Proven Experience
We at Condor Instruments have based our products on dozens of research projects around the world, bringing us proven experience in a wide range of areas that contributes to the generation of numerous analyses, diagnoses and data.
Actigraphy-based evaluation of sleep quality and physical activity in individuals with spinal cord injury
Abstract: Sleep disturbances are frequently reported by individuals with spinal cord injury (SCI) and are associated both with poor quality of life and reduced ability to participate in rehabilitation and daily life activities.
Evaluation of Sleep Quality from the Perspective of Comfort for Postgraduate Nursing Students
Sleep Quality Assessment from the Perspective of Comfort for the Nursing Graduate Students Abstract: Sleep is considered essential for human beings, as it has a restorative function. Circadian rhythm disruptions affect cognitive performance and represent a risk factor for several chronic diseases. This problem becomes even more frequent among healthcare workers and university students due to multiple environmental factors that can directly affect their sleep-wake behavior.
Sleep pattern evaluation in medical students at Medical Sciences Multicampi School of Rio Grande do Norte / Sleep pattern evaluation in medical students at Medical Sciences Multicampi School of Rio Grande do Norte
Abstract: Sleep disorders are common in medical students and can harm academic training. Curriculum demands tend to desynchronize the sleep-wake cycle and alter sleep quality, sometimes forcing students to choose between maintaining regular sleep patterns or meeting academic requirements.This study evaluated the sleep pattern of medical students at the Multicampi School of Medical Sciences of the State of Rio Grande do Norte, located in Caicó-RN, which adopts a curriculum based on Problem Based Learning (PBL).
Biomechanical procedure to assess sleep restriction on motor control and learning
Abstract: The analysis of sleep quality during long periods and its impact on motor control and learning performance are crucial aspects for human health. The aim of this study is to analyze effects of chronic sleep restriction on motor performance. It is intended to establish motor control indicators in sleep quality analysis. A wearable actigraphy that records accelerometry, ambient light, and body temperature was used to monitor the sleep habits of 12 healthy subjects for two weeks before performing motor control and learning tests.
Baseline Pupil Diameter Is Not a Reliable Biomarker of Subjective Sleepiness
Abstract: Sleepiness is commonly seen as reflecting the basic physiological need to sleep and is associated with physiological and neurobiological changes. Subjective evaluations of sleepiness, however, are neither representative of cognitive and physical performances, nor of physiological sleepiness. Finding a simple, rapid, and objective marker of sleepiness is essential in order to prevent errors and accidents, but this has remained largely unsuccessful. The aim of this study was to determine whether the baseline pupil diameter is a physiological biomarker of sleepiness at all times of day and to isolate the regulatory components involved.
Chronic Low Quality Sleep Impairs Postural Control in Healthy Adults
Abstract: The lack of sleep, both in quality and quantity, is an increasing problem in modern society, often related to workload and stress. A number of studies have addressed the effects of acute (total) sleep deprivation on postural control. However, up to date, the effects of chronic sleep deficits, either in quantity or quality, have not been analyzed.
Rest-activity and feed-fast cycles associated with the use of electronic equipment: behavioral aspects and temporal patterns
Abstract: Worldwide electricity for domestic use is a recent phenomenon that has incorporated temporal modulations in the expression of biological rhythms, such as eating and sleeping habits. After its popularization, electronic technologies were created and incorporated into our daily routines. Access to electricity promotes greater flexibility in the temporal organization of our activities by making it easier to control the extension of the activity phase to later hours of the night. Thus, this situation can represent a temporal challenge to the organism, generated by the oscillations of temporal cues, advancing or delaying the occurrence of rhythmic events such as eating/fasting, activity/rest, and metabolism.
Circadian Light Exposures of Shift Working Nurses
Abstract: Studies have linked adverse health outcomes to work during the body’s subjective night. Certain shift schedules result in light exposure profiles that may cause circadian disruption. Previous studies estimated average artificial illuminance to quantify light at night (LAN) at work which limits their validity and scope. However, daylight, shift length, commuting exposures and light during restricted sleep opportunities compete with LAN as causative agents, as do non-photic factors such as social disruption, activity and food intake during the subjective night. Investigations into the effects of light in shift work should be supported by 24-hour light exposure measurements, e.g. to establish dose-response relationships. The purpose of the study was to collect and suggest interpretations of 24-hour exposure data, and investigate both daytime and night-time workers’ light cycles in more detail.
Circadian ontogeny through the lens of nonparametric variables of actigraphy
Abstract: Studies focusing on human rhythmicity show that human circadian rhythm undergoes constant changes across lifespan. Changes in rest-activity patterns can be studied through nonparametric variables of actigraphy: L5 (an individual’s least active 5 h), M10 (an individual’s most active 10 h) and RA (relative amplitude of the rest-activity rhythm). The variable RA is the normalized difference between L5 and M10 – the higher the RA, the greater the difference between these two variables.
Circadian rhythm abnormalities and autonomic dysfunction in patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis
Abstract: Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients frequently show autonomic symptoms which may be associated with a hypothalamic dysfunction. This study aimed to explore circadian rhythm patterns in rest and activity and distal skin temperature (DST) and their association with self-reported outcome measures, in CFS/ME patients and healthy controls at two different times of year.
Comparison between an African town and a neighbouring village shows delayed, but not decreased, sleep during the early stages of urbanization
Abstract: The well-established negative health outcomes of sleep deprivation, and the suggestion that availability of electricity may enable later bed times without compensating sleep extension in the morning, have stimulated interest in studying communities whose sleep pattern may resemble a pre-industrial state. Here, we describe sleep and activity in two neighbouring communities, one urban (Milange) and one rural (Tengua), in a region of Mozambique where urbanization is an ongoing process. The two communities differ in the amount and timing of daily activity and of light exposure, with later bedtimes (≈1 h) associated with more evening and less daytime light exposure seen in the town of Milange.
Comparison of sleep parameters assessed by actigraphy of healthy young adults from a small town and a megalopolis in an emerging country
Abstract: The analysis of sleep quality and its impact on diurnal sleepiness is a crucial aspect of human health. Modern life in large cities compels people to spend fewer hours sleeping than they need. A wearable actigraphy that records accelerometry, light and body temperature was used to register the sleep habits of 54 healthy subjects for 14 days. Of them, 28 participants resided in a town that could be regarded as a rural environment while the other subjects lived in the largest metropole of South America. The subjects filled in three questionnaires to assess sleep quality (Pittsburgh Sleep Quality Index – PSQI), sleepiness (Epworth Sleepiness Scale – ESS) and chronotype (Morningness-Eveningness Questionnaire – MEQ-HO).
Comparison of sleep quality assessed by actigraphy and questionnaires to healthy subjects
Abstract: Sleep quality analysis is crucial for human health and it is related to duration, rhythm and quality. The goal of this study is to analyze objective assessment of the sleep-wake cycles with actigraphy, subjective questionnaires and their relationship with sleep quality indices. A wearable actigraph recorded the sleep habits of 41 healthy subjects for 9 days. Afterwards, the subjects filled in two questionnaires about sleep quality (Pittsburgh Sleep Quality Index) and sleepiness (Epworth Sleepiness Scale). The subjects were divided into two groups based on cut-off scores and the actigraphy parameters were compared between groups. Group 1 in ESS and PSQI categorization had less diurnal sleepiness and better sleep quality, respectively, than Group 2. Measurements of regularity (IS), fragmentation (IV), active phase amplitude (M10), rest amplitude (L5), and relative amplitude (RA) were compared between groups. Group 2 had higher L5 values. Parameter L5 (lowest of 5 consecutive hours of activity) was concluded to be relevant to identify the sleep conditions of the subjects.
Behavior, verbal fluency and Circadian rhythms in individuals with Autism Spectrum Disorder (ASD) before and after the use of melatonin
Abstract: The common characteristics of the Autism Spectrum Disorder (ASD) highlighted by the DSM-5 are: communication deficit, difficulty making friends or relating, routine dependence, resistance to change and obsession with inappropriate items. Such behaviors can be observed since childhood, but with variations in each individual, which led the ASD to be considered a “continuum” that varies from less compromised (mild) to very compromised (severe). Among the complex symptoms of ASD in the different degrees, a high prevalence of sleep disorders stands out, with a negative influence on behavioral changes, mood instability, deficits in neurocognitive functions including memory, attention, verbal creativity, cognitive flexibility and abstract reasoning.
Circadian rhythms are disrupted in patients and preclinical models of Machado-Joseph disease
Abstract: Machado-Joseph disease (MJD) is caused by an abnormal CAG repeat expansion in the ATXN3 gene, leading to the expression of a mutant ataxin-3 (mutATXN3) protein. Patients with MJD exhibit a wide range of clinical symptoms, including motor incoordination. Emerging evidence highlights circadian rhythm disruptions as early indicators and potential risk factors for the progression of neurodegenerative conditions. Circadian rhythms are regulated by internal clocks, with the suprachiasmatic nucleus (SCN) acting as the master pacemaker to synchronize timing across the body’s behavioral and physiological functions. While sleep disturbances have been observed in MJD, the role of clock regulation in its pathophysiology remains largely unexplored in spinocerebellar ataxias. This study aimed to investigate circadian rhythms, characterize associated disruptions and uncover the mechanisms underlying clock dysregulation in patients and preclinical models of MJD.
Daytime sleepiness affects gait auditory synchronization ability
Abstract: Sleep disturbances in modern life lead to cognitive and motor performance impairments in everyday tasks such as gait. The most common symptom of these disturbances is daytime sleepiness, which can be assessed by questionnaires such as the Epworth Sleep Scale (ESS). The ESS evaluates sleep health and daytime dysfunction. The goal of this study is to assess the influence of sleepiness on a motorauditory synchrony task, rhythmic gait. High and low sleepiness clusters were formed based on the participants ESS scores.
The effect of alternating work shifts on the food consumption of shifting workers
Abstract: Studies have described unhealthy eating habits and irregular meal times among shifting workers. However, the impact of rotation between daytime, evening, and night work hours and days off, within a short period of time, on the pattern of food consumption is scarcely discussed in the literature. Objective: Evaluating the effect of shift rotation on the duration of food consumption, “eating duration” (ED), as well as the effects of the duration of food consumption on energy and macronutrient intake.
The effect of ingesting a high-protein meal during the night shift on the postprandial metabolic response the following day: a crossover, randomized, controlled study
Abstract: Shift work has been associated with nutritional and metabolic diseases, considering that quality, quantity, and timing of meals are thought of as important factors associated with the development of chronic diseases and weight gain in shift workers. However, the impact of night feeding on the metabolic response of shift workers is little explored in the literature. Objective: Evaluating the acute effect of a high-protein meal compared to a normoprotein meal served in the evening on the postprandial metabolic response of night workers the following day.
Biological time. Circadian rhythms and their implications for health
Abstract: Over the course of evolution, humans have adapted to the cyclical patterns generated by the Earth’s movements and, consequently, present daily variations in their physiology and behavior. The circadian rhythms of all the organs and cells in the body are in perfect synchrony, producing a well-defined organic structure over time. The science that studies biological rhythms is chronobiology. The main structure that regulates circadian rhythms in mammals is the suprachiasmatic nuclei, a set of neurons at the base of the brain. People’s preference to set a certain time, the chronotype, is determined by the genetics of the internal clock, by age and by light. When for certain circumstances the internal clock is out of sync with external time, it is called circadian maladjustment. The most typical cause of circadian maladjustment is nocturnal tornadoes, but it can also occur due to anonymous lighting or poor hourly regularity. Circadian maladjustment is a health risk, and can lead to a higher incidence of metabolic alterations, such as diabetes, cardiovascular diseases and alterations in sleep and cognition.
Evaluating the efficacy of Internet-Based Exercise program Aimed at Treating knee Osteoarthritis (iBEAT-OA) in the community: a study protocol for a randomized controlled trial
Abstract: Knee osteoarthritis (OA) is the most common joint disease worldwide. As of today, there are no disease-modifying drugs, but there is evidence that muscle strengthening exercises can substantially reduce pain and improve function in this disorder, and one very well tested physiotherapy protocol is the ‘Better Management of Patients with Osteoarthritis’ developed in Sweden. Given the high prevalence of knee OA, a potentially cost-effective, digitally delivered approach to treat knee OA should be trialled. This study aims to explore the benefits of iBEAT-OA (Internet-Based Exercise program Aimed at Treating knee Osteoarthritis) in modulating pain, function and other health-related outcomes in individuals with knee OA.
Melatonin and circadian rhythms in autism: Case report
Abstract: Among the most co-occurring conditions in autism spectrum disorders (ASD), there are sleep disorders which may exacerbate associated behavioral disorders and lead to intensification of existing autistic symptoms. Several studies investigating the use of melatonin in the treatment of sleep disorders in ASD have shown comparative efficiency in sleep with little or no side effects. Here we report a case of ASD with non-24-hour rhythm and the effect of melatonin in circadian parameters by actigraphy. Visual analysis of the first 10 days recorded and the periodogram suggest that this patient showed a non-24-hour rhythm. This ASD subject showed before melatonin administration an activity/rest rhythm lower than 24 hours.
Modification of a personal dosimetry device for logging melanopic irradiance
Abstract: Performance characterizations were carried out before and after a modification to the optics of the Condor Instruments’ ActTrust light and activity data loggers to improve the spectral performance for measuring melanopic-weighted irradiance in non-visual studies. The results confirm the intended improvement, so that the device provides the best-known single-sensor match to the melanopic response. In addition, the device includes a separate sensor which remained well-matched for illuminance logging.
Nocturnal motor activity and light exposure: Objective actigraphy-based marks of melancholic and non-melancholic depressive disorder. Brief report
Abstract: Differentiation of melancholic (MEL) and non-melancholic (N-MEL) depression results from subjective assessment of psychomotor disturbance, which obscures their accurate diagnosis. CORE instrument assigned participants with severe or refractory depression to MEL or N-MEL group. Participants underwent 7 days of actigraphy. Data was fitted to a cosinusoidal curve corresponding to a 24-h rhythm. Nocturnal activity was significantly higher in N-MEL. ROC curve shows that average night activity discriminates participants with 71% sensitivity and 100% specificity (area under the curve = 0.84). Actigraphy contribute to the objective differentiation of depression subtypes, and have implications for research on their neurobiology and clinical management.
Non-visual effects of light: How to use light to promote circadian entrainment and elicit alertness
Abstract: In addition to stimulating the visual system, light incident on the retina stimulates other biological functions, also referred to as non-visual responses. Among the most notable biological functions are human circadian rhythms, which are bodily rhythms that, in constant darkness, oscillate with a period close to, but typically slightly longer than 24 hours. Twenty-four-hour light-dark patterns incident on the retina are the major synchronizer of circadian rhythms to the local time on Earth. Entrainment of circadian rhythms has been implicated in health and well-being. Light can also elicit an acute alerting effect on people, similar to a ‘cup of coffee. This review summarizes the literature on how light affects entrainment and alertness and how it can be used to achieve these aims.
Optical performance characterization of light-logging actigraphy dosimeters
Abstract: There are several wearable products specially developed or marketed for studying sleep, circadian rhythms, and light levels. However, new recommendations relating to human physiological responses to light have changed what measurements researchers may demand. The performances of 11 light-logging dosimeters from eight manufacturers were compared. The directional and spectral sensitivities, linearity, dynamic range, and resolution were tested for seven models, and compared along with other published data. The sample mainly comprised light-logging actigraphy dosimeters wearable as badges, in accordance with measurement protocols for larger-scale field studies. A proposed standard for optical performance assessments is set out.
Design and construction of a luminosity and temperature measurement device for the study of human biological rhythms
Abstract: This study presents the conception, design, and construction of a device to perform measurements related to the study on the alteration of human biological rhythms in prolonged exposure to artificial lighting. Data collection includes the luminosity and temperature of a hospital environment, meeting the criteria proposed for its use in a research project at the Clinic Hospital of Porto Alegre. The sensors for these environmental parameters are connected to two types of microcontrollers, both capable of storing and transmitting the results for further analysis.
The relationship between sleep and sleep habits and quality knowledge levels, and the components of attention in university students
Abstract: The sleep phase delay characterized by late sleeping and waking times, observed during adolescence, may persist after young people join university. This delay results in shortening the sleep duration of students who study in the morning, as they are forced to wake up earlier during the school week. This behavior can modify sleep habits and quality and, thus, affect the attention of those in the morning shift. Knowing that attention is a basic process capable of interfering with other cognitive processes and that knowledge plays a role in decision making, we have investigated the relationship between sleep and sleep habits and quality knowledge levels, and the components of attention of young people from a public university in the state of Rio Grande do Norte.
The relationship between light exposure in the classroom, the sleep-wake cycle and attention in adolescents from different cities of the state of Rio Grande do Norte
Abstract: In adolescents, sleep phase delay is associated with reduced sleep duration, increasing daytime sleepiness and poor academic performance. Poor performances may be related to the reduction in attention, a cognitive process with components that present Circadian variation, and, like the sleep-wake cycle, it may be modulated by light-dark cycles. Therefore, this study aims to verify the existence of relationships between light intensity in the classroom and the sleep-wake cycle, sleep quality, daytime sleepiness and attention in morning shift adolescents from private schools in the capital (Natal: Latitude: 05º 47′ 42″ South, Longitude: 35º 12′ 34″ West) and in the countryside (Santa Cruz: Latitude: 6° 13′ 46″ South, Longitude: 36° 1′ 24″ West) of the state of Rio Grande do Norte. The study included 115 adolescents (Capital: 56 and Countryside: 59), of both genders (41 boys), enrolled in the 1st and 2nd years of high school.
Rhythmic changes in Fabry disease: Inversion and non-oscillatory pattern in 6-sulfatoxymelatonin daily profile
Abstract: Fabry disease is a progressive disease characterized by an enzymatic deficiency of acid alpha-galactosidase and glycosphingolipids storage within the lysosomes. The disease has two phenotypes: classic and nonclassic. Excessive daytime sleepiness is a common sign reported by patients and can be caused by a circadian rhythm sleep disorder. Activity and rest cycle, variation of body temperature and melatonin biosynthesis are known rhythmicity markers. In the face of this evidence, our goal was to evaluate the rhythmic profile in Fabry’s disease patients using rhythmicity markers.
Sleep and light exposure across different levels of urbanization in Brazilian communities
Abstract: Quilombos are settlements originally founded by Africans and African descendants (Quilombolas) in remote parts of Brazil to escape slavery. Due to individual histories, Quilombos nowadays exhibit different states of industrialization, making them ideal for studying the influence of electrification on daily behaviour. In a comparative approach, we aimed to understand whether and how human sleep changes with the introduction of artificial light. We investigated daily rest-activity-rhythms and sleep-patterns in the Quilombolas’ by both wrist actimetry and the Munich ChronoType Questionnaire (MCTQ; the results of these two instruments correlated highly).
SleepData - Sleep Disorders Clinical Platform
Abstract: This dissertation presents the design and development of SleepData, a new information platform for managing clinical data on sleep disorders. The platform integrates data from multiple sources produced by a variety of monitoring devices and laboratory tests. SleepData provides tools for statistical analysis and diagnostic support tools, especially designed to study patients with delayed sleep phase syndrome (DSS) and insomnia.
Social jetlag impairs balance control
Abstract: We assessed the impact of a common sleep disturbance, the social jetlag, on postural control during a period involving workdays and free days. The sleep habits of 30 healthy subjects were recorded with a wrist actimeter for nine days (starting on Friday) and they participated in a set of four postural control tests carried out on Friday and on Monday. In addition, the subjects filled in questionnaires about their sleep conditions and preferences. Actimetry measurements were used to calculate the Mid Sleep Phase (MSP). The difference between the MSP values on the workdays and free days measures the social jetlag. There were significant differences in sleep variables between workdays and free days. Postural control performance improved on Monday, after free sleep over the weekend, when compared with the tests performed on Friday. It seems that social jetlag affects brain areas involved in the control of posture, such as thalamus and the prefrontal cortex as well as the cerebellum, resulting in a worse performance in postural control. The performance improvement in the posture tests after the free days could be attributed to a lower sleep debt.
The Psychological and Physiological Part of Emotions: Multimodal Approximation for Valence Classification
Abstract: In order to develop more precise and functional affective applications, it is necessary to achieve a balance between the psychology and the engineering applied to emotions. Signals from the central and peripheral nervous systems have been used for emotion recognition purposes, however, their operation and the relationship between them remains unknown. In this context, in the present work we have tried to approach the study of the psychobiology of both systems in order to generate a computational model for the recognition of emotions in the dimension of valence. To this end, the electroencephalography (EEG) signal, electrocardiography (ECG) signal and skin temperature of 24 subjects have been studied.
The Use of Actigraphy for Risk Stratification in Pediatric Obstructive Sleep Apnea
Abstract: Sleep disordered breathing (SDB) in children is a spectrum of abnormal breathing patterns, characterized by a limitation of airflow during sleep. Upper airway resistance and collapse of the pharynx can cause varying degrees of obstruction, which can be exacerbated by the presence of adenotonsillar hypertrophy, obesity, and craniofacial or neuromuscular disorders. The spectrum of SDB ranges from primary snoring (PS), to upper airway resistance syndrome (UARS), to the most severe diagnosis of obstructive sleep apnea (OSA).1 Obstructive sleep apnea can be further stratified into mild, moderate, and severe categories. This spectrum is based on the frequency and severity of airflow obstructions, arousals, and gas exchange abnormalities during sleep.
Validation of a national actigraph (Brazil)
Abstract: The actigraph consists of a wrist device equipped with an accelerometer, a microprocessor, and an internal memory, which is capable of detecting and storing movement recordings. Actigraphy is used to assess sleep disorders such as Circadian rhythm disorders, insomnia, and excessive daytime sleepiness. This method has some advantages over polysomnography such as a longer evaluation period, simplicity in use and interpretation, and low cost. This study aims to validate the Actigraph ActTrust in the assessment of sleep and wake, comparing it with polysomnography.
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