Objective

The objectives of the analyzer were defined at the start of the study to include the following:

1. Use profiles
2. Review of the system components
3. Overview product function
4. Operational sequence
5. Detailed human factors critique

User Profile

Before the analysis was conducted a profile of the users was defined as described below:

1. LAB TECHNICIANS (29%) Highly trained and task oriented users who work daily with sophisticated pieces of equipment.
2. DOCTORS (27%) Not specifically trained group of users interested mainly in quick, accurate and reliable data.
3. MEDICAL ASSISTANTS AND NURSES (31%) This group requires simple operational sequences, which can be easily repeated in a consistent manner.  Typically clerical persons or recent high school graduates with little training.
   1. User environments include the following:
   2. Private labs with technicians
   3. Hospitals with technicians and nurses
   4. Doctor's offices with medical assistants

System Components

System components were identified and documented

1. Seralyzer III unit
2. Electronic Pipette
3. Electronic Pipette Controller
4. Disposable Pipette Tips and Case
5. Reagent Strips
6. 5 Test Modules (Need names of tests)
7. 2 Workstations with translucent covers
8. Test result pad
9. 2 Power cords

Product Purpose and Function

A brief description of the device was also defined.
The Seralyzer III is a photo-chemically based blood system. 

1. A blood sample is properly diluted with an Electronic Pipette System
2. The sample is then placed on a test specific reactive plastic strip and introduced into the analyzer. 
3. There are 5 different assays, each with a corresponding electronic test that plugs into the analyzer.  Based on the test module, the analyzer provides the proper temperature and time to catalyze a chemical  reaction the corresponding  strip. 
4. The reaction produces a change which is interpreted by the analyzer and displayed to the technician as numbers. 
5. The technician records these numbers on a piece of and can then run the next sample.

Seralyzer Unit Controls

The device was then reviewed based on its features interacted by the user.
Keypad Overview and Operation Sequence
One 20 key membrane control area consisting of a 10-digit telephone style keypad and 10 other keys with the following labels and functions:
CLEAR - Clears the display of any numbers entered by the user
REPORT - Sends results to a printer if one is attached.
MENU - Displays all available functions.  User presses corresponding digit to access that function.  The functions listed on the display include: (see section 5.0 for a full   description of each function).

1. 1 - CONTROL
2. 2 - CALIBRATE
3. 3 - BATCH DILUTION
4. 4 - DISPENSE
5. 5 - RECALL
6. 6 - TIME/DATE
7. 7 - SEQ #
8. 8 - CONFIGURE

NEXT  - Proceed to the next option of displayed parameters.  
STOP - Interrupts current procedure and returns user to menu.
DILUTE - Starts dilution and pipetting sequence.
PIPETTE/START - Serves to initiate pipetting sequence for sampling.
ENTER - Confirms entry of digits and selection of parameters.
One rotary adjustment control  for the LCD contrast. (Unlabeled)
One toggled power switch. (With "1/0" labels)

Digital Display- One 2 line by 24 character liquid crystal display.

1. An auditory "Beep" that prompts users for  action and alerts errors.
2. Four short beeps - Test run is complete
3. One short beep - Pipette operation is complete error.
4. LED Displays
5. One green LED indicating power on. (Unlabeled)
6. Electronic Pipette Controller
7. Control
8. One toggled power switch. (With "1/0" labels)
9. Electronic Pipette
10. Controls:
11. One push button pipette tip ejector.
12. One  "trigger" which signals the EPC  to  proceed with a pipette function.
13. One green LED indicating power on.(unlabeled)

General Operation

Repeated use of the product was conducted and videotaped as defined in the user manual. Critical observations of each step during these procedures were documented and grouped according to phases of analysis.
1. Turn on EPC
2. Turn on Seralyzer unit  (Display  will  show software version and other data)
3. Select desired test module and insert into the Seralyzer Unit
4. Depress the MENU key.
5. Depress the STOP key.
6. If the instrument is calibrated, the unit will display the date and time with the  available options. If instrument is not calibrated, it will prompt user to start cal. procedure.
7. Select from menu functions 1-4 by pressing the corresponding digit, or press MENU to display functions 5-8.
8. Follow instructions on display. (Each function is outlined below)

Placing a Reagent Strip On The Reagent Table
Note:  Do not allow your fingers or any substance to touch the reagent pad.
1.  Locate proper strip container.
2.  Remove ONE reagent strip from container and immediately replace the cap tightly.
3.  Pull the reagent table out to the end stop.
4.  Press the strip guide lever and slide the strip to the end stop with reagent pad facing up.
5.  Release the lever so that the strip is straight and secure underneath the three "fingers".

Loading a Pipette Tip
1.  Hold pipette vertically over the  top of a pipette tip in a tray
2.  Using firm and even pressure, push the pipette into the tip and then remove the pipette from the tray.
3.  Push the tip onto the pipette using your other hand.

Human Factors Critique

Pipette
Pipette cable interferes with operation and dispensing process because it hangs down from the pipette and stretches across the work area. 
Flat area for the logo is uncomfortable to grasp in relation to the rest of the pipette.
Trigger is too sensitive increasing probability of accidental activation. There is no mechanical feedback indicating that the trigger has been pressed. 
No feedback on the pipette operation except an auditory signal. This  encourages users to continually look at the display and cause inadvertent bumping of the pipette into the sample tube.

Test Modules
Test modules have sharp edges and corners
Color of modules (brown) does not show dirt well (especially blood).
Handle is too shallow and has an uncomfortable shape for gripping.
Recessed logo on module is a trap for dirt.
When modules are inserted, there is no visual indication that they are properly in position

Display and Control Panel
None of the LEDs are labeled
The bezel around the display is slightly recessed and catches dirt.
Gap around control panel is difficult to clean.
The control panel is not laid out according to function or frequency of use.
Display is difficult to read when using the pipette. 

Overall Housing
Lips and edges are dust and spill traps.
The texture may trap dirt and be difficult to clean.
Underside of keypad area is exposed. Could be a splash hazard.
Back edge of machine provides no protection against spills for back panel and cables.
No handles or visual clues on how to pick machine up to move it for cleaning or placement.

Plastic Workstations
Test modules are difficult to remove from workstation, without a natural grip.
No place to put plastic cover it when it is removed forcing users to constantly pick it up or leave it off completely.
The tinting of the covers is too dark; can't see module labels underneath.
Workstations are difficult to use with the left hand.

Workplace Layout and Reagent Strips
Lab bench height is variable while the display angle is fixed.
Surface area of all equipment is excessive and occupies significant bench area.
The strips are not easily distinguishable from each other. 
There is no obvious relationship  between  a strip and its corresponding test module.
It is difficult to remove a single strip form its container and recap the container.

Back Panel
Power switches are on opposite sides of  each other.  Does not promote consistency.
Cable port lack any markings.  Users can become confused.