Smartphone Application for Automated Measurement of Capillary Refill Time (CRT)
Doctors often check how quickly colour returns to your fingertip after a gentle squeeze to assess blood flow, but results can vary between different doctors. This study is testing a new smartphone app called 'CRTApp' which aims to provide a more consistent way to measure this. We're doing this by taking a short video of a patient's fingertip in the intensive care unit (ICU) and having both the app and three different medical staff review it. The main goal is to see if the app's measurements match the measurements from the medical staff. We'll also look at how factors like skin tone and lighting might affect how well the app works.
At a glance
What is this study about?
When doctors want to check how well blood is flowing to your body's tissues, especially during serious illness, they might gently press on your fingertip and see how quickly the colour returns. This quick test is called 'capillary refill time'. While it's a helpful bedside check, different doctors might get slightly different results because it's judged by eye.
This study is looking at a new smartphone app called 'CRTApp' that aims to make this measurement more accurate and consistent. The app uses a short video of your fingertip after it's been gently pressed, and then automatically calculates the capillary refill time. The idea is that this app could give doctors a more reliable way to monitor blood flow, which is very important for patients in intensive care.
To see if the app works well, we're comparing its measurements with those from experienced medical staff. For each patient in the study, we'll take a short video of their finger. Three different medical staff will then watch this video and record their measurement of the capillary refill time. At the same time, the special app will analyse the very same video to give its own automated measurement. By comparing these results, we can understand how accurate and reliable the app is, and if it could be a useful tool for doctors in the future.
Key takeaways
- Checking blood flow is important, especially in ICU.
- This study evaluates a smartphone app for measuring blood flow.
- The app aims for more consistent results than human observation.
- Participation involves a simple, quick video of your finger.
- Your privacy is a top priority with strict data handling.
Who may be eligible?
To be part of this study, you need to be at least 18 years old and currently staying in an intensive care unit (ICU). You also need to have a reason for doctors to check your capillary refill time, such as monitoring your blood flow or if they suspect you might have problems with blood circulation.
It's important that you, or a close family member if you're unable to decide yourself, agree to take part. This means you understand what's involved and give your permission.
However, some people won't be able to join. This includes if you have wounds or skin problems on your fingers where the measurement would be taken, known serious problems with blood vessels in your arms or legs, or if you've had a finger removed. Also, if you have tattoos, significant scars, or prominent moles on your fingers that might interfere with the video measurement or make it possible to identify you from the video, you wouldn't be able to participate.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- Are you 18 years old or older?
- Are you currently an adult patient in intensive care?
- Do your doctors need to check your blood flow (capillary refill)?
- Do you have any severe skin problems or tattoos on your fingertips?
- Do you have severe circulation problems in your limbs or any missing fingers?
What does participation involve?
If you join this study, your participation will be quite straightforward and won't involve any extra appointments or medication. A member of the medical team will take a short video of one of your fingertips. Before filming, one of your fingers will be gently pressed with a clear glass slide for about ten seconds, and then the pressure will be released while a short video is recorded. The video will focus only on your finger. This measurement is a standard part of care in the ICU, so it won't add any extra procedures to your treatment. The video will be handled carefully to protect your privacy and will only be used for the study. There will be no follow-up visits specifically for the study after the video is taken. The total duration of your involvement will be just a few minutes during a single measurement.
Potential risks and benefits
Locations (1)
- CHU BicêtreVerified postcodeLe Kremlin-Bicêtre, France
Common questions
What is 'capillary refill time'?
It's a quick check doctors do by gently pressing your fingertip to see how fast the colour returns, which helps them understand your blood circulation.
What does the smartphone app do?
The app uses a short video of your finger to automatically measure how quickly the colour returns, aiming to provide a more accurate and consistent result than just looking by eye.
Who is running this study?
This study is being conducted by medical researchers to validate a new tool, specifically in a hospital setting.
Will my privacy be protected?
Yes, great care will be taken with your video. It will be identified by a code, not your name, and deleted from the phone straight away after securely transferring. No videos will be stored in the cloud or sent over the internet.
Do I have to do anything special if I join?
No, you don't need to do anything extra. The study only involves taking a short video of your fingertip during a routine health check you might already receive.
How to find out more
Xavier MONNET, PhD
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
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