Using facial reaction analysis and machine learning to objectively assess palatability of medicines in children

Abstract

AbstractFor orally administered drugs, palatability is key in ensuring patient acceptability and treatment compliance. Therefore, understanding children’s taste sensitivity and preferences can support formulators in making paediatric medicines more acceptable. Presently, we explore if the application of computer-vision techniques to videos of children’s reaction to gustatory taste strips can provide an objective assessment of palatability.Primary school children tasted four different flavoured strips: no taste, bitter, sweet and sour. Data was collected at home, under the supervision of a guardian, with responses recorded using the Aparito Atom5™ app and smartphone camera. Participants scored each strip on a 5-point hedonic scale. Facial landmarks were identified in the videos, and quantitative measures such as changes around the eyes, nose and mouth were extracted to train models to classify strip taste and score. We received 197 videos and 256 self-reported scores from 64 participants. The hedonic scale elicited expected results: children like sweetness, dislike bitterness and have varying opinions for sourness. The findings revealed the complexity and variability of facial reactions and highlighted specific measures, such as eyebrow and mouth corner elevations, as significant indicators of palatability. This study into children’s taste specificities can improve the measurement of paediatric medicine acceptability. An objective measure of how children feel about the taste of medicines has great potential in helping find the most palatable formulation. Moreover, collecting data in the home setting allows for natural behaviour, with minimal burden for participants.Author summaryWhen formulating medicines for children, understanding the taste profile is crucial to ensure they are not excessively unpleasant. In this study, we assessed if facial reactions in response to taste stimuli can be used to easily measure children’s feelings about the taste. We recorded videos of children trying different taste strips and analysed their facial expressions in response to each taste. The strips had different flavours: bitter, sweet, sour, and one with no taste. We also asked the children to rate each strip on scale of 1 to 5. We collected data from 64 children. The results confirmed that children generally like sweet tastes and do not like bitter ones. Their opinions on sour taste varied. Moreover, we found that specific facial reactions, like changes in their eyebrows and mouth corners were good indicators of taste preferences. The analysis of facial expressions can help formulators make medicines for children taste better. By objectively measuring how children feel about the taste of medicines, we can create more acceptable medicines for them. The collection of this data at home ensured children were in their comfortable environment, making it easier for them to be part of the study.