Frequently Asked Questions
What are the minimum computer requirements necessary to run nVISION software?
IBM-compatible PC, with 486 or faster CPU
Microsoft Windows 95 or Windows 98 operating systems
16 MB memory
10 MB free space on hard drive
CD-Rom drive (24X speed)
Video card with 640 x 480 VGA resolution
1 Serial communications port (COM1 or COM2)
Microsoft-compatible mouse Windows-compatible printer
You will also need a Nonin memory pulse oximeter and the appropriate serial cable.
How do I download data from my Nonin pulse oximeter to a PC with nVISION installed?
To download data, you need a compatible Nonin serial cable. Connect the appropriate end of the serial cable to the pulse oximeter and the other end to the PC’s communications port. (The ends of the 1000MC, 1000RTC and 1000PFC are conveniently labeled “computer” and “oximeter”, indicating the appropriate connection.) If using an extension cable, it is necessary to disconnect this prior to downloading.
What is the minimum amount of stored data that can be analyzed?
In order for data to be stored in the pulse oximeter’s memory, the duration of monitoring needs to be a minimum of 2 minutes.
After data is downloaded to a computer, is the data cleared from the pulse oximeter’s memory?
No, the data remains in the pulse oximeter’s memory until it is cleared—by following the procedure to clear data stored in memory for the respective pulse oximeter.
How long does it take to download data?
The amount of time it takes to download data is dependent upon the pulse oximeter and the amount of data stored in the memory. Most Nonin pulse oximeters transfer data very quickly—taking just 1-3 minutes to transfer all data in memory.
Does nVISION calculate an Index for SpO2 and Pulse Rate?
Yes, nVISION calculates the Index and the Adjusted Index for a patient recording. The Index is a calculated value determined by the number of events identified during the recording divided by the number of hours of the recording.
For example, if a patient’s recording contains 300 events over a recording period of 4 hours, the Index is calculated as:
300 = 75 (events/hour)
The Adjusted Index is a calculated value based on the number of events identified during the recording period divided by the difference of the total recording time minus the amount of excluded time.
For example, if a patient’s recording contains 300 events over a recording period of 4 hours and 1 hour of data is excluded due to artifact, the Adjusted Index is calculated as: 300/3 = 100 (events/hour)
What is the Body-Mass Index and how is it calculated?
Body-mass index (“BMI”) is a measurement of an individual’s height/weight ratio. It is calculated by dividing an individual’s weight in kilograms by the square of that individual’s height in meters. nVISION automatically calculates this value if the patient’s height and weight are entered.
Which Nonin pulse oximeter provides Respiration Rate (“RR”)?
Respiration rate data is available using the Model 8800. Respiration rate is calculated as breaths per minute. This measurement is a breath-by-breath averaging (either 4 or 8 breaths depending upon the setting of the option switches on the pulse oximeter).
Can I adjust the analysis parameters when viewing data?
Yes, the analysis parameters are fully adjustable, allowing the flexibility to analyze and reanalyze the data using different criteria. The immediate results can be useful when reviewing data requiring additional sensitivity (as when detecting less severe/”mild” cases of nocturnal desaturations).
Can I set the system defaults for the analysis parameters?
Yes, nVISION provides the feature of allowing the user to set the system defaults for analysis parameters. The system defaults can be set in the System Analysis Parameters window, which is accessible when no patient recordings are open.
Note: Once the system defaults are modified, all new patient recordings downloaded thereafter will be analyzed based on the new parameters unless case-specific analysis parameters are selected.
Can I obtain statistical information on a specific area of interest in a patient recording?
Yes, nVISION features the ability to obtain summary statistics for a “data window” when the Strip Chart Report is active, which may be especially useful when reviewing data for possible exclusion. Summary statistics provide average, minimum, maximum and number of events for each data type—SpO2, Pulse Rate (and Respiration Rate if available).
Is data ever removed or deleted by nVISION?
Data is never removed or deleted by nVISION software. However if the pulse oximeter is not able to track a patient’s blood oxygen saturation, pulse rate and/or respiration rate, the data is not available for later interpretation. This unavailable data will appear as a “gap” in the graphical representation of the data. Depending upon the scale of the graph, the gap may or may not be visible.
Can I adjust the display parameters when printing reports?
Yes, the x and y-axis are fully adjustable on the Strip Chart Report and the Full Study Report. Such flexibility allows you to determine the amount of data to view/print on a page and provides many options for documenting a patient recording.
Can I combine two or more patient recordings into one data file?
Yes, two or more recordings can be merged. The merged recordings will be shown with a “gap” to identify that the data is not contiguous. This gap is automatically indicated by crosshatched shading.
Note: If the date and time are not set in the pulse oximeter prior to recording data, the gap between the merged recordings will default to 10 minutes.
How can I exclude artifactual data and how is the excluded data identified on the reports?
Data can be excluded when the Strip Chart Report is active. Bring the mouse “arrow” to the point where the excluded data is to begin. Using the mouse, press and hold the left mouse button and drag the cursor to the point where the excluded data (artifact) is to end. The excluded data is identified by crosshatched shading.
Excluded data is not included in the overall study analysis, however it is calculated as a numerical value listed as “% Artifact.” % Artifact is the percent of the recording determined (by the oximeter and the user) to be artifactual.
Can I view data in an ASCII text file?
Yes, data can be exported from a patient recording so that it can be imported into a spreadsheet (i.e. Microsoft Excel). The data will be saved into an ASCII text file that allows you to view and edit the data independent of nVISION software.
Will nVISION automatically save changes to a patient recording?
No, any changes must be saved before closing the file. If a file is closed without saving the changes using the “Save” or “Save As” commands, the changes will not be saved.
When should I archive patient recordings/data sets?
Archive and storage of patient records are important issues that will need to be addressed by the user. At a minimum, Nonin recommends backing up all patient recordings by copying the files from the PC’s hard drive onto another medium such as CD-Rom, zip disk or floppy disk.