Sensors and Senses

In January 2015 engineers from the Creativity Lab at Samsung Electronics introduced a prototype of a smartphone application and device called the Early Detection Sensor & Algorithm Package (EDSAP) as a stroke-detection tool. After two years of development, they are close to delivering the product. EDSAP’s sensors, which are applied to the head via a headset, collect electrical waves caused by brain activity and wirelessly transfer the information to a smartphone application that analyzes the data and determines the threat of stroke. The developers hope the data can provide additional health information such as stress levels, anxiety and quality of sleep.

While wearable sensors coupled with smartphone applications will soon be available, devices already exist that monitor physiological signals pertaining to various body systems, including cardiac, respiratory, circulation, nervous system and skin. Technical innovations seem to be unlimited and often ahead of medicine and physiology.

It is not quite the case with EDSAP. EDSAP is an application of continuous quantitative electroencephalography (qEEG), which has been used in medicine for decades. Recent advances in qEEG have enabled automation and expanded diagnostic utility in monitoring acute changes of cerebral blood flow and real-time diagnosis of conditions such as stroke. However, even in an intensive-care environment, qEEG data still requires expert human cross-checking and verification.

Making the technology widely available to lay people will speed up the acquisition of knowledge and development of diagnostic capabilities in the end, but the path to that end is not straightforward. The ability to measure physiological parameters does not mean one understands the implications of that measurement. Acquiring “big data” of background information alone does not provide for the quality of data and meaningful use of it. Real-time use of wearable sensors for diagnosis and decision-making by monitored subjects is still far off. Technology alone cannot get us there; biomedical sciences have to lead the process. For now, it is important to remain optimistic and to create realistic expectations for the public.

New technologies enable us to ask questions we have not considered before, but in diving we have some outstanding questions that wearable technologies could eventually answer. For example, EDSAP could help monitor the effects of nitrogen narcosis, oxygen toxicity, high-pressure nervous syndrome, stress and anxiety. Seizures due to oxygen toxicity are the most critical among those mentioned. Seizures underwater carry a high risk of drowning. Controlling the exposure to high partial pressure of oxygen alone is not reliable for prevention of seizures because of the great variability in individual susceptibility. Thus for operational safety it would be important to recognize the warning signs in an exposed diver that would trigger protective measures.

However, capturing data in wet conditions is a bit more problematic than in dry conditions. In the best case, it results in weaker signals and more noise. In the same time, the changes we would like to detect in healthy divers to predict risk before injury occurs may be of a lesser magnitude than changes involved with acute disease in a clinical environment or the time may be too short to act. This makes the application of wearable sensors more complicated in diving.

Divers currently have available sensors for routine self-recording of their heart rate and breathing rate. More sensors have been announced recently. For researchers involved with the physiology of diving, breakthroughs may soon be possible. For divers, it will take patience and participation in the research studies to help turn wearable sensors into practical tools.


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