May 23, 2024

Biosensors have become an important tool in biomedical diagnostics and monitoring

due to their ability to detect physiological parameters non-invasively and continuously. Traditional biosensors usually require samples such as blood or tissue to function, but non-invasive biosensors have the significant advantage of being able to monitor physiological signals without requiring contact with the body.

Wearable Biosensors

One of the most active areas of research in non-invasive biosensing is wearable biosensors. These are biosensors that can be integrated into wearable devices like watches, clothing, and skin patches to continuously monitor various vital signs and biomarkers. Companies like Apple, Fitbit, and Garmin have led consumer adoption of wearable biosensors to track activities, heart rate, sleep, etc. However, researchers are working to enhance the capabilities of wearable biosensors to enable comprehensive health monitoring. Some key areas of focus include multi-analyte sweat sensors to detect metabolites, non-invasive glucose monitors, and advanced electrocardiogram (ECG) and photoplethysmogram (PPG) sensors for cardiac monitoring. The miniaturization of sensor components and integration into fabrics, tattoos, and skin-like patches is making wearable biosensing more comfortable and largely invisible to users. Wearable biosensors hold significant promise for remote healthcare, fitness tracking, and early disease detection.

Optical Biosensing

Optical techniques form the basis of many non-invasive biosensing methods due to light’s ability to penetrate tissues. Near-infrared (NIR) spectroscopy is widely used for non-invasive glucose monitoring by measuring absorption signals from biological samples. Other emerging optical techniques being explored include Raman spectroscopy, photoacoustic spectroscopy, optical coherence tomography (OCT), and hyperspectral imaging. Researchers are working on novel biomarker detection using signatures from molecular vibrations, resonant light scattering, and tissue microstructures. For example, Raman spectroscopy biosensors can potentially detect molecules in expired air, saliva or interstitial fluid through the skin. OCT is being investigated for non-invasive angiogenesis imaging and cancer screening. Advanced image processing models are further improving the accuracy and specificity of optical biosensing. The development of low-cost, portable optical biosensor devices could enable widespread non-invasive screening and home healthcare applications.

Wearable Bioimpedance Sensors

Bioimpedance analysis is another promising non-invasive technique gaining attention for continuous health monitoring applications. Bioimpedance sensors measure the impedance properties of tissues which provide insights into fluid levels, muscle mass, fat content, and blood flow. Miniaturized wearable bioimpedance sensors integrated into adhesive patches or embedded in fabrics and skin are being researched. These can be used for non-invasive monitoring of hemodynamic parameters, hydration levels, edema, and other physiological changes. For example, multi-frequency bioimpedance sensors have shown potential for cuff-less blood pressure monitoring. Advanced signal processing of bioimpedance waveforms also enables tracking of stroke volume, cardiac output and other cardiovascular metrics invaluable for point-of-care diagnostics. Wearable bioimpedance sensors are low-power, low-cost and could enable widespread body composition analysis and remote cardiac monitoring outside clinical settings.

Non-invasive Neuromonitoring

Neurological conditions affect millions worldwide but non-invasive continuous monitoring solutions remain limited. Researchers are actively pursuing novel non-invasive sensors for neuromonitoring applications. Electroencephalography (EEG) headsets using dry electrode systems have enabled non-medical grade EEG recording, paving the way for consumer brain-computer interfaces and neurofeedback devices. Advanced signal processing of EEG signatures also shows promise for non-invasive diagnosis of conditions like epilepsy, sleep disorders, Alzheimer’s etc. Other emerging technologies involve using NIRS, fNIR, and fMRI to non-invasively monitor brain activity, oxygenation and hemodynamics. MEG scanners are offering sensitive detection of magnetic fields from neuronal currents without contacts. Translational research is ongoing to leverage these non-invasive neuroimaging and sensing techniques through portable, personalized systems for remote neurological monitoring, diagnostics, and therapeutics.

non-invasive biosensors are rapidly advancing thanks to developments in materials, microfabrication, analytical techniques and computational modeling. Their integration into wearables and development of user-friendly interfaces is improving user experiences. Widespread application of non-invasive biosensing technologies holds immense potential for remote healthcare, clinical decision support, disease screening, pharmaceutical research, sports physiology, and more. However, further validation studies and performance benchmarking against existing standards will be important to drive real-world clinical adoption.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it