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CDT Open
Detect Changes in Your Brain's Ability to Plan and Reason. At Home!

Research Collaborators

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Direct Link to App

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Direct Link to App

How to Use the CDT Open App!

CDT Open is FREE!
Detect Brain Decline From Home

CDT OpenMax is the Paid Subscription Version of CDT Open

Benefits of Subscribing to CDT OpenMax

  • Numbering Writing Analysis to Detect Tremoring. 

    • Can be an early sign of Parkinson’s Disease.​

  • View All Reports in the App.

    • No need to download and find reports on your phone.

  • Request Graphs of All Your Scores

    • Graphs make it easy to see how your scores change over time.

  • Option to Purchase Future Neurological Tests

How to Draw a Clock

Video Instructions

Written Instructions

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See Below for Written Instructions on "How to Draw a Clock" Translated into Different Languages

How to Fill in the Number Writing Worksheet
for Detecting Tremor

How the Number Writing Analysis Works

Download Worksheet

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Research Updates

Part 1 - CDT Open Analyzes NHATS Clocks

Part 2 - CDT Open Analyzes Early Impairment in NHATS Clock Drawings

The Clock Draw Test (CDT) is a simple but effective way to assess your brains ability to plan and reason, because these are required to draw a normal clock. The inability to draw a normal clock can be a sign of dementia or traumatic brain injury. However, CDT Open does NOT diagnose dementia, but is meant to be a Computerized Cognitive Assessment Aid (CCAA) that gives indication about whether someone's cognitive abilities are functioning normally -- even severe dehydration can cause someone to draw an abnormal clock. All you have to do is draw a clock showing "10 minutes past 11" using pen and paper! Then take a picture of this clock and upload it to the app. CDT Open is FREE, because we believe in health equity. Each person can request one clock analysis per month.

Video [12 min]: An Objective & Quantitative Clock Draw Test
When to Start Screening for Dementia?

Routine screening for signs of dementia should start around 55 years of age, especially for those who suffer from high blood pressure, diabetes, chronic pain, or had traumatic brain injury. CDT Open is an effective tool to track your brain's ability to plan and reason through a simple drawing test. Consistent changes in your ability to draw clocks normally may be a sign of cognitive impairment, which precedes dementia. Those who have no family history of dementia, yet who have the above risk factors should be actively screening. Those who do have a family history of dementia should definitely be actively screening. At the least, every time this person visits a doctor or pharmacy for themselves and is 55+, they should do a clock draw test -- we made CDT Open free so that no one would have to pay for it. 

Translations of Written Instructions on How to Draw a Clock
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Translations of The Instructions

What The Monthly Score Report Looks Like
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Intended Use: CDT Open is a Computerized Cognitive Assessment Aid, a software device that uses an algorithm that analyzes the shape of hand-drawn clocks to provide an interpretation of cognitive function.


Indications for Use: CDT Open is indicated as an adjunctive tool for evaluating cognitive function, such as memory, information processing, attention and concentration, and executive functioning, in individuals over 18 years of age on a single occasion or over periodic assessments. Results should be interpreted in consultation with  qualified healthcare professionals before conclusions about medical conditions are made.

Warnings: CDT Open is not a standalone diagnostic device. CDT Open is not intended to be used to identify the presence or absence of clinical diagnoses.

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