176
V. Laxmi et al.
Various blood-based point-of-care devices are available in the market today, these
devices use either whole blood or plasma for analyte detection and reading in an automated way using finger-prick blood sample. Common analytes test which are available via point-of-care testing are measurement of glucose, prostate-specific antigen
(PSA), C-reactive protein (CRP), cardiac markers, Human chorionic gonadotropin
(hCG), electrolytes, and ferritin. The i-STAT handheld blood analyzer (Abott pointof-care) uses different cartridges for testing separate group or panel of analytes.
It can provide rapid quantitative results with accuracy comparable to conventional
systems. Measurements utilize different cartridges to measure total β hCG (diagnosis
of pregnancy), BnP (B-type Natriuretic Peptide), CK-MB (creatinine Kinase MB),
cTnI (detecting myocardial infarction) and for electrolytes [6, 21]. Point-of-care
tests for measuring cholesterol, lipids, and glucose are also available (Abbott-Alere).
Recently, a point-of-care device for measuring prostate-specific antigen (PSA) has
been reported by OPKO diagnostics [38].
3 Red Blood Cells (RBCs)
Red blood cells form the majority of cell volume in human blood. Healthy RBCs look
like biconcave discs of diameter in the range of 6–8 μm and thickness approximately
2.5 μm. Healthy humans have a normal count of 4.5–5.5 million per microliter of
blood. RBCs are deformable and they do not have any nucleus. RBCs contain several
proteins such as antioxidant reagents, structural protein, and hemoglobin, in which
~97% is hemoglobin [39]. The primary role of hemoglobin is to transport oxygen
throughout the human body. Hemoglobin has iron atoms which are responsible for
the red color of the blood. The normal values of the hemoglobin (Hb) for male
ranges between 13.5 and 17.5 g/dL whereas, for an adult female it is between 11.5
and 15.5 g/dL [40]. Another important term related to red blood cell quantification is
the hematocrit (Hct) also known as the packed cell volume (PCV). Hematocrit is the
proportion of blood volume that is occupied by red blood cells. Normal hematocrit
for average males varies from 40 to 54% and for average females vary from 36 to
48% [41]. Clinically, complete blood count gives the information of red blood cells
in terms of RBCs count, hemoglobin value, and RBCs total volume (hematocrit).
Deviations in these parameters from the normal range lead to disorders related to
RBCs. Anemia and Polycythemia are among the most common RBCs disorders [39].
Anemia is caused due to scarcity of red blood cells whereas polycythemia results
due to relatively high population of RBCs [39]. According to WHO recommendation, hemoglobin is the key parameter to monitor anemia in human. There are
several types of anemia caused either due to large blood loss, or low production of
RBCs, or high destruction of RBCs in the body. Sickle cell anemia is directly linked
with hemoglobin. It is caused due to the structural change in hemoglobin leading
to reduced deformability in RBCs. Malaria is also related to RBCs; it is caused by
plasmodium falciparum parasite. This parasite is responsible for structural changes
which results in impaired deformability of the RBCs [39, 42]. Malaria-infected RBCs
V. Laxmi et al.
Various blood-based point-of-care devices are available in the market today, these
devices use either whole blood or plasma for analyte detection and reading in an automated way using finger-prick blood sample. Common analytes test which are available via point-of-care testing are measurement of glucose, prostate-specific antigen
(PSA), C-reactive protein (CRP), cardiac markers, Human chorionic gonadotropin
(hCG), electrolytes, and ferritin. The i-STAT handheld blood analyzer (Abott pointof-care) uses different cartridges for testing separate group or panel of analytes.
It can provide rapid quantitative results with accuracy comparable to conventional
systems. Measurements utilize different cartridges to measure total β hCG (diagnosis
of pregnancy), BnP (B-type Natriuretic Peptide), CK-MB (creatinine Kinase MB),
cTnI (detecting myocardial infarction) and for electrolytes [6, 21]. Point-of-care
tests for measuring cholesterol, lipids, and glucose are also available (Abbott-Alere).
Recently, a point-of-care device for measuring prostate-specific antigen (PSA) has
been reported by OPKO diagnostics [38].
3 Red Blood Cells (RBCs)
Red blood cells form the majority of cell volume in human blood. Healthy RBCs look
like biconcave discs of diameter in the range of 6–8 μm and thickness approximately
2.5 μm. Healthy humans have a normal count of 4.5–5.5 million per microliter of
blood. RBCs are deformable and they do not have any nucleus. RBCs contain several
proteins such as antioxidant reagents, structural protein, and hemoglobin, in which
~97% is hemoglobin [39]. The primary role of hemoglobin is to transport oxygen
throughout the human body. Hemoglobin has iron atoms which are responsible for
the red color of the blood. The normal values of the hemoglobin (Hb) for male
ranges between 13.5 and 17.5 g/dL whereas, for an adult female it is between 11.5
and 15.5 g/dL [40]. Another important term related to red blood cell quantification is
the hematocrit (Hct) also known as the packed cell volume (PCV). Hematocrit is the
proportion of blood volume that is occupied by red blood cells. Normal hematocrit
for average males varies from 40 to 54% and for average females vary from 36 to
48% [41]. Clinically, complete blood count gives the information of red blood cells
in terms of RBCs count, hemoglobin value, and RBCs total volume (hematocrit).
Deviations in these parameters from the normal range lead to disorders related to
RBCs. Anemia and Polycythemia are among the most common RBCs disorders [39].
Anemia is caused due to scarcity of red blood cells whereas polycythemia results
due to relatively high population of RBCs [39]. According to WHO recommendation, hemoglobin is the key parameter to monitor anemia in human. There are
several types of anemia caused either due to large blood loss, or low production of
RBCs, or high destruction of RBCs in the body. Sickle cell anemia is directly linked
with hemoglobin. It is caused due to the structural change in hemoglobin leading
to reduced deformability in RBCs. Malaria is also related to RBCs; it is caused by
plasmodium falciparum parasite. This parasite is responsible for structural changes
which results in impaired deformability of the RBCs [39, 42]. Malaria-infected RBCs