Gastric Alimetry

Performance Metrics

Clinical Evidence

The evidence base is unusually deep for a diagnostic of this age, and unusually concentrated. Most of it comes from the University of Auckland group that founded Alimetry, with company staff among the authors. Author disclosures are noted for each study below. The foundational paper (Gharibans et al., Science Translational Medicine 2022, PMID 36130019) mapped 43 patients with chronic nausea and vomiting syndromes against 43 matched controls. Meal responses were weaker in patients (median amplitude 23.3 versus 38.0 microvolts) and rhythms less organised. The clinically important finding was the split: 62 per cent of patients had normal mapping studies and higher psychological comorbidity, while 31 per cent had clearly abnormal studies whose biomarkers tracked their symptoms. Reference intervals came next (Varghese et al., American Journal of Gastroenterology 2023, PMID 36534985): 110 healthy controls, a median principal gastric frequency of 3.04 cycles per minute, a rhythm index reference of 0.25 or above. These intervals are what the report compares each patient to. Diagnostic performance is reported as classification against a reference, not against a tissue gold standard, because none exists at clinical scale. Schamberg et al. (Scientific Reports 2023, PMID 37696955) ran a protocolised retrospective comparison with conventional electrogastrography across 178 subjects. The Gastric Alimetry rhythm index separated patients with abnormal mapping from controls and normal-mapping patients with sensitivity 1.0 and specificity 0.96 against a blinded consensus panel (area under the curve 0.82). That comparison had only 13 abnormal-mapping patients against 136 controls and normal-mapping patients. Distinguishing all nausea-and-vomiting patients from controls, the same metric had sensitivity 0.35 and specificity 0.95, because most patients have normal gastric rhythms. The authors note that the consensus-panel reference is self-referential to the field's own methods, and say this explains the perfect sensitivity scored by both tests. Wang et al. (American Journal of Gastroenterology 2024, PMID 37782524) tested 75 patients with gastric emptying scintigraphy and mapping at the same time. Spectral analysis found a motility abnormality in 33.3 per cent against 22.7 per cent for scintigraphy, and 42.7 per cent combined. Delayed emptying did not predict any mapping phenotype. Reproducibility across three tests up to six months apart was high in 28 participants (Law et al., Neurogastroenterology and Motility 2024, PMID 38689428): intra-individual coefficients of variation of 0.2 to 1.9 per cent. The largest prospective study is the multicentre cohort behind the standardised classification scheme (Varghese et al., Gastro Hep Advances 2025, PMID 39802489). It enrolled 210 patients meeting Rome IV criteria: 83 per cent were phenotyped and 37.6 per cent had a spectral abnormality. Symptom patterns independent of gastric amplitude were more strongly tied to depression and anxiety scores. Management impact is measured in small series. Varghese et al. (Clinical and Translational Gastroenterology 2023, PMID 37589479) reviewed 50 consecutive patients at two New Zealand centres. The paper declares no competing interests, but co-author C. Daker is listed as an Alimetry member in the disclosures of other 2023 papers. The test aided a management decision in 84 per cent, and mean annual healthcare cost fell from $39,724 to $19,937 (P = 0.037) in a before-and-after comparison. The one randomised study is a 16-patient pilot from Western Sydney (Abraham et al., Journal of Neurogastroenterology and Motility 2026, PMID 41261563, one contractor author). It randomised the order in which two specialists saw scintigraphy and mapping results. Combined results raised diagnostic and management certainty, and the two tests changed management at similar rates (75 versus 62.5 per cent, not significantly different). That design randomises the reading order, not the patients' care, so the evidence grade stays prospective rather than randomised-controlled. No study yet shows that mapping-guided management improves symptoms or quality of life. The longitudinal cohort designed to test it (BMJ Open 2023 protocol, PMID 38011983) has not reported.

Inside the Auris+ Listing

Regulatory Approvals

Safety Record

No adverse-event reports, recalls or enforcement actions naming Alimetry or Gastric Alimetry were found in the openFDA device event, recall and enforcement databases when queried on 12 September 2026. The original 510(k) summary (K213924) records minor, transient irritation at the electrode sites in the 25-patient comparison study and nothing else. The device is non-invasive and carries no radiation, which is part of its case against scintigraphy. The clinical risk is interpretive: a normal mapping study is the commonest result in symptomatic patients and does not exclude disease, and a pattern label in the report is a phenotype, not a diagnosis. The report carries caution statements when recording quality or protocol fall outside target ranges.

Intended Use & Indications

The FDA indications for use read: "The Gastric Alimetry System is intended to record, store, view and process gastric myoelectrical activity as an aid in the diagnosis of various gastric disorders. The modified Gastric Alimetry System is indicated for patients 12 years and older." The system is prescription-only and used in healthcare facilities by trained staff, with specialist gastroenterologists as the report readers. The 510(k) summary describes the report as myoelectrical signal data for manual analysis together with computed summaries and plots. The cleared claim is an aid to diagnosis of gastric disorders in general; the condition-specific language (nausea and vomiting syndromes, gastroparesis, functional dyspepsia) comes from the peer-reviewed literature, not from the clearance.