Page 88 - JSOM Spring 2026

From Paper Tubes to Millimeter Waves

Fostering Biological Operational Security

Anna M. Gielas, PhD

ABSTRACT
Emerging technologies for monitoring vital signs are increas- missions. 7,12–15 This article addresses this challenge in four sec-
ingly being adapted for surveillance purposes. As these tools tions. First, it illustrates the growing risk through two exam-
grow more sophisticated, traditional countermeasures em- ples, mmWave radar and Wi-Fi sensing technologies. Second,
ployed by Special Operations Forces (SOF) may no longer be it introduces biological Operational Security (bio-OPSEC) as a
sufficient. This brief highlights examples of biological surveil- framework to systematically understand and anticipate emerg-
lance technologies and proposes a holistic response by con- ing surveillance risks, thereby offering a more cohesive and
ceptualizing the management of biological signatures during proactive approach than fragmented or reactive countermea-
operations as biological Operational Security (bio-OPSEC). sures. Third, the article explores why SOF medics are well-po-
SOF medics–by virtue of their tactical perceptiveness and med- sitioned to contribute to bio-OPSEC and, fourth, it outlines
ical acumen—can play a vital role in bio-OPSEC, enhancing introductory practical approaches.
awareness and mitigating their team’s vulnerabilities. Drawing
on insights from bio-sensing technologies and security studies Example 1: Radar Systems
this in brief article introduces actionable approaches for im-
plementing bio-OPSEC. mmWave and Doppler radar technologies have advanced
to the point where they can detect minute chest movements
Keywords: OPSEC; surveillance technologies; mmWave radar; caused by heartbeats and respiration without any physical
signature management; bio-OPSEC; WiFi sensing contact, even at a few meters’ distance. While studied for
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contactless monitoring in pediatric and geriatric care, these ra-
dars can pose surveillance risks in operational environments.
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For instance, multiple studies demonstrate that 77GHz fre-
hat does a sheet of paper have in common with millimeter- quency-modulated continuous wave (FMCW) radar—a type
Wwave (mmWave) radar technology? They both help de- of mmWave system—can monitor heart rates with high preci-
tect the human heartbeat. Two centuries ago, the tool was pa- sion. 18,19 Vital signs can be detected through barriers made of
per. While examining a young woman with heart disease, the wood and brick with a thickness of 5 and 10cm, respectively.
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French physician René Laënnec found himself in a dilemma. Short-range operation also remains feasible in fog, rain, and
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He felt uncomfortable placing his ear directly on his patient’s darkness. Adversaries could potentially exploit such radar
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chest—a method known as immediate auscultation, which technologies to detect human presence, monitor activity, or
was common practice in 1816. Seeking an alternative, Laën- gather intelligence without the need for traditional line-of-
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nec rolled a thick sheet of paper into a tube, placed one end sight surveillance methods.
on her chest and the other to his ear. The physician discovered
that heart sounds could be heard more clearly using mediate For high-resolution contactless tracking of respiration and
rather than immediate auscultation. This simple insight not heartbeat, Doppler and FMCW radars generally operate in the
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only led to his invention of the stethoscope and sparked a rev- 60–77GHz frequency range. Detecting these bands is not fea-
olution in the study of the human heart but also marked a sible with commonly used radio frequency (RF) detectors, be-
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foundational moment in the history of medical monitoring. cause the latter typically operate far below this range. Reliable
While Laënnec relied on a sheet of paper, today’s health moni- interception therefore requires wide-band spectrum analyzers.
toring devices are highly sophisticated technologies. For SOF teams that routinely find themselves in denied and
technologically advanced areas, updating their RF-surveillance
These devices range from wearables to clinical-grade biomedi- devices may become relevant.
cal systems that track vital signs such as heart rate and respira-
tion. While they offer numerous advantages, these devices also Example 2: Wi-Fi Sensing
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introduce new risks to the Special Operations Forces (SOF)
community. 5–11 A key concern is their potential to be exploited Passive Wi-Fi sensing relies on disruptions in wireless signal
for surveillance by adversaries, which could compromise the propagation, which allow the detection of human movement and
stealth of sensitive operations like special reconnaissance micromovement, including shifts in posture and breathing. 22,23
Correspondence to Anna M. Gielas, 81 Stock Street, Flat 0/1 Paisley, PA2 6NQ United Kingdom or amg203@cantab.ac.uk
Dr. Anna M. Gielas is a Research Associate with the Emerging Threats Working Group at the University of Oxford (UK).

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