Walmart has patented a design for a shopping cart that could measure your speed and heart rate.
The retailer wants to be able to track every element of customers' experience in store - including temperature and even the mount of force applied to the handle - to see if help is required.
Described as "biometric feedback cart handle", the exciting new technology would first measure "baseline" of data, before comparing it at different points across a visit.
This data would then be relayed back to a central server, which would send an alert to an assistant to help the shopper if it's indicated that they were "not satisfied".
It follows on from retailers already using Bluetooth beacons to track people around stores, with tech like gaze detection even telling companies what is grabbing customers' attention in a window display.
Walmart itself has already patented technology to allow it to eavesdrop on shoppers in stores.