Sensors and transducers detect biological compounds
The advent of small biosensors in recent years opens the way to a true revolution in medical diagnostics and health-care. Their tiny size and their capability to react with specific molecules make them ideally suited for mobile applications.
The measurable signals produced by these reactions enable us to make non-invasive, low-cost systems which have a vast field of practical applications in medical diagnostics, and both medical and environmental screening and monitoring.
Here are brief explanations of some of these new devices along with traditional devices you may encounter in mobile healthcare technology:
Carbon nanotubes are microscopic, hollow cylinders whose walls are composed of carbon atom lattices. In biomedical diagnostics, this highly porous material can be coated with antibodies or other substances reacting with specific viruses, bacteria, tumour cells, etc. As the target samples are trapped, a measurable electrical signal is generated which allows their detection even at very low concentrations.
Nano Field Effect Transistor - Nano FET
In a Nano Field Effect Transistor, captured target molecules change the electronic properties of the transistor and thus generate a measurable electronic signal. It can advantageously replace time consuming, complicated screening processes in the laboratory. Demonstrated functionality includes for example the detection of Methicilin Resistant Staphylococcus Aureus whose resistance to antibiotics and its rapid propagation in environments such as hospitals and, increasingly, in the food chain demands fast and early detection.
Nanowires are literally nano-diameter sized wires made of conducting or semi-conducting materials such as gold or silicon. Target binding to their surface, specific to the biorecognitive doping material used, results in a measurable change in conductance. Their greatest potential is in the real-time, label-free detection of DNA.
Chemical resistors take advantage of the change in electrical resistance when nanoparticles of gold attach to a specific molecule. Practical examples include the detection of volatile organic compounds (VOC) in a subject’s breath, allowing for example the non-invasive diagnosis of lung cancer.
Biopotential electrodes have been around for a long time and remain indispensable for many physiological measurements and recordings including the electrocardiogram (ECG), the electroencephalogram (EEG), the electromyogram (EMG) and the electrooculogram (EOG). Whilst there is no advantage to replace the standard, wet gel silver/silver-chloride electrodes in laboratory or hospital environments, some dry-gel and gel-less designs are well suited for specific measurements in mobile applications.
Data acquisition and signal processing prepare the data for transmission, typically to a mobile device.
Here you can learn more about acquisition and processing systems designed for this.
Thanks to the IEEE 802 standard, today's mobile communications are versatile and reliable.
Proven, well established standards combined with existing and upcoming communications technology allow seamless integration with sensing devices.
Analyse and interpret
To be useful, the signals from any sensing device need to be analysed and interpreted according to the purpose of the device?
This is the job of dedicated software applications, usually mobile apps, web or cloud based applications.
Use biosensors in real-life
The ultimate purpose of mobile sensing is of course to make diagnostics, screening and monitoring available for real-life purposes.
Find out more about laboratory tests and methods which can use this technology.