Transcript Using smart phone technology to calculate and monitor

Using smart phone technology to calculate and monitor gravity infusions
Lee, P1 and Davies M2.
1ABM University Health Board, Medical Device Training, Swansea, United Kingdom, 2University of Nottingham, Computer Science, United Kingdom
Results
Introduction
Gravity infusion is one of the earliest methods known of delivering Intravenous
(IV) therapy and millions of gravity infusions are administered each year in the
UK. There are error-prone steps involved in setting up and monitoring these
infusions and since there is no technology involved to assist with the procedure,
it can be difficult to guarantee the accuracy and consistency of the prescribed
fluid delivery.
•The final version was issued in April 2010, and to date over 20,000 copies
have been sold in over 25 different countries.
Lack of maths skills and dose calculation error has been identified in the
literature and there have been numerous incidents where calculating or entering
the wrong dose has led to patient harm or death.
Website feedback includes;
We present a new method for accurately setting the fluid delivery, based on a
handheld mobile application that includes a novel approach to help estimate
flow rates and double-checking the steps involved in setting it up. This new
method can reduce errors and slips with gravity drug infusions, as well as
making each step simpler and less stressful for nurses to carry out correctly.
•User feedback has been positive, and some areas now use this tool as a
training aid in university teaching.
"Great app! Love the visual aspect, gives you an idea of what the drip rate should look like as no
one stands and counts!! Well done!!!“
"Brilliant app for teaching! Simple clean interface and perfect for visual learners. Delighted to find a
couple of REAL people behind the app who were accessible, friendly and really helpful. Well done!"
Background
Gravity infusion delivers medication to patients without the use of any complex
medical device such as an infusion pump or a syringe driver. In the UK National
Health Service (the NHS) around 15 million infusions are carried out every
year4. Unfortunately, there are approximately 700 unsafe incidents reported
annually, and many more going unreported.1
Figure 1: Screen for calculating drip rates
Figure 2: Screen for checking drip rates
Figure 3: Simulated Drip Chamber screen
The problem of drug dose calculation error has been identified in the literature
and there have been numerous incidents where calculating or entering the
wrong dose and subsequent administering has led to patient harm or death.2,3,4
Simple pocket cards, computer software and posters were developed but a
portable hand-held calculator was preferred. Errors inputting numbers is known
to exist5 so a dedicated app was developed to reduce these known interface
errors.
Method
Using the following information a basic prescription could be calculated.
1. Total volume of the drug to be infused (in milliliters)
2. Total time of infusion (hours/minutes)
3. The drip factor (number of drops per ml: shown on the giving set packaging)
Using the formula below the calculation programme was developed;
Drops per minute =
Total volume (mL)
Total time (hr/min)
x
Drip Factor
60
Applying ‘user-centered’ design approaches with ‘agile methodologies’ to allow
users to feed into the design process helped to develop a system that would
suit their needs. We followed the recommendations of ISO Standard 14971,
(Application of risk management to medical devices) and ISO Standard 62366
(Application of usability engineering to medical devices) and used Nielsen‘s
usability heuristics for user interface design6. In particular, we adhered to the
Institute for Safe Medication Practice’s guidelines for symbols and
nomenclature.7
We developed a mobile solution (Figure 1), which can be used for training
purposes and also as a ‘checker’ for nurses when carrying out gravity infusions.
The app has features for calculating, setting and checking infusions (Figure 2).
A simulated ‘Drip-Chamber’ screen, running at the set drip-rate offers both
visual and audible assistance to the user. This is further supported by utilising
the built-in vibration device within the iphone handset.
The IV Drip Rate App ©
Discussion and Conclusions
The app was initially developed for ipod/ipad and not for mobile phones as this
may go against organisation’s mobile phone policies. However, many patients
have downloaded the app themselves to check their own infusions. The
software is restricted to IOS(apple) products but 2014 should see the launch of
an android version. A plan to achieve CE marking as a medical device is also
ongoing.
Whilst this device can assist in calculating infusion drip-rates, the need to
regularly check patients and their infusions can never be replaced. The use of
smart-phone technology in intravenous therapy applications can assist in the
difficult process of drip-rate calculation and monitoring.
We are now carrying out user studies in hospitals to ascertain the variations in
prescriptions versus delivery in the healthcare setting. We are also examining
the use of ‘Augmented Reality’ interfaces that would allow the user to capture
drip-rates using the phone's camera.
References
1. National Patient Safety Agency, Safer Practice Notice 1, Improving Infusion Device Safety. NPSA, London,2004.
2. American Medical News, Revealing their medical errors: Why three doctors went public," August 15th 2011.
www.amednews.com/article/20110815/profession/308159942/4
3. How to ensure patient safety in drug dose calculation, Nursing Times, 108(42), 2012. www.nursingtimes.net
4. Lee P, Risk-score system for mathematical calculations in intravenous therapy, Nursing Standard, 22(33):35-42,
2008.
5. Thimbleby H & Cairns P, Reducing Number Entry Errors: Solving a Widespread, Serious Problem, Journal Royal
Society Interface, 7(51):1429 -1439,2010.
6. Nielsen J (1993) Usability Engineering. Morgan Kaufmann. p. 362. ISBN 978-0-12-518406-9
7. Institute of Safe Medicines Practice: 2013. List of Error-Prone Abbreviations, Symbols, and Dose Designations
P.T.Lee: June 2014