Blood Pressure Measurement

Updated

I recovered from a stroke, in 2011, attributed to hypertension. This post was published in 2023 within a longe post, and republished in 2025 and 2026. It discussed how blood pressure is measured and how accurate “home use” monitors on the market since 2o10 are or can be. I have owned and used several of the monitors on the market since 2011 including monitors sold under the brands Omron, A and D Medical and BIOS and other brands manufactured by Thermor.

Pressure

The noises of the heartbeat, the flow of blood through blood vessels, and the detectable pulse in blood vessels have been known for a very long time. Medical science credits the idea that blood circulated through the body by vessels from and to the heart to William Harvey, in 1628. This theory was a better idea than the idea of “humours” postulated by classical and medieval Greek, Roman, Arabic, and middle Eastern writers. The idea that the heart is a pump and that blood flows in arteries and veins implies that there is pressure in the arteries and veins. Humans do not have a sense to directly detect when their blood pressure is not normal or healthy. Blood pressure measurement is a medical technology are used to investigate the operation of the human circulatory system. Measurement of pressure was identified and tested at the end of the 19th century. The Wikipedia entry for the Sphygnomanometer summarizes the invention and development of devices to measure blood pressure:

  • the invention of the mercury column devices (1881), analagous to Torricelli’s 17th century mercury barometer,
  • the invention of the inflatable brachial cuff (1896),
  • the medical research by Korotkov, and the existence of Korotkoff sounds,
  • the adoption by the medical profession of blood pressure measurement devices with inflatable cuffs, and
  • the ausculatory method of determining blood pressure.

For a long period in the 20th century, blood pressure was believed to be measurable, objective and univeral The Wikipedia entry for Blood Pressure noted, as of late 2023, “Blood pressure is one of the vital signs … that healthcare professionals use in evaluating a patient’s health.”

Systolic pressure is the maximum pressure during one heartbeat. Diastolic pressure is the minimum pressure between two heartbeats. The units of measurement are millimeters of mercury (abbreviated mmHg), derived from the original mercury column sphygnomanometer. The conversion factor to pounds per square inch (psi): 51.75 mmHg = 1 psi.

Advocacy groups, including the American Heart Association (“AHA”) and medical charities, and members of the health care communities may say that the normal blood pressure of a “normal healthy” adult is 120 mmHg systolic and 80 mmHg diastolic, written as 120/80, spoken “120 over 80”; in psi: 2.32/1.55. The AHA’s online pamphlet Understanding Blood Pressure Readings classifies 5 bands of BP readings. Instead, Wikipedia, referring to modern medical consensus places states:

Blood pressure is classified by two measurements, the systolic and diastolic pressures, which are the maximum and minimum pressures, respectively. For most adults, normal blood pressure at rest is within the range of 100–130 millimeters mercury (mmHg) systolic and 60–80 mmHg diastolic. For most adults, high blood pressure is present if the resting blood pressure is persistently at or above 130/80 or 140/90 mmHg. … Ambulatory blood pressure monitoring over a 24-hour period appears more accurate than office-based blood pressure measurement.

Wikipedia, September 2022, Hypertension

Blood pressure is variable. Average pressure is higher than 120/80:

“… the average blood pressure, age standardized, since 1975 to the present, at approx. 127/79 in men and 122/77 in women, although these average data mask significantly diverging regional trends.”

… in many older people, systolic blood pressure often exceeds the normal adult range”.

Wikipedia, September 2022, Blood Pressure

Blood pressure is affected by physiological, environmental and psychological factors, and fluctuates rapidly:

Blood pressure fluctuates from minute to minute and normally shows a circadian rhythm over a 24-hour period, with highest readings in the early morning and evenings and lowest readings at night. Loss of the normal fall in blood pressure at night is associated with a greater future risk of cardiovascular disease and there is evidence that night-time blood pressure is a stronger predictor of cardiovascular events than day-time blood pressure. Blood pressure varies over longer time periods (months to years) and this variability predicts adverse outcomes. Blood pressure also changes in response to temperature, noise, emotional stress, consumption of food or liquid, dietary factors, physical activity, changes in posture (such as standing-up), drugs, and disease. The variability in blood pressure and the better predictive value of ambulatory blood pressure measurements has led some authorities, such as the National Institute for Health and Care Excellence (NICE) in the UK, to advocate for the use of ambulatory blood pressure as the preferred method for diagnosis of hypertension

Wikipedia, September 2022, Blood Pressure

Health care professionals recognize 2 situations where elevated blood pressure readings do not demonstrate hypertension:

Hypertension is described (by the AHA stage 2, above) as a medical condition in which the blood pressure in the arteries is persistently elevated – systolic blood pressure is elevated (>140 mmHg) with a normal diastolic blood pressure. Isolated systolic hypertension may present a health concern. Where elevated readings (>140/>90) appear twice, a medical doctor can diagnose hypertension. Wikipedia defines hypertension:

… a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high blood pressure, however, is a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide.

High blood pressure is classified as primary (essential) hypertension or secondary hypertension. About 90–95% of cases are primary, defined as high blood pressure due to nonspecific lifestyle and genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, excess body weight, smoking, and alcohol use. The remaining 5–10% of cases are categorized as secondary high blood pressure, defined as high blood pressure due to an identifiable cause, such as chronic kidney disease, narrowing of the kidney arteries, an endocrine disorder, or the use of birth control pills.

Wikipedia, September 2022, Hypertension

Wikipedia entries provide information on related subjects:

The American Heart Association (AHA):

Hypertension Canada:

Measurement

Blood Vessel Sounds

The ausculatory method is a non-invasive method to measure blood pressure by measuring the air pressure in an airtight bladder in a cuff. Ausculatory blood pressure measurement started after the stethoscope and the sphygnomanometer came into use in the 19th century. The ausculatory method was a manual method administered by trained professionals – medical doctors and nurses. In the 20th century medical offices, clinics and hospitals were equipped with sphygnomanometers. In the early attempts to measure blood pressure, the experimenters used mercury column devces. like early barometers. For much of the 20th century, sphygomanomers were predominantly calibrated to the ambient air pressure for proper use.

A cuff is wide enough to apply pressure without bruising or injury to the limb. The limb is usually an arm. The cuff is applied above the elbow. The bladder in the cuff are inflated with ambient air. While the flow of blood in a major artery, usually the brachial artery in an upper arm, is being been restricted the air pressure in the cuff is measured. The steps of the process:

  • inflating the cuff while listening to the pulse in the artery with a stethoscope and stopping when the beating was no longer audible,
  • recording the highest pressure in the cuff as the systolic pressure,
  • releasing pressure gradually, and
  • recording the lower pressure in the cuff when the beat resumed as the diastolic pressure.

Vibrations

The oscillometric method is non-invasive and measures the pressure in a cuff. Oscillations in the circulatory system were noted in medical literature as early as 1876. The oscillometric method is dependent on the development of transducers and monitors by the medical electronics industry. Oscillometric monitors detect and count oscillations caused by the pulsing of blood though an artery while the pressure in the cuff is used to measure blood pressure.

Using air in a hose to trigger a switch had been used in devices with pressure switches to could monitor traffic of vehicles and even pedestrians in the 20th century. Automobile service stations used hoses and bells to alert staff that vehicles were approaching the gas pumps. Such devices are still on the market in the early 21st century to monitor entry to some properties.

The oscillometric method is used in electrically powered automated devices that inflate the cuff, detect when blood flow through the limb has paused, take readings, release the cuff, record and display blood pressure and pulse. It is analogous to a health care worker’s using a stethoscope and an aneroid sphygnomanometer, but it is different. There a number of ways of designing electriconic pressure measurement instruments.

The first commercial oscillometric blood pressure monitor was patented in the USA in 1976. This kind of monitor could detect the oscillations in the patient’s circulatory system and the pressure applied by the cuff when the oscillations of the artery in the limb to which the cuff was applied had stopped. The authors of a paper in the Journal of Human Hypertension, (available in Springer Nature‘s unlocked service) explains how oscillometric devices work:

… With every arterial pulse wave there is a small rise and fall in the volume of the limb, which in turn causes an increase and then a decrease in the pressure within the encircling cuff, which can be detected using a solid-state transducer. When the cuff encircling a limb is inflated with [a] electronic pump … the rising pressure in the cuff eventually stops arterial blood flowing into the underlying limb and pulsation ceases. This is detected by the machine which continues to inflate the cuff for a second or two more to ensure that the limb flow has stopped completely. At this point, inflation stops, and a valve opens allowing the pressure in the cuff to reduce slowly … The pressure within the cuff is monitored carefully by the machine. At first it only detects the pulseless reduction in pressure. As the pressure in the cuff falls to below the pressure of the peak of the arterial pulse, the machine begins to detect a small pressure wave which reflects the difference between the pressure in the cuff and that in the artery. With further cuff deflation these pressure differences become greater until the cuff begins to fall away from the limb and less of the volume pulsation is detected. The machine therefore records within it a series of pulse waves, which are initially flat, then very slight, then increase to a peak and then diminish until they are hardly detected.

….

Automated oscillometric machines differ with respect to their algorithms, transducers, inflation and deflation rates, cuff sizes and materials, all of which may affect the estimation of BP. These may result in significant differences in estimations of systolic and diastolic BP compared with auscultatory readings in the same patient. Some machines may be accurate in one subject group but not necessarily in others e.g. in obese or pregnant subjects.

Phillip Lewis on behalf of the British and Irish Hypertension Society’s Blood Pressure Measurement Working Party “Oscillometric measurement of blood pressure: a simplified explanation. A technical note …” , J Hum Hypertens 33, 349–351 (2019)

Wikipedia explains, more generally:

Digital meters employ oscillometric measurements and electronic calculations rather than auscultation. They may use manual or automatic inflation, but both types are electronic, easy to operate without training, and can be used in noisy environments. They calculate systolic and diastolic pressures by oscillometric detection, employing either deformable membranes that are measured using differential capacitance, or differential piezoresistance, and they include a microprocessor. They estimate mean arterial blood pressure and measure pulse rate; while systolic and diastolic pressures are obtained less accurately than with manual meters, and calibration is also a concern. Digital oscillometric monitors may not be advisable for some patients, such as those with arteriosclerosis, arrhythmia, preeclampsia, pulsus alternans, and pulsus paradoxus, as their calculations may not be correct for these conditions, and in these cases, an analog sphygmomanometer is preferable when used by a trained person.

https://en.wikipedia.org/wiki/Sphygmomanometer#Digital

Many institutions (e.g. hospitals, medical clinics and medical offices), use automated oscillometric devices. The devices built to professional standards are accepted as relatively accurate and reliable by medical professionals. Devices built for hospitals and clinics may load information into networked health records. Some institutions, particularly medical offices, still have aneroid sphygnomanometers that display pressure on a dial.

Digital oscillometric devices were marketed to, and purchased by institutions. Single reading automated oscillometric devices became common or standard. Automated oscillometric devices capable of taking 3 consecutive readings and providing an average reading have been acquired by some institutions. They are less time consuming for health care providers.

Some oscillometric devices owned by pharmacists are available for public use. Many pharmacies in Victoria BC and across Canada have them. A special type of automated oscillometric meter for ambulatory measurement. The patient is fitted with a cuff at attached to an elecric monitor in a clinic. The monitor inflated the cuff at intervals and takes readings over a long period.

Home Use Monitors

What, Why

Home use oscillometric devices share some of technology of the devices manufactured for medical establishments and professionals. The basic function of home blood pressure monitors is take single readings and display readings. Many devices have added features. Home devices have “chips” and “boards” to start routines when buttons are pushed, but are not capable of running programs like home computers and smart phones. Few have the capability to connect to routers and to other network devices. Some monitors have Bluetooth radios and connect to smartphones running an app.

Some people may buy a device to detect high blood pressure without a medical examination. Many buy one after a diagnosis to get and record information.

The opportunity for prolonged rest can make home readings seem lower than professional measurements. Home measurement avoids readings affected (inflated) by white coat syndrome. Using a home monitor accurately requires practice. Operating a home use monitor involves little exertion or effort, after a person has applied the cuff in the correct position. Differences in readings arise from the way that users prepare, attach cuffs and operate devices. Many home use devices can deliver acceptably accurate readings, if:

  • the device is working and operated correctly,
  • the cuff is applied properly,
  • the patient has been inactive, is warm and comfortable and seated, sitting with the correct posture.

The use of home devices is encouraged by Hypertension Canada.

Home blood pressure monitoring (HBPM)
can be used in the diagnosis of hypertension,
and monitoring on a regular basis should be
considered for all hypertensive patients and
particularly those with:

  • Inadequately controlled hypertension
  • Diabetes mellitus
  • Chronic kidney disease
  • Suspected non-adherence
  • Demonstrated or suspected white coat effect
  • BP controlled in the office but not at home (masked hypertension)
    If white coat or masked hypertension is suggested by HBPM, it should be confirmed by repeat HBPM or ABPM before treatment decisions are made.
2020 HYPERTENSION HIGHLIGHTS Pamphlet https://hypertension.ca/wp-content/uploads/2023/05/2020-Guidelines-Highlights.pdf

The pamphlet is supported by a paper published in the professional section of Hypertension Canada’s resources, and in the journal of the Canadian Medical Association (“CMA Journal”). The paper outlines that physicians must measure blood pressure directly (in practice bp may often be taken by a nurse with a “professional” automated oscillometric monitor) before diagnosing or treating hypertension. The authors write:

Because detection and management of hypertension rely on
accurate BP measurement, it is important to use a device that
has been validated and confirmed for accuracy. Validated auto-
mated oscillometric devices are preferred to auscultatory sphygmomanometers as they are easier to use, less prone to human
error and end-digit preference (i.e., where the observer rounds off the last digit), and have better reproducibility. Validation
demonstrates relative equivalency between the tested device
and rigorously performed manual auscultatory measurements.
Globally, only 10% of devices have evidence of validation for
accuracy. In Canada, 90% of BP devices sold at pharmacies are
validated compared with only 45% of BP devices sold by online
retailers. Exceptions where automated devices are inaccurate
and manual BP measurement is preferred include in patients
with persistent or high burden of arrhythmias, and populations
in which an automated device has not been validated (e.g., children and pregnant people, for whom this guideline is not intended).
Even when a validated automated device is used, the accuracy of BP measurement may be influenced by many factors. A standardized procedure with proper preparation and positioning, appropriate equipment, and multiple averaged measurements reduces variability.

Gopil et al. CMAJ 2025 May 26;197:E549-64. doi: 10.1503/cmaj.241770, https://www.cmaj.ca/content/cmaj/197/20/E549.full.pdf

The mechanism for automated devices to be validated, and the definition of a validated automated device are not clear.

Oscillomatric devicesare dependent on the accuracy of sensors, the accuracy of algorithms and the hard coded programs installed by manufacturers. Devices from different manufacturers may read and report blood pressure differently.

Basic Features, Use

Most home use devices are sold as packaged sets with:

  • an operating unit which has
    • the pump that which inflates the cuff;
    • sensors that detect the pulsing artery and the pressure in the cuff;
    • control buttons and
    • a display screen;
  • a power transformer and/or several batteries;
  • a cuff; and
  • a printed manual or reference booklet

Most devices include an electric pump that inflates the cuff. Some require manual inflation with a manual inflation device (a squeezable bulb or pump) that can be operated while the person being monitored is wearing the cuff. A device with an electric pump takes about 30 seconds to inflate the cuff and deflate the cuff for a single reading.

Most devices have an LCD display (usually monochrome) that display icons and numerals. There are icons that flash as the cuff deflates and/or as the pump inflates the cuff and the cuff deflates. An icon flashes when a heartbeat or pulse is detected, according the design decisions of the manufacturer Conventionally the icon is heart shaped. When the cuff is being inflated or deflated, the pressure in the cuff changes every few seconds. When the cuff has been deflated the device displays reading as counted by the device using its algorithms. When the cuff has been is deflated and the reading is complete the device displays the reading of three parameters:

  • systolic pressure,
  • diastolic pressure, and
  • pulse (in beats per minute).

Numerals are displayed digitally. Some devices will also display:

  • an icon that the patient or the cuff has moved;
  • an icon for “irregular heartbeat” and the number of irregular beats during the monitored period,
  • an icon that the device has detected atrial fibrillation; and
  • some other error codes that are explained in a printed manual supplied by the manufacturer.

Most devices have features that remind the user that the expected or normal adult blood pressures are 120/80. These may include some or all of: graphics printed on the monitor or cuff, icons that light up when the device completes a reading, or text in the device documentation. The graphics and icons may not be appropriate for many persons, because the idea of normal is a little flexible.

A patient must install the cuff, take the reading and record the result. Manufacturers address this in the device documentation. The readings have to be recorded in some way if a person wants to remember them and communicate them to health care professional. Some write them down. Some put them electronic programs including word processor tables, spreadsheet and data base tools.

The American Heart Association’s 2025 web article Home Blood Pressure Monitoring provides a series of good practices around the use of home blood pressure monitors:

It’s important to have them make sure your home monitor is accurate and that you have the correct cuff size and fit. A cuff that is the incorrect size will cause an inaccurate blood pressure reading.

When preparing to take your blood pressure:

  • Plan ahead. Don’t smoke, drink caffeinated beverages or exercise within 30 minutes before taking your blood pressure. Empty your bladder.
  • Take multiple readings and record the results. Each time you measure, take two readings one minute apart. Record the results using a printable tracker. If your monitor has built-in memory to store your readings, take it with you to your medical appointments. Some monitors may also let you upload your readings to a secure website. 
  • Don’t take the measurement over clothes. Remove the clothing over the arm that will be used to measure blood pressure.
  • You can use either arm. Usually there is not a big difference between readings on them.
  • Be still. Allow at least five minutes of quiet rest before measurements. Don’t talk or use the phone.
  • Sit correctly. Support your arm on a flat surface and make sure it is at heart level (prop a pillow underneath your arm if needed). The middle of the cuff should be placed on the upper arm at heart level. The bottom of the cuff should be placed directly above the bend of the elbow on your bare skin, not over clothing. Check your monitor’s instructions for an illustration or have your healthcare professional show you how.
  • Measure at the same time every day. Take the readings at the same time each day. Talk with your healthcare professional about how often to take your blood pressure.

These recommendation to take multiple readings separated by at least a minute alludes to compression of the limb where the cuff has been applied and venous congestion but do not explain. It is a technical subject that I am relucant to try to explain. Manufacturers, academics and health care professional have guidelines. Many favour taking the average of multiple readings in a fairly short period of time but differ in their views on the time interval between readings. The American Heart Association guidelines (2025 web article cited above):

Each time you measure, take two readings one minute apart. Record the results …. If your monitor has built-in memory to store your readings, take it with you to your medical appointments. Some monitors may also let you upload your readings to a secure website. 

Cuffs

Cuffs are specific for a brand and model – the hoses have specific fittings for specific devices – and cannot be used with most other home monitor devices.

A cuff is a package of fabric. It might be flat. It is used after being pulled into a cylindrical shape. The exterior is made of a durable material, which holds an inflatable, airtight, interior bladder. The top of the cuff forms the exterior of the cuff, which is wrapped around a body part – usually the upper arm of an adult. The hose connecting the cuff to the device projects from a fitting on the exterior surface. The fastening device is attached to one end of the cuff also to the exterior of the cuff where the cuff overlaps when the cuff is drawn into a cylinder wrapping the limb. The inflatable cuff is the inner layer of the cuff assembly. Its outer layer has a fastener sewed into the shell. The hose fitting is on the outside so that it will be on the outside of the cuff as it is inflated.

Many home devices have flat cuffs that are wrapped around a limb. The fabric shell places enough pressure on the cuff to ensure the cuff contacts the arm. It is necessary have the cuff contacting the limb, and to close and fasten the cuff.It is not necessary to pull the cuff tight – it tightens when it is inflated.

The adhesive hook and loop fastener system(commonly known as Velcro) is used in devices built in and after the late 20th century. The hooked fabric and the loop fabric are both on the outside of the cuff. A short section of hooked fabric is at the free end of the cuff.

The most common and least expensive cuff uses a D-Ring , a flat D shaped metal slider, and Velco. The free end is passed through the D-ring and pulled back to form the cuff into a cylinder. The free and with the hooked fabric and press into the loop fabric to close the cuff and hold it in place. This can be awkward for a person to manipulate with one hand. The cuff should contact bare skin and not bunch up or wrinkle too much, which may cause random vibrations that the machine algorithm may read as stray oscillations.

Some home device cuffs are preshaped with a flexible internal plastic shell which pulls the cuff into a curve around the limb where the cuff is applied. This makes the cuff easier to fit on an arm, and easier to fasten. Omron makes the preshaped cuff part of the package with its Series 7 and Series 10 Upper Arm Monitors. Other manufacturers, e.g. A&D Medical sell a preformed cuff compatible with some of its monitors as an optional accessory,

Some cuffs (e.g. BIOS Diagnostic Easy-Fit BD41RC) are assembled into cylinders is secured with ratcheting dials and wire. The dial is pressed and turned to lock the mechanism, tighten the cuff and hold the cuff in contact with the limb. This works like BOA”devices 1trademarked BOA systems are made or licensed by the US firm Boa Technology, Inc. that secure some sporting footwear . In theory this can work. There are points where the fabric and the device fastenings may cause random vibrations that the machine algorithm may read as stray oscillations – i.e. irregular beats.

Options/Features

Memory

Most home use monitors can record several readings, organized by the date and time, as calculated in the system clock, in memory. Many devices organize the readings as taken from a specific person identified in records made by the device with a user number. The device manuals and other available material do not discuss the technology used to operate the device and to make and manage records of readings.

The programs in some automated monitors permit the user to calculate the average of readings in a period time. Omron series 7 and series 10 devices have a program to average the values in all readings taken within a 15 minute period.

Some professional monitors take a series of three consecutive readings, and calculate the average. The technology for this has used or emulated in home devices. The method of getting the device to calculate the average of three reading in series and the name of the feature varies.

Omron series 10 devices have the capability, called “TruRead” to be set to take a series of three consecutive readings and display the average of the three. The monitor must be configued to use tru-read or single readings as the default. The devices allow the user to select the interval between the readings as 15, 30, 60 or 120 seconds. A triple reading with the waiting period set at 60 seconds takes about 4 minutes.

BIOS makes devices with the capability, called “Averaging Mode” that is selected by chosing by pressing a button on the unit. BIOS takes the readings, with a 30 second interval between readings.

I have not searched for information about other devices with the capability

Beat parameters

Some devices measure the intervals between beats. Several devices display an “irregular” heartbeat warning icon where the monitor detects a rhythm. Irregularity can appear from the pulse rate, which can be expected to be between 60 and 100 beats per minute. It is not clear from the device what any particular manufacturer consider to be irregular, which may be stated in a manual or other producd document. The method of detecting irregularities is not normally stated in the product material. The medical term Arrythmia covers many conditions.

The warning is triggered in some Omron devices when the rhythm was 25% higher or lower than the average rhythm more than once during the monitored period. Some devices would display another icon indicating if 2 or 3 such irregular beats occurred.

The irregular heart beat icon on home devices can be triggered by movement, occur when the cuff is not attached properly, or when the user coughs or sneezes.

AFib Detection

Atrial Fibrillation is a condition diagnosed with the use of an EKG (also know as ECG (Electro-Cardi0gram). The term covers several arrythmias, including a form of tachycardia.

Omron makes the “Complete™ Wireless Upper Arm Blood Pressure Monitor + EKG”, known by model number BP7900, marketed in the USA with the marketing claim that it was “developed with AliveCor, the market leader in FDA-cleared personal EKG technology, and uses an advanced new algorithm for improved detection of AFib.” The EKG feature is described as a single-lead EKG.

In a professional EKG is taken on a conventional 12 lead device, “… ten electrodes are placed on the patient’s limbs and on the surface of the chest. The overall magnitude of the heart’s electrical potential is then measured from twelve different angles (“leads”) and is recorded over a period of time (usually ten seconds). In this way, the overall magnitude and direction of the heart’s electrical depolarization is captured at each moment”. Patients can be fitted with a mobile EKG known as a Holter monitor.

Several oscillometic home monitor device manufacturers claim that certain of their those devices can detect AFib without an EKG. A web site discusses how an automated home monitor can do this:

There are two main approaches on the market in 2026… Pulse-wave analysis is the most common method; the cuff inflates, the sensor reads the tiny oscillations in … [the] artery wall, and a proprietary algorithm decides whether the rhythm looks regular or irregular. The OMRON Platinum 2a new model in 2026 sold in the USA, also known as the Omron model BP-7465… use[s] this technique …

….

When a monitor flags an irregular rhythm, it usually displays a small heart symbol with a wavy line. This does not diagnose AFib. It tells you that during this reading, the rhythm looked suspicious enough to flag. Most devices with true AFib detection will explicitly say “AFib” or show a dedicated icon. Generic “irregular heartbeat” alerts on cheaper monitors often only catch premature beats, not true atrial fibrillation.

Blood Pressure Monitors for Atrial Fibrillation in 2026, Cleve Land Heart (NB not the Cleveland Clinic)

Cleve Land Heart is not a source with known authority. It is not the famous non-profit Cleveland Clinic or the publisher of the Cleveland Clinic’s Heart Advisor newsletter. Nor is it the Jordanian entity that identifies itself on the web as clevelandheart.net.

BIOS had an algorithmic AFib warning in its model BD 410. The AFib detection feature was engaged by activating the triple reading Averaging Mode.

Omron did not have an algorithmic AFib warning in its series 7 models and early iterations of its series 10 models (BP7450 and BP7455) but included the feature in the series 10 BP 7465 in some markets including the USA.

AFib detection by an algorithm on a blood pressure monitor has value, noted in the abstract of a metaanalysis of studies in 2024:

There is considerable and consistent evidence suggesting high diagnostic accuracy of AF detection algorithms implemented in automated BP monitors during routine BP measurements in and out of the office. AF diagnosis requires verification (electrocardiography) before treatment is administered.

Atrial Fibrillation Screening During Routine Automated Office, Home, and Ambulatory Blood Pressure Measurement, K. G. Kyriakoulis et al, Hypertension Volume 81, Number 7, https://doi.org/10.1161/HYPERTENSIONAHA.123.22563
Bluetooth, WiFi

Some devices -e.g. Omron BP7430, BP7450, BP7455, and A&D Medical UA-810CNBLE – have Bluetooth radios to upload data to another device with a Bluetooth radio. This features may have value to some users who can store readings on mobile device. It is unlikely that users will be able to send readings from their devices or mobile phones to medical professionals.

Some retailers advertise devices with Bluetooth as wireless. Technically this may be correct -Bluetooth is a radio. However few home blood pressure monitors can connect to a WiFi router, or a computer, or to the internet.

Accuracy

The problem

There are differences between monitors and cuffs, and inherent margins of measurement error.

Device manuals may contain implicit disclaimers about the precision of readings. The manual for the BIOS BD410 (made by Thermor Limited) says: “1.2C Many questions arise when two blood pressure devices are compared in an effort to check accuracy. ….”. Monitors distributed in Canada are required to declare a margin of error in the pressure readings under technical specifications in the manuals packed with the monitors. Examples:

BrandModelTerm
BIOSBD410static accuracy± 3 mm Hg
BIOSBD410pulse accuracy± 5%
OmronBP7350CANaccuracy± 3 mm Hg
OmronBP7450CANaccuracy± 3 mm Hg
OmronBP7450CANpulse accuracy± 5%
A&D MedicalUA-810CNBLEstatic accuracy± 3 mm Hg
A&D MedicalUA-810CNBLEpulse accuracy± 5%

Medaval (see below), advocates for more stringent standards for the validation of monitors and other diagnostic technology. It said in its open letter May 30, 2018, published on its site, referring to EU rules that came into effect in 2020:

… for every blood pressure measurement technology developed, there are dozens of different devices that use this technology. The original manufacturers often have several devices aimed at different groups and these can be provided in different languages or even, in some counties, under different brands. When it comes to OEM versions, some devices are sold under several brands or the housing may be changed to suit a particular style. Under the new regulations each and every one of these must undergo either a new validation or an equivalence.

….

There are now, numerous sites that purport to provide “best” and “top” lists of monitors but are really just advertising sites for Amazon and some other marketing sites. Many of these contend to perform their own “validations” but which are statistically useless. Furthermore, many of the brands listed are, when examined, untraceable. Yet they are presented as reliable brands with “Clinically Validated” devices, often with accompanying FDA and other approvals, and several positive fake reviews.

A few big names (usually Omron) are included in the list to make it seem legitimate but the real target devices are the brands promoted as being equally reliable but far cheaper and, therefore, best value and, of course, best buy.

ISO, IEC, National Standards Organizations

Standards organizations do not test devices, pronounce on whether devices meet standards, or express opinions on whether devices work properly or are fit for purpose. Standards documents are long technical documents, and copyrighted. The international standards may be cited by manufacturers who distribute their devices in international commerce. However data showing how devices have been tested in compliance with testing standards, or meet performance goals is never published.

Two important standard organizations:

National standards bodies are listed in the national bodies section of the Wikipedia article. Some endorse or adopt ISO and IEC standards. Some publish standards which may differ from ISO and IEC. In Canada, there is an historical organization the CSA Group and a governmentally mandated Standards Council of Canada.

Citations of ISO and IEC standards follows the format nnnnn[-p]:[yyyy] Title, where nnnnn is the number of the standard, p is an optional part number, yyyy is the year published, and Title describes the subject.

Wikipedia maintains a dynamic page called List of ISO Standards which includes the standards cited by some device manufacturers:

nnnnnpyyyyTitle
1060
3
A2
1997,
2009		*Withdrawn and replaced. See 24024
Plastics – Homopolymer and copolymer resins of vinyl chloride
1099352009Biological evaluation of medical devices – Tests for in vitro cytotoxicity.
10993102021Biological evaluation of medical devices – Tests for skin sensitization
1348512016Medical devices – Quality management systems – Requirements for regulatory purposes
1497112007Medical devices – Application of risk management to medical devices
2402412021Plastics – Homopolymer and copolymer resins of vinyl chloride – 1: Designation system and basis for specifications
2402422021Plastics – Homopolymer and copolymer resins of vinyl chloride – 2: Preparation of test samples and determination of properties
810601Non-invasive sphygmomanometers
Requirements and test methods for non-automated measurement type
8106022013,
2020		Non-invasive sphygmomanometers
Clinical investigation of intermittent automated measurement type

Wikipedia maintains a page called List of IEC Standards which includes standards cited by some device manufacturers:

nnnnnpyyyyTitle
606011
A1		2006
2012		Medical electrical equipment – part 1 General requirements for basic safety and essential performance
606011-22014Medical electrical equipment – part 1-2 General requirements for basic safety and essential performance – Collateral Standard: Electromagnetic disturbances – Requirements and tests
606011-6
A1		2010
2013		Medical electrical equipment – part 1-6: General requirements for basic safety and essential performance – Collateral standard: Usability
606011-112015Medical electrical equipment – part 1-11: General requirements for basic safety and essential performance – Collateral Standard: Requirements for medical electrical equipment and medical electrical systems used in the home healthcare environment
610004-2Electromagnetic compatibility
610004-3Electromagnetic compatibility
610004-4Electromagnetic compatibility
610004-5Electromagnetic compatibility
610004-6Electromagnetic compatibility
610004-11Electromagnetic compatibility
610004-39Electromagnetic compatibility
62304

A1		2006

2015		Medical Device Software – Software Life Cycle Processes
6236612015Medical devices – Application of usability engineering to medical devices
Validated by Medaval

Medaval publishes a web site. Medaval is:

…. a non-profit organisation servicing consumers who are oblivious to the science behind medical devices.

The purpose of the site is to provide, for all purchasers of medical devices, an identifiable mark, the Medaval Certificate of Accreditation and its Brand logo, Certified as Accurate, indicating proven measurement accuracy to current standards.

The site provides a unique and comprehensive resource for information on medical devices that will provide the user, whether a health professional or lay patient, with an up-to-date assessment of the accuracy and quality of all devices providing measurements or indices of health and disease.

We survey blood pressure monitors, blood glucose meters and pulse oximeters available on the market. These are assessed for accuracy in strict compliance to standard protocols and are awarded star-ratings accordingly.

It maintains a database it calls a Validated Medical Device Registry, and search resources . It includes devices as validated and marks entries for individual devices with validation references or a query mark where no clinical validation information can be found. It has stringent rules for proof of clinical validation:

Medaval accepts these four methods of completing an Independent Scientific Clinical Validation of a medical device. A primary validation must be in a general sample from the population for which the device is intended. Validations in special groups only cannot be considered as applicable to a general population.

  • Publication in a peer-reviewed scientific journal: The vast majority of these are listed on PubMed. Validations must have been completed according to a standard protocol.
  • Equivalence according to Medical Device Regulations (MDR) standards: In order to ensure scientific standards, MDR equivalence regulations are now required by Medaval in order to prove that the measurement technologies in different devices are identical and that validations of that technology must, therefore, apply accordingly. These new standards became mandatory within the EU in May 2021.
  • Published report by a recognised organisation: Some devices are tested by organisations recognised by government or professional bodies. The reports must contain the information to enable a full assessment according to the relevant protocol.
  • Medaval assessment: Medaval assesses strict compliance of a study according to protocol requirements, produces a report and has the report peer-reviewed before publication.

Few manufacturers conduct the required studies. Medaval ignores many good devices that have not been as validated, according to its policy, when there are no published studies.

Regulatory

The European Commission, the executive cabinet of the European Union has the power to initiate and even enact rules and regulations – in principle to legislate for the Union – within the structure of the Union. The legisltative powers of the Commission, the Council and the European Parliament are a subject of some complexity. The Council and the European Parliament have passed directives and regulations on health care products including medical products for human use, EU regulation 2017/745 .

Medaval has advocated that blood pressure monitors and other diagnostic devices should be validated for clinical accuracy.

The Canadian federal government and provincial governments do not legislate how home monitors are supposed to be built. The Canadian federal department of health has a list of approved standards, including standards for electromedical devices, a requires persons operating some facilities to hold federal licences. The standards are those of national and international agencies including the Canadian Standards Group (CSA), and the IEC. Many CSA standards are republications of IEC standards, noted briefly above.

Consumer Guidance

Hypertension Canada has and has had a program to list Recommended Devices. The list is on the Web and is updated on an ongoing basis. A listing allows the manufacturers to mark the packaging with a check mark and the logo of Hypertension Canada. As of 2025, the mark indicated that the products was approved. (At one time Hypertension Canada supported Gold and Silver marks. 3“Those with a Gold rating meet the highest and most current international standards, and those with the Silver ratings meet the highest international standards available prior to their most recent updates. (Both Gold and Silver levels are accepted as accurate)”.)

Hypertension Canada does not say it has tested samples of rated models. Hypertension Canada requires manufacturers seeking approval to say that they have processes that manufacture devices that meet the CSA and IEC standards.

There are Web sites that discuss and recommend monitors.

BP Monitors Lab is published by an Amazon Affiliate. An Amazon Affiliate earns commisions when consumers follow a link on their page to Amazon to buy monitors the Affiliate has recommended.

It says it “helps … pick a home blood pressure monitor”. It says:

BP Monitor Lab is written and edited by our own small editorial team. We publish under the site name rather than a personal byline, because that is what is true. No doctor or nurse is on staff here.

….

  • We read the maker’s own manuals, spec sheets and validation pages, and we link to them.
  • We check whether a device is still sold, and we say so when it is not.
  • We check clearance numbers against the FDA’s public 510(k) database before we print one.
  • We follow blood pressure guidance from the American Heart Association and the American College of Cardiology, and we cite it.
  • ….
  • We do not test devices ourselves. We have no lab and we take no readings. When you see an accuracy figure here, it came from a published study or from the maker, and we name the source.
  • We do not give medical advice. We cannot tell you what your numbers mean or what to do about them. Your doctor can.

Home Device Manuals

The manufacturers of home devices distributed in Canada provide instructions to users in manuals. The manuals are found in sealed packages with the devices and generally note available to purchasers until they have bought the device and opened the package. The publication date of the manual, if stated, may suggest the year in which a device was first mass produced and put on the market.

Manuals will contain any safety information required by law and some information about the operation and features of the device. A manufacturer may make a statement about the expected service life of the product. Omron does but other manufacturers do not. Few manufacturers disclose the key components – the sensors, pumps, seals, switches and chips used to build the devices.

The manufacturer will say something about the process of taking a reading with a home device and the expected time required to take readings. A manual will advise taking readings in a quiet place, at the same time, keeping warm, avoiding stress and not taking readings for at least 30 minutes after bathing, consuming alcohol or caffeine, smoking or exercising. Similar advice can also be found in resources like the American Heart Association sited note above, orthe Canadian advocacy entity Hypertension Canada’s pamphlet for professionals.

Omron suggests that a person sit down and rest for at least 5 minutes before starting a reading. Omron also said in (section 3.3) its manuals for BP7430 and BP 7450 devices that there should be a period of rest of 2-3 minutes after one reading and before a second reading.

Some information will be disorganized or confusing. For instance the manuals of many devices address electrical interference. Examples of the text used are noted here.

The 2019 Omron 7 Series Upper Arm Blood Pressure Monitor manual and the 2021 Omron 10 Series Upper Arm Blood Pressure Monitor manual recited, in the section on “Safety Information”:

DO NOT use use this monitor in areas containing high frequency surgical equipment, magnetic resonance imaging equipment, computerized tomography scanners. This may result in incorrect operation of the monitor and/or cause an inaccurate reading.

….

During measurement, make sure that no mobile device or any other electrical device that emits electromagnetic fields is within 12 inches (30 cm) of this monitor. This may result in incorrect operation of the monitor and/or cause an inaccurate reading.

The 2023 BIOS Blood Pressure Monitor BD410 Instruction manual recited:

“1.2B

….

Using the unit in the immediate vicinity of mobile phones, microwave appliances or other devices with strong electromagnetic fields may result in impaired functioning.”

Thes passages quoted do not explain what state a mobile phone should be in or which services and device radios enabled (airplane mode, cellular radio, wifi radio, bluetooth radio on or off, or totally off). They do not mention proximity to a WiFi router. They do not discuss which appliances have electromagnetic fields. Does a dehumidifier (a device with cooling coils like a refrigerator or air conditioner) have an electromagnetic field?

Medical Electronics Retail

Home monitors are medical consumer electronics. Home use devices cannot be maintained or serviced by consumers. They are sold without prescriptions in the retail sections of pharmacies or “drug stores”(in the UK “chemists”) . In Victoria, British Columbia, many such stores are part of retail store chains. The chains include London Drugs, Shoppers Drug Mart, Pharmasave, and Rexall. Chain stores and other retain drug stores acquire monitors from wholesale distributors. The devices are branded devices. The brands available include national and international brands and store brands.

Manufacturers design new features and products, but follow the business models of their industry. Certain components are made the same way for years, with incremental changes. The manufacturers do not have model years, but they will market devices as instance or models of their “brand”. They only make a limited number of models available in several markets.

There can be confusion between models made during manufacturing, related to a marketing strategies. In 2019 Omron began producing an upper arm blood pressure monitor marketed in Canada in the 2020s. The Omron monitor known by the model number BP7430CAN and the phrase “Series 7” in the model name was sold in Canadian retail stores for several years. (The letters “CAN” in the number indicated a model for the Canadian market with labels and manual that were in English and French.) By 2021 Omron had developed the basic model of series 10 group of monitors (similar to the series 7 models) including the models BP7450CAN and BP7455CAN (on the market in Canadian retail stores in 2026). Both resembled the BP7430 and were sold with a similar cuff (the cuff had the same Omrom model number). Series 10 devices were similiar to the series 7, with changes:

  • The display had white lettering on a black or dark grey background;
  • A memory function that had not been in the BP7430- that calculated the average of readings taken within 10 minute of each other;
  • A “Tru-Read” mode of measurement – the device could be set to calculate the average of three measurements in succession in a few minutes.

The Tru-Read feature is similar to a feature in some machines used in hospitals and clinics and a few other home use devices marketed by Omron’s competitors.

By autumn 2026 Omron had another series 10 model sold in the USA (and marketed on the Internet) BP7465, the BP 7465 Platinum model. The BP 7465 was marketed as detecting and warning of symptoms of Atrial Fibrillation. In Canada Omron sold its remaining inventory of BP7450 and BP7455 devices in retail stores at discounted sale prices. Omron sold a variety of Series 10 devices online in Canada as Series 10 Iron, Bronze, Silver, Gold and Platinum devices, at different prices. The Devices all had the preformed cuff. This illustrates the paradoxes of innovation and investment. Omron invested in innovation and decided to promote the newer technology. A Series 10 device with innovations made since Series 7, including changes to the cuff, is a useful device. Not all Series 10 devices have the right sensors, chip and program that can deliver an Atrial Fibrillation warning.

Manufacturers and Brands

Omron – based in Mukō, a city in the Kyoto urban area in the Kyoto prefecture in Japan, manufactured in Vietnam;

Thermor Limited (in Canada, based in Newmarket, Ontario. Thermor was founded as Taylor Instrument Companies of Canada, founded in Toronto,. Ontario before 1939, (4not to be confused with other brands or businesses names named “Taylor” including the modern USA firms (1) Taylor Technologies associated with maintaining swimming pools, or (2) Taylor USA, which distributes scales, thermometers and other measuring devices. Thermor uses the BIOS brand “BIOS Weather” for what seem to be precise, high quality thermometers and hygrometers. Thermor uses the BIOS brands BIOS Medical, BIOS Diagnostic for blood pressure monitors and medical electronics. Thermor also manufactures devices sold as store brands by retail chains – for instance Be Better, a store brand sold in Rexall pharmacies in Canada. The BIOS web presence of Thermor is at the BIOS Medical site. Most Thermor devices, including BIOS brand blood pressure monitors, are manufactured in China.

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