Biomedical Engineering Reference
In-Depth Information
Off-chip On-chip
Electrokinetic
Bulky
Detector
LOC
Procedure
Incinerator
Off-chip/On-chip valves
Active
Passive
Passive
Passive
Pneumatic
Portable
Detector
Pla c
Material Choice
& Manufacturing
Storage &
Transportation
1
Sample
Pre-treatment
Fluid
Acutation
Fluid
Control
Signal
Detection
Mixing
Disposal
Setting
High-income;
Centralized
Low-income;
Centralized
High-income;
Point-of-care
Low-income;
Point-of-care
1
Our numbers are rough estimates for most transportation and storage conditions, excluding extremely hot and cold environments.
High cost
& Low cost
Off-chip by
technician
Off-chip by
technician
Electrokinetic;
Pneumatic
Electrokinetic;
Pneumatic
Pneumatic;
Capillary
Technician; Mach-
ine; On-chip valves
Technician; Mach-
ine; On-chip valves
Expensive, bulky,
w/ ground electricity
Bulky detector,
w/ ground electricity
Portable detector
4 to 25°C
Active of Passive
Incineration
Low cost
4 to 40°C
Active of Passive
Incineration
4 to 25+°C,
rough handling
Low cost
On-chip
Passive
Passive
Self-contained
4 to 40+°C,
rough handling
Pneumatic;
Capillary
Low-cost, portable
detector
Very low cost
On-chip
Passive
Passive
Self-contained
Fig. 1.1
Appropriateness of technologies for important LOC procedures according to setting
(centralized versus point-of-care) and resource-level (high income versus low income) ([
5
]-
reproduced by permission of the Royal Society of Chemistry)
Fig. 1.2
Distribution of disease burden (DALYs) in high-income, middle-income and low-income
countries [
17
]
and cheap, and the disposable must be extremely cheap. All components of the
device (including the instrument and disposable) must be robust and rugged under
a variety of environmental conditions.
Clinical need is another feature distinguishing POC tests in the developed versus
the developing worlds (Fig.
1.2
). The burden of disease in the developed world
skews heavily toward noncommunicable diseases: cardiovascular disease (stroke,
heart disease), cancer, respiratory disease (COPD and asthma), and neuropsychiatric
conditions are some of the more significant causes [
17
]. By contrast, in the
developing world, while noncommunicable diseases are prevalent, a significant
burden of disease is attributed to infectious diseases, many of which can be
treated and prevented. Major infectious diseases according to the burden of disease
include HIV/AIDS, tuberculosis, malaria, diarrheal diseases, and lower respiratory
infections. Maternal and perinatal conditions and nutritional deficiencies are also
significant causes of disease and disability in the developing world.
Point-of-care tests based on LOC technologies have the potential for rapid and
portable diagnosis of a range of conditions. The rest of this chapter will describe
