S9 - How to fix a corrupted S9 data card

[dave21]

Good thread. I just got my S9 and jumped right in to analyze my data by pulling the SD card out of the S9 and loading the data onto the ResScan software. Thanks to all who helped me get out of trouble, since I used my camera as the SD card reader. When the camera wrote something onto the card, the S9 wouldn't read it. Forgetting about my adventures, though, let's step back and discuss design objectives. Here are some speculative points for comment:

I'm glad you're back up and running

1. Assuming you have no SD card plugged in, how many days of detailed data does the S9 hold? Hard to believe it's only 7 days???

At the moment this is unchartered territory. Unfortunately I'm not willing to try this as I don't want to my data. My guess is however that if you don't have an SD card inserted that it might keep up to 30 days detailed data in memory, but could be more likely 7 days seeing that the S9 deletes detailed data > 8 days old automatically on the SD card.

2. I discovered that the S9 automatically loads the last nights data onto the SD card after the machine is shut off.

That's interesting, I hadn't seen this before, but I can understand why it would do this. I presume by OFF you mean that the display has gone off? Rather than having the display ON but you've just powered it off so you don't get any air?

3. IMPORTANT: I also noted that it only loads data onto the SD card which hasn't been transferred already. That is, if yo decide to put a new SD card in, you get nothing but the new data. Therefore, try to keep all the data on one card.

Correct, if the data has been loaded onto any SD card it doesn't seem to write data to a newly inserted/formatted card.

4. Lesson learned: Lock the SD card before feeding it into any reader. If you then unlock it before putting it back into the S9, you should be good to go.

Ultimately this is the best way to do it, and although ResMed could have gone with a MicroSD card slot, I'm glad they went with a Full SD card slot as MicroSD cards you can't write protect

4. I assume all prior data stays in the S9. However, any future data is also copied to the SD card. It needs about 3 MB per day. That's a year of data on a 1 GB card.

If you don't have the SD card in then I'm not sure whether you do or don't get the detailed data. You should definitely get the Summary data, maybe someone is willing to give this a test and see?

5. Given all that, I guess the machine is designed to provide info for a doc at say 2 month intervals. Therefore the card is needed if the machine only holds 7 days of data.

The problem is that even though the machine will store up to a years worth of data on the SD card it's only Summary data, so after 8 days the Doctor can get at the Summary data, e.g. AHI, AI, HI, Central, Duration on machine per day etc, but can't get at the Detailed data. You can resolve this by manually keeping a folder on your PC that takes the latest detailed data and create a DATALOG folder with all your detailed information in if you're concerned about this.

6. If someone uses the RESScan software (not bad, by the way!), rather than depending on their provider for periodic printouts, it would be nice to know where the data is and how to back it up.

That's easy, open up the PATIENT MANAGER screen and it tells you where the PATIENT folder is on your hard disk. You can back this up reguarly.

7. Questions: The ResScan software seems to do a good job of collecting the data from the SD card and adding it to the prior data set. Where is that data and how can it be backed up so that ResScan can read it if a hard drive crashes? ..or does the data have to stored on a drive in pieces and then loaded onto an SD card to be read by ResScan?

As with (Q6) - just backup that folder, install ResScan to another computer then overwrite the Patients folder with your backed up version.

Thanks
Dave

[dsm]

Re what data gets saved without an SD card.

The docs are pretty clear on this - only summary data is saved on the machine.

The SD card behaves like a ResLink card - leave it out & no detailed data gets
saved anywhere. On the S9 there is of course as already mentioned, the 7 days
high res data & the 30 days detailed data. Both these only get saved on the SD
card.

DSM

[bigk]

Detailed Data is 30 days I believe; Compliance data is 365 days and high rate data is 7 days.

Detailed data gets erased by the S9 every 8 days, on a rolling 7 day cycle, so you have 7-8 days of the latest detailed data on the SD card.

The clinical manual says 30 days..

Type of data S9 device SD Card
Compliance and therapy summary and statistic data (usage, AHI, pressure, and leak) - 365 nights
Detailed data – 30 nights
High resolution flow data – 7 nights

[dsm]

Detailed Data is 30 days I believe; Compliance data is 365 days and high rate data is 7 days.

Detailed data gets erased by the S9 every 8 days, on a rolling 7 day cycle, so you have 7-8 days of the latest detailed data on the SD card.

The clinical manual says 30 days..

Type of data S9 device SD Card
Compliance and therapy summary and statistic data (usage, AHI, pressure, and leak) - 365 nights
Detailed data – 30 nights
High resolution flow data – 7 nights

I'm quite satisfied that dave21 meant high-res data on a rolling 7 day cycle. It was spelled out earlier in the thread, several times

Cheers

DSM

[DreamDiver]

This has been a most educational thread. Thank you for posting this.
As to the types of data, I believe there are three:
From the 'S9 Autoset / S9 Elite Data Management Guide':

Via SD Card:
365 summary sessions
30 detailed sessions
7 high-rate detailed sessions

Via S9 USB Adapter
365 summary sessions

I've compared days that have had high-rate data removed with days that include high-rate data
Sans high-rate data: Events, minute ventilation, pressure, leak, AHI, snore index, flow limitation
With high-rate data: Events, minute ventilation, pressure, leak, AHI, snore index, flow, flow limitation

The only difference is flow. Ergo, flow is the only high-rate data currently being captured by the S9. I haven't tried the oximeter, but I'm guessing it counts merely as detailed data and not high-rate data because it's probably only sampled on a per-second basis. Plethysmographic pulse rate is also included with oximetry. It would be interesting to get high-rate plethysmography, and the machine could probably be made capable of recording it, but it is more likely rate-plot data and not the signal itself. Oximetry and pulse rate are likely detailed data and not high-rate data.

Why on earth they would drop the flow data after seven days boggles the mind. This software is meant for institutions with maybe hundreds of S9 patients, at best, not tens of thousands. Any institution with thousands of S9 patients is going to have a facility for hosting data that far outstrips the capability of this software. For the number of patients involved, and the amount of data a card and modern hard drives can hold, ResMed may have missed the mark on how much data is worth storing, both on the card and on the computer. Since you can decide just how much detailed data you want to download, you don't have to download six months of data if you don't want to wait until lunch time to read it. More data is always better.

[dsm]

This has been a most educational thread. Thank you for posting this.
As to the types of data, I believe there are three:
From the 'S9 Autoset / S9 Elite Data Management Guide':

Via SD Card:
365 summary sessions
30 detailed sessions
7 high-rate detailed sessions

Via S9 USB Adapter
365 summary sessions

I've compared days that have had high-rate data removed with days that include high-rate data
Sans high-rate data: Events, minute ventilation, pressure, leak, AHI, snore index, flow limitation
With high-rate data: Events, minute ventilation, pressure, leak, AHI, snore index, flow, flow limitation

The only difference is flow. Ergo, flow is the only high-rate data currently being captured by the S9. I haven't tried the oximeter, but I'm guessing it counts merely as detailed data and not high-rate data because it's probably only sampled on a per-second basis. Plethysmographic pulse rate is also included with oximetry. It would be interesting to get high-rate plethysmography, and the machine could probably be made capable of recording it, but it is more likely rate-plot data and not the signal itself. Oximetry and pulse rate are likely detailed data and not high-rate data.

Why on earth they would drop the flow data after seven days boggles the mind. This software is meant for institutions with maybe hundreds of S9 patients, at best, not tens of thousands. Any institution with thousands of S9 patients is going to have a facility for hosting data that far outstrips the capability of this software. For the number of patients involved, and the amount of data a card and modern hard drives can hold, ResMed may have missed the mark on how much data is worth storing, both on the card and on the computer. Since you can decide just how much detailed data you want to download, you don't have to download six months of data if you don't want to wait until lunch time to read it. More data is always better.

DreamDiver,

I suspect the SpO2 data is similar in sampling rate to this spec for the Nonin xPOD (there is also a similar Nonin iPOD that has a built-in probe) ...

For Type 1 ...
Serial Data Format #1
Packet Description
Three bytes of data are transmitted 1 once per second.

For Type 2 ...
Serial Data Format #2
Packet Description
A frame consists of 5 bytes; a packet consists of 25 frames. Three packets (75 frames) are transmitted each second.

I believe the original SpO2 unit that was used on the early Resmed ResLinks, matched the Type #1 data. But I am wondering if the newer SpO2 adapters coming, might allow the Type #2 data flow.

http://www.nonin.com/documents/Xpod%20S ... ations.pdf

http://www.nonin.com/documents/ipod%20S ... ations.pdf

DSM

[gpk111]

Dave,
You believe the detailed data is overwritten every 7 days or so even if you leave the same SD card in and the capacity is say 1 GB? At 3MB of detailed data per day, it seems seneless to overwrite the data. Any further explanation appreciated.

[gpk111]

Clicking on Tools>Patient Manager will show you the location the data is stored to. I just back up the entire folder every day.

BigK, any thoughts about how to feed the backed up data to ResScan in case of a crash?

[dsm]

Dave,
You believe the detailed data is overwritten every 7 days or so even if you leave the same SD card in and the capacity is say 1 GB? At 3MB of detailed data per day, it seems seneless to overwrite the data. Any further explanation appreciated.

gpk111

What I understand is that for the high-volume data, the machine rewrites using a round robin approach. Possibly to prevent the data flooding the card allowing that Resmed can't stop people from using cards of different sizes.

I believe the same may apply to the 30 days data so, it may be that using a bigger card is to no useful purpose ?.

DSM

[bigk]

Clicking on Tools>Patient Manager will show you the location the data is stored to. I just back up the entire folder every day.

BigK, any thoughts about how to feed the backed up data to ResScan in case of a crash?

Well I had Resscan on one PC and eventually put it on another PC. I simply copied the entire patient directory (in my name) to the new computer and all the data was there and available.

[bigk]

I believe the same may apply to the 30 days data so, it may be that using a bigger card is to no useful purpose ?.

DSM

I think that's right - someone else already indicated this is a hard limit.

[bigk]

Detailed Data is 30 days I believe; Compliance data is 365 days and high rate data is 7 days.

Detailed data gets erased by the S9 every 8 days, on a rolling 7 day cycle, so you have 7-8 days of the latest detailed data on the SD card.

The clinical manual says 30 days..

Type of data S9 device SD Card
Compliance and therapy summary and statistic data (usage, AHI, pressure, and leak) - 365 nights
Detailed data – 30 nights
High resolution flow data – 7 nights

I'm quite satisfied that dave21 meant high-res data on a rolling 7 day cycle. It was spelled out earlier in the thread, several times

Cheers

DSM

And I'm quite satisfied he didn't as he clearly contradicted me which is why I quoted the manual. (it's even in the bit you quoted)

[dave21]

Sorry for the confusion, it was a typo, I did mean high resolution data

[dsm]

Sorry for the confusion, it was a typo, I did mean high resolution data

I was in nooo doubt - you have made a great contribution to our knowledge in this area.

DSM

[DreamDiver]

Dave,
You believe the detailed data is overwritten every 7 days or so even if you leave the same SD card in and the capacity is say 1 GB? At 3MB of detailed data per day, it seems seneless to overwrite the data. Any further explanation appreciated.

gpk111

What I understand is that for the high-volume data, the machine rewrites using a round robin approach. Possibly to prevent the data flooding the card allowing that Resmed can't stop people from using cards of different sizes.

I believe the same may apply to the 30 days data so, it may be that using a bigger card is to no useful purpose ?.

DSM

DSM, gpk111, dave21,

I suspect the same. I haven't reached 30 days yet, but I'm wondering if when we get to 30 days and click download all/overwrite existing, all 'detailed' data would also disappear from the patient record in ResScan 3.10 past 30 days.

Again - this seems like folly. What if you happen to hit that combination by mistake in a clinical setting, but you really needed that data from last year to compare with this year? You would be out of luck big time.

Creating a round-robin file removal system is a fairly simple scripting task. So is assessing card size and allowing that number to guide how many files remain in round robin fashion. It's just slightly more complicated to create a formula that will derive maximum number of summary, detailed and high-rate data storeable at clinic-preferred amounts on different sized cards, still allowing a round-robin override for card sanity and data integrity. Data in the patient folder on a hard-drive however should be sacrosanct.

There should be methods for insuring the clinician knows they're about to delete actual patient records from the system, along with a method to insure this doesn't happen if holding patient data is preferred. I'm thinking along the lines of a clinician because if this were to happen in an office setting, when the patient asks for a HIPAA copy of their records and it's missing, they're not going to want to hear 'it got lost'. Again - this is a situation that needs to be addressed at least in the ResScan archiving software ASAP, if not immediately in the round-robin firmware on the next version of the S9.