Simplified Blood Pressure Monitor

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DEVELOPMENT PROCESS:

We initially had two low-fidelity prototypes. We approached the prototype designs based on the need for a very simple and straight forward usability of blood pressure monitors. We wanted to design the interface in such a way that it only takes as few steps as possible in order to measure blood pressure, make analysis of previous readings, and send data to physicians.

Prototype I

Prototype II

High Fidelity Prototype:

After much discussion and looking through several diagrams, we picked one of our two prototypes. Our high fidelity prototype was developed using Macromedia Flash MX. Several changes from the low fidelity prototype were made due to our limited knowledge of Flash. As we were building our interface, it was unavoidable for us not to make several changes from our original idea so as to make the interface more interesting and visually appealing. We had to modify the shape and position of the screen and some buttons from our original low fidelity prototype.

Great deal of time in our development process was spent on how to use flash to accommodate our need for building high fidelity prototype. Even though we knew what we wanted to do, it was extremely difficult to make implementation using Flash since our knowledge of Flash is limited.

Once the high fidelity prototype was built, the usability test was performed on several users.

*SBPM home screen

Task Lists for test subjects:

Task 1:

Performing initial setup of the device:

• This situation is presented the very first time the device is turned on.
• The user has to choose between "1" or "2" for "number of users" option.
• The user then has to enter name(s) and doctor's email address.
• User then has to set current time and date.

These are the only critical and necessary information for successful usage of the device and transfer of data between patients and their doctors. The interface was designed to make it as simple as possible to operate and send data to doctors.

*Initial Setup screen with pop-up calendar

Task 2:

Login as user1 or user2, and perform normal blood pressure test:

• User has to pick his/her name using physical arrow keys on the device.
• User then press "enter" key pad to make the device ready for normal testing procedure.
• User then selects "activity level" from three options presented. The three options are "Very Stressed", "Moderate" for moderately stress, and "Resting" for no stress at all.
• After selecting "activity level", user has to select "mood" level. The three mood level options are "Stressed out", "Moderate" and "Relaxed" moods.
• After "mood level" is selected, user then press "enter" button on the device to begin blood pressure reading.

Blood pressure reading is displayed as "systolic/diastolic". For example, if the systolic reading is 118 and diastolic reading is 75, the screen will display "118/75". After the readings are displayed, the user is presented with options to accept the reading by pressing "enter" button or re-take blood pressure reading by pressing "start" button.

*SBPM Activity/Mood selection screen

Task 3:

Add another user and perform normal blood pressure test:

• User adds another name and doctor's email address to the interface.
• User then proceeds to perform the same procedure as Task 2.

Users' background information:

User 1:

This user is 65 yrs old male, retired. His computer knowledge includes normal office applications such as MSWord, Excel, PowerPoint, email etc... He is currently writing a book, so he is fairly expert in using computer software applications. He also owns a PDA and therefore he is also familiar with personal electronic devices and their functionalities. He needs to wear glass for reading purposes and hence this makes him a great candidate for readability testing of the screen contents on our interface. Even though he doesn't have arthritis, he sometime has pain on his wrist, causing it hard for him to hold handheld devices for long period of time. This is something to consider while designing the hardware for our interface. He is a college graduate and well educated. So he is quick in learning the working process of new things such as our interface prototype.

User 2:

This user is 21 yrs old male. He is an extremely efficient computer user. He works part time as a cashier at Giant grocery store and hence he is familiar with touch screens. He also has a personal computer and plays computer games frequently. We believe this may be a contributing factor in his fast eye movement his ability to observe screen contents.

User 3:

This user is 43 yrs old female. This particular user is a novice computer user. She has a very limited knowledge of operating personal handheld devices. She has never used a PDA or similar devices. She told us that she uses computer only to read and send emails to friends and families, and occasionally browse the world wide web. Her only experience with touch screen is when signing to pay for purchases and withdrawing money from her bank ATM machine.

User 4:

This user is doctor currently undergoing internship at a Hospital. She is 32 yrs old. She is very familiar with blood pressure reading and didn't need to be explained about what "systolic" and "diastolic" are. Having to use PDA everyday, she is also very familiar with small personal handheld devices, and examining patients' records from handheld devices.

User 5:

This is a 59 yrs old "Pleasant View Nursing Home" employee in Mount Airy, MD. She is also familiar with blood pressure measurement procedures. She has never operated any personal hand-held devices such as PDA, but she has a personal computer at home. She also operates personal computers and check patients' information from database at work everyday.

 

Observations

Performing initial setup of the device:

Most users are fairy quick in completing Task 1 "Initial Setup Screen". Few on them paused for a moment when they got to the "name2" field. When asked why they paused later after the experiment, they told us that since they selected "1" for number of users, they were confused about the "name2" field. So they had to pause a moment to think what the "name2" field is for. Some figured out by themselves they did not need to enter any information for "name2" field. But we had to tell some users that they only need to enter information on "name2" field only if they selected two users. On average it took the users two minutes to complete Task 1. "User1" and "User4" took only couple of seconds to complete the task.

Login as different users, and perform normal blood pressure test:

Some users were confused over which keys to use in selecting user name. By default no names are highlighted. The interface was designed so that each user has to use arrow keys to select his/her name. Our interface has some buttons inside the screen pictorially similar to physical buttons on the device. For some users we had to tell them that all buttons inside the screen have similar functionalities as the buttons outside the screen. But some users were able to figure out themselves which buttons they can use to accomplish the tasks.

Activity Level and Mood Level Screen:

All users, except user1, when they reached the screen for selecting the "activity level", they paused momentarily to find the correct button to use. At first, they were trying to find the buttons inside the screen for moving up and down between the activity levels. After realizing they had to use the physical "up/down" keys, they were able to move on quickly.

*Activity level option highlighted

Finding the "Start" button to begin blood pressure test:

For all users, there were a lot of momentary pauses in finding the "start" button to begin the blood pressure reading. There are smaller sub-screens inside the main screen for the purpose of giving hints and direction to users. At first, users did not know what button to press to begin the blood pressure reading procedure. They were confused about the small sub-screens. They did not notice the change in contents of other smaller sub-screens while they were working on tasks relating to different sub-screens. Therefore most of the users had momentary pauses in find the "start" button to begin blood pressure reading.

The time it took to complete this particular task varies greatly among different test subjects. "User3" took the most time, taking 5 minutes to complete the entire task. "User1" and "User4" took approximately 1 minute 35 seconds, while "User2" took two minutes to complete this task. 

 

Identified Problems and Rankings:

What we realized from our Usability Test is that our prototype needs much more improvements. Below is list of problems and their rankings (on scale of 1 to 5, where 5 being the most serious)

1. Initial setup screen users' information field.

• Some users are confused about two users' information field being presented when they have selected a single user. Therefore, our interface needs to be modified so that username field is presented according to the number of users selected.
• Problem ranking: 4

2. Activity/Mood level screen.

• Users have difficulty trying to select the activity/mood levels. We have decided to modify the interface in such a way that users can just click on the level in order for them to select that particular level (eg. stressed, relax etc...).
• Problem ranking: 4

3. Finding "start" button to begin blood pressure test.

• Some users did not find the onscreen instruction that tells them to press "start" to begin test. Therefore, possible solution is to highlight the instruction so users can see it easily, or create a single consistent sub-screen for all instructions so that users can always refer to this sub-screen when they are ready to move on to other tasks.
• Problem ranking: 5

*SBPM press "Start" button to begin test

4. Selection of user names.

• Some users complain about difficulty finding the onscreen instruction to press "enter" button after their names are selected to start the process of blood pressure reading without prior instruction about having to do so. We believe a consistent instruction screen will solve this problem.
• Problem ranking: 4

5. Frequent use of "enter" button.

• Some users are irritated by having to press "enter" button again to get the device on "ready" mode right after they have pressed the same "enter" button on previous step when they were selecting their user names. Possible solution is to put the interface on "ready" mode right after users have selected their names.
• Problem ranking: 3

6. Button location.

• Some users complain about the directional buttons and "enter" button being placed at different locations. They are irritated by having to move around the select things. Possible solution is to place the "enter" button in the middle of directional keys.
• Problem ranking: 3

 

| ©2005 SBPM