2 Glucometers and Diabetes

Diabetes is one of the most common diseases today. It is essential to produce glucometers whose one of many advantages is to

empower diabetics to take care of themselves without the need to visit doctors. Glucometers help to detect and confirm

hypoglycemia and infections. High blood sugar may also be a sign of infection or illness that needs to be treated.

2.1 Diabetes Fundamentals

Diabetes mellitus commonly known as “ diabetes ” is a common health problem throughout the world. It prevents the body

from producing enough insulin, does not produce insulin, produces defective insulin, or has resistance to the same. Insulin is a

hormone produced in the pancreas. According to the World Health Organization statics, the global prevalence of diabetes

mellitus is approximately 155 million people and expected to increase to 300 million in the year 2025. Medical Management

of Diabetes and Heart Disease Book, Marcel Dekker Inc.

Glucometry is a technique that obtains the value of glucose concentration in peripheral or central blood. These values expressed

either in mgr/dl or mmol are important clinical values for metabolic disorders such as diabetes mellitus, denutrition, and other

consequences like hyperosmolar coma, malabsorption syndrome, and most critical hypoglycemia. A glucometer and proper

pharmaceutical treatment is fundamental for glycemic control of diabetic patients. At home, some glucometers include different

kinds of strips to monitor other variables such as ketones which are produced when a patient is experiencing hyperglycemia.

Figure 1 shows a general diagram of a blood pressure monitor. It shows different peripherals for communication between the

user and the device. The most important part is the test strip, this is the sensor to collocate the blood and get a determined

measurement with the analog-to-digital converter (ADC) of the microcontroller unit (MCU). The other peripherals depend on

the designer.

Figure 1. Blood glucose monitor block diagram

2.2 Glucose Sensors

The first step to measure the glucose in the blood is to convert the glucose concentration into a voltage or current signal, this is

possible with special sensor strips for amperometry. The sensor uses a platinum and silver electrode to form part of an electric

circuit where hydrogen peroxide is electrolyzed. The hydrogen peroxide is produced as a result of the oxidation of glucose on

a glucose oxide membrane. The current through the circuit provides a measurement of the concentration of hydrogen peroxide,

giving the glucose concentration.

Implementing a Glucometer and Blood Pressure Monitor Medical Devices, Rev. 1, 4/2010

Freescale Semiconductor, Inc.

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Glucometers and Diabetes