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=**Indirect Method of Non-invasive In-vitro Measurement of D-Glucose**=


 * Article URL: [] [1] **


 * Introduction:** The design idea introduces an electromagnetic coupling method for designing a non-invasive blood glucose sensor. Two 8cm-long coils generate a magnetic field which induces a current flow in the circuit. The intensity of the induced current depends on the conductivity of the medium. The research group used calf’s blood as the medium for tests. They added D-glucose to calf’s blood to make a total of 14 different blood glucose concentrations. The experimental result shows a proportional correlation between the output voltage of the sensor and blood glucose level.


 * Background:** 25.8 million children and adults in the United States have diabetes [2]. Today’s most common and accurate blood glucose monitors require blood samples and test strips. Diabetic patients have to prick their fingers several times a day to get their blood glucose level tested for proper insulin injection. Discomfort caused by pricking fingertips and other body parts is one of the major issues that concerns most diabetic patients.

In addition to this, the strips for blood glucose testing are expensive. Accuracy is crucial for blood glucose monitoring systems. Patients have to purchase glucose meters and test strips from the same manufacturer due to the calibration of the meters. If one uses a mismatched test strip on a meter, it might give an inaccurate blood glucose reading, and the patient could potentially die for taking a wrong dose of insulin. Despite the fact that diabetic patients need to use a glucose meter with a test strip, manufacturers do not sell them together, forcing consumers to purchase them separately. In fact, some test strips are three times more expensive than the meters of the same brand, which causes a financial burden to most diabetic patients.

Invasive glucose monitoring systems also affect the environment. Improperly dispose of used test strips, lancets and needles may put others at risk of infection and physical injury from needle sticks and cuts. If someone suffers from a needle stick injury, he or she may need to rush to the emergency room or a doctor’s office for lab tests and treatments.

In conclusion, today’s blood glucose meters do not possess four E’s of sustainability [3]: energy, environment, economics, and equity. The following analysis will examine how the design idea impacts the four E’s of sustainability and embodies the green engineering design principles.

Patients can reuse the 8cm-long coils so that they do not need to buy a new sensor for each blood test. This design also saves the energy to decompose medical wastes such as used test strips, lancets, and needles. This healthcare technology breakthrough, if further develops to use in humans, will eliminate biohazards which can potentially pollute the environment if people do not dispose them properly. Indeed, the non-invasive design can reduce the spread of infectious diseases such as HIV and AIDS as it does not require blood samples for testing. The biggest reason test strips cost so much is that the science is very specific in order to yield an accuracy within a very tiny margin of error [4]. Manufacturers devote so much money for research and tests in order to produce blood glucose monitoring systems that will give accurate results. The non-invasive blood glucose sensor eliminates the costs for manufacturing test strips, lancets, and needles. In addition, diabetic patients will not have to buy expensive test strips. This design impacts the market for blood glucose monitoring systems. Diabetic patients benefit from the design in a way that they do not have to prick their fingertips for blood samples. As a result, it is a more comfortable design approach for patients who are concerned about the pain. With the elimination of test strips, manufacturers can save money for research as well.
 * Sustainability Analysis:**
 * Energy**
 * Environment**
 * Economy**
 * Equity**

1. Engineer processes and products holistically, use systems analysis, and integrate environmental impact assessment tools. The research group implemented the design with improvements in manufacturing costs, patients’ comfort, and sensor’s accuracy.
 * Green Engineering Design Principles Analysis:**

2. Conserve and improve natural ecosystems while protecting human health and well-being. This design eliminates sharps which may put one’s family, trash haulers, landfill employees, pets, and wild animals at risk of infection and physical injury.

3. Use life-cycle thinking in all engineering activities. This design reduces medical wastes produced by the system.

4. Ensure that all material and energy inputs and outputs are as inherently safe and benign as possible. The research scientists used calf's blood as the medium for testing and measurement. In order to use the proposed design idea on humans, they will have to test the sensor on a human subject.

5. Minimize depletion of natural resources. The non-invasive blood glucose sensor eliminates the resources for producing test strips, lancets, and needles.

6. Strive to prevent waste. It reduces medical wastes and biohazards such as test strips and needles.

7. Develop and apply engineering solutions, while being cognizant of local geography, aspirations, and cultures. The design applies Lenz's law which indirectly measures glucose concentration in blood. Patients' comfort is one of their major considerations for the design approach since a lot of diabetic patients are concerned about the pain by pricking fingertips and other body parts.

8. Create engineering solutions beyond current or dominant technologies; improve, innovate, and invent (technologies) to achieve sustainability. This design idea is a possible way to improve the shortcomings that invasive blood glucose meters have.

9. Actively engage communities and stakeholders in development of engineering solutions. Before conducting research on this design idea, the research scientists studied the market for blood glucose monitoring systems and identified the areas that need to improve.

[1] Rouane, Amar. "Indirect Method of Non Invasive In-vitro Measurement of D+ Glucose." Sensors & Transducers Journal 93.6 (2008): 69-81. Print.

[2] "Diabetes Statistics - American Diabetes Association." Diabetes Statistics - American Diabetes Association. American Diabetes Association, 26 Jan. 2011. Web. 27 Apr. 2011. <[]>.

[3] D. Braun and Cal Poly Electrical and Computer Engineering Students, "Cal Poly’s wiki for Sustainability in Integrated Circuits." Web. 16 Jan. 2011. <[]>.

[4] "Diabetic Test Strips Are Expensive :I Buy Diabetic Test Strips." I Buy Diabetic Test Strips. 2011. Web. 24 Apr. 2011. <[]>.