# Review on Electrical Impedance Tomography: Artificial Intelligence Methods and its Applications
## 5 EIT Clinical-Based Applications
### Gastric-Emptying Measurement  
In Gastric measurement, impedance methods can be used to examine stomach emptying as meal changes the resistivity in the upper abdomen of the body. The gastric wall conductivity is about 5 m Siemens cm\({}^{-1}\)[73]. Emptying can be calculated depending upon the meal being either less or more conductive, as this can be noted as a difference in an EIT image. On the other hand, conductivity can rise if the level of the conductivity is low in a meal by the secretion of gastric juices and, therefore, can complicate the measurement of the EIT variations, as secretion cannot be differentiated from emptiness. Acid secretion can be reduced by using Cimetidine but ethically it is not allowed to use this medicine because, for instance, physiology of the stomach of the young children can be affected [74]. Researchers have obtained steady emptying curves by using a comparatively conductive meal to overcome this problem.  
The management of certain gastric disorders is the most important test after eating for measuring the rate of emptying of the stomach. Gamma scintigraphy is the most common technique for the calculation of gastric stenosis: the rate of gamma emission after the patient takes a radiolabelled test substance is calculated in the area around the stomach. This may be significant as the radiation dose is also important when making regular check-ups in adults or examining infants. Intubation techniques may be used in these cases. For instance, in the case of studying dye dilution, to supply a small quantity of material having string coloring the patient swallows a nasogastric tube. The nasogastric tube can extract the samples of stomach contents. The volume of the stomach at any point of time can be found from the ratio of the quantity of the dye delivered to its concentration in the gastric sample. [PERSON] et al. [75] did a comparison for EIT between the dye dilution method and isotope scintigraphy, which needs gastric intubation. The experiment was conducted on 19 volunteers whereby 16 electrodes in a circular array were placed at an equal distance from each at the level of the eighth costral villages. To reduce acid secretion, Cimetidine was given. The outcomes of the experiments highlighted that the profiles of gastric emptying that Electrical Impedance Tomography gives are similar to the other methods that are applied. The advantage of it that on the same patient, numerous another experiment can be done and the technique is also non-invasive as there are no known threats. Authors in [76] have performed experiments on 18 infants and concluded that after taking the conductive drink the time for the stomach volume is reduced by half. There are more emptying times in infants with pyloric stenosis as compared to infants that do not have this. The resistivity of the stomach area is affected due to its size and content [77]. [PERSON] et al. in [78] have studied the application of EIT to calculate gastric acid secretion. Standard intubation test was conducted on 19 healthy people. Stimulated acid output (SAO) and basal acid output (BAO) (millimoles per hour) were calculated after and before pentagastrin. They have concluded that the likely change of gastric impedance can be beneficial as a non-invasive test for calculating gastric acid secretion.