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Cheng LK, Nagahawatte ND, Avci R, Du P, Liu Z, Paskaranandavadivel N. Strategies to Refine Gastric Stimulation and Pacing Protocols: Experimental and Modeling Approaches. Front Neurosci 2021; 15:645472. [PMID: 33967679 PMCID: PMC8100207 DOI: 10.3389/fnins.2021.645472] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
Gastric pacing and stimulation strategies were first proposed in the 1960s to treat motility disorders. However, there has been relatively limited clinical translation of these techniques. Experimental investigations have been critical in advancing our understanding of the control mechanisms that innervate gut function. In this review, we will discuss the use of pacing to modulate the rhythmic slow wave conduction patterns generated by interstitial cells of Cajal in the gastric musculature. In addition, the use of gastric high-frequency stimulation methods that target nerves in the stomach to either inhibit or enhance stomach function will be discussed. Pacing and stimulation protocols to modulate gastric activity, effective parameters and limitations in the existing studies are summarized. Mathematical models are useful to understand complex and dynamic systems. A review of existing mathematical models and techniques that aim to help refine pacing and stimulation protocols are provided. Finally, some future directions and challenges that should be investigated are discussed.
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Affiliation(s)
- Leo K Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of General Surgery, Vanderbilt University Medical Center, Nashville, TN, United States.,Riddet Institute, Palmerston North, New Zealand
| | - Nipuni D Nagahawatte
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Recep Avci
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States.,Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States
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Onen D, Jalilian E, Neshev E, Mintchev MP. Parametric study of neural gastric electrical stimulation in acute canine models. IEEE Trans Biomed Eng 2007; 54:429-35. [PMID: 17355054 DOI: 10.1109/tbme.2006.888823] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Manipulation of gastric motility by gastric electrical stimulation (GES) has been suggested as a minimally invasive alternative treatment of gastric motility disorders and obesity. However, only neural GES (NGES) has been successful in invoking gastric contractions. Nevertheless, the relationship between these contractions and the controlling NGES parameters has not been quantified. We aimed at determining the relationship between the electrical energy delivered to the tissue as a function of NGES parameters, and the strength and duration of the resulting invoked gastric contractions. Five healthy mongrel dogs underwent subserosal prepyloric implantation of two NGES electrode pairs. Gastric motility was captured by a force transducer implanted in the vicinity of the distal pair of stimulating electrodes. Custom-designed implantable stimulator delivered NGES with 8-16 V (peak-to-peak) amplitudes, and 60-100% duty cycles. Normalized motility index (MI) was utilized to quantify the contractions recorded from the force transducer. The MI increased with increasing voltage amplitudes. However, it remained remarkably constant across all duty cycles when voltage was held constant. Calculated motility generation efficiency indices (MGEI) indicated that highest energy efficiency for invoked motility was achieved at the lowest duty cycle. The parametric data obtained in the present study can be utilized to optimize the power efficiency of implantable gastric neurostimulators.
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Affiliation(s)
- Denis Onen
- Department of Electrical and Computer Engineering, University of Calgary, Calgary, AB T2N IN4, Canada
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Jalilian E, Onen D, Neshev E, Mintchev MP. Implantable neural electrical stimulator for external control of gastrointestinal motility. Med Eng Phys 2006; 29:238-52. [PMID: 16675282 DOI: 10.1016/j.medengphy.2006.03.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 03/13/2006] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
Functional electrical stimulation has been suggested as a possible avenue for treating a variety of gastrointestinal motility-related disorders such as gastroparesis, chronic constipation and morbid obesity. The aims of the present study were to design a radio-frequency controlled multi-channel implantable neural gastrointestinal electrical stimulator and test it in an acute canine model. The stimulation parameters can be reprogrammed after implantation, allowing the execution of parametric studies and the investigation of their efficacy in producing controlled gastrointestinal contractions. Bipolar pulse trains of 50Hz frequency, 8-16V(pp) amplitude, 10-100% duty cycle, 1-120s duration, and 2s to 1h pause between successive stimulation sessions were delivered to the stomachs of nine dogs. The resulting contractions were measured by force transducers and digitally recorded on a personal computer. The acute studies confirmed the effectiveness of electrical stimulation in producing invoked gastric contractile activity under the control of the implantable neurostimulator.
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Affiliation(s)
- Ehsan Jalilian
- Department of Electrical and Computer Engineering, University of Calgary, Alta., Canada
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Abstract
Gastroparesis is a chronic disabling condition of impaired gastric motility that results in decreased quality of life. Currently available medical therapy consists of prokinetic and/or antiemetic therapy, dietary modifications, and nutritional supplementation. For patients with medication-resistant gastroparesis a non-pharmacological therapy, gastric electric stimulation, has evolved over the last decade. Based on the frequency of the electrical stimulus, gastric electric stimulation can be classified into low- and high-frequency gastric electric stimulation. The first method aims to normalize gastric dysrhythmia and entrain gastric slow waves and accelerates gastric emptying, whereas high-frequency gastric electric stimulation is unable to restore normal gastric emptying, but nevertheless stunningly reduces symptoms, such as nausea and vomiting, re-establishes quality of life, nutritional state in all patients, and metabolic control in patients with diabetic gastroparesis. Gastric electric stimulation presents a new possibility in the treatment of gastroparesis.
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Affiliation(s)
- Hubert Monnikes
- Department of Medicine, Division of Hepatology, Gastroenterology, and Endocrinology, Campus Virchow-Klinikum, Charité-Universitatsmedizin Berlin, Berlin, Germany.
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Abstract
The theoretical and computational study of the electromagnetic forward and inverse problems in ellipsoidal geometry is important in electrogastrography because the geometry of the human stomach can be well approximated using this idealized body. Moreover, the anisotropies inherent to this organ can be highlighted by the characteristics of the electric potential associated with current dipoles in an ellipsoid. In this paper, we present a forward simulation for the stomach using an analytic expression of the gastric electric potential that employs a truncated expansion of ellipsoidal harmonics; we then demonstrate that an activation front of dipoles propagating along the body of an ellipsoid can simulate gastric electrical activity. In addition to the usefulness of our model, we also discuss its limitations and accuracy.
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Affiliation(s)
- Andrei Irimia
- Living State Physics Laboratories, Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235-1807, USA
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Familoni BO, Abell TL, Gan Z, Voeller G. Driving gastric electrical activity with electrical stimulation. Ann Biomed Eng 2005; 33:356-64. [PMID: 15868726 DOI: 10.1007/s10439-005-1738-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Gastric electrical stimulation (GES) therapy is generating a lot of interest, but it is still investigational. Its efficacy in driving gastric electrical activity and improving motility, and the ideal frequency for bringing this about are still controversial. In this study, a rule-based computer model of tissue electrical response to stimulation was developed to examine the interaction between tissue electrical refractoriness and the onset of tissue activation. The results were compared to response to GES in 8 dogs implanted with electrodes and strain gauges and stimulated at frequencies ranging from 3 to 30 cycles/min. Simulated electrical control activity at an intrinsic frequency of 5/min was entrained from 2.0 cycles/min to 7.92 cycles/min. The regularity of the ECA elicited by stimulation depended on the number of pulses injected. Electrical stimulation in canine stomach entrained the native electrical control activity from a baseline average of 5.14 +/- 0.32 cycles/min up to 9.2 cycles/min. Contractile response to stimulation at 20-30 cycles/min were significantly higher (p < 0.05). Computer simulation of GES may be a useful tool to complement and reduce some of the costs associated with empirical studies of gastric electrical stimulation in establishing its possible use in treating drug refractory gastroparesis.
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Affiliation(s)
- Babajide O Familoni
- Department of Electrical & Computer Engineering, The University of Memphis, Memphis, TN, USA.
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Irimia A, Bradshaw LA. Theoretical and computational methods for the noninvasive detection of gastric electrical source coupling. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:051920. [PMID: 15244860 DOI: 10.1103/physreve.69.051920] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2003] [Indexed: 05/24/2023]
Abstract
The ability to study the pathology of the stomach noninvasively from magnetic field measurements is important due to the significant practical advantages offered by noninvasive methods over other techniques of investigation. The inverse biomagnetic problem can play a central role in this process due to the information that inverse solutions can yield concerning the characteristics of the gastric electrical activity (GEA). To analyze gastrointestinal (GI) magnetic fields noninvasively, we have developed a computer implementation of a least-squares minimization algorithm that obtains numerical solutions to the biomagnetic inverse problem for the stomach. In this paper, we show how electric current propagation and the mechanical coupling of gastric smooth muscle cells during electrical control activity can be studied using such solutions. To validate our model, two types of numerical simulations of the GEA were developed and successfully used to demonstrate the ability of our computer algorithm to detect and accurately analyze these two phenomena. We also describe our analysis of experimental, noninvasively acquired gastric biomagnetic data as well as the information of interest that our numerical method can yield in clinical studies. Most importantly, we present experimental evidence that the coupling of gastric electrical sources can be observed using noninvasive techniques of measurement, in our case with the use of a superconducting quantum interference device magnetometer. We discuss the relevance and implications of our achievement to the future of GI research.
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Affiliation(s)
- Andrei Irimia
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, 37235, USA.
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Irimia A, Bradshaw LA. Theoretical ellipsoidal model of gastric electrical control activity propagation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 68:051905. [PMID: 14682818 DOI: 10.1103/physreve.68.051905] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2003] [Indexed: 05/24/2023]
Abstract
A theoretical model of electric current propagation in the human stomach is developed using an approach in which the shape of the organ is assumed to be a truncated ellipsoid whose dimensions can be determined from anatomic measurements. The gastric electrical activity is simulated using a ring of isopotential electric current dipoles that are generated by a pacemaker situated in the gastric corpus. The dipoles propagate in the direction of the pylorus at a frequency of three cycles per minute. The advantages of employing ellipsoids in the analytical formulation of this gastric model are discussed in addition to the realism and usefulness of the approach.
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Affiliation(s)
- Andrei Irimia
- Living State Physics Laboratories, Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235-1807, USA
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