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Author Topic: HRM accuracy  (Read 15297 times)

Longjog @ GS-Sport-Servicecenter

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HRM accuracy
« on: November 12, 2011, 08:58:44 am »

Hello,

Yesterday Ive made a testrun with my Polar S810i and GH-625XT (F-GGH-2P-1111022). As told the Herartrate seems to be monitored to high by GH-625XT.

Here is the result of the measuring. Both watches did have recording-intervall of 5 seconds. (Polar intervall is fix. GS did record 5 most the time, but there were longer intervalls up to 6,9 s also.  At the end, when I stopped running, the last two intervals were more than 33 seconds.)
To compare the heartrates of the both watches recorded at the same time, I sorted the recordewd values manually.


It seems the values of GS-watch were increasing and decreasing periodicaly. Most the time the values of GH-625XT were to high. The accuracy is very bad; not useable for effective training based on heartrate-zones.

Please improve this with the highest priority!

Best regards

Longjog
« Last Edit: November 12, 2011, 09:02:08 am by Longjog @ GS-Sport-Servicecenter »
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http://www.gs-sport-servicecenter.de.vu/

GH-625M, GH-625XT, GH-505, GH-561, GB-580P, BT-338
Germany

canadien

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Re: HRM accuracy
« Reply #1 on: November 12, 2011, 10:31:11 am »

Hi Longjog, I just wonder if you really had the F-GGH-2P-1111022 firmware

Because in this post from yesterday you had the wrong one:

http://www.usglobalsat.com/forum/index.php?topic=3973.msg11211#msg11211
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TWG_TECH8

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Re: HRM accuracy
« Reply #2 on: November 12, 2011, 11:01:53 am »

Hello,

Yesterday Ive made a testrun with my Polar S810i and GH-625XT (F-GGH-2P-1111022). As told the Herartrate seems to be monitored to high by GH-625XT.

Here is the result of the measuring. Both watches did have recording-intervall of 5 seconds. (Polar intervall is fix. GS did record 5 most the time, but there were longer intervalls up to 6,9 s also.  At the end, when I stopped running, the last two intervals were more than 33 seconds.)
To compare the heartrates of the both watches recorded at the same time, I sorted the recordewd values manually.


It seems the values of GS-watch were increasing and decreasing periodicaly. Most the time the values of GH-625XT were to high. The accuracy is very bad; not useable for effective training based on heartrate-zones.

Please improve this with the highest priority!

Best regards

Longjog

Hi Longjog,

Thanks for information.
Maybe we can try to figure out the reason step by step:
1. To use the same belt for testing between GH-625 and GH-625XT to check the problem comes from belt or device;
2. The measure HR with two conditions: statistic and dynamic to check it is algorithm or timing issue;
3. Starting timer of GH-625XT without wearing belt to check the peak comes from noise or not;

Look forward to your further updated;
Have a nice weekend,

Geoffrey   
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gerhard

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Re: HRM accuracy
« Reply #3 on: November 12, 2011, 03:29:42 pm »

Maybe we can try to figure out the reason step by step:
1. To use the same belt for testing between GH-625 and GH-625XT to check the problem comes from belt or device;
2. The measure HR with two conditions: statistic and dynamic to check it is algorithm or timing issue;
3. Starting timer of GH-625XT without wearing belt to check the peak comes from noise or not;

Another example below. Comparing a common ANT HR belt with the 625XT. F-GGH-2P-1111022 firmware.
A very slow run, quite cold so not much sweat. The data is clipped some for the first 8 minutes, both ANT and 625XT displayed high readings, even if I had moistened the bands and wore them for 30 min (with contact with clock) prior to running. The belts are much the same in this aspect.
When using the belt with zingos 505, the displayed value has been similar in both ANT devices.
The ANT readings are much more what I expect.

I have been out of battery for the ANT belt for a couple of weeks and have no other good comparisons.
Since the 11-11-02 update, the occasionally high readings have been improved. The high readings at maximum effort is much reduced (but I have only my perception to compare with). There are a few unexpected peaks in the data but no constant high values.

I have used the 625XT without HR (just to get GPS data to compare with the other device). The belt has then been in my backpack. Quite often there has been data from the belt, maybe one sample every minute about 70-100bpm. There has been moist training clothes in the backpack too, but I do not think they have been in contact with the belt.
No belt close to the 625XT, I get no data.

For me, the still a little high distance reading is a bigger issue. As the GPS data is more accurate to the position, this should be doable.
With the latest update, the data at faster runs are better than previously, less change at slower runs.

http://hem.bredband.net/gerhardnospam/tmp/st3/delsj%C3%B6ar-hr.jpg
(Link will likely be removed in a couple of months.)
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Hubert

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Re: HRM accuracy
« Reply #4 on: November 14, 2011, 07:34:19 am »

Hi all,

unfortunalely my HRM test yesterday wasn't very successful, because the GH-625XT switched itself Off during my run  :(

And so it will be too much work for me to bring the two results for HRM values (from GH-625XT and GH-625)
in a comparable format and display like Longjog did it before.

Most the time the values of GH-625XT were to high. The accuracy is very bad; not useable for effective training based on heartrate-zones.

Please improve this with the highest priority!

Best regards, Longjog

However - when I look at my results, they are looking quite similar to Longjogs pictures.
GH-625XT values are too high and are moving more up and down.

But when I compare my two graphs of HRM, I can see, that there are also more spikes in
the old GH-625 values than expected. This could have two reasons:
* Either my heart creates the spikes (which could be true, because my doctor discovered
   some heart problems.
* Or the spikes are created by the new belt (I used the GH-625XT belt only). Maybe next
   time I will use the old GH-625 belt (hoping the battery is still alive...).

However - I don't believe that it is caused by the belt. I think it's a problem of the watch.
So, I agree to what Longjog said:

The accuracy is very bad; not useable for effective training based on heartrate-zones.
Please improve this with the highest priority!

Regards, Hubert

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GH-625XT, Firmware: F-GGH-2P-1112231 (Beta)
GH-505 M, Firmware: F-GGH-2C-1007161 (Beta)
GH-625 M, Firmware: F-GGH-2A-1001073 (Version XII)
with GS-Sport Gym Pro v1.6.8 and Sporttracks 2.1.3326

canadien

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Re: HRM accuracy
« Reply #5 on: November 14, 2011, 08:38:07 pm »

For those who would like to make a fast and effective comparison, do some push-up and search for online bpm counter in google. It uses tapping on your keyboard or mouse.

Turn on your watch, take your pulse and make comparison.

Here's one website:

http://www.all8.com/tools/bpm.htm

PS
I used this because I lent my 625 and there is no way for me to compare right now.
« Last Edit: November 14, 2011, 11:08:22 pm by canadien »
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Rookie

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Re: HRM accuracy
« Reply #6 on: November 18, 2011, 08:55:01 am »

I did training with my exercise bike which have build in HRM and I compared 625xt behaving with that.
I noticed when I did intervall training, after each heavy part of it when heart rate was high, 625xt had very long delay to show actual (lower) heart rate. Build in HRM shows more reliable heart rate from begining of recovery part of training.

Overall 625xt shows same or few Bpm more than build in HRM on exercise bike.

Rookie
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TWG_TECH8

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Re: HRM accuracy
« Reply #7 on: November 18, 2011, 10:44:13 am »

Maybe we can try to figure out the reason step by step:
1. To use the same belt for testing between GH-625 and GH-625XT to check the problem comes from belt or device;
2. The measure HR with two conditions: statistic and dynamic to check it is algorithm or timing issue;
3. Starting timer of GH-625XT without wearing belt to check the peak comes from noise or not;

Another example below. Comparing a common ANT HR belt with the 625XT. F-GGH-2P-1111022 firmware.
A very slow run, quite cold so not much sweat. The data is clipped some for the first 8 minutes, both ANT and 625XT displayed high readings, even if I had moistened the bands and wore them for 30 min (with contact with clock) prior to running. The belts are much the same in this aspect.
When using the belt with zingos 505, the displayed value has been similar in both ANT devices.
The ANT readings are much more what I expect.

I have been out of battery for the ANT belt for a couple of weeks and have no other good comparisons.
Since the 11-11-02 update, the occasionally high readings have been improved. The high readings at maximum effort is much reduced (but I have only my perception to compare with). There are a few unexpected peaks in the data but no constant high values.

I have used the 625XT without HR (just to get GPS data to compare with the other device). The belt has then been in my backpack. Quite often there has been data from the belt, maybe one sample every minute about 70-100bpm. There has been moist training clothes in the backpack too, but I do not think they have been in contact with the belt.
No belt close to the 625XT, I get no data.

For me, the still a little high distance reading is a bigger issue. As the GPS data is more accurate to the position, this should be doable.
With the latest update, the data at faster runs are better than previously, less change at slower runs.

http://hem.bredband.net/gerhardnospam/tmp/st3/delsj%C3%B6ar-hr.jpg
(Link will likely be removed in a couple of months.)

Hi Gerhard,

Thanks for information providing. The current firmware we change the noise filter time gap from 5s to 12s as same as GH-625. So it will get improved.
In your case, I think perhaps belt will generate noise after gets rub against dry clothe. So watch has some little spike.
Since SirFIV GPS allows to get 3D fix under lower signal, for sure the coordinates is with bigger drift. For SirF III, it should be shown as 2D fix.
For our firmware scenario, distance will updated by every 3D fix points, and skip 2D points.
I think it might a reason why GH-625XT has a bigger distance than GH-625.

Sincerely,

Geoffrey
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TWG_TECH8

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Re: HRM accuracy
« Reply #8 on: November 18, 2011, 10:49:22 am »

Hi all,

unfortunalely my HRM test yesterday wasn't very successful, because the GH-625XT switched itself Off during my run  :(

And so it will be too much work for me to bring the two results for HRM values (from GH-625XT and GH-625)
in a comparable format and display like Longjog did it before.

Most the time the values of GH-625XT were to high. The accuracy is very bad; not useable for effective training based on heartrate-zones.

Please improve this with the highest priority!

Best regards, Longjog

However - when I look at my results, they are looking quite similar to Longjogs pictures.
GH-625XT values are too high and are moving more up and down.

But when I compare my two graphs of HRM, I can see, that there are also more spikes in
the old GH-625 values than expected. This could have two reasons:
* Either my heart creates the spikes (which could be true, because my doctor discovered
   some heart problems.
* Or the spikes are created by the new belt (I used the GH-625XT belt only). Maybe next
   time I will use the old GH-625 belt (hoping the battery is still alive...).

However - I don't believe that it is caused by the belt. I think it's a problem of the watch.
So, I agree to what Longjog said:

The accuracy is very bad; not useable for effective training based on heartrate-zones.
Please improve this with the highest priority!

Regards, Hubert

Hi Hubert,

Did you use the new firmware with HRM improvement?
Can you please confirm the problem comes belt or devices again?
Last time we found the white light display really has little noise than green light display. ??? But I am not sure it was root cause. Maybe we have to find out more strong algorithm. ;)

Have a nice weekend,

Geoffrey

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TWG_TECH8

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Re: HRM accuracy
« Reply #9 on: November 18, 2011, 10:55:31 am »

For those who would like to make a fast and effective comparison, do some push-up and search for online bpm counter in google. It uses tapping on your keyboard or mouse.

Turn on your watch, take your pulse and make comparison.

Here's one website:

http://www.all8.com/tools/bpm.htm

PS
I used this because I lent my 625 and there is no way for me to compare right now.

Do you need a Kalenji watch for training? 8)
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TWG_TECH8

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Re: HRM accuracy
« Reply #10 on: November 18, 2011, 10:58:15 am »

I did training with my exercise bike which have build in HRM and I compared 625xt behaving with that.
I noticed when I did intervall training, after each heavy part of it when heart rate was high, 625xt had very long delay to show actual (lower) heart rate. Build in HRM shows more reliable heart rate from begining of recovery part of training.

Overall 625xt shows same or few Bpm more than build in HRM on exercise bike.

Rookie


Hi Rookie,

It shows GH-625XT has little higher reading and slow recovery time, isn't it?
How about the most time performance?

Sincerely,

Geoffrey
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gerhard

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Re: HRM accuracy
« Reply #11 on: November 18, 2011, 06:51:00 pm »

Thanks for information providing. The current firmware we change the noise filter time gap from 5s to 12s as same as GH-625. So it will get improved.
In your case, I think perhaps belt will generate noise after gets rub against dry clothe. So watch has some little spike.
The comparisions are done against the ANT belt, I cannot compare with the 625.
For the missing data at the start, the 625XT may be slightly better. The band is slightly more flexible. But I do not have much data.
For spike in the start, the belts behave much the same. Likely due to rubbing before sweater is wet. No problem.
The occasional high data during the activities are a problem. Not a major one for me. The example is the worst I have, most are quite similar with a few 625XT "raised levels" where I expect the ANT belt to be correct. No clear explanation to when this occurs.

Since SirFIV GPS allows to get 3D fix under lower signal, for sure the coordinates is with bigger drift. For SirF III, it should be shown as 2D fix.
For our firmware scenario, distance will updated by every 3D fix points, and skip 2D points.
I think it might a reason why GH-625XT has a bigger distance than GH-625.
The comparisons to a competitor Sirf-III has been done when the devices have synced the same time and synced well with many sats. The 625XT positioning is generally much better than the Sirf-III, but the total distance is more to what I expect in the Sirf-III.
In "lunch run" scenario, then the difference is much smaller. I just wait until I have 3D fix (which is faster on 625XT) before I start. The improvement seem to start after the update (I use 3 sec recording too). Quite often after some 40 minutes, the difference suddenly increases. Maybe the Sirf-III picks up more sats and increases accuracy? It is hard to tell from the tracks.
The beta firmware shows more improvement over time than my initial 5*5K test did, it is getting better.
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Rookie

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Re: HRM accuracy
« Reply #12 on: November 20, 2011, 04:28:44 pm »

I did training with my exercise bike which have build in HRM and I compared 625xt behaving with that.
I noticed when I did intervall training, after each heavy part of it when heart rate was high, 625xt had very long delay to show actual (lower) heart rate. Build in HRM shows more reliable heart rate from begining of recovery part of training.

Overall 625xt shows same or few Bpm more than build in HRM on exercise bike.

Rookie


Hi Rookie,

It shows GH-625XT has little higher reading and slow recovery time, isn't it?
How about the most time performance?

Sincerely,

Geoffrey
Mainly, as said, performance is quite same or bit higher heart rate than build in HRM shows. There wasn't too big difference. Biggest difference was slow react after heart rate change.

Most positive HRM experience I have had with ANT+ devices, GH-505 and GB-580P. I have not any HRM problem ever with those. So, I hope that future models will be with ANT+, it is absolutely much better.

Rookie
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Re: HRM accuracy
« Reply #13 on: November 24, 2011, 04:56:35 pm »

I did training with my exercise bike which have build in HRM and I compared 625xt behaving with that.
I noticed when I did intervall training, after each heavy part of it when heart rate was high, 625xt had very long delay to show actual (lower) heart rate. Build in HRM shows more reliable heart rate from begining of recovery part of training.

Overall 625xt shows same or few Bpm more than build in HRM on exercise bike.

Rookie


Hi Rookie,

It shows GH-625XT has little higher reading and slow recovery time, isn't it?
How about the most time performance?

Sincerely,

Geoffrey
Mainly, as said, performance is quite same or bit higher heart rate than build in HRM shows. There wasn't too big difference. Biggest difference was slow react after heart rate change.

Most positive HRM experience I have had with ANT+ devices, GH-505 and GB-580P. I have not any HRM problem ever with those. So, I hope that future models will be with ANT+, it is absolutely much better.

Rookie
I did couple more similar tests, so now I have tested three times with 625xt and compared heart rate to build in HRM of my exersice bike.
Two times GPS was activated and both times I had similar issues. After hard parts of training, there was too high heart rate for while.
Once I used GPS off (indoor mode) and then heart rate was exactly same than heart rate on exersice bike.

I have to do one or two test more (with and without GPS) to make sure if GPS could be root cause of these issues.

Rookie
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TWG_TECH8

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Re: HRM accuracy
« Reply #14 on: November 24, 2011, 11:25:02 pm »

Thanks for information providing. The current firmware we change the noise filter time gap from 5s to 12s as same as GH-625. So it will get improved.
In your case, I think perhaps belt will generate noise after gets rub against dry clothe. So watch has some little spike.
The comparisions are done against the ANT belt, I cannot compare with the 625.
For the missing data at the start, the 625XT may be slightly better. The band is slightly more flexible. But I do not have much data.
For spike in the start, the belts behave much the same. Likely due to rubbing before sweater is wet. No problem.
The occasional high data during the activities are a problem. Not a major one for me. The example is the worst I have, most are quite similar with a few 625XT "raised levels" where I expect the ANT belt to be correct. No clear explanation to when this occurs.

Since SirFIV GPS allows to get 3D fix under lower signal, for sure the coordinates is with bigger drift. For SirF III, it should be shown as 2D fix.
For our firmware scenario, distance will updated by every 3D fix points, and skip 2D points.
I think it might a reason why GH-625XT has a bigger distance than GH-625.
The comparisons to a competitor Sirf-III has been done when the devices have synced the same time and synced well with many sats. The 625XT positioning is generally much better than the Sirf-III, but the total distance is more to what I expect in the Sirf-III.
In "lunch run" scenario, then the difference is much smaller. I just wait until I have 3D fix (which is faster on 625XT) before I start. The improvement seem to start after the update (I use 3 sec recording too). Quite often after some 40 minutes, the difference suddenly increases. Maybe the Sirf-III picks up more sats and increases accuracy? It is hard to tell from the tracks.
The beta firmware shows more improvement over time than my initial 5*5K test did, it is getting better.

Hi Gerhard,

Thanks for feedback. I am curious about "lunch run" scenario, whar is this? :)
We use the same scenario on distance calculation, but it still has slight different. I would like to know where did you check distacne, from SportTracks or on device? There are little different results.
Now we are working new firmware with more enchancement, please keep loving and using our products.
Please introduce your friends if statisfied our services.


Sincerely,

Geoffrey
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