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Crispino A, Loppini A, Uzelac I, Iravanian S, Bhatia NK, Burke M, Filippi S, Fenton FH, Gizzi A. A cross species thermoelectric and spatiotemporal analysis of alternans in live explanted hearts using dual voltage-calcium fluorescence optical mapping. Physiol Meas 2024; 45:065001. [PMID: 38772394 DOI: 10.1088/1361-6579/ad4e8f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 05/21/2024] [Indexed: 05/23/2024]
Abstract
Objective.Temperature plays a crucial role in influencing the spatiotemporal dynamics of the heart. Electrical instabilities due to specific thermal conditions typically lead to early period-doubling bifurcations and beat-to-beat alternans. These pro-arrhythmic phenomena manifest in voltage and calcium traces, resulting in compromised contractile behaviors. In such intricate scenario, dual optical mapping technique was used to uncover unexplored multi-scale and nonlinear couplings, essential for early detection and understanding of cardiac arrhythmia.Approach.We propose a methodological analysis of synchronized voltage-calcium signals for detecting alternans, restitution curves, and spatiotemporal alternans patterns under different thermal conditions, based on integral features calculation. To validate our approach, we conducted a cross-species investigation involving rabbit and guinea pig epicardial ventricular surfaces and human endocardial tissue under pacing-down protocols.Main results.We show that the proposed integral feature, as the area under the curve, could be an easily applicable indicator that may enhance the predictability of the onset and progression of cardiac alternans. Insights into spatiotemporal correlation analysis of characteristic spatial lengths across different heart species were further provided.Significance.Exploring cross-species thermoelectric features contributes to understanding temperature-dependent proarrhythmic regimes and their implications on coupled spatiotemporal voltage-calcium dynamics. The findings provide preliminary insights and potential strategies for enhancing arrhythmia detection and treatment.
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Affiliation(s)
- Anna Crispino
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alessandro Loppini
- Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Ilija Uzelac
- Virginia Commonwealth University, Richmond, VA, United States of America
| | - Shahriar Iravanian
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Neal K Bhatia
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Michael Burke
- Department of Cardiovascular Medicine, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Simonetta Filippi
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Flavio H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Alessio Gizzi
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
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Xu W, Wang T, Foong D, Schamberg G, Evennett N, Beban G, Gharibans A, Calder S, Daker C, Ho V, O'Grady G. Characterization of gastric dysfunction after fundoplication using body surface gastric mapping. J Gastrointest Surg 2024; 28:236-245. [PMID: 38445915 DOI: 10.1016/j.gassur.2023.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/09/2023] [Accepted: 12/22/2023] [Indexed: 03/07/2024]
Abstract
BACKGROUND Adverse gastric symptoms persist in up to 20% of fundoplication operations completed for gastroesophageal reflux disease, causing significant morbidity and driving the need for revisional procedures. Noninvasive techniques to assess the mechanisms of persistent postoperative symptoms are lacking. This study aimed to investigate gastric myoelectrical abnormalities and symptoms in patients after fundoplication using a novel noninvasive body surface gastric mapping (BSGM) device. METHODS Patients with a previous fundoplication operation and ongoing significant gastroduodenal symptoms and matched controls were included. BSGM using Gastric Alimetry (Alimetry Ltd) was employed, consisting of a high-resolution 64-channel array, validated symptom-logging application, and wearable reader. RESULTS A total of 16 patients with significant chronic symptoms after fundoplication were recruited, with 16 matched controls. Overall, 6 of 16 patients (37.5%) showed significant spectral abnormalities defined by unstable gastric myoelectrical activity (n = 2), abnormally high gastric frequencies (n = 3), or high gastric amplitudes (n = 1). Patients with spectral abnormalities had higher Patient Assessment of Upper Gastrointestinal Disorders-Symptom Severity Index scores than those of patients without spectral abnormalities (3.2 [range, 2.8-3.6] vs 2.3 [range, 2.2-2.8], respectively; P = .024). Moreover, 7 of 16 patients (43.8%) had BSGM test results suggestive of gut-brain axis contributions and without myoelectrical dysfunction. Increasing Principal Gastric Frequency Deviation and decreasing Rhythm Index scores were associated with symptom severity (r > .40; P < .05). CONCLUSION A significant number of patients with persistent postfundoplication symptoms displayed abnormal gastric function on BSGM testing, which correlated with symptom severity. Our findings advance the pathophysiologic understanding of postfundoplication disorders, which may inform diagnosis and patient selection for medical therapy and revisional procedures.
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Affiliation(s)
- William Xu
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Tim Wang
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Daphne Foong
- Alimetry Ltd, Auckland, New Zealand; School of Medicine, Western Sydney University, Penrith, Australia
| | - Gabe Schamberg
- Department of Surgery, University of Auckland, Auckland, New Zealand; Alimetry Ltd, Auckland, New Zealand
| | - Nicholas Evennett
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Grant Beban
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Armen Gharibans
- Alimetry Ltd, Auckland, New Zealand; Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Stefan Calder
- Alimetry Ltd, Auckland, New Zealand; Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Charlotte Daker
- Alimetry Ltd, Auckland, New Zealand; Department of Gastroenterology, North Shore Hospital, Auckland, New Zealand
| | - Vincent Ho
- School of Medicine, Western Sydney University, Penrith, Australia; Department of Gastroenterology and Hepatology, Campbelltown Hospital, Campbelltown, Australia
| | - Greg O'Grady
- Department of Surgery, University of Auckland, Auckland, New Zealand; Alimetry Ltd, Auckland, New Zealand; Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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Seo SHB, Wells CI, Dickson T, Rowbotham D, Gharibans A, Calder S, Bissett I, O'Grady G, Erickson JC. Validation of body surface colonic mapping (BSCM) against high resolution colonic manometry for evaluation of colonic motility. Sci Rep 2024; 14:4842. [PMID: 38418514 PMCID: PMC10902299 DOI: 10.1038/s41598-024-54429-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 02/13/2024] [Indexed: 03/01/2024] Open
Abstract
Abnormal cyclic motor pattern (CMP) activity is implicated in colonic dysfunction, but the only tool to evaluate CMP activity, high-resolution colonic manometry (HRCM), remains expensive and not widely accessible. This study aimed to validate body surface colonic mapping (BSCM) through direct correlation with HRCM. Synchronous meal-test recordings were performed in asymptomatic participants with intact colons. A signal processing method for BSCM was developed to detect CMPs. Quantitative temporal analysis was performed comparing the meal responses and motility indices (MI). Spatial heat maps were also compared. Post-study questionnaires evaluated participants' preference and comfort/distress experienced from either test. 11 participants were recruited and 7 had successful synchronous recordings (5 females/2 males; median age: 50 years [range 38-63]). The best-correlating MI temporal analyses achieved a high degree of agreement (median Pearson correlation coefficient (Rp) value: 0.69; range 0.47-0.77). HRCM and BSCM meal response start and end times (Rp = 0.998 and 0.83; both p < 0.05) and durations (Rp = 0.85; p = 0.03) were similar. Heat maps demonstrated good spatial agreement. BSCM is the first non-invasive method to be validated by demonstrating a direct spatio-temporal correlation to manometry in evaluating colonic motility.
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Affiliation(s)
- Sean H B Seo
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Cameron I Wells
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Department of Surgery, Auckland District Health Board, Auckland, New Zealand
| | - Tully Dickson
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - David Rowbotham
- Department of Gastroenterology, Auckland City Hospital, Te Whatu Ora Health New Zealand, Auckland, New Zealand
| | - Armen Gharibans
- Alimetry Ltd, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Stefan Calder
- Alimetry Ltd, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Ian Bissett
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Department of Surgery, Auckland District Health Board, Auckland, New Zealand
| | - Greg O'Grady
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | - Jonathan C Erickson
- Alimetry Ltd, Auckland, New Zealand.
- Department of Physics and Engineering, Washington and Lee University, Lexington, USA.
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Du P, Maharjan A, Calder S, Schultz M, Schamberg G, Gharibans A, O'Grady G, Cakmak YO. Transcutaneous Auricular Vagus Nerve Stimulation Normalizes Induced Gastric Myoelectrical Dysrhythmias in Controls Assessed by Body-Surface Gastric Mapping. Neuromodulation 2024; 27:333-342. [PMID: 36997454 DOI: 10.1016/j.neurom.2023.02.078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/24/2023] [Accepted: 02/13/2023] [Indexed: 03/31/2023]
Abstract
OBJECTIVES Transcutaneous auricular vagus nerve stimulation (TaVNS) is a supplementary treatment for gastric symptoms resulting from dysrhythmias. The main objective of this study was to quantify the effects of 10, 40, and 80 Hz TaVNS and sham in healthy individuals in response to a 5-minute water-load (WL5) test. MATERIALS AND METHODS Eighteen healthy volunteers aged between 21 and 55 years (body mass index: 27.1 ± 3.2) were recruited. Each subject fasted for up to eight hours and participated in four 95-minute sessions, which consisted of 30 fasted baseline, 30 minutes TaVNS, WL5, and 30 minutes post-WL5. Heart rate variability was assessed using sternal electrocardiogram. Body-surface gastric mapping and bloating (/10) were recorded. One-way ANOVA with post hoc Tukey test was performed to test the difference between TaVNS protocols in terms of frequency, amplitude, bloating scores, root mean square of the successive differences (RMSSD), and stress index (SI). RESULTS On average, the subjects consumed 526 ± 160 mL of water, with volume ingested correlated to bloating (mean score 4.1 ± 1.8; r = 0.36, p = 0.029). In general, the reduction in frequency and rhythm stability during the post-WL5 period in sham was normalized by all three TaVNS protocols. Both 40- and 80-Hz protocols also caused increases in amplitude during the stim-only and/or post-WL5 periods. RMSSD increased during the 40-Hz protocol. SI increased during the 10-Hz protocol but decreased during the 40- and 80-Hz protocols. CONCLUSION TaVNS proved effective in normalizing gastric dysrhythmias by WL5 in healthy subjects by altering both parasympathetic and sympathetic pathways.
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Affiliation(s)
- Peng Du
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Ashim Maharjan
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Stefan Calder
- Department of Surgery, The University of Auckland, Auckland, New Zealand; Alimetry Ltd, Auckland, New Zealand
| | - Michael Schultz
- Department of Medicine, University of Otago, Dunedin, New Zealand
| | | | - Armen Gharibans
- Department of Surgery, The University of Auckland, Auckland, New Zealand; Alimetry Ltd, Auckland, New Zealand
| | - Gregory O'Grady
- Department of Surgery, The University of Auckland, Auckland, New Zealand; Alimetry Ltd, Auckland, New Zealand
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Wang WJ, Foong D, Calder S, Schamberg G, Varghese C, Tack J, Xu W, Daker C, Carson D, Waite S, Hayes T, Du P, Abell TL, Parkman HP, Huang IH, Fernandes V, Andrews CN, Gharibans AA, Ho V, O’Grady G. Gastric Alimetry Expands Patient Phenotyping in Gastroduodenal Disorders Compared with Gastric Emptying Scintigraphy. Am J Gastroenterol 2024; 119:331-341. [PMID: 37782524 PMCID: PMC10872929 DOI: 10.14309/ajg.0000000000002528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/04/2023] [Indexed: 10/03/2023]
Abstract
INTRODUCTION Gastric emptying testing (GET) assesses gastric motility, however, is nonspecific and insensitive for neuromuscular disorders. Gastric Alimetry (GA) is a new medical device combining noninvasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared with GET. METHODS Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99m TC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: (i) sensorimotor, (ii) continuous, and (iii) other. RESULTS Seventy-five patients were assessed, 77% female. Motility abnormality detection rates were as follows: GET 22.7% (14 delayed, 3 rapid), GA spectral analysis 33.3% (14 low rhythm stability/low amplitude, 5 high amplitude, and 6 abnormal frequency), and combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included sensorimotor 17% (where symptoms strongly paired with gastric amplitude, median r = 0.61), continuous 30%, and other 53%. GA phenotypes showed superior correlations with Gastroparesis Cardinal Symptom Index, Patient Assessment of Upper Gastrointestinal Symptom Severity Index, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores ( P > 0.05). Delayed emptying was not predictive of specific GA phenotypes. DISCUSSION GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with increased correlation with symptoms and psychometrics compared with gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders.
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Affiliation(s)
- William Jiaen Wang
- Gastrointestinal Motility Disorders Unit, Western Sydney University, Australia
- Department of Gastroenterology and Hepatology, Campbelltown Hospital, Australia
- Gastroenterology and Hepatology, Princess Alexandra Hospital, Australia
| | - Daphne Foong
- Gastrointestinal Motility Disorders Unit, Western Sydney University, Australia
| | - Stefan Calder
- Department of Surgery, Auckland City Hospital, New Zealand
- Auckland Bioengineering Institute, University of Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | - Gabriel Schamberg
- Department of Surgery, Auckland City Hospital, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | - Chris Varghese
- Department of Surgery, Auckland City Hospital, New Zealand
| | - Jan Tack
- Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Belgium
| | - William Xu
- Department of Surgery, Auckland City Hospital, New Zealand
| | - Charlotte Daker
- Department of Gastroenterology, North Shore Hospital, Auckland, New Zealand
| | - Daniel Carson
- Department of Surgery, Auckland City Hospital, New Zealand
| | | | - Thomas Hayes
- Department of Surgery, Auckland City Hospital, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, New Zealand
| | - Thomas L. Abell
- Division of Gastroenterology, University of Louisville, KY, USA
| | - Henry P. Parkman
- Gastroenterology Section, Department of Medicine, Lewis Katz School of Medicine, Temple University, USA
| | - I-Hsuan Huang
- Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, Belgium
| | | | | | - Armen A. Gharibans
- Department of Surgery, Auckland City Hospital, New Zealand
- Auckland Bioengineering Institute, University of Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | - Vincent Ho
- Gastrointestinal Motility Disorders Unit, Western Sydney University, Australia
- Department of Gastroenterology and Hepatology, Campbelltown Hospital, Australia
| | - Greg O’Grady
- Department of Surgery, Auckland City Hospital, New Zealand
- Auckland Bioengineering Institute, University of Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
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Foong D, Calder S, Varghese C, Schamberg G, Xu W, Daker C, Ho V, Andrews CN, Gharibans AA, O’Grady G. Gastric Alimetry ® Test Interpretation in Gastroduodenal Disorders: Review and Recommendations. J Clin Med 2023; 12:6436. [PMID: 37892572 PMCID: PMC10607701 DOI: 10.3390/jcm12206436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/04/2023] [Accepted: 10/08/2023] [Indexed: 10/29/2023] Open
Abstract
Chronic gastroduodenal symptoms are prevalent worldwide, and there is a need for new diagnostic and treatment approaches. Several overlapping processes may contribute to these symptoms, including gastric dysmotility, hypersensitivity, gut-brain axis disorders, gastric outflow resistance, and duodenal inflammation. Gastric Alimetry® (Alimetry, New Zealand) is a non-invasive test for evaluating gastric function that combines body surface gastric mapping (high-resolution electrophysiology) with validated symptom profiling. Together, these complementary data streams enable important new clinical insights into gastric disorders and their symptom correlations, with emerging therapeutic implications. A comprehensive database has been established, currently comprising > 2000 Gastric Alimetry tests, including both controls and patients with various gastroduodenal disorders. From studies employing this database, this paper presents a systematic methodology for Gastric Alimetry test interpretation, together with an extensive supporting literature review. Reporting is grouped into four sections: Test Quality, Spectral Analysis, Symptoms, and Conclusions. This review compiles, assesses, and evaluates each of these aspects of test assessment, with discussion of relevant evidence, example cases, limitations, and areas for future work. The resultant interpretation methodology is recommended for use in clinical practice and research to assist clinicians in their use of Gastric Alimetry as a diagnostic aid and is expected to continue to evolve with further development.
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Affiliation(s)
- Daphne Foong
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Stefan Calder
- Department of Surgery, Auckland City Hospital, Auckland 1023, New Zealand
- Alimetry Ltd., Auckland 1010, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
| | - Chris Varghese
- Department of Surgery, Auckland City Hospital, Auckland 1023, New Zealand
| | - Gabriel Schamberg
- Alimetry Ltd., Auckland 1010, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
| | - William Xu
- Department of Surgery, Auckland City Hospital, Auckland 1023, New Zealand
| | - Charlotte Daker
- Department of Gastroenterology, North Shore Hospital, Auckland 0620, New Zealand
| | - Vincent Ho
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia
- Department of Gastroenterology and Hepatology, Campbelltown Hospital, Sydney, NSW 2560, Australia
| | - Christopher N. Andrews
- Division of Gastroenterology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Armen A. Gharibans
- Department of Surgery, Auckland City Hospital, Auckland 1023, New Zealand
- Alimetry Ltd., Auckland 1010, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
| | - Greg O’Grady
- Department of Surgery, Auckland City Hospital, Auckland 1023, New Zealand
- Alimetry Ltd., Auckland 1010, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand
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O'Grady G, Varghese C, Schamberg G, Calder S, Du P, Xu W, Tack J, Daker C, Mousa H, Abell TL, Parkman HP, Ho V, Bradshaw LA, Hobson A, Andrews CN, Gharibans AA. Principles and clinical methods of body surface gastric mapping: Technical review. Neurogastroenterol Motil 2023; 35:e14556. [PMID: 36989183 PMCID: PMC10524901 DOI: 10.1111/nmo.14556] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/29/2023] [Accepted: 02/12/2023] [Indexed: 03/30/2023]
Abstract
BACKGROUND AND PURPOSE Chronic gastric symptoms are common, however differentiating specific contributing mechanisms in individual patients remains challenging. Abnormal gastric motility is present in a significant subgroup, but reliable methods for assessing gastric motor function in clinical practice are lacking. Body surface gastric mapping (BSGM) is a new diagnostic aid, employs multi-electrode arrays to measure and map gastric myoelectrical activity non-invasively in high resolution. Clinical adoption of BSGM is currently expanding following studies demonstrating the ability to achieve specific patient subgrouping, and subsequent regulatory clearances. An international working group was formed in order to standardize clinical BSGM methods, encompassing a technical group developing BSGM methods and a clinical advisory group. The working group performed a technical literature review and synthesis focusing on the rationale, principles, methods, and clinical applications of BSGM, with secondary review by the clinical group. The principles and validation of BSGM were evaluated, including key advances achieved over legacy electrogastrography (EGG). Methods for BSGM were reviewed, including device design considerations, patient preparation, test conduct, and data processing steps. Recent advances in BSGM test metrics and reference intervals are discussed, including four novel metrics, being the 'principal gastric frequency', BMI-adjusted amplitude, Gastric Alimetry Rhythm Index™, and fed: fasted amplitude ratio. An additional essential element of BSGM has been the introduction of validated digital tools for standardized symptom profiling, performed simultaneously during testing. Specific phenotypes identifiable by BSGM and the associated symptom profiles were codified with reference to pathophysiology. Finally, knowledge gaps and priority areas for future BSGM research were also identified by the working group.
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Affiliation(s)
- Gregory O'Grady
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Chris Varghese
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Gabriel Schamberg
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | | | - Peng Du
- Alimetry Ltd, Auckland, New Zealand
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - William Xu
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - Jan Tack
- Department of Gastroenterology, University Hospitals, Leuven, Belgium
| | | | - Hayat Mousa
- Division of Gastroenterology, Lustgarten Motility Center, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Thomas L Abell
- Division of Gastroenterology, Hepatology and Nutrition, University of Louisville, Louisville, Kentucky, USA
| | - Henry P Parkman
- Department of Medicine, Temple University Hospital, Philadelphia, Pennsylvania, USA
| | - Vincent Ho
- Western Sydney University, Sydney, New South Wales, Australia
| | | | | | - Christopher N Andrews
- Division of Gastroenterology and Hepatology, University of Calgary, Calgary, Alberta, Canada
| | - Armen A Gharibans
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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Drake CE, Cheng LK, Muszynski ND, Somarajan S, Paskaranandavadivel N, Angeli-Gordon TR, Du P, Bradshaw LA, Avci R. Electroanatomical mapping of the stomach with simultaneous biomagnetic measurements. Comput Biol Med 2023; 165:107384. [PMID: 37633085 DOI: 10.1016/j.compbiomed.2023.107384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/17/2023] [Accepted: 08/14/2023] [Indexed: 08/28/2023]
Abstract
Gastric motility is coordinated by bioelectric slow waves (SWs) and dysrhythmic SW activity has been linked with motility disorders. Magnetogastrography (MGG) is the non-invasive measurement of the biomagnetic fields generated by SWs. Dysrhythmia identification using MGG is currently challenging because source models are not well developed and the impact of anatomical variation is not well understood. A novel method for the quantitative spatial co-registration of serosal SW potentials, MGG, and geometric models of anatomical structures was developed and performed on two anesthetized pigs to verify feasibility. Electrode arrays were localized using electromagnetic transmitting coils. Coil localization error for the volume where the stomach is normally located under the sensor array was assessed in a benchtop experiment, and mean error was 4.2±2.3mm and 3.6±3.3° for a coil orientation parallel to the sensor array and 6.2±5.7mm and 4.5±7.0° for a perpendicular coil orientation. Stomach geometries were reconstructed by fitting a generic stomach to up to 19 localization coils, and SW activation maps were mapped onto the reconstructed geometries using the registered positions of 128 electrodes. Normal proximal-to-distal and ectopic SW propagation patterns were recorded from the serosa and compared against the simultaneous MGG measurements. Correlations between the center-of-gravity of normalized MGG and the mean position of SW activity on the serosa were 0.36 and 0.85 for the ectopic and normal propagation patterns along the proximal-distal stomach axis, respectively. This study presents the first feasible method for the spatial co-registration of MGG, serosal SW measurements, and subject-specific anatomy. This is a significant advancement because these data enable the development and validation of novel non-invasive gastric source characterization methods.
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Affiliation(s)
- Chad E Drake
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Leo K Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Surgery, Vanderbilt University, Nashville, TN, USA
| | | | | | | | | | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | | | - Recep Avci
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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Schamberg G, Calder S, Varghese C, Xu W, Wang WJ, Ho V, Daker C, Andrews CN, O'Grady G, Gharibans AA. Comparison of Gastric Alimetry ® body surface gastric mapping versus electrogastrography spectral analysis. Sci Rep 2023; 13:14987. [PMID: 37696955 PMCID: PMC10495352 DOI: 10.1038/s41598-023-41645-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 08/29/2023] [Indexed: 09/13/2023] Open
Abstract
Electrogastrography (EGG) non-invasively evaluates gastric motility but is viewed as lacking clinical utility. Gastric Alimetry® is a new diagnostic test that combines high-resolution body surface gastric mapping (BSGM) with validated symptom profiling, with the goal of overcoming EGG's limitations. This study directly compared EGG and BSGM to define performance differences in spectral analysis. Comparisons between Gastric Alimetry BSGM and EGG were conducted by protocolized retrospective evaluation of 178 subjects [110 controls; 68 nausea and vomiting (NVS) and/or type 1 diabetes (T1D)]. Comparisons followed standard methodologies for each test (pre-processing, post-processing, analysis), with statistical evaluations for group-level differences, symptom correlations, and patient-level classifications. BSGM showed substantially tighter frequency ranges vs EGG in controls. Both tests detected rhythm instability in NVS, but EGG showed opposite frequency effects in T1D. BSGM showed an 8× increase in the number of significant correlations with symptoms. BSGM accuracy for patient-level classification was 0.78 for patients vs controls and 0.96 as compared to blinded consensus panel; EGG accuracy was 0.54 and 0.43. EGG detected group-level differences in patients, but lacked symptom correlations and showed poor accuracy for patient-level classification, explaining EGG's limited clinical utility. BSGM demonstrated substantial performance improvements across all domains.
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Affiliation(s)
- Gabriel Schamberg
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | - Stefan Calder
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
| | - Chris Varghese
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - William Xu
- Department of Surgery, The University of Auckland, Auckland, New Zealand
| | - William Jiaen Wang
- School of Medicine, Western Sydney University, Sydney, Australia
- Department of Gastroenterology and Hepatology, Campbelltown Hospital, Sydney, Australia
- Department of Gastroenterology and Hepatology, Townsville University Hospital, Townsville, Australia
- Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Australia
| | - Vincent Ho
- School of Medicine, Western Sydney University, Sydney, Australia
- Department of Gastroenterology and Hepatology, Campbelltown Hospital, Sydney, Australia
| | - Charlotte Daker
- Department of Gastroenterology, North Shore Hospital, Auckland, New Zealand
| | | | - Greg O'Grady
- Department of Surgery, The University of Auckland, Auckland, New Zealand
- Alimetry Ltd, Auckland, New Zealand
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Armen A Gharibans
- Department of Surgery, The University of Auckland, Auckland, New Zealand.
- Alimetry Ltd, Auckland, New Zealand.
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
- Perelman School of Medicine, University of Pennsylvania, Pennsylvania, United States.
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10
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Tsianou CC, Kvetina J, Radochova V, Kohoutova D, Rejchrt S, Valis M, Zdarova Karasova J, Tacheci I, Knoblochova V, Soukup O, Bures J. The effect of single and repeated doses of rivastigmine on gastric myoelectric activity in experimental pigs. PLoS One 2023; 18:e0286386. [PMID: 37262057 DOI: 10.1371/journal.pone.0286386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 05/16/2023] [Indexed: 06/03/2023] Open
Abstract
BACKGROUND Rivastigmine is a pseudo-irreversible cholinesterase inhibitor used for therapy of Alzheimer's disease and non-Alzheimer dementia syndromes. In humans, rivastigmine can cause significant gastrointestinal side effects that can limit its clinical use. The aim of this study was to assess the impact of rivastigmine on gastric motor function by means of electrogastrography (EGG) in experimental pigs. METHODS Six experimental adult female pigs (Sus scrofa f. domestica, hybrids of Czech White and Landrace breeds; 3-month-old; mean weight 30.7 ± 1.2 kg) were enrolled into the study twice and created two experimental groups. In group A, a single intragastric dose of 6 mg rivastigmine hydrogen tartate was administered in the morning to fasting pigs before EGG recording. In group B, rivastigmine was administered to overnight fasting animals in a dietary bolus in the morning for 7 days (6 mg per day). On day 8, an intragastric dose of 12 mg rivastigmine was given in the morning to fasting pigs before EGG. EGG recording was accomplished by means of an EGG standalone system. Recordings from both groups were evaluated in dominant frequency and EGG power (areas of amplitudes). RESULTS In total, 1,980 one-minute EGG intervals were evaluated. In group A, basal EGG power (median 1290.5; interquartile range 736.5-2330 μV2) was significantly higher in comparison with the power of intervals T6 (882; 577-1375; p = 0.001) and T10 (992.5; 385-2859; p = 0.032). In group B, the dominant frequency increased significantly from basal values (1.97 ± 1.57 cycles per minute) to intervals T9 (3.26 ± 2.16; p < 0.001) and T10 (2.14 ± 1.16; p = 0.012), respectively. In group B, basal EGG power (median 1030.5; interquartile range 549-5093) was significantly higher in comparison with the power of intervals T7 (692.5; 434-1476; p = 0.002) and T8 (799; 435-1463 μV2; p = 0.004). CONCLUSIONS Both single as well as repeated intragastric administration of rivastigmine hydrogen tartrate caused a significant decrease of EGG power (areas of amplitudes) in experimental pigs. EGG power may serve as an indirect indicator of gastric motor competence. These findings might provide a possible explanation of rivastigmine-associated dyspepsia in humans.
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Affiliation(s)
| | - Jaroslav Kvetina
- Biomedical Research Centre, University Hospital, Hradec Kralove, Czech Republic
| | - Vera Radochova
- Animal Laboratory, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Darina Kohoutova
- Biomedical Research Centre, University Hospital, Hradec Kralove, Czech Republic
- The Royal Marsden NHS Foundation Trust, London, United Kingdom
| | - Stanislav Rejchrt
- 2nd Department of Internal Medicine-Gastroenterology, Faculty of Medicine in Hradec Kralove and University Hospital Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | - Martin Valis
- Department of Neurology, Faculty of Medicine in Hradec Kralove and University Hospital Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | - Jana Zdarova Karasova
- Biomedical Research Centre, University Hospital, Hradec Kralove, Czech Republic
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Ilja Tacheci
- 2nd Department of Internal Medicine-Gastroenterology, Faculty of Medicine in Hradec Kralove and University Hospital Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | | | - Ondrej Soukup
- Biomedical Research Centre, University Hospital, Hradec Kralove, Czech Republic
| | - Jan Bures
- Biomedical Research Centre, University Hospital, Hradec Kralove, Czech Republic
- Institute of Gastrointestinal Oncology, Military University Hospital Praha, Praha, Czech Republic
- Department of Medicine, First Faculty of Medicine, Charles University, Nové Město, Czech Republic
- Military University Hospital Praha, Praha, Czech Republic
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11
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Wang WJ, Foong D, Calder S, Schamberg G, Varghese C, Tack J, Xu W, Daker C, Carson D, Waite S, Hayes T, Du P, Abell TL, Parkman HP, Huang IH, Fernandes V, Andrews CN, Gharibans AA, Ho V, O'Grady G. Gastric Alimetry ® improves patient phenotyping in gastroduodenal disorders compared to gastric emptying scintigraphy alone. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.05.18.23290134. [PMID: 37292604 PMCID: PMC10246136 DOI: 10.1101/2023.05.18.23290134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Objectives Gastric emptying testing (GET) assesses gastric motility, however is non-specific and insensitive for neuromuscular disorders. Gastric Alimetry® (GA) is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling. This study assessed patient-specific phenotyping using GA compared to GET. Methods Patients with chronic gastroduodenal symptoms underwent simultaneous GET and GA, comprising a 30-minute baseline, 99m TC-labelled egg meal, and 4-hour postprandial recording. Results were referenced to normative ranges. Symptoms were profiled in the validated GA App and phenotyped using rule-based criteria based on their relationships to the meal and gastric activity: i) sensorimotor; ii) continuous; and iii) other. Results 75 patients were assessed; 77% female. Motility abnormality detection rates were: GET 22.7% (14 delayed, 3 rapid); GA spectral analysis 33.3% (14 low rhythm stability / low amplitude; 5 high amplitude; 6 abnormal frequency); combined yield 42.7%. In patients with normal spectral analysis, GA symptom phenotypes included: sensorimotor 17% (where symptoms strongly paired with gastric amplitude; median r=0.61); continuous 30%; other 53%. GA phenotypes showed superior correlations with GCSI, PAGI-SYM, and anxiety scales, whereas Rome IV Criteria did not correlate with psychometric scores (p>0.05). Delayed emptying was not predictive of specific GA phenotypes. Conclusions GA improves patient phenotyping in chronic gastroduodenal disorders in the presence and absence of motility abnormalities with improved correlation with symptoms and psychometrics compared to gastric emptying status and Rome IV criteria. These findings have implications for the diagnostic profiling and personalized management of gastroduodenal disorders. Study Highlights 1) WHAT IS KNOWN Chronic gastroduodenal symptoms are common, costly and greatly impact on quality of lifeThere is a poor correlation between gastric emptying testing (GET) and symptomsGastric Alimetry® is a new medical device combining non-invasive gastric electrophysiological mapping and validated symptom profiling 2) WHAT IS NEW HERE Gastric Alimetry generates a 1.5x higher yield for motility abnormalities than GETWith symptom profiling, Gastric Alimetry identified 2.7x more specific patient categories than GETGastric Alimetry improves clinical phenotyping, with improved correlation with symptoms and psychometrics compared to GET.
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12
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Athavale ON, Avci R, Cheng LK, Du P. Computational models of autonomic regulation in gastric motility: Progress, challenges, and future directions. Front Neurosci 2023; 17:1146097. [PMID: 37008202 PMCID: PMC10050371 DOI: 10.3389/fnins.2023.1146097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/27/2023] [Indexed: 03/17/2023] Open
Abstract
The stomach is extensively innervated by the vagus nerve and the enteric nervous system. The mechanisms through which this innervation affects gastric motility are being unraveled, motivating the first concerted steps towards the incorporation autonomic regulation into computational models of gastric motility. Computational modeling has been valuable in advancing clinical treatment of other organs, such as the heart. However, to date, computational models of gastric motility have made simplifying assumptions about the link between gastric electrophysiology and motility. Advances in experimental neuroscience mean that these assumptions can be reviewed, and detailed models of autonomic regulation can be incorporated into computational models. This review covers these advances, as well as a vision for the utility of computational models of gastric motility. Diseases of the nervous system, such as Parkinson’s disease, can originate from the brain-gut axis and result in pathological gastric motility. Computational models are a valuable tool for understanding the mechanisms of disease and how treatment may affect gastric motility. This review also covers recent advances in experimental neuroscience that are fundamental to the development of physiology-driven computational models. A vision for the future of computational modeling of gastric motility is proposed and modeling approaches employed for existing mathematical models of autonomic regulation of other gastrointestinal organs and other organ systems are discussed.
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13
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Wang Y, Chen JDZ, Nojkov B. Diagnostic Methods for Evaluation of Gastric Motility-A Mini Review. Diagnostics (Basel) 2023; 13:803. [PMID: 36832289 PMCID: PMC9955554 DOI: 10.3390/diagnostics13040803] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/11/2023] [Accepted: 02/18/2023] [Indexed: 02/23/2023] Open
Abstract
Gastric motility abnormalities are common in patients with disorders of gut-brain interaction, such as functional dyspepsia and gastroparesis. Accurate assessment of the gastric motility in these common disorders can help understand the underlying pathophysiology and guide effective treatment. A variety of clinically applicable diagnostic methods have been developed to objectively evaluate the presence of gastric dysmotility, including tests of gastric accommodation, antroduodenal motility, gastric emptying, and gastric myoelectrical activity. The aim of this mini review is to summarize the advances in clinically available diagnostic methods for evaluation of gastric motility and describe the advantages and disadvantages of each test.
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Affiliation(s)
| | | | - Borko Nojkov
- Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA
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14
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Erickson JC, Stepanyan E, Hassid E. Comparison of Dry and Wet Electrodes for Detecting Gastrointestinal Activity Patterns from Body Surface Electrical Recordings. Ann Biomed Eng 2023; 51:1310-1321. [PMID: 36656453 DOI: 10.1007/s10439-023-03137-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 12/25/2022] [Indexed: 01/20/2023]
Abstract
Gastrointestinal motility patterns can be mapped via electrical signals measured non-invasively on the body surface. However, short-term (≈ 2-4 h) meal response studies as well as long-term monitoring (≥ 24 h) may be hindered by skin irritation inherent with traditional Ag/AgCl pre-gelled ("wet") electrodes. The aim of this work was to investigate the practical utility of using dry electrodes for GI body-surface electrical measurements. To directly compare dry vs. wet electrodes, we simultaneously recorded electrical signals from both types arranged in a 9-electrode array during an ≈ 2.5 h colonic meal-response study. Wavelet-based analyses were used to identify the signature post-meal colonic cyclic motor patterns. Blinded comparison of signal quality was carried out by four expert manual reviewers in order to assess the practical utility of each electrode type for identifying GI activity patterns. Dry electrodes recorded high-quality GI signals with signal-to-noise ratio of 10.0 ± 3.5 dB, comparable to that of wet electrodes (9.9 ± 3.6 dB). Although users rated dry electrodes as slightly more difficult to self-apply, they caused no skin irritation and were thus better tolerated overall. Dry electrodes are a more comfortable alternative to conventional wet electrode systems, and may offer a potentially viable option for long-term GI monitoring studies.
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Affiliation(s)
- Jonathan C Erickson
- Department of Physics and Engineering, Washington and Lee University, Lexington, VA, USA.
| | - Elen Stepanyan
- Department of Physics and Engineering, Washington and Lee University, Lexington, VA, USA
| | - Emily Hassid
- Department of Physics and Engineering, Washington and Lee University, Lexington, VA, USA
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