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| Brand: Omron
Category: Health And Beauty
List Price: $89.99
Buy New: $69.99 (On sale from $84.95)
You Save: $14.96 (18%)
New (12) from $69.99
Rating:  210 reviews
Sales Rank: 71
Autographed: No
Memorabilia: No
Batteries: 4
Batteries Included: Yes
Shipping Weight (lbs): 4
Dimensions (in): 7 x 5 x 9
Legal Disclaimer: Warranty does not cover misuse of product.
MPN: OMRHEM790IT
Model: HEM 790 IT
UPC: 073796790905
EAN: 0073796790905
ASIN: B000O58QM0
Release Date: April 1, 2007
Availability: Usually ships in 1-2 business days
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| Customer Reviews:
 OMRON HEM-790 IT BP UNIT REVIEW October 28, 2008
OMRON HEM-790 IT BP UNIT REVIEW
I bought OMRON HEM-790 IT to replace a 12 year old Sunbeam-Oster 7622 BP unit which never worked properly and gave erratic reading. Highly skeptical that consumer level BP monitoring can actually work, I took CR (Consumer Report) recommendation, and bought an OMRON unit equipped with IntelliSense technology. The major concern of the purchase was the unit's accuracy, and thus the thrust of this report is to give a qualitative description of measurement methodology and a quantitative approximation of its accuracy.
The unit comes with AC adaptor, batteries and ComFit pressure cuff, software and usb cable. After connecting the cuff hose and the AC adaptor to the unit then quickly setting the date & time, the unit is ready for measurement! The unit pumps up the cuff with a small internal motor, about 10 mmHg per second to about 20 to 40 mmHg above the systolic value. Then it deflates, at about the same rate, giving a pressure reading of the cuff about one a second. The whole inflation and deflation process takes about half a minute; too fast to use a stethoscope and read off the values while listening for the Korotkoff (turbulence) sound. At the end of the measurement, the unit will display the systolic and diastolic values on a huge display, and store those values in the memory so that eventually it can be downloaded to a pc and plotted. One hundred readings can be stored for user A, and another hundred for user B, so the unit can accommodate two regular users, and unlimited guests (their readings not stored in memory). Taking more than 100 readings will overwrite the oldest stored data in the memory, therefore it is recommended to download the data regularly (every month or so).
To download the data, the unit is connected to a USB port in a similar fashion to a digital camera. Unlike a digital camera, however, you cannot see the BP monitor as a drive; but you can simply download its data and plot it with the software that came with it. The data can also be exported into a CSV file, which Excel or JMP can read. The headers of the download are the systolic and diastolic pressures, pulse, and heart beats irregularity numbers. Each measurement will be a line in this table. The software is not the highlight of the unit but adequate.
The unit uses the oscillometric method to measure blood pressure. In the oscillometric method, a cuff is inflated until the blood flow is completely cut off, then the cuff is slowly deflated. As the blood starts to flow during the partial restriction of the arteries, and then without restriction, the transducer connected to the cuff hose measures the oscillating pressure of the cuff. The unit computes the values for systolic and diastolic blood pressure from the pressure oscillations using a fit algorithm rather than from listening for the Korotkoff sound used in the auscoltatory method. The fit values are determined so that measurements match that of auscoltatory method, which is considered the golden standard. (The auscoltatory method uses a mercury column to measure the pressure of the cuff, and a stethoscope is used to listen to the Korotkoff sound as the blood flow goes from completely restricted to unrestricted.) Oscillometric methods may produce inaccurate reading for a variety of reasons such as for circulatory problems.
To assess the unit accuracy for repeatability, I took 30 consecutive measurements in groups of three. There was a rest time of 2 min between the groups and also the cuff was adjusted between the groups. There was a 30 sec rest time between each measurement within a group. I took the average of the 30 measurements for the systolic and then for the diastolic to be the true systolic and diastolic BP value; the deviation of each measurement from this average to be the repeatability error. The first observation was that the error did not have a trend, thus the BP measurement itself did not change the actual BP of the patient. Second, the errors were similar in groups of three, suggesting that the large part of the error was due to the position of the cuff. I found the largest deviation from the mean to be +-12 Hgmm for the systolic and +-7 mmHg for the diastolic, while majority of the error data was +-10 mmHg for the systolic and +-4mmHg for the diastolic . This error could be reduced to 2/3 of that, using the TruRead setting, which basically means that the unit takes three subsequent measurements and averages them out. The error could be further reduced by adjusting the cuff between each of the three measurements. In the language of statistics, I found that the one sigma repeatability error of the unit to be about 4 to 5 % for both systolic and diastolic values which can be reduced to 3 to 4% using TruRead.
I am speculating, that there is a cuff error regardless of measurement methodology, simply because depending on how a cuff is wrapped, it may need different amount of pressure just to conform it to the arm, before it can exert any pressure on the arm.
Significantly, the unit zeros itself at the start of each measurement, thus a rainy weather is not going to reduce BP readings, and conversely, the sunny weather is not going to raise it. The reading at Denver should also be the same as one at Half Moon Bay. I do not know if the PB of an individual is influenced by air pressure, but the reading should not be.
I also found that BP measurements, taken in a half an hour time frame at a doctor's office and later by this unit were within 9 mmHg. However, the measurement at the doctor's office were also taken with the oscillometric method, therefore I do not know with certainty where to assign this measurement discrepancy.
Based on this limited set of data, one unit, one size arm, one set of measurement, this unit seems to be a decent one that produced a fairly accurate reading. It can definitely resolve the regions of normal BP, borderline BP and various levels of high BP. It is light years ahead of similar PB measurement units produced in years past. It is true, that physicians have capability for a more accurate BP reading (if they take advantage of it) but they have access to far fewer readings. The unit's strength is that it can collect lots of BP readings, so statistics can compensate for the lack of absolute accuracy. From data collected on a regular bases, one might find trends that a physician might otherwise miss.
I do not have long term reliability / drift data on the unit, but it does come with a 5 year warranty. Based on this information and the unit's affordability, I would recommend this unit.
Blood Pressure Monitor October 27, 2008
I recently purchased the Omron HEM-790IT Automatic Blood Pressure Monitor. I have been using it for several weeks now. I like the fact that three measurements are taken sequentially at an intervals from 15 seconds to two minutes as set by the user. The average of these three measurements is then displayed on the face of the monitor. Also the pulse rate, time of day and date are displayed along with the BP measurement. Weekly averages may also be displayed. There is also a connection for your PC although I haven't investigated that as yet. Overall I like this monitor and find it easy to use and reliable.
 Good Unit... October 11, 2008
1 out of 1 found this review helpful
So far, so good. Had the unit about a month and am pleased. The 2 person software tracking combined with the "A/B" switch on the unit allows easy separate monitoring. Price seems a little high given the almost all plastic construction. Cuff is comfortable. Downloads to PC via USB work fine and quick. Negatives: (1) AC cord is very short and does NOT provide any recharging of the batteries. (2) PC software is NOT Vista compatible and there does not appear to be, at this time, any free upgrade option.
Omron HEM 790IT BLOOD PRESSURE MONITOR October 9, 2008
0 out of 1 found this review helpful
Everyone in the family is using it . Easy to us .
Only 1 problem I can see NOT MADE IN THE USA !
Easy to use BP monitor October 6, 2008
1 out of 1 found this review helpful
This device is very easy to use. The display is large and easily read. Wrap the cuff around your upper arm as directed, press a button, relax, and let the meter do its thing. The cuff provided with this meter will fit my 19" circumference arm. If the cuff is not properly positioned the meter will stop with an error. I am confident this meter will produce reasonably accurate readings every time. I like the monitors ability to take 3 readings in succession and average them to produce a final reading.
The only negative comment I have relates to the included Health Management Software. The software is very poorly written. The charting and report printouts are confusing and difficult to interpret. The displayed and printed output has very limited options for resizing and formatting the graphs to make them more readable.
I highly recommend this monitor. The included software not so great. If you do not want/need to track your readings on a computer save a few bucks and purchase the Omron HEM-780. (Same features without the computer interface)
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