By Tripti Chanda

In the 16th century, the first wearable clock was invented: the Nuremberg egg, which was a precursor for the present-day pocket-watch. It was the first wearable technology for humans. We have come a long way since then and have arrived at a time when various instruments are continually monitoring our movement while directly in contact or remotely. The latest in this line is wearable sensors.

Not only do these sensors have to be effective in monitoring our biological processes for assessment, they also need to be extremely durable and as harmless as possible when malfunctioning, which is a lot to ask for from such a small gadget.

Adoptions by the academia

In a recent development, a team led by researchers from IIT Bombay have made a piezo-resistive sensor. This sensor is made out of polyurethane foam which is coated with carbon nanomaterial ink. The ink here provides the conductive medium due to the presence of a large number of nanotubes in a matrix of graphene oxide. There are conductive sheets on the top and bottom too.

Since the sensor is pressure-sensitive, when this foam is compressed, the air is expelled from the gaps, reducing the resistance. This makes the ink matrix more conductive.

The speciality of this sensor is that it can detect small-scale movements caused by low pressure (nearly 2.7kPa) and large-scale changes due to high pressure, which is a departure from the usual sensors. From the motion of the vocal cords in the throat while speaking, to the degree of bend in finger joints, the sensor can detect it all. Along with speech, it can also monitor respiration.

Assessing real-time data

While in the US, John Rogers of the Northwestern University of Chicago is breaking barriers in patient-care. What looks like a white sticking plaster, is actually a sensor able to send a significant amount of data to the doctors working on the recovery of a patient while the patient is home.

The sensor assesses which muscle groups in the body are working or not following a stroke in a patient, and can pinpoint the functioning and the problems. This technology takes patient care from sterile hospital rooms to the patient’s homes where the data can provide an indication of the real-time functioning of the body’s muscles and how the patient is reacting in real-life situations.

Further applications in healthcare

Both the sensors are game changers in their fields. The first one is still a study, and more work and research need to be done before all its functionality can be realised. However, looking at the performance already assessed, it can be easily seen that this sensor would have various applications. From voice recognition to voice synthesis, the utilisation would range from military to medical. The mechanised voice of mute patients could be replaced by their real ones.

Looking beyond, the applications would also be in prosthetics, inside or outside the body. The degree of movement is sensed by the pressure change but for people for whom the movement is not possible even after the application of enough pressure, this is a boon, enabling lost movement.

The other sensor is working outside of controlled hospital setting and sending back real-time values. At the moment, it is only working for the muscles of the heart but could be soon used for other tissues and functionalities. Expanding on this, entire systems or even a body suit would not be a foreign concept.

What the future holds

If both these sensors were to be compounded, the advantages of remote sensing and data collection could be added to form a sensor which would bring medical care and doctors to our very homes. This would enable doctors to take on multiple patients, decrease the deficiency of doctors to a significant degree and make medical care in itself cheaper and more accessible.

With further development of this technology, the sensor itself could analyse and form targeted treatments for each physical ailment. It would also help in making sure that the patients follow the treatment prescribed. In all, this could be the beginning of the entry of a tiny new doctor in town.