Collecting Physical Measurements

Physical measurements are often acquired for research studies. In Onyx, each physical measurement is considered a stage of the participant interview, so the general procedures for controlling an interview stage apply to physical measurement stages (see this figure).

All Onyx interview stages, including physical measurements, are highly customizable. Each study defines which physical measurements must be collected, the sequence in which they must be collected (if there are any dependencies among the measurements), and establishes a way to determine if any of the measurements are contraindicated. Since Onyx is so customizable, it allows studies to include directions to staff members right in the Onyx pages used to collect the physical measurements.

Due to the fact that each study's physical measurement stages are unique, this chapter covers typical physical measurement stages. Example stage pages are taken from the Onyx example-webapp. In particular, this chapter covers these topics:

• Key concepts related to using Onyx to record physical measurements
• Workflow of a physical measurement stage
• Example physical measurement stage

Key Concepts

Mechanical Instruments

Mechanical instruments do not have any electronic components and so do not need to be plugged in. Onyx cannot read measurements directly from these instruments. Some examples are:

• Grip strength dynamometer (used to measure grip strength)
• Tape measure (used to measure circumference of upper arm, waist, hips)
• Mechanical stadiometer (used to measure height)

For measurements that use mechanical instruments, you enter the values manually in Onyx. See this figure

Electronic Instruments

Electronic instruments are those that have electronic components. They usually have an on/off switch. They must be plugged in, or they are battery-powered, or perhaps both.

Here are some examples:

• Electrocardiogram
• Bone densitometer
• Electronic sphygmomanometer

Many electronic instruments can be connected directly to an Onyx workstation, so that Onyx can capture measurements automatically. If this is the case, they usually have their own software programme that you start from Onyx. See this figure. Some examples of electronic instruments that have their own software are:

• Minispir spirometer
• Sphygmocor CP (used to measure arterial stiffness)

Manual Entry of Measurements

Onyx permits manual entry of physical measurements. Manual entry is possible when measurements are done using:

• Mechanical instruments
• Electronic instruments that do not connect directly to an Onyx workstation
• Electronic instruments that are usually connected to Onyx---when the connection is not working

Automatic Capture of Measurements

Onyx can capture measurements automatically from instruments connected to the workstation. The capture is done in one of these ways, depending on the instrument:

• By launching the instrument's own computer programme
• By running a custom Onyx component that captures the measurements

Instruments Reserved for the Workstation

Each physical measurement stage requires a particular type of instrument, and each Onyx workstation must have a particular instrument of that type available to do the measurement. The Onyx Workstation page lists the instruments available on the workstation on which you are working. See Managing an Onyx Workstation.

When you start a physical measurement stage, Onyx checks the instrument list for the workstation to see if an instrument of the appropriate type is available. If Onyx determines that an appropriate instrument is available, you will be able to do the measurement. If Onyx does not find a suitable instrument for the measurement, you will not be allowed to proceed with the stage until an instrument is registered on the workstation. (see Registering an Instrument). Registering instruments makes your work easier (fewer barcodes to scan) and ensures that it will be possible to identify which instrument was used to take a particular measurement for a particular participant.

Multiple Measurements

Depending on how the study defined a physical measurement stage, you may be allowed or required to enter more than one reading of a measurement.

Validation of Measurements

A study can define the range of values that are acceptable for a physical measurement. If your study defined acceptable values for a particular physical measurement stage, Onyx will validate the values you enter for the measurement. If a value you enter is not acceptable, a dialog will inform you, and you will have to enter an acceptable value in order to be able to finish the stage. Onyx can also check for discrepancies among multiple measurements

On-screen Report of Measurements

The last page of a physical measurement stage includes a report of the data collected during the stage. See this figure.

Workflow of a Physical Measurement Stage

Since your study has defined its own physical measurement stages, this guide cannot give step-by-step procedures for taking physical measurements in your version of Onyx. Instead, this section describes the general workflow of a physical measurement procedure in Onyx.

this figure shows the general workflow of a physical measurement stage. For more details, see the section this figure.

Typical Steps in a Physical Measurement Stage

This section explains the steps in a typical physical measurement stage. It describes the steps shown in this figure in more detail.

1. Contraindication page. Optional. A study can check for contraindications if necessary.
2. Instrument selection. Only necessary if several instruments appropriate for the measurement are registered on the workstation. See Registering an instrument.
3. Selection of automatic or manual measurement mode. This is only necessary if both modes of capturing data are possible. For example, you may need to choose manual entry for an electronic instrument when the connection (between Onyx and the instrument) is not working.
4. Automatic Data Capture. For electronic instruments with their own software.
5. The user starts the instrument's programme from Onyx.
6. The instrument programme is displayed on the Onyx workstation.
7. The user takes the measurements using the instrument programme, and then closes the programme.
8. When the instrument programme closes, Onyx fetches the measurement data from the programme and displays it in Onyx.
9. Manual Data Entry. The user enters measurements taken manually. When the instrument is mechanical or when the connection to an electronic instrument with its own software is not working.
10. Data Validation. Optional. If the study defined data validation, Onyx validates the data, and if there are any problems, notifies the user so they can redo the measurement.
11. Onscreen Report of Measurement Data. The user can display a report of the measurement data (captured automatically or entered manually).

Example Physical Measurement Stage: Spirometry

This section includes pages from an example physical measurement stage (a stage that collects spirometry measurements) and gives you a few pointers for recording physical measurements in Onyx.

The example Spirometry stage uses an instrument that is connected directly to the Onyx workstation. The instrument has its own programme that the user starts from Onyx. If the connection between the Onyx workstation and the spirometer is not functioning for some reason, the user could also read start the instrument's programme outside Onyx, take the measurements, and then enter them manually in Onyx.

1. Contraindication page. Optional. A study can check for contraindications if necessary. this figure shows an example contraindication page.
   
   Example of a contraindication page from a physical measurement stage

   

   
   
2. Instrument selection. This is only necessary if several instruments appropriate for the measurement are registered on the workstation. If several instruments are available, you would have to select one of them by scanning or entering its barcode (and selecting enter) as shown in this figure.
   
   Example of selecting an instrument for a physical measurement stage

   

   
   
3. Selection of automatic or manual measurement mode. This is only necessary if both modes of capturing data are possible. For example, you would need to choose manual entry for an electronic instrument if the connection (between Onyx and the instrument) is not working. this figure shows an example of how a physical measurement stage could prompt the user to select automatic data capture or manual data entry. The user would select the Start button to start the instrument's own programme and then uses the programme to do the measurements. The user would select the Add button to add a set of measurements manually.
   
   Example of choosing between manual data entry or automatic data capture for a physical measurement stage

   

   
   
4. Automatic Data Capture. For a particular physical measurement stage, automatic data capture may be required or it may be an option that the user chooses. In either case, the user would have to start the instrument's programme and then the procedure would be similar to the following:
   
   1. After the user starts the instrument's programme from Onyx, it may take a moment or two for the programme to start. A couple of dialogs may be displayed while the programme is starting up. this figure shows some dialogs that might be displayed as the programme starts up. Usually, the user would select OK for such dialogs. The user would be trained how to use the instrument's software and could read the programme's documentation for more information.
      Example dialogs that may be displayed as the instrument's programme starts during a physical measurement stage

      

      
      
   2. The instrument programme is displayed on the Onyx workstation. this figure shows an example of an instrument's own programme. The user makes the necessary measurements using the instrument's programme.
      Example of an instrument's programme started from Onyx during a physical measurment stage

      

      
      
   3. When the measurements are finished, the user would exit the programme.
      
   4. When the instrument programme closes, Onyx fetches the measurement data from the programme.
      
      
5. Manual Data Entry. For a particular physical measurement stage, manual data entry may be required or it may be an option that the user chooses. Manual data entry is required for mechanical instruments and electronic instruments that do not connect directly to Onyx. It may be an option for electronic instruments that have their own programme for doing measurements. If the user enters the data manually, the procedure will be similar to the following:
   
   1. Onyx would display a Manual Data Entry page or dialog. this figure shows an example of such a dialog.
      Example of a dialog for entering data manually in a physical measurement stage

      

      
      
   2. The user makes the necessary measurements, enters them in the dialog, and saves them.
      
      
6. Validation. If the study included data validation in the stage, Onyx would validate the data. If an error is detected, Onyx would display a message to inform the user about the error and to prompt them to make a new measurement.
   If a measurement passes validation, Onyx adds the measurement to a list displayed in Onyx. this figure shows an example of how measurements would be listed in Onyx.
   
   Example of a list of measurements acquired during a physical measurement stage

   

   
   
7. Onscreen Report of Measurement Data. The last page of the stage includes a report of the measurement data (captured automatically or entered manually). this figure shows an example of how automatic measurements would be listed in Onyx.
   
   Example of an onscreen report of measurement data

   

   
   Additional Measurements. If additional measurements are required, the user would select Start again (to take another automatic measurement) or Add again (to enter another measurement manually).

Pointers for Physical Measurement Stages

Here are a good practices related to physical measurement stages:

• If your study has defined calibration procedures for any or all of the instruments used for physical measurement stages, your centre should calibrate the instruments following standard operating procedures and according to the schedule defined by your study. See Calibrating an instrument.
• Follow Onyx's on-screen instructions carefully.
• When working in an instrument's programme, follow on-screen instructions carefully and read the programme's user documentation for more information.
• If multiple measurements are required, be sure to acquire them all. Depending on how the stage has been customized, Onyx will probably prompt you if more measurements are needed.
• After you have obtained the required measurements, view the onscreen report and check that the data displayed in Onyx seems to be valid.

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