Walmart has been awarded a patent for a system that would store a person's medical information in a blockchain database and allow first responders to retrieve it in the event of an emergency.The patent, issued last week by the U.S. Patent and Trademark Office, describes three key parts to the system: a wearable device in which the blockchain is stored; a biometric scanner for an individual's biometric signature; and an RFID scanner to scan the wearable device, ideally a bracelet or wrist band.According to the patent, first responders would scan the device to access an encrypted private key. They would decrypt that using the biometric identifier and, with a second public key, retrieve the victim's records.Walmart has been revving up its focus on healthcare. The retail giant has touted the idea of “optimized networks” to improve consumer price and cost transparency while steering patients to providers with better performance ratings.In April, reports surfaced that Walmart is in early talks to acquire Humana. The two companies already partner on Medicare Part D drug plans, but an official deal has yet to be announced.With the patent for a blockchain-enabled medical records storage system, Walmart is following companies like Apple, Microsoft and Google parent Alphabet that have taken a swing to develop medical record tools. To date, medical records have been a mixed bag for the larger tech companies. Google discontinued its PHR product in 2011 while Apple this month has opened its Health Records API to developers and researchers and said the PHR is now connected with more than 500 hospitals and clinics.