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AcuPebble SA100 offers automated sleep apnoea diagnosis equivalent to cardiorespiratory polygraphy

London, 26th January 2022

AcuPebble SA100 is clinically equivalent to cardiorespiratory polygraphy for the automated diagnosis of obstructive sleep apnoea (OSA) at home, a paper published in the BMJ Open has revealed. A powered clinical trial conducted by the Royal Free Hospital in London demonstrated both the accuracy and usability of the small device, which has the potential to open more efficient patient pathways for OSA diagnosis.

Currently, OSA diagnosis in the UK uses either full polysomnography or limited cardiorespiratory polygraphy (CR-PG). Due to high demand on these services, CR-PG is often conducted by the patient at home, requiring them to attend hospital for training and then to wear several bands, sensors and probes overnight. This is cumbersome for the patient, which in turn affects the quality of their sleep. When the sensor is returned, the signals must be manually interpreted by an expert clinician to determine the diagnosis, a process which can take up to two hours per patient.

Actor wearing cardiorespiratory polygraphy

In contrast, AcuPebble SA100 consists of a single wearable sensor, attached to the neck with a medical adhesive, and a user-friendly mobile application. In the morning, the study is uploaded and the result automatically generated and sent to the clinician instantly. This makes the process easier and more comfortable for the patient, while the device’s low cost and automated diagnosis offer significant financial and time savings for the NHS and other healthcare organisations.

Woman wearing sensor

The Royal Free Hospital study involved 150 patients, all of whom had been referred for OSA diagnosis. Each patient was trained on the use of type III CR-PG, which they took to use at home, and was also given AcuPebble SA100, but without any training on how to use the system. After both devices were worn overnight and returned, two expert clinicians manually scored the cardiorespiratory polygraphy signals to reach a diagnosis, which was then compared to the automated result generated by AcuPebble SA100.

In all cases, AcuPebble SA100 matched the experts’ diagnosis with positive and negative likelihood ratios over 10 and below 0.1, respectively. Comparing against the current American Academy of Sleep Medicine’s AHI-based criteria demonstrated 95.33% accuracy, 96.84% specificity, 92.73% sensitivity, 94.4% positive-predictive value and 95.83% negative-predictive value1. In addition, all patients were able to use the system correctly, and 97% said they preferred using AcuPebble SA100 over cardiorespiratory polygraphy.

Dr Swapna Mandal, Consultant Respiratory Physician at the Royal Free Hospital, led the clinical trial. She said: “These study results are great news for both sleep clinicians and patients. Demand for OSA diagnosis has been growing rapidly in recent years, and the long and often complex diagnostic pathway, along with the ongoing Covid pandemic, has left us with a backlog of patients to see. With AcuPebble SA100 now proven to be clinically equivalent to the current ambulatory gold standard, we have a way to diagnose more patients and improve their quality of life.”

AcuPebble SA100 sensor in hand

AcuPebble devices sense the physiological sounds generated by the body, detecting, amongst others, respiratory and cardiac disease biomarkers. Processed acoustic signals are transferred to a mobile device and to the cloud, where patented algorithms extract the parameters doctors need to diagnose or manage conditions such as sleep apnoea, COPD and asthma. Automatic processing means that the demand on a clinician’s time is greatly reduced.

AcuPebble SA100 is the first product to be developed and commercialised by UK-based medical device company Acurable, and builds on more than ten years of research led by Professor Esther Rodriguez-Villegas at the Wearable Technologies Lab in Imperial College London. Prof. Rodriguez-Villegas commented: “Our mission at Acurable is to improve the life of millions of people across the world, by enabling earlier detection, faster treatment and better management of chronic conditions. These study results prove that AcuPebble SA100 has the potential to change the way OSA is diagnosed, making the process easier and quicker for patients and reducing time and cost burdens for healthcare professionals.”

AcuPebble SA100 launched in the UK and Europe in late 2020, and in November 2021 Acurable announced that the product had received FDA clearance for home sleep apnoea testing. The company intends to open an office and launch the product in the USA later this year.


About Acurable

Acurable creates accurate and user-friendly wearable medical devices intended to be used by patients at home. Its award-winning, patented technology enables for the first time the automated diagnosis and management of respiratory conditions at home. It is a breakthrough in respiratory medicine and the product of more than 10 years’ research at Imperial College London by Acurable’s founder, Professor Esther Rodriguez Villegas. Its first product, AcuPebble SA100, is the first wearable medical device to obtain the CE mark for the automated diagnosis of obstructive sleep apnoea at home. Acurable is backed by investors from Alma Mundi Ventures and Kindred Capital. For more information, please visit