Publications

CamNtech Research Library

CamNtech products have been trusted by specialist researchers for over 25 years.

Our research library contains peer reviewed publications citing the use of our devices.

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Found 73 Results

The actigraphic documentation of circadian sleep-wake rhythm dysregulation in Myotonic Dystrophy Type 1

Study Objectives The present study aimed at identifying the sleep-wake rhythm in patients with myotonic dystrophy type 1 (DM1) compared to healthy controls. Methods Patients with genetic diagnosis of DM1 and healthy controls underwent a 7-day actigraphic recording and filled out a daily sleep diary to evaluate the sleep-wake rhythm. All participants underwent a physical […]

Related Product: MotionWatch

Publication Date: October 15, 2021


Event-related desynchronization in motor imagery with EEG neurofeedback in the context of declarative interference and sleep

Motor imagery (MI) in combination with neurofeedback (NF) is a promising supplement to facilitate the acquisition of motor abilities and the recovery of impaired motor abilities following brain injuries. However, the ability to control MI NF is subject to a wide range of inter-individual variability. A substantial number of users experience difficulties in achieving good […]

Related Product: MotionWatch

Publication Date: October 12, 2021


Effects of the selective orexin-2 receptor antagonist JNJ-48816274 on sleep initiated in the circadian wake maintenance zone: a randomised trial

The effects of orexinergic peptides are diverse and are mediated by orexin-1 and orexin-2 receptors. Antagonists that target both receptors have been shown to promote sleep initiation and maintenance. Here, we investigated the role of the orexin-2 receptor in sleep regulation in a randomised, double-blind, placebo-controlled, three-period crossover clinical trial using two doses (20 and […]

Related Product: MotionWatch

Publication Date: October 9, 2021


Rest activity rhythms characteristics of breast cancer women following endocrine therapy

Rest-activity rhythm (RAR) disruptions are frequently associated with chemotherapy in breast cancer (BC), but they are less known in BC with endocrine therapy (ET). The aim of this ancillary study was to characterize the RAR and estimated sleep characteristics from actigraphy in BC patients either treated (ET+) or untreated with ET (ET−), compared to healthy […]

Related Product: MotionWatch

Publication Date: October 8, 2021


Effects of 2-hour nighttime nap on melatonin concentration and alertness during 12-hour simulated night work

A nighttime nap is expected to mitigate melatonin suppression during night work by blocking light input to the retina, but it is unclear. In the present study, we investigated the effects of a nap break on melatonin level, subjective sleepiness, and vigilance performance during simulated night work. Eleven healthy young males (mean ± SD age: […]

Related Product: MotionWatch

Publication Date: September 27, 2021


Are we still in the dark? A systematic review on personal daily light exposure, sleep-wake rhythm, and mood in healthy adults from the general population

Insufficient light exposure is assumed to be related to a wide array of health problems, though few studies focus on the role of whole-day light exposure in the habitual setting in the development of these health problems. The current review aims to describe the association between personal light exposure in the habitual setting and sleep-wake […]

Related Product: MotionWatch

Publication Date: August 19, 2021


Circadian rhythm and quality of life in older adults

Sleep is critical to physical and mental health for people of all ages, but older adults are particularly vulnerable to the consequences of poor sleep health. The purpose of this pilot study was to explore patterns of sleep and the relationships between circadian rhythm disorders and quantity of life in 34 community-dwelling older adults. Participants […]

Related Product: MotionWatch

Publication Date: June 17, 2021


Time-of-day effects on objective and subjective short-term memory task performance

The time-of-day along with the synchrony effect (better performance at optimal times of the day according to the chronotype) on the cognitive performance has been well established in previous research. This influence is mediated by both circadian and homeostatic processes consistent with the Borbély two-process model. This experiment focused on the objective and subjective performance […]

Related Product: MotionWatch

Publication Date: June 14, 2021


Efficacy of early warning signals and spectral periodicity for predicting transitions in bipolar patients: An actigraphy study

Early-warning signals (EWS) have been successfully employed to predict transitions in research fields such as biology, ecology, and psychiatry. The predictive properties of EWS might aid in foreseeing transitions in mood episodes (i.e. recurrent episodes of mania and depression) in bipolar disorder (BD) patients. We analyzed actigraphy data assessed during normal daily life to investigate […]

Related Product: MotionWatch

Publication Date: June 7, 2021


Registration of 24-hour accelerometric rest-activity profiles and its application to human chronotypes

By collecting data continuously over 24 hours, accelerometers and other wearable devices can provide novel insights into circadian rhythms and their relationship to human health. Existing approaches for analyzing diurnal patterns using these data, including the cosinor model and functional principal component analysis, have revealed and quantified population-level diurnal patterns, but considerable subject-level variability remained […]

Related Product: Actiheart

Publication Date: May 31, 2021


MotionWatch 8 Wrist Actimetry Data Analysis: from ambulatory recording to real life monitoring

On the National Sleep Research Resource (NSRR) platform, there’s a year’s worth in real-life wrist actigraphy data using a Motionwatch8. The data analysis suggested in this paper reveals a data structure that allows the design of parameters to be used in real life monitoring and may drive the developments of devices. The analysis is totally […]

Related Product: MotionWatch

Publication Date: May 13, 2021


Different Circadian Rest-Active Rhythms in Kleine-Levin Syndrome: A prospective and case-control study

Study objectives Kleine-Levin-syndrome (KLS) is a rare recurrent hypersomnia. Our study aimed at monitoring the movements of patients with KLS using actigraphy and evaluating their circadian rhythm. Methods Twenty young patients with KLS and 14 age-matched controls were recruited. Each individual wore an actigraphy for more than 6 months to monitor at least two attacks. […]

Related Product: MotionWatch

Publication Date: April 14, 2021


Sleep deprivation therapy to reset the circadian pacemaker in a non-24-hour sleep-wake disorder: a case report

Non-24-hour sleep-wake disorder (N24SWD) is one of several chronic circadian rhythm sleep-wake disorders (CRSWDs). It is defined as progressive daily shifts in sleep onset and wake times. It mainly affects sight-impaired persons, is relatively rare in sighted patients, and is difficult to treat, with no guidelines. We report a case of N24SWD in a sighted […]

Related Product: MotionWatch

Publication Date: April 1, 2021


Quantifying Circadian Aspects of Mobility-Related Behavior in Older Adults by Body-Worn Sensors—An “Active Period Analysis”

Disruptions of circadian motor behavior cause a significant burden for older adults as well as their caregivers and often lead to institutionalization. This cross-sectional study investigates the association between mobility-related behavior and subjectively rated circadian chronotypes in healthy older adults. The physical activity of 81 community-dwelling older adults was measured over seven consecutive days and […]

Related Product: MotionWatch

Publication Date: March 18, 2021


Sex Differences in Rest-Activity Circadian Rhythm in Patients With Metabolic Syndrome

Rest-Activity circadian Rhythm (RAR) can be used as a marker of the circadian timing system. Recent studies investigated the relationship between irregular circadian rhythms and cardiovascular risk factors such as hypertension, obesity, and dyslipidemia. These factors are related to the Metabolic Syndrome (MS), a clustering of metabolic risk factors that increases the risk of several […]

Related Product: MotionWatch

Publication Date: March 18, 2021


Weekly, seasonal and chronotype‐dependent variation of Dim‐Light Melatonin Onset

In humans, the most important zeitgeber for entrainment is light. Laboratory studies have shown that meaningful changes in light exposure lead to phase shifts in markers of the circadian clock. In natural settings, light is a complex signal varying with external conditions and individual behaviors; nonetheless, phase of entrainment is assumed to be fairly stable. […]

Related Product: MotionWatch

Publication Date: February 20, 2021


Can actigraphy be used to define lithium response dimensions in bipolar disorders?

Background: Actigraphy is commonly used in case-control studies to explore sleep-wake patterns and circadian rhythmicity in bipolar disorders (BD). However, there is limited ecological research regarding actigraphy parameters associated with response to lithium (Li_Resp). Methods: Outpatients with BD-I (n=70) and BD-II (n=20) who were all prescribed prophylactic Li undertook 21 consecutive days of actigraphy recording. […]

Related Product: MotionWatch

Publication Date: February 2, 2021


A brief report of sleep and circadian rhythm quotas in a population of dog owners in North Carolina USA

Objectives To characterize sleep and circadian rhythms of a sample population of healthy, dog-owning adults from North Carolina, USA. Methods Actigraphy was used to analyze sleep-wake patterns in forty-two dog owners from the Raleigh area in North Carolina. Sleep quotas, including sleep duration, efficiency, and fragmentation were measured alongside a Non-parametric Circadian Rhythms Analysis (NPCRA) […]

Related Product: MotionWatch

Publication Date: January 22, 2021


Sleep, Circadian Rhythmicity and Response to Chronotherapy in University Students: Tips from Chronobiology Practicals

Chronobiology is not routinely taught to biology or medical students in most European countries. Here we present the results of the chronobiology practicals of a group of students of the University of Padova, with a view to highlight some interesting features of this group, and to share a potentially interesting cross-faculty teaching experience. Thirty-eight students […]

Related Product: PRO-Diary

Publication Date: January 21, 2021


Circadian Patterns of Patients with Type 2 Diabetes and Obstructive Sleep Apnea

Sleep apnea, a condition that modifies sleep and circadian rhythms, is highly prevalent in patients with diabetes. However, it is not known if there is an association between sleep apnea, circadian alterations and glycemic regulation in this type of patient. Here, a polysomnographic study was carried out on 21 women and 25 men (mean age […]

Related Product: MotionWatch

Publication Date: January 11, 2021


The acute effects of sleep restriction therapy for insomnia on circadian timing and vigilance

Sleep‐restriction therapy (SRT) has been shown to improve insomnia symptoms by restricting sleep opportunity. Curtailment of time in bed affects the duration and consolidation of sleep, but also its timing. While recent work suggests that people with insomnia are characterised by misalignment between circadian and behavioural timing of sleep, no study has investigated if SRT […]

Related Product: PRO-Diary

Publication Date: December 13, 2020


Sleep− wake cycle dysregulation in idiopathic REM sleep behaviour disorder

Alteration of the circadian sleep−wake rhythm has been suggested in patients affected by idiopathic rapid eye movement sleep behaviour disorder. Because actigraphy is the validated instrument to monitor the sleep−wake cycle, the aim of the present study was to investigate the circadian sleep−wake rhythm in patients with idiopathic rapid eye movement sleep behaviour disorder compared […]

Related Product: MotionWatch

Publication Date: December 1, 2020


Effect of vestibular stimulation using a rotatory chair in human rest/activity rhythm

The vestibular system is responsible for sensing every angular and linear head acceleration, mainly during periods of motor activity. Previous animal and human experiments have shown biological rhythm disruptions in small rodents exposed to a hypergravity environment, but also in patients with bilateral vestibular loss compared to a control population. This raised the hypothesis of […]

Related Product: MotionWatch

Publication Date: September 26, 2020


Timed physical exercise does not influence circadian rhythms and glucose tolerance in rotating night shift workers: The EuRhythDia study

Objectives: Night shift workers are at cardiometabolic risk due to circadian misalignment. We investigated whether infrequent exercise before each night shift that intentionally would not improve physical performance improves glucose tolerance and 24-h blood pressure profiles and synchronizes circadian rhythms of melatonin and cortisol in rotating night shift workers. Methods: A total of 24 rotating […]

Related Product: MotionWatch

Publication Date: September 25, 2020


Prediction of individual differences in circadian adaptation to night work among older adults: application of a mathematical model using individual sleep-wake and light exposure data

Circadian misalignment remains a distinct challenge for night shift workers. Variability in individual sleep-wake/light-dark patterns might contribute to individual differences in circadian alignment in night shift workers. In this simulation study, we compared the predicted phase shift from a mathematical model of the effect of light on the human circadian pacemaker to the observed melatonin […]

Related Product: MotionWatch

Publication Date: September 6, 2020


Disturbances of Continuous Sleep and Circadian Rhythms Account for Behavioral Difficulties in Children with Autism Spectrum Disorder

Sleep disorders are among the most common comorbidities in children with Autism Spectrum Disorder (ASD), and subjectively defined sleep disturbances have been related to ASD symptom severity. However, no study has investigated the differential impact of objectively measured sleep and circadian rhythm disturbances on behavioral difficulties in this population. Fifty-two children with ASD aged 3–10 […]

Related Product: MotionWatch

Publication Date: June 24, 2020


Rest-activity rhythm in breast cancer survivors: an update based on non-parametric indices

Recently we evaluated by actigraphy the rest-activity circadian rhythm (RAR) in breast cancer (BC) survivors at 5 years from primary diagnosis, as well as in a control group with similar age and body mass index (BMI). RAR, analyzed by Cosinor method, resulted significantly different in BC survivors compared to healthy subjects: BC survivors showed lower […]

Related Product: MotionWatch

Publication Date: April 24, 2020


Sleep-Wake Cycle in Alzheimer’s Disease Is Associated with Tau Pathology and Orexin Dysregulation

Background:Alzheimer’s disease (AD) is the most common form of dementia. It is mainly characterized by a progressive deterioration of cognition, but sleep-wake cycle disturbances frequently occur. Irregular sleep-wake cycle, insomnia, and daytime napping usually occur in patients with AD in the course of the disease. Objective:The aim of the present study was to verify the […]

Related Product: MotionWatch

Publication Date: February 10, 2020


Disruption in daily eating-fasting and activity-rest cycles in Indian adolescents attending school.

A lifestyle with erratic eating patterns and habits predisposes youngsters to obesity. Through a two-phase feasibility study among Indian students living in the Delhi area, we longitudinally examined the following: (1) the daily eating-fasting cycles of students (N = 34) in school and college using smartphones as they transition from high school (aged 13–15 years; […]

Related Product: MotionWatch

Publication Date: January 10, 2020


Pupillometry evaluation of melanopsin retinal ganglion cell function and sleep-wake activity in pre-symptomatic Alzheimer’s disease

Background Melanopsin-expressing retinal ganglion cells (mRGCs), intrinsically photosensitive RGCs, mediate the light-based pupil response and the light entrainment of the body’s circadian rhythms through their connection to the pretectal nucleus and hypothalamus, respectively. Increased awareness of circadian rhythm dysfunction in neurological conditions including Alzheimer’s disease (AD), has led to a wave of research focusing on […]

Related Product: MotionWatch

Publication Date: December 10, 2019


Summer-winter difference in 24-h melatonin rhythms in subjects on a 5-workdays schedule in Siberia without daylight saving time transitions

The study aimed to quantify a seasonal change in circadian rhythms and its relationship to the social/sleep regimen in humans living in Novosibirsk (55°N), using the naturalistic situation that daylight saving time transitions have been abolished in Russia. Sixty-three volunteers entered the study, and 46 completed it. One group got up at ~6 a.m. and […]

Related Product: MotionWatch

Publication Date: December 1, 2019


Smart Rehabilitation for Neuro-Disability: A Review

Neurological disorders are increasing globally due to various factors such as change in lifestyle patterns as well as personal and professional stress. Scientists belonging to various research and development organizations from a variety of disciplines are working together to invent new rehabilitation devices. Emerging trends in electronics and information technology-enabled devices provide a platform for […]

Related Product: MotionWatch

Publication Date: November 20, 2019


Sleep-wake disorders in Alzheimer’s disease: further genetic analyses in relation to objective sleep measures

This paper presents updated analyses on the genetic associations of sleep disruption in individuals with Alzheimer’s disease (AD). We published previously a study of the association between single nucleotide polymorphisms (SNPs) found in eight genes related to circadian rhythms and objective measures of sleep-wake disturbances in 124 individuals with AD. Here, we present new relevant […]

Related Product: MotionWatch

Publication Date: November 19, 2019


The Effect of a Common Daily Schedule on Human Circadian Rhythms During the Polar Day in Svalbard: A Field Study

All Arctic visitors have to deal with extreme conditions, including a constant high light intensity during the summer season or constant darkness during winter. The light/dark cycle serves as the most potent synchronizing signal for the biological clock, and any Arctic visitor attending those regions during winter or summer would struggle with the absence of […]

Related Product: MotionWatch

Publication Date: October 9, 2019


Variation near MTNR1A associates with early development and interacts with seasons

Melatonin is a circadian regulatory hormone with neuroprotective properties. We have previously demonstrated the association of the genetic variant rs12506228 near the melatonin receptor 1A gene (MTNR1A) with intolerance to shift‐work. Furthermore, this variant has been connected to Alzheimer’s disease. Because of the previously suggested role of melatonin signalling in foetal neurocognitive and sleep development, […]

Related Product: MotionWatch

Publication Date: October 7, 2019


The Relationship between Fatigue and Actigraphy-Derived Sleep and Rest-Activity Patterns in Cancer Survivors

Study Objectives: To investigate objectively-measured sleep and rest-activity cycles in fatigued and non-fatigued cancer survivors. We hypothesized that sleep and rest-activity cycles would be more disturbed in people experiencing clinically-relevant cancer-related fatigue, and that objective measures of sleep would be associated with the severity of fatigue in cancer survivors. Methods: Cancer survivors (n = 87) […]

Related Product: MotionWatch

Publication Date: September 6, 2019


A 6-day combined wake and light therapy trial for unipolar depression

Background There are a dozen studies on double or triple chronotherapy in depression (sleep deprivation [wake therapy] + light therapy + sleep advance/stabilization). We investigated efficacy and feasibility of a modified triple chronotherapy protocol. Methods Thirty-five hospitalized patients with moderately severe non-seasonal depressive disorder, mostly free from antidepressants, underwent a 6-day protocol consisting of partial sleep deprivation late in […]

Related Product: MotionWatch

Publication Date: August 19, 2019


Response to Treatment With Lemborexant: Subjects With Irregular Sleep-Wake Rhythm Disorder and Alzheimer’s Disease Dementia

Irregular sleep-wake rhythm disorder (ISWRD) is a circadian rhythm sleep disorder, distinct from insomnia, which is characterized by the irregular distribution of sleep bouts across the 24-hour period rather than consolidated sleep at night. ISWRD symptoms are common in patients with Alzheimer’s disease dementia (AD-D). Pathology of ISWRD includes disturbed circadian rhythmicity, neuronal loss in […]

Related Product: MotionWatch

Publication Date: July 14, 2019


Decreased need for sleep as an endophenotype of bipolar disorder: an actigraphy study

Reports of subjective sleep impairments have been replicated in adults with bipolar disorder (BD), young BD patients, and even children of parents with BD. Furthermore, circadian rhythm alterations are a core feature of BD. Despite the impairment in circadian rhythms and altered sleep included in various heuristic developmental models of BD, thus far, biomarkers have […]

Related Product: MotionWatch

Publication Date: July 1, 2019


Effects of a dawn-dusk simulation on circadian rest-activity cycles, sleep, mood and well-being in dementia patients

Light is the most powerful “zeitgeber” signal to synchronize circadian sleep-wake cycles. In dementia, these rhythms are often fragmented — probably due to loss of neuronal function of the suprachiasmatic nuclei (the biological “master clock” in the brain) and/or weakness of external zeitgebers. We investigated the effects of a prototype dawn-dusk simulator (DDS) on circadian […]

Related Product: MotionWatch

Publication Date: June 25, 2019


Rest-activity circadian rhythm in breast cancer survivors at 5 years after the primary diagnosis

Rest-activity circadian rhythm (RAR) is a marker of the circadian timing system. Particular attention has been given to RAR characteristics in cancer diseases. Specifically, alterations of RAR parameters have been found, at different stages of clinical pathway, in breast cancer (BC) patients. No studies to date have analyzed RAR alterations in breast cancer survivors several […]

Related Product: MotionWatch

Publication Date: June 10, 2019


Beyond the low frequency fluctuations morning and evening differences in human brain

Human performance, alertness, and most biological functions express rhythmic fluctuations across a 24-hour-period. This phenomenon is believed to originate from differences in both circadian and homeostatic sleep-wake regulatory processes. Interactions between these processes result in time-of-day modulations of behavioral performance as well as brain activity patterns. Although the basic mechanism of the 24-hour clock is […]

Related Product: MotionWatch

Publication Date: June 6, 2019


Living in Biological Darkness: Objective Sleepiness and the Pupillary Light Responses Are Affected by Different Metameric Lighting Conditions during Daytime

Nighttime melatonin suppression is the most commonly used method to indirectly quantify acute nonvisual light effects. Since light is the principal zeitgeber in humans, there is a need to assess its strength during daytime as well. This is especially important since humans evolved under natural daylight but now often spend their time indoors under artificial […]

Related Product: MotionWatch

Publication Date: June 2, 2019


Pregnancy Induces an Earlier Chronotype in Both Mice and Women

Daily rhythms generated by endogenous circadian mechanisms and synchronized to the light-dark cycle have been implicated in the timing of birth in a wide variety of species. Although chronodisruption (e.g., shift work or clock gene mutations) is associated with poor reproductive outcomes, little is known about circadian timing during pregnancy. This study tested whether daily […]

Related Product: MotionWatch

Publication Date: April 24, 2019


Hypothalamic‐pituitary‐adrenal axis differentially responses to morning and evening psychological stress in healthy subjects

Aim The hypothalamic‐pituitary‐adrenal (HPA) axis responds to changing environmental demands including psychological stressors. The aim of the present study was to assess whether the time of day effects on the acute response of HPA axis activity to acute psychological stress. Method We studied 27 healthy young subjects. The subjects were participated two experiments as follows. […]

Related Product: MotionWatch

Publication Date: March 3, 2019


Strategies to decrease social jetlag: Reducing evening blue light advances sleep and melatonin

The timing of sleep is under the control of the circadian clock, which uses light to entrain to the external light‐dark cycle. A combination of genetic, physiological and environmental factors produces individual differences in chronotype (entrained phase as manifest in sleep timing). A mismatch between circadian and societal (e.g., work) clocks leads to a condition […]

Related Product: MotionWatch

Publication Date: December 2, 2018


Impact of long-term daylight deprivation on retinal light sensitivity, circadian rhythms and sleep during the Antarctic winter.

Long-term daylight deprivation such as during the Antarctic winter has been shown to lead to delayed sleep timing and sleep fragmentation. We aimed at testing whether retinal sensitivity, sleep and circadian rest-activity will change during long-term daylight deprivation on two Antarctic bases (Concordia and Halley VI) in a total of 25 healthy crew members (mean […]

Related Product: MotionWatch

Publication Date: November 1, 2018


Suppression of salivary melatonin secretion under 100-Hz flickering and non-flickering blue light

Background Bright light at night is known to suppress melatonin secretion. Novel photoreceptors named intrinsically photosensitive retinal ganglion cells (ipRGCs) are mainly responsible for projecting dark/bright information to the suprachiasmatic nucleus and thus regulating the circadian system. However, it has been shown that the amplitude of the electroretinogram of ipRGCs is considerably lower under flickering […]

Related Product: MotionWatch

Publication Date: October 19, 2018


Does the moon influence sleep in small-scale societies?

Objectives The lunar cycle is expected to influence sleep-wake patterns in human populations that have greater exposure to the environment, as might be found in forager populations that experience few environmental buffers. We investigated this “moonlight” hypothesis in two African populations: one composed of hunter-gatherers (with minimal environmental buffering) and the other rural agriculturalists (with […]

Related Product: MotionWatch

Publication Date: October 4, 2018


Sleep and neurobehavioral performance vary by work start time during non-traditional day shifts

Introduction It is established that shiftwork causes sleep loss and circadian misalignment. Individuals who work non-traditional day shifts that encroach into typical sleep times, such as those in the service and transportation sectors, may also experience sleep and circadian disruption. We aimed to determine how neurobehavioral performance and sleep would be affected by work start […]

Related Product: MotionWatch

Publication Date: October 1, 2018


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