurial
journey towards developing ProtonDx as
a spinout.
II. Lacewing: A Lab-Free Molecular Test
Lacewing's unique capabilities can be summarized as accurate,
rapid, handheld, low cost and multi-infection. It
aims to bring the capabilities of a molecular lab to the
palm of your hands. Lacewing allows for rapid testing of
COVID-19 and other respiratory
infections where it is needed: in
pharmacies, at work, at school, in
care homes, and eventually in your
own home. Fig 3 represents the
diagnostic workflow. Lacewing
relies on a swab, extracting the
sample in under 5 minutes to collect
the RNA of the virus. When
loaded into the device, a molecular
reaction called Reverse-Transcriptase
Loop-Mediated Isothermal
Amplification (RT-LAMP) is
triggered to reverse-converse and
amplify the SARS-CoV-2 RNA. The
reaction is facilitated by reagents
such as enzymes and primers, and
an isothermal heating at 63 °C.
Detection is performed using IonSensitive
Field-Effect Transistors
(ISFETs) in an unmodified CMOS
process, leveraging the economies
of scale of
Exposure
Figure 1. Evolution of the COVID-19 infection during the weeks following exposure.
the semiconductor
industry into the world
of diagnostics. The microchip
integrates an array of 78 × 56
ISFETs which monitor the release
of protons during DNA amplification
and dedicated data processing
algorithms are applied to identify
the signal associated with the
amplification. The results are sent
in under 15 minutes to our smartphone
app, detecting the presence
of SARS-CoV-2 in the patient sample.
The data is then synchronized
to electronic health records, and
THIRD QUARTER 2021
geo-tagged on a map for real-time surveillance of the
pandemic. The map is available online as a web interface,
reporting automatically and anonymously all tests
run by Lacewing anywhere in the world. This is essential
for health organizations and governments, providing
essential data to help plan a strategy for management
of the pandemic.
III. The Story of Lacewing
Lacewing is a case of application of circuits and systems
into healthcare to address a global health challenge.
It has indeed been validated with a wide range
of molecular targets, including antimicrobial resistance
[1], aspergillus [2] and tropical diseases [3]. But
more than a test for diagnosis diseases, Lacewing is
a state-of-the-art electrochemical imaging platform
Symptoms
Pathogen
Antibodies
Antigen Tests
Molecular Tests
Antibody Tests
Week -1 Week 1 Week 2 Week 3 Week 4 Week 5 Week 6
30 mm
30 mm
Figure 2. The time relationship between diagnostic tests and COVID-19 infection.
IEEE CIRCUITS AND SYSTEMS MAGAZINE
85
50.95 mm
Infection
50.95 mm
IEEE Circuits and Systems Magazine - Q3 2021

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