̽��ֱ�� of Cambridge - sleeping

Cambridge Festival Speaker Spotlight: Dr Sam Nallaperuma-Herzberg

zs332 — Tue, 11 Mar 2025 13:39:34 +0000

Dr Sam Nallaperuma-Herzberg is a Senior Research Associate at Cambridge ̽��ֱ��’s Department of Computer Science and Technology, and a Fellow in Artificial Intelligence (AI) for Science and Society at the Accelerate Programme for Scientific Discovery.

Scientists develop ‘smart pyjamas’ to monitor sleep disorders

sc604 — Tue, 18 Feb 2025 11:06:44 +0000

̽��ֱ��team, led by the ̽��ֱ�� of Cambridge, developed printed fabric sensors that can monitor breathing by detecting tiny movements in the skin, even when the pyjamas are worn loosely around the neck and chest.

̽��ֱ��sensors embedded in the smart pyjamas were trained using a ‘lightweight’ AI algorithm and can identify six different sleep states with 98.6% accuracy, while ignoring regular sleep movements such as tossing and turning. ̽��ֱ��energy-efficient sensors only require a handful of examples of sleep patterns to successfully identify the difference between regular and disordered sleep.

̽��ֱ��researchers say that their smart pyjamas could be useful for the millions of people in the UK who struggle with disordered sleep to monitor their sleep, and how it might be affected by lifestyle changes. ̽��ֱ��results are reported in the Proceedings of the National Academy of Sciences (PNAS).

Sleep is vital for human health, yet more than 60% of adults experience poor sleep quality, leading to the loss of between 44 and 54 annual working days, and an estimated one percent reduction in global GDP. Sleep behaviours such as mouth breathing, sleep apnoea and snoring are major contributors to poor sleep quality, and can lead to chronic conditions such as cardiovascular disease, diabetes and depression.

“Poor sleep has huge effects on our physical and mental health, which is why proper sleep monitoring is vital,” said Professor Luigi Occhipinti from the Cambridge Graphene Centre, who led the research. “However, the current gold standard for sleep monitoring, polysomnography or PSG, is expensive, complicated and isn’t suitable for long-term use at home.”

Home devices that are simpler than PSG, such as home sleep tests, typically focus on a single condition and are bulky or uncomfortable. Wearable devices such as smartwatches, while more comfortable to wear, can only infer sleep quality, and are not effective for accurately monitoring disordered sleep.

“We need something that is comfortable and easy to use every night, but is accurate enough to provide meaningful information about sleep quality,” said Occhipinti.

To develop the smart pyjamas, Occhipinti and his colleagues built on their earlier work on a smart choker for people with speech impairments. ̽��ֱ��team re-designed the graphene-based sensors for breath analysis during sleep, and made several design improvements to increase sensitivity.

“Thanks to the design changes we made, the sensors are able to detect different sleep states, while ignoring regular tossing and turning,” said Occhinpinti. “ ̽��ֱ��improved sensitivity also means that the smart garment does not need to be worn tightly around the neck, which many people would find uncomfortable. As long as the sensors are in contact with the skin, they provide highly accurate readings.”

̽��ֱ��researchers designed a machine learning model, called SleepNet, that uses the signals captured by the sensors to identify sleep states including nasal breathing, mouth breathing, snoring, teeth grinding, central sleep apnoea (CSA), and obstructive sleep apnoea (OSA). SleepNet is a ‘lightweight’ AI network, that reduces computational complexity to the point where it can be run on portable devices, without the need to connect to computers or servers.

“We pruned the AI model to the point where we could get the lowest computational cost with the highest degree of accuracy,” said Occhinpinti. “This way we are able to embed the main data processors in the sensors directly.”

̽��ֱ��smart pyjamas were tested on healthy patients and those with sleep apnoea, and were able to detect a range of sleep states with an accuracy of 98.6%. By treating the smart pyjamas with a special starching step, they were able to improve the durability of the sensors so they can be run through a regular washing machine.

̽��ֱ��most recent version of the smart pyjamas are also capable of wireless data transfer, meaning the sleep data can be securely transferred to a smartphone or computer.

“Sleep is so important to health, and reliable sleep monitoring can be key in preventative care,” said Occhipinti. “Since this garment can be used at home, rather than in a hospital or clinic, it can alert users to changes in their sleep that they can then discuss with their doctor. Sleep behaviours such as nasal versus mouth breathing are not typically picked up in an NHS sleep analysis, but it can be an indicator of disordered sleep.”

̽��ֱ��researchers are hoping to adapt the sensors for a range of health conditions or home uses, such as baby monitoring, and have been in discussions with different patient groups. They are also working to improve the durability of the sensors for long-term use.

̽��ֱ��research was supported in part by the EU Graphene Flagship, Haleon, and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI).

Reference:
Chenyu Tang, Wentian Yi et al. ‘A deep learning-enabled smart garment for accurate and versatile monitoring of sleep conditions in daily life.’ PNAS (2025). DOI: 10.1073/pnas.2420498122

Researchers have developed comfortable, washable ‘smart pyjamas’ that can monitor sleep disorders such as sleep apnoea at home, without the need for sticky patches, cumbersome equipment or a visit to a specialist sleep clinic.

We need something that is comfortable and easy to use every night, but is accurate enough to provide meaningful information about sleep quality

Luigi Occhipinti

Illustration and photograph of 'smart pyjamas'

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Meditation-relaxation therapy may offer escape from the terror of sleep paralysis

cjb250 — Wed, 12 Aug 2020 04:00:25 +0000

Sleep paralysis is a state involving paralysis of the skeletal muscles that occurs at the onset of sleep or just before waking. While temporarily immobilised, the individual is acutely aware of their surroundings. People who experience the phenomenon often report being terrorised by dangerous bedroom intruders, often reaching for supernatural explanations such as ghosts, demons and even alien abduction. Unsurprisingly, it can be a terrifying experience.

As many as one in five people experiences sleep paralysis, which may be triggered by sleep deprivation, and is more frequent in psychiatric conditions like post-traumatic stress disorder. It is also common in narcolepsy, a sleep disorder involving excessive daytime sleepiness and sudden loss of muscle control.

Despite the condition being known about for some time, to date there are no empirically-based treatments or published clinical trials for the condition.

Today, in the journal Frontiers in Neurology, a team of researchers report a pilot study of meditation-relaxation therapy involving 10 patients with narcolepsy, all of whom experience sleep paralysis.

̽��ֱ��therapy was originally developed by Dr Baland Jalal from the Department of Psychiatry, ̽��ֱ�� of Cambridge. ̽��ֱ��current study was led by Dr Jalal and conducted in collaboration with Dr Giuseppe Plazzi’s group at the Department of Biomedical and Neuromotor Sciences, ̽��ֱ�� of Bologna/IRCCS Istituto delle Scienze Neurologiche di Bologna, Italy.

̽��ֱ��therapy teaches patients to follow four steps during an episode:

Reappraisal of the meaning of the attack – reminding themselves that the experience is common, benign, and temporary, and that the hallucinations are a typical by-product of dreaming
Psychological and emotional distancing – reminding themselves that there is no reason to be afraid or worried and that fear and worry will only make the episode worse
Inward focused-attention meditation - focusing their attention inward on an emotionally-involving, positive object (such as a memory of a loved one or event, a hymn/prayer, God)
Muscle relaxation – relaxing their muscles, avoiding controlling their breathing and under no circumstances attempting to move

Participants were instructed to keep a daily journal for four weeks to assess sleep paralysis occurrence, duration and emotions. Overall, among the 10 patients, two-thirds of cases (66%) reported hallucinations, often upon awakening from sleep (51%), and less frequently upon falling asleep (14%) as rated during the first four weeks.

After the four weeks, six participants completed mood/anxiety questionnaires and were taught the therapy techniques and instructed to rehearse these during ordinary wakefulness, twice a week for 15 min. ̽��ֱ��treatment lasted eight weeks.

In the first four weeks of the study, participants in the meditation-relaxation group experienced sleep paralysis on average 14 times over 11 days. ̽��ֱ��reported disturbance caused by their sleep paralysis hallucinations was 7.3 (rated on a ten-point scale with higher scores indicating greater severity).

In the final month of the therapy, the number of days with sleep paralysis fell to 5.5 (down 50%) and the total number of episodes fell to 6.5 (down 54%). There was also a notable tendency towards reductions in the disturbance caused by hallucinations with ratings dropping from 7.3 to 4.8.

A control group of four participants followed the same procedure, except participants engaged in deep breathing instead of the therapy – taking slow deep breaths, while repeatedly counting from one to ten.

In the control group, the number of days with sleep paralysis (4.3 per month at the start) was unchanged, as well as their total number of episodes (4.5 per month initially). ̽��ֱ��disturbance caused by hallucinations was likewise unchanged (rated 4 during the first four weeks).

“Although our study only involved a small number of patients, we can be cautiously optimistic of its success,” said Dr Jalal. “Meditation-relaxation therapy led to a dramatic fall in the number of times patients experienced sleep paralysis, and when they did, they tended to find the notoriously terrorising hallucinations less disturbing. Experiencing less of something as disturbing as sleep paralysis is a step in the right direction.”

If the researchers are able to replicate their findings in a larger number of people – including those from the general population, not affected by narcolepsy – then this could offer a relatively simple treatment that could be delivered online or via a smartphone to help patients cope with the condition.

“I know first-hand how terrifying sleep paralysis can be, having experienced it many times myself,” said Dr Jalal. “But for some people, the fear that it can instil in them can be extremely unpleasant, and going to bed, which should be a relaxing experience, can become fraught with terror. This is what motivated me to devise this intervention.”

Reference
Jalal, B et al. Meditation-Relaxation (MR Therapy) for Sleep Paralysis: A Pilot Study in Patients with Narcolepsy. Frontiers in Neurology; 12 Aug 2020; DOI: 10.3389/fneur.2020.00922

Sleep paralysis – a condition thought to explain a number of mysterious experiences including alleged cases of alien abduction and demonic night-time visits – could be treated using a technique of meditation-relaxation, suggests a pilot study published today.

I know first-hand how terrifying sleep paralysis can be, having experienced it many times myself. But for some people, the fear that it can instil in them can be extremely unpleasant, and going to bed, which should be a relaxing experience, can become fraught with terror

Baland Jalal

Wikipedia

̽��ֱ��Nightmare by Henry Fuseli, 1781

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Sleeping over eight hours a day associated with greater risk of stroke

cjb250 — Wed, 25 Feb 2015 21:00:00 +0000

Previous studies have already suggested a possible association between sleep and risk of stroke, but today’s study, published in the journal Neurology, is the first to provide detailed information about the British population and to examine the relationship between a change in sleep duration over time and subsequent stroke risk.

Researchers from the Department of Public Health and Primary Care at the ̽��ֱ�� of Cambridge followed just under 10,000 people aged 42-81 years of age from the European Prospective Investigation into Cancer (EPIC)–Norfolk cohort over 9.5 years. During 1998-2000 and then again four years later, they asked the cohort how many hours on average they slept in a day and whether they generally slept well.
Almost seven out of ten participants reported sleeping between six and eight hours a day, whilst one in ten reported sleeping for over eight hours a day. Participants who slept for less than six hours or more than eight hours were more likely to be older, women and less active.

Over the almost ten year period of the study, 346 participants suffered a stroke, either non-fatal or fatal stroke. After adjusting for various factors including age and sex, the researchers found that people who slept longer than eight hours a day were at a 46% greater risk of stroke than average. People who slept less than six hours a day were at an 18% increased risk, but the small number of people falling in this category meant the association was not statistically significant*.

Participants who reported persistently long sleep – in other words, they reported sleeping over eight hours when asked at both points of the study – were at double the risk of stroke compared to those with persistently average sleep duration (between six and eight hours a day). This risk was even greater for those whose reported sleep increased from short to long over the four years – their risk was close to four times that of people who maintained an average sleep duration.

In addition to studying the EPIC-Norfolk cohort, the researchers carried out a study of combined data from 11 other studies related to identify the association between sleep duration and patterns of stroke risk. Their final analysis, including 560,000 participants from seven countries, supported the findings from the EPIC-Norfolk cohort study.

Yue Leng, a PhD candidate at the ̽��ֱ�� of Cambridge, says: “It’s apparent both from our own participants and the wealth of international data that there’s a link between sleeping longer than average and a greater risk of stroke. What is far less clear, however, is the direction of this link, whether longer sleep is a symptom, an early marker or a cause of cardiovascular problems.”

While older people have less work and fewer social demands and therefore often have the option of sleeping longer, previous research has shown that in fact, they tend to sleep on average for shorter periods.

̽��ֱ��researchers say it is unclear yet why the link between sleep and stroke risk should exist. Lack of sleep has been linked with factors such as disrupted metabolism and raised levels of the ‘stress hormone’ cortisol, all of which may lead to higher blood pressure and increased stroke risk. However, the current study suggests that the association between longer sleep duration and higher risk of stroke was independent of normal risk factors for cardiovascular disease.

Professor Kay-Tee Khaw, senior author on the study, adds: “We need to understand the reasons behind the link between sleep and stroke risk. What is happening in the body that causes this link? With further research, we may find that excessive sleep proves to be an early indicator of increased stroke risk, particularly among older people.”

̽��ֱ��study was supported by the Medical Research Council and Cancer Research UK.

* ̽��ֱ��absolute risk of stroke was 4.1% for less than six hours’ sleep, 3.1% for six to eight hours, and 5.3% for over eight hours. Note: these figures are before adjustment for age, sex, etc. – figures for after adjustment were not available.

Reference
Leng, Y et al. Sleep duration and risk of fatal and nonfatal stroke: A prospective study and meta-analysis. Neurology; 25 Feb 2015

People who sleep for more than eight hours a day have an increased risk of stroke, according to a study by the ̽��ֱ�� of Cambridge – and this risk doubles for older people who persistently sleep longer than average. However, the researchers say it is unclear why this association exists and call for further research to explore the link.

It’s apparent both from our own participants and the wealth of international data that there’s a link between sleeping longer than average and a greater risk of stroke

Yue Leng

Alex

Sleeping lady

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Tradition explains why some meerkats are late risers

bjb42 — Wed, 07 Jul 2010 00:00:00 +0000

After studying meerkats in the Kalahari for the past 10 years, Dr Alex Thornton and colleagues from the Department of Zoology found that some groups of meerkats always got up later out of their sleeping burrows than their neighbours.

These differences appear to have been maintained as local traditions, with patterns of behaviour in different groups being spread by learning from others.

Studying social traditions among animals in the wild is difficult because it is hard to prove that differences in behaviour are due to the social spread of information rather than genetics or environmental factors.

This is the first time such traditional patterns of daily activity have been observed in animals outside the laboratory, and the study is published this week in Proceedings of the Royal Society B.

According to lead author Dr Thornton: "Studies of animal traditions are essential for understanding the biological origins of human culture."

"Because most previous studies examined groups of animals separated by large distances it has been extremely difficult to work out whether behavioural differences between groups really are traditions, or whether they might be better explained by genetic differences or differences in the local ecology."

Dr Thornton's study site in the Kalahari Desert is shared by fifteen meerkat groups with overlapping territories, and group differences in getting-up time could not be explained by differences in ecological conditions.

And as male meerkats always breed outside the group that they were born into, genes get shuffled between groups, so genetic factors are unlikely to account for group differences.

"We found that new immigrants adopted the behaviour of their new groups and that differences between groups were maintained despite groups changing in size and structure as old members died and new ones were born," says Dr Thornton.

"So it seems that, like afternoon tea or an apéritif before dinner, meerkat getting-up times are local traditions passed down through the generations."

Just as afternoon tea is traditional in England but not in France, different groups of meerkats have different ways of doing things, Cambridge zoologists have found.

So it seems that, like afternoon tea or an apéritif before dinner, meerkat getting-up times are local traditions passed down through the generations.

Dr Alex Thornton

Meerkat

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