Development of a paper-based sensor for continuous breath analysis for monitoring patient health

Breathing rate has been described as the single most sensitive marker of patient deterioration (NICE, 2017). Yet, in general wards, breathing rate is only monitored through visual assessment (observing the patient from a distance and counting the rising and falling of the chest) for 30 seconds every 12 hours. As well as being time-consuming, qualitative, and highly prone to human error, several high-profile cases have highlighted that missing observations in sepsis cases have led to avoidable patient death, including babies (PHSO, 2013).

Sepsis is a life-threatening condition responsible for 52,000 deaths in the UK annually (UK Sepsis Trust, 2018), second only to cardiovascular disease. Sepsis survivors often suffer from long-term mental and physical effects, including amputations, organ failure, chronic pain, fatigue and post-traumatic stress disorder (NHS England, 2015). Globally, the disease claims 6 million lives a year, including 1 million newborn babies and 100,000 maternal deaths (WHO, 2017).

For every hour's delay in the treatment of sepsis, the patient's risk of death increases by 7.6% (Kumar et al., 2006), meaning that by the next observation a sepsis patient's chance of death may have increased to 50%. Yet, sepsis is a highly treatable condition if detected early. Estimates indicate that earlier identification and treatment of sepsis across the UK could save 14,000 lives annually, as well as avoid 400,000 hospital bed days, potentially saving the economy £2.8 billion (YHEC, 2017).

With funding from Innovate UK, Spyras will develop an affordable, disposable wearable medical device for continuous real-time breathing analysis in general wards. Our connected device has the potential to automatically alert clinicians to patients showing early signs of deterioration. Compared to competitive devices already on the market, our paper-based sensor is lower cost and more accurate. We will demonstrate device performance in healthy subjects, ready for post-project clinical trials.

As a result of late diagnosis and treatment of sepsis in UK hospitals, 59,000 patients enter intensive care units from post-operative and post-natal wards, at a direct treatment cost to the NHS of £188 million; 12,000 die during this first period of admission, while 19,400 are rehospitalised within 30 days and have long-term post-sepsis complications (Norman et al., 2017). The use of our device solely in this application could save 5,250 lives annually in the UK.