Grove - medical sensors

Measurement of muscle activity - medical solutions available for everybody

One of the interesting applications of the Grove medical modules presented here is the creation of apparatus for measuring the activity of human muscles. Muscle activity sensors are devices designed to study muscle activity by detecting the presence of electrical voltage on the muscles. These types of devices are commonly used in medical diagnostics - the process of analyzing muscle activity is technically called electromyography (EMG). How is it working?

When you want to tense your right hand muscles, your brain sends an electrical impulse to the innervation of the corresponding muscles. As a result, the motor functions of the neurons of muscle fibers are stimulated, which contribute to the structure of the muscles. The more you tense your muscles, the more muscle fibers will be synchronously energized, which will translate into a greater strength of muscle tone. The muscle sensors you can buy in this category detect the electrical signals in your muscles, which represent their contraction and relaxation. These devices are then able to convert these signals into analog signals which can be written and read. For this purpose, analog-to-digital converters installed in a given microcontroller are used. Moreover, measuring muscle activity can somewhat resemble the way an analog voltmeter works. The difference is that the raw output from the muscle activity sensor is not a DC or periodically varying voltage, but an irregularly varying EMG voltage. Interestingly, the course of muscle tension resembles sound waves that imitate, for example, a piece of music. EMG sensors have practical application in neuromuscular analysis that helps determine the right set of exercises for a human being. Science!

Grove medical sensors - heart rate measurement is no longer a problem

The heart rate measurement is performed with the use of electronic equipment. Such a test should very often be performed, especially in the elderly. Now they can be made at home. By using the Grove medical sensors available in Botland, you are able to construct an intelligent medical robot or a simple measuring apparatus in just a few simple steps.

One way is to create a tool for photoplethysmography. This method uses the measurement of changes in the volume of blood that is subjected to the intensity of light transmitted through blood vessels - usually for a specific organ such as the heart or liver. There are two types of photoplethysmography - transmission and reflection. The first one consists in sending a light beam and receiving it by an appropriate sensor. The second, reflection photoplethysmography, generally speaking, consists in transmitting a light beam to the surface of the blood supply and reflecting it towards the measuring sensor. Advanced medical sensors used in programmable electronics are capable of implementing similar processes to monitoring the human heart's pulse. We can determine the heart rate ourselves with great precision - check how many diastolic heart beats occur in a minute. The amount of blood flowing in the body depends on the number of heart beats. In measuring the heart rate, hemoglobin plays a key role as it stores the energy of light. Any change in the amount of this energy produces electrical signals that exactly match the frequency of the heartbeat.

Medical sensors analyzing heart rates precisely

Another interesting device in this category is the Grove medical sensor that allows you to accurately measure your heart rate. The basic design of the human heart rate sensor includes an LED, a photoresistor, or a photodiode. Your heartbeat causes a change in the amount of blood that flows to different parts of your body. The tissues in the measurement area are illuminated by the light emitted from the LED. As in the above case, the light beam is reflected by the tissues or transmitted further through the area with more blood supply. The amount of light energy that will be received by the sensor is determined by the volume of blood flowing through the measurement area. In addition, the output from the sensor changes proportionally with each heartbeat. Ultimately, greatly simplifying and shortening the process, the output signal from the sensor is passed through an appropriately selected high-pass and low-pass filter, and then converted into a pulse train by a comparator or an analog-to-digital converter. Such a transducer is included in a microcontroller that can be purchased in this category!