Biomedical Engineering Reference
In-Depth Information
between the human body with the physicians through a “biomedical interface”
that collects the biomedical information from the body for data processing and
communication. For healthcare in the home, however, the tele-medical system,
relies extensively on the development of an “interface” between the human
body and the computer/communication facilities. In contrast to the highly de-
veloped information processing and transfer technology and established clinical
diagnostic criteria, the acquisition of biomedical information (physiological
and biochemical parameters) is an active area being pursued in our group.
As compared with the electrochemical and optical biosensors mentioned
above, thermal biosensors are intrinsically insensitive to the optical and elec-
trochemical properties of the samples, and do not require frequent calibration
of the transducers, since the transducers are highly stable and are normally iso-
lated from the buffer and sample fluids. Recently, highly sensitive integrated
thermal biosensors have been developed in our group. As discussed above, they
employ micromachining and semiconductor technology as well as control soft-
ware of computer data for simultaneous determination of multianalytes (up to
four) in mixed samples [19]. Glucose, lactate and urea in1
L whole blood sam-
ples could be directly determined with a miniaturized sensor without any pre-
treatment of the samples. These achievements show promise for further devel-
opment of a fully integrated analytical system based on a thermal biosensor
array and microchannel fluid handling. This system will eventually be incorpo-
rated with computer and telecommunication facilities to accomplish the tele-
medical monitoring and diagnostic system for home healthcare.
m
4.2
Home Diagnostics
Immense progress in the field of glucose analysis, which is of special signifi-
cance for diabetes patients, was achieved with integrated silicon thermopiles,
miniaturised enzyme thermistors, and new calorimetric microbiosensors. Some
years ago, our group [36] started development of microbiosensors that could be
produced by micromachining. As an intermediary step, miniaturised enzyme
thermistor models were produced which were found to perform unexpectedly
well, in spite of their relatively simple design. With respect to sensitivity, pre-
cision, physical dimensions, and column longevity (cost per assay), these devi-
ces were quite competitive with instruments currently being used for home
measurements of blood glucose in diabetics. This could be improved provided a
suitable pump and sample injection valve could be developed [21]. Carefully
selected enzyme support materials made it possible to run untreated whole-
blood samples directly through the immobilised enzyme column.
4.3
Other Developments
The feasibility of miniaturizing thermal biosensors in different constructions,
sizes and materials, by employing conventional machining and micromachining
technologies could be further exploited in several directions. The miniaturiza-
Search WWH ::
Custom Search