UVA MOBI-COG

The MOBI-COG application is a complete automation of a well-known dementia screening test called the Mini-Cog test. The app runs on a mobile device, such as a tablet or a smartphone. The intended use case of MOBI-COG is to let an elderly take the test using a large-screen tablet device where he is posed with a set of words to remember, followed by a clock drawing test, and finally a test to recall the words. At the end of the test, the system analyzes the recalled words and the clock drawn by the user on the touch screen, and provides a score as done in a paper-based Mini-Cog test. A family member should be administering the test in case the patient is not capable of taking it alone or is using the application for the first time.

The test requires the patient to perform three tasks- remembering words, drawing a clock, and recalling words.

The first task for the patient in the test is to remember a set of three words. The patient is shown three randomly chosen words on the mobile device, and is prompted to read aloud and remember them. Since the application is supposed to be used by an elderly, the font size of the words to remember is made bigger than usual.

The second task for the patient is a clock drawing test. In the pen and paper version of this test, the patient is given a piece of paper with a circle drawn on it and is asked to draw the digits and hands of the clock showing a given time of the day. The patient is supposed to write each of the twelve numbers of a clock near the appropriate hour mark position and to draw hands showing the given time. MOBI-COG automates this by showing a large circle on the screen asking the patient to draw the numbers and hands to show a given time. The time is chosen randomly and is of the form ‘X minutes past Y’, where X is kept a multiple of 5 for simplicity. For example, the time may be 10 minutes past 6. As the patient draws the digits and the hands using his/her finger on the touch screen, our app identifies the digits and their intended position.

The third task for the patient is to recall the three words that he/she was shown in step 1. In a traditional Mini-Cog test, a patient utters or writes down the recalled words on a piece of paper and a caregiver makes an assessment. In MOBI-COG, the user is prompted by the system to speak the word aloud. The system infers the word and matches it to the corresponding word from the first task. As it is sometimes hard to infer the right word from the speech, especially when the person is a non-native English speaker, MOBI-COG also comes with an option of text input.

When the three tasks are performed by a patient, the app provides a summary of the test results as well as the details. The summary includes the number of words that the patient recalled correctly, how many of the twelve positions had any digit drawn, how many of the digits were drawn correctly at the right position, and the closeness (angular distance) of the two clock hands to their correct positions. This information is shown graphically using five 5-starred rating bars along with numerical values. The detailed result, on the other hand, shows the details of each of these, i.e. which words were recalled correctly and which were not, which of the twelve numbers were missing or misplaced, and the exact amount of angular deviations of the drawn clock hands.

Compared to a pen and paper based test, the benefits of MOBICOG include convenience, uniform scoring, instant results, ease of administering and taking a test, and the ability to keep history of test scores. This application can be used for day-to-day primary dementia screening in a home environment, and should not be used as an alternative to seeing a caregiver; rather it is desirable that the history of test results, which is stored into the system, is shared with the caregiver for a better understanding of the patient’s condition.