Glossary

A¶

ABPM

Initialism of ambulatory blood pressure monitor.

acrometron

[statistics]

The measure of the highest predicted value of a rhythm.

Contrast with bathymetron.

acrophase

[statistics]

The time at which the peak of a rhythm occurs, relative to a defined reference timepoint selected by the investigator (e. g., local midnight for circadian rhythms).
The phase angle of the peak of a cosine wave fitted to the raw data of a rhythm (time series).

Used for a cosine wave fitted to the raw data of a rhythm (time series). Can be either used for the best-fit curve or applied to the actual rhythm, in which case the acrophase will likely vary from cycle to cycle.

Units of measure:

Angular measurement: degrees, radians
Time measurement: seconds, minutes, hours, days, months, years, decades, centuries, with minutes and hours for circadian rhythms, days or months for infradian rhythms
Episodic measurment: number of heart beats, number of respirations…

ref: AAMCC ⧉, circadian.org ⧉

activity of daily living (ADL)

[medicine]

the things a person normally does in daily living including any daily activity performed for self-care (such as feeding, bathing, dressing, grooming), work, homemaking, and leisure

health professionals routinely refer to the ability or inability to perform ADLs as a measurement of the functional status of a person

(source: Wikipedia ⧉)

ADL

[medicine]

See activity of daily living.

ambulatory blood pressure monitor (ABPM)

A small device that a person can carry or wear for measuring blood pressure at regular intervals throughout the day and night.

Contrast with home blood pressure monitor (HPBM).

See Wikipedia ⧉.

amplitude

[statistics]

A measure of one half the extent of rhythmic change in a cycle estimated by the sinusoidal (or other) function used to approximate the rhythm, e.g., the difference between the maximum and MESOR of a best fitting cosine.

Units: original physiological units, e.g., number of heart beats, mmHg in blood pressure, etc.

(source: AAMCC ⧉)

angular frequency

special case of frequency of a periodic process expressed in degrees or radians per unit of time obtained by equating one cycle to 2π, e.g., ω in equation y(t) = M + A cos(ωt + φ) used to approximate a rhythm. Observe relation between angular frequency and frequency: ω = 2π/ τ = 2πf since frequency is the reciprocal of the period: f = 1/ τ Note: equivalent to angular velocity, usually visualized on polar coordinates.

artery

[physiology]

A blood vessel that carries blood from the heart to the body.

Contrast with vein.

B¶

bathymetron

[statistics]

The measure of the lowest predicted value of a rhythm.

Contrast with acrometron.

bathyphase

The time of the lowest point of a mathematical model (e. g., cosine curve) fitted to a time series and describing a rhythm. If a sine or a cosine curve is fitted, the bathyphase will differ 180' from the acrophase, measured in relation to a defined reference time point selected by the investigator (e.g., local midnight for circadian rhythms); may be expressed in degrees as the lag from the phase reference (360° = I period) or in calendar time units (e. g., hours and minutes for circadian rhythms, days or months for infradian rhythm). (source: AAMCC ⧉)
n. The time at which the trough of a rhythm occurs. Note: This term is very rarely used. Unit of measurement: hours (h) or degrees of circumference (°) in relation to an absolute or arbitrary reference. Caveat: The official units of time and of plane angle in the International System of Units are, respectively, the second and the radian. // Cf. Acrophase. (source: circadian.org ⧉)

biology

[definition needed]

biometric, biometrics

[definition needed]

blood flow

[definition needed]

blood pressure

[physiology]

the pressure exerted by the blood on the walls of the blood vessels

Unless indicated otherwise, blood pressure refers to systemic arterial blood pressure, i.e., the pressure in the large arteries delivering blood to body parts other than the lungs, such as the brachial artery (in the arm). The pressure of the blood in other vessels is lower than the arterial pressure.

Systemic arterial blood pressure is maintained by:

The contraction of the left ventricle,
The resistance of the arterioles and capillaries,
The elasticity of the arterial walls, as well as
The viscosity and volume of the blood.

Blood pressure is expressed as relative to the ambient atmospheric pressure. Its values are universally stated in millimeters of mercury (mmHg).

(source: Wikipedia ⧉)

blood pressure excess

See HBI.

blood pressure mean

[definition needed]

body motion

[definition needed]

C¶

capillary

[physiology]

One of the tiny blood vessels that connect the arterioles (the smallest divisions of the arteries) and the venules (the smallest divisions of the veins). The capillaries form a fine network in many parts of the body.

CAHRV

See chronome alterations of heart-rate variability.

cardiovascular

[physiology]

adj. Of or pertaining to or involving the heart and blood vessels.

Contrast with vascular, a narrower concept that excludes the heart.

The circulatory system is composed of the heart and blood vessels, and carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.

Cardiovascular diseases affect the heart and blood vessels and include arteriosclerosis, coronary artery disease, heart valve disease, arrhythmia, heart failure, hypertension, orthostatic hypotension, shock, endocarditis, diseases of the aorta and its branches, disorders of the peripheral vascular system, and congenital heart disease.

(source: medterms.com ⧉)

cardiovascular variability

[definition needed]

D¶

decreased heart rate variability

See deficient heart rate variability

deficient heart rate variability (DHRV)

[chronomedicine] a standard deviation of heart rate (determined around the clock for 7-days at 1-hour or shorter intervals) below the threshold of 7 beats per minute, a criterion to be further qualified for gender and age.

desynchronization

A state of two or more previously synchronized rhythmic variables that have ceased to exhibit the same frequency and/or the same acrophase relationships and show changing time relations.

DHRV

Initialism for decreased heart rate variability.

[medicine]

The nature of a disease; the identification of an illness.
A conclusion or decision reached by diagnosis

(source: medterms.com ⧉)

diagonal matrix

[linear and multilinear algebra; matrix theory]

a square matrix in which all off-diagonal entries are zero

diastole

[physiology]

The period of time when the heart relaxes after contraction.

Contrast with systole.

diastolic

[physiology]

adj. Of or pertaining to diastole.

[blood pressure] Of or pertaining to the lowest, nadir, pressure within the blood stream occurring in between heart beats.

Contrast with systolic.

diastolic blood pressure

[physiology]

The lowest blood pressure in the arteries during the cardiac cycle, during the resting phase of the heart

Contrast with systolic blood pressure.

disease

[medicine]

illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs)

(source: medterms.com ⧉)

disorder

[medicine]

a condition in which there is a disturbance of normal functioning

In many cases, the terms disease, disorder, morbidity and illness are used interchangeably. In some situations, specific terms are considered preferable.

double amplitude

[statistics]

[definition needed]

double product

[statistics]

[definition needed]

E¶

ecphasia

Odd acrophase outside reference values of gender- and age-matched peers.

ecfrequentia

Odd frequency outside reference values of gender- and age-matched peers.

syn. frequency alteration, frequence desynchronization

elastance

[physiology]

the quality of recoiling without disruption upon removal of pressure
an expression of the ability to recoil without disruption when pressure is removed, such as that of an air- or fluid-filled organ, e.g., the lung or urinary bladder, measured in terms of unit of pressure change per unit of volume change

Symbol E.

The reciprocal of compliance.

entrainment

interaction between two or more organismic rhythms or the effect upon rhythm(s) of an (external) synchronizer, resulting in identical frequencies among interactions or in frequencies constituting integral multiples of one another (frequency multiplication or demultiplication).

excessive pulse pressure

[chronomedicine]

The problem of too large a difference between diastolic and systolic blood pressure (between when the heart contracts and relaxes, respectively).

F¶

free-running: pertaining to continuance of bioperiodicity with a natural frequency, usually at least slightly different from any known environmental schedule.
frequency: the number of occurrences of a given type of event or the number of members in a population falling into a specified class.; Note: in the study of periodicity it is the number of cycles occurring per time unit, i.e., f is the reciprocal of the period (τ) f = 1/τ

G¶

H¶

HBI

See hyperbaric index.

heart attack

[medicine]

The death of heart muscle due to the loss of blood supply.

The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue.

(source: medterms.com ⧉)

heart rate

[physiology]

the frequency of the cardiac cycle

Heart rate is considered one of the four vital signs, along with temperature, blood pressure, and respiratory rate. Heart rate is usually calculated as the number of contractions (beats) of the heart in one minute and expressed as "beats per minute" (bpm).

(source: Wikipedia ⧉)

heart rate variability (HRV)

[physiology]

[preliminary]

The oscillation either in the interval between consecutive heartbeats or between consecutive instantaneous heart rates.

I¶

illness: [medicine]; Impairment of normal physiological function affecting part or all of an organism.; disease
infradian: [chronobiology]; adj. Of or pertaining to biologic variations or rhythms occurring in cycles less frequent than every 24 hours, e.g., 19 to 22 days.

J¶

jitter: [electronics and signal processing] Small rapid variations in a waveform resulting from fluctuations in the voltage supply or mechanical vibrations or other sources.; [imaging] Low amplitude irregularities in echo location on an ultrasound display, attributed to electronic noise, mechanical disturbances, and other variables.; [neurophysiology] Muscle jitter. The normal electric variability -- chaos -- measured by single-fiber EMG, in the interval between two action potentials of successive discharges of the same single muscle fiber in the same motor unit.; [cardiology] See heart rate variability.

K¶

Korotkoff sounds: [medicine]; The sounds that medical personnel listen for when they are taking blood pressure using a non-invasive procedure.

L¶

least squares: [linear and multilinear algebra]; [matrix theory]; A mathematical optimization technique which, when given a series of measured data, attempts to find a function which closely approximates the data (a "best fit"). It attempts to minimize the sum of the squares of the ordinate differences (called residuals) between points generated by the function and corresponding points in the data.; (source: Wikipedia ⧉)
least squares approximation: [statistics]; See least squares.
least squares estimation: [statistics]; See least squares.
linear algebra: [mathematics]

M¶

macrophase: [statistics]; the lag between the reference time (midnight, or 0000 hours in a 24-hour day) and the time of the highest value among the individual data points or averages of data points
mathematics: [domains] a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement
matrix theory: [mathematics]
mean arterial pressure: [physiology]
medical device: any physical item used in medical treatment; Examples: cardiac pacemaker, thermometer, wheelchair
medicine: [domains] the art and science of the diagnosis and treatment of disease and the maintenance of health.
MESOR (midline estimating statistic of rhythm): [statistics]; n. An estimate of central tendency of the distribution of values of an oscillating variable. A rhythm-determined average. The average value around which the variable oscillates.; The MESOR is a circadian rhythm-adjusted mean based on the parameters of a cosine function fitted to the raw data. Note: When a process is known to be rhythmic, and the data points are not equidistant or the sample size is small, the MESOR often provides a more appropriate unbiased estimator of central tendency than does the arithmetic mean of the raw data. // Cf. Mean level. (source: circadian.org ⧉); In the case of single cosine approximation, the value midway between the highest and the lowest values of the (cosine) function that best fits the data.
MESOR-hypertension: hypertension as indicated by measurements taken during multiple days; For systolic and/or diastolic blood pressure, a transient or lasting elevation of the circadian rhythm-adjusted mean (MESOR) as validated statistically against the person's (patient's) own MESOR at another time and/or against a peer reference standard.; Though the condition is sometimes categorized as a vascular variability disorder, the MESOR is a type of average and not a measure of variability per se. One way to look at this is to say that on the basis of the data, the circadian variation is assessed by fitting a model to the data, and this model is characterized by three parameters: the MESOR, the 24-hour amplitude, the 24-hour acrophase. (If considered, a two-component model is characterized by five parameters, the three components of the one-component model plus the 12-hour amplitude and the 12-hour acrophase).
morbidity: [medicine]; a diseased condition or state; the incidence or prevalence of a disease or of all diseases; (source: Dorlands)
multilinear algebra: [mathematics]

N¶

nurse clinician: a registered nurse who has received special training and can perform many of the duties of a physician

O¶

orthogonal matrix: [linear and multilinear algebra]; [matrix theory]; See also coefficient matrix, triangular matrix.

P¶

parametric

adj.

Dependent on the parameters (particularly intensity and duration) of the Zeitgeber. Note: In strict terms, all biological responses are parametric. However, the expression non-parametric entrainment is often used to denote entrainment that is primarily due to the timing (rather than the intensity or duration) of the synchronizing stimulus. Antonym: = non-parametric.
Dependent on the parameters (usually the mean and variance) of a distribution. Note: In inferential statistics, the most common parametric tests are the t-test and the analysis of variance (ANOVA). Antonym: = non-parametric.

(source: circadian.org ⧉)

peak

n. The point of culmination of an oscillatory function. Synonym: crest.

(source: circadian.org ⧉)

percentage time elevation (PTE)

[definition needed]

period

The duration of one complete rhythmic cycle, measured from peak to peak, or form one reference time to the next, as from midnight to midnight in a 24-hour period.

physical therapy

[domains] A branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities.

physiological monitoring

[definition needed]

physiology

[domains]

The properties and functions of animal and vegetable organs and tissues.
The branch of the biological sciences dealing with the functioning of organisms.

prediction interval

A range of values expected to contain, on the average, a specified proportion of a population or of a distribution (of values) from an individual.

pre-disease

[medicine] A condition that is not at a stage or level that would classify it as disease but that indicates greatly increased predisposition to disease. An individual with pre-disease often lacks symptoms of the related disease.

Examples include:

Precancerous lesions
Increased intraocular pressure (preglaucoma)
Prehypertension
Hyperlipidemia
Prediabetes
Osteopenia (bone density that is low but not low enough to be considered osteoporosis)

prehabilitation

[physical therapy]

strength and conditioning exercises for specific muscles that help to reduce injury risks, before an injury actually occurs

the focus on physical therapy services that prevent the need for extended rehabilitation services by approaching the preventative aspects of injury or illness

pre-surgical physical therapy aimed at reducing the negative impacts of, or speeding recovery from, surgery

Contrast with rehabilitation.

primary care

[medicine]

the medical care received on first contact with the medical system, before being referred elsewhere

primary care provider

a physician chosen by or assigned to a patient, who both provides primary care and acts as a gatekeeper to control access to other medical services

pulse pressure

[physiology]

the difference between diastolic and systolic blood pressure (between when the heart contracts and relaxes, respectively).

pulse transit time

[physiology]

The time that the pulse wave needs for the propagation from the aorta to the peripheral vessels.

Pulse transit time is closely connected to blood pressure and the condition of the arterial vessels.

Q¶

R¶

rehabilitation

restoration, following disease, illness, or injury, of the ability to function in a normal or near-normal manner

the return of function after illness or injury, often with the assistance of specialized medical professionals

the process of restoration of skills by a person who has had an illness or injury so as to regain maximum self-sufficiency and function in a normal or as near normal manner as possible

the restoration of normal form and function after injury or illness

the restoration of the ill or injured patient to optimal functional level in the home and community in relation to physical, psychosocial, vocational, and recreational activity

the process of restoring a part of the body or a person to near-normal functioning after an injury or disease

Contrast with prehabilitation.

residual

[statistics]

the difference between results obtained through theoretical calculation and those obtained through observation

resonance

property of a system oscillating (or capable of oscillating) with some natural frequency (or rhythm) to exhibit an increased amplitude (or to begin oscillating) when subjected to an external periodic influence or force with a frequency similar to that of the system, the amplitude of the resonant frequency increasing as the outside periodic influence approaches the natural frequency of the system.

retinopathy

[medicine]

Any disease of the retina, the light-sensitive membrane at the back of the eye.

The type of retinopathy is often specified.

Arteriosclerotic retinopathy is retinal disease due to arteriosclerosis ("hardening of the arteries").

Diabetic retinopathy is retinal disease associated with diabetes.

See also hypertensive retinopathy is retinal disease due to high blood pressure.

(source: medterms.com ⧉)

rhythm

a periodic component of (biologic) time series, demonstrated by inferential statistical means, preferably with objectively quantified characteristics (i.e., frequency, acrophase, amplitude, MESOR, and/or waveform).

S¶

self-care: [definition needed]
self-help: [definition needed]
specialist, medical specialist: [definition needed]
spectral analysis: n. A mathematical procedure that evaluates the contribution of putative periodic components of a time series to the actual temporal profile of the series. // Cf. Fourier analysis.; (source: circadian.org ⧉)
sphygmochron: [chronomedicine]; A report that is formatted for the interpretation of a patient's blood pressure and heart rate measurements over a defined period, such as 1 day, 2 days, or 7 days, by comparison with the blood pressure and heart rate profile of the patient's peer group.; a 24-hour blood pressure record based on a computer comparison of a given subject's data with time-specified reference limits of clinically healthy peers of the same gender and age. Sphygmochrons provide, by complementary (parametric and nonparametric) approaches, an inferential statistical basis for the diagnosis of blood pressure disorders; a special form that summarizes a computer comparison of individual blood pressure profiles over time, with reference limits derived from databases obtained from clinically healthy peers
sphygmomanometer: An inflatable cuff used to measure blood pressure.; Operation: The cuff is placed around the upper arm, at roughly the same vertical height as the heart while the subject is in a sitting position. The cuff is inflated until the artery is completely occluded. Listening with a stethoscope to the brachial artery at the elbow, the examiner slowly releases the pressure in the cuff. As the pressure in the cuffs falls, a "whooshing" or pounding sound is heard (see Korotkoff sounds) when blood-flow first starts again in the artery. The pressure at which this sound began is noted and recorded as the systolic blood pressure. The cuff pressure is further released until the sound can n. longer be heard and this is recorded as the diastolic blood pressure.
square matrix: [linear and multilinear algebra]; [matrix theory]; a matrix having the same number of rows as columns; a matrix of size n.X n
standard deviation: [statistics]; the square root of the variance of some statistical population, data set, or probability distribution; The standard deviation may be thought of as the average difference of the scores from the mean of distribution, how far they are away from the mean. A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values.; See Wikipedia article ⧉
statistics: [mathematics]; a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters
stroke: [medicine]; The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain.; A stroke is also called a cerebrovascular accident or, for short, a CVA.; (source: medterms.com ⧉)
systole: [physiology]; The contraction of the chambers of the heart, which drives blood out of the chambers.; Contrast with diastole.
systolic: [physiology]; adj. Of or pertaining to systole.; [blood pressure] Of or pertaining to the highest, peak, pressure within the blood stream occurring during each heart beat.; Contrast with diastolic.
systolic blood pressure: [physiology]; the peak blood pressure in the arteries during the cardiac cycle, during the contraction phase of the heart; Contrast with diastolic blood pressure.

T¶

technician, medical office technician: [definition needed]
triangular matrix: [linear and multilinear algebra]; [matrix theory]; See also coefficient matrix, orthogonal matrix.

U¶

ultradian: [chronobiology]; adj. Of or pertaining to biologic variations or rhythms occurring in cycles more frequent than every 24 hours.; Contrast with circannual, circadian, circaseptan, infradian.

V¶

variability

[statistics]

The state of being variable.

(source: Dorlands)
In statistics, statistical dispersion (also called statistical variability or variation) is variability or spread in a variable or a probability distribution.

Common examples of measures of statistical dispersion are the variance, standard deviation and interquartile range.

Dispersion is contrasted with location or central tendency, and together they are the most used properties of distributions.

(source: See Wikipedia ⧉)

variance

[statistics]

A measure of the variation shown by a set of observations; the average of the squared deviations from the mean; it is the square of the standard deviation.

Of a random variable or distribution, the expected, or mean, value of the square of the deviation of that variable from its expected value or mean.

The variance is a measure of the amount of variation within the values of that variable, taking account of all possible values and their probabilities or weightings (not just the extremes which give the range).

(source: Wikipedia ⧉)

variation

The act or state of varying; a partial change in the form, position, state, or qualities of a thing.

[statistics] See variance.

vascular

[physiology]

adj. Of or relating to the blood vessels of the body.

The blood vessels of the body, as a group, are referred to as the vascular system.

The blood vessels are composed of arteries, veins and capillaries — arteries that pass oxygen-rich blood to the tissues of the body; veins which return oxygen-depleted blood from the tissues to the lungs for oxygen; and the capillaries that are the tiniest vessels and are between the arteries and veins.

(source: medterms.com ⧉)

vascular variability

[physiology]

[definition needed]

W¶

wearable: adj. Suitable for wear or able to be worn on the body

X¶

Y¶

Z¶

Zeitgeber: An environmental agent or event that provides the cue for setting or resetting a biological clock.; To be synchronized with our environment, we need the input of Zeitgebers. The most important Zeitgeber in nature is light. Social factors, chemical factors and activity can also serve as Zeitgebers. Light is a so-called photic type Zeitgeber, whereas activity, for example, is called a non-photic Zeitgeber for the biological clock.; Zeitgeber comes from the German Zeit, time + Geber, giver = time-giver. The term Zeitgeber was introduced into science about 1954 by Jurgen Aschoff, then the Director of the Max-Planck-Institute in Erling-Andechs, near Munich.; (source: medterms.com ⧉)

Glossary

A¶

B¶

C¶

D¶

E¶

F¶

G¶

H¶

I¶

J¶

K¶

L¶

M¶

N¶

O¶

P¶

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U¶

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W¶

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