IEEE Systems, Man and Cybernetics Magazine - April 2023 - 53

the specificity was 91.8% compared
with the results of radiologist
examinations [28]. In a study by
Pedraza et al., the sensitivity of
using POCUS in the emergency setting
was 93.2%, and the specificity
was 90%. It is comparable to the
level of duplex US examinations
performed in the radiology department
[29]. The study conducted by
Fischer et al. demonstrated a sensitivity
of 100% and a specificity of
95.8% for the diagnostic yield of
using POCT after 2 h of didactic
and hands-on training [30]. On the
other hand, a prospective cohort
study by Caronia et al. reported
that internal medicine residents'
examination using POCUS was insufficient to detect all
proximal DVT [31]. Thus, existing research suggests that
emergency and inpatient physicians can operate POCUS
equipment well after some simple training. More important,
POCUS has good accuracy in diagnosing acute proximal
DVT.
With the progressive
development of
electronics technology
and biotechnology,
the need for bedside
diagnostics,
continuous monitoring,
and equipment
miniaturization is
increasing.
counted 1,002 consecutive adults
with suspected lower-extremity
DVT at a mean age of 58. The
results showed that four different
POC D-dimer assays would save
€155 per person per year compared
with laboratory D-dimer testing
strategies [35]. In 2006, Dempfle
used whole heparinized blood to
diagnose DVT, and a 96.9% sensitivity
demonstrated that POC
D-dimer had very rapid operatorindependent
performance. With
quantitative assays, this assay is
particularly suitable for use in the
emergency department [36]. At the
same time, all POC D-dimer assays
had diagnostic capabilities similar
to those measured in the laboratory. Therefore, POC
D-dimer testing is an alternative to laboratory-based testing
that can be considered in the early diagnosis of DVT.
POC D-Dimer
The symptoms of early DVT are benign, and the presentation
of symptoms varies in patients. By using POC D-dimer
for early detection of DVT, the possibility of occurrence of
DVT in early patients can be identified, leading to
improved examination and therapeutic outcomes [32].
POC D-dimer, used under the rules of a clinical diagnostic
strategy, can improve screening for DVT in a nonmedical
setting and reduce the need to refer patients without DVT
to the hospital. Table 4 summarizes the ability of POC
D-dimer to diagnose DVT at the bedside.
Buller et al. evaluated the safety and efficacy of a clinical
diagnosis of POC D-dimer in 2009. They enrolled 1,028
patients with suspected DVT from The Netherlands for a
prospective study. In a screening of all the patients by POC
D-dimer, 49% of the patients were considered to have a low
risk of DVT occurrence. Furthermore, 1.4% of these lowrisk
patients developed DVT within the subsequent three
months. This suggests that POC D-dimer has room for
improvement despite its high screening capacity [33]. In
2019, new polymer microfluidic cartridge
POC D-dimer detection equipment was
developed by Lakey et al. It showed that
an in-house biofunctionalized interdigitated
electrodes and portable impedance
readers could be used to measure moderate
concentrations of D-dimer in clinical
plasma samples, and the results
could be obtained within 15 min. It
advances the rapid diagnostic capability
of POC D-dimer [34]. In 2015, a review
Reference
method
Prospective
study
Duplex US
PPG
PPG is a method to estimate blood volume using an optical
sensor to detect the intensity of light reflected from the surface
of tissues and the intensity of light after light enters
tissues. In particular, the measurement of light reflection
intensity is referred to as light reflection rheography (LRR).
A series of physiological parameters, including the blood
flow rate, venous emptying, and the venous referring time
(VRT), plays important roles in diagnosing DVT and can
also be achieved by the PPG method. Table 5 summarizes
the sensitivity and specificity of PPG using different features
in DVT diagnosis.
In 1991, Thomas et al. conducted a five-month prospective
study evaluating 131 legs in 119 patients and reported a
sensitivity of 92% and a specificity of 84%. It indicates that
most of the positive patients could be detected by the PPG
method [37]. In 2005, an experiment was conducted with
63 healthy subjects and 44 patients, comparing each in the
right and left legs. Having compared differences in PPG
pulse wave timing and amplitude between the right and
left legs, the results showed a sensitivity of 90.6%, a specificity
of 88.9%, and an accuracy of 90.2%. The result suggests
that PPG equipment can diagnose DVT directly and
Table 4. Selected studies using POC D-dimer
in the diagnosis of DVT.
Number of subjects
(control/patient) Sensitivity (%) Specificity (%)
-
1,028
15
560 (337/223)
-
96.9
-
-
60.8
Study
Buller 2009 [33]
Lakey 2019 [34]
Dempfle 2006 [36]
April 2023 IEEE SYSTEMS, MAN, & CYBERNETICS MAGAZINE 53
IEEE Systems, Man and Cybernetics Magazine - April 2023

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