Inclusion Criteria:  Aged >18 years old; Male or female patients; Patients planned GEBT; Negative PCR on nasopharyngeal swab 24 or 48 hours prior to the test; Signed informed consent.  Exclusion Criteria:  Females who are pregnant or lactating. History of skin allergies or a history of extreme sensitivity to cosmetics or lotions Fragile skin vulnerable to skin tears. Damaged epigastric skin (open wounds, rash, inflammation) Patients unable to remain in a relaxed reclined position for the test duration