Development of a Nasogastric Tube Insertion Simulator: A Collaborative Interdisciplinary Effort 

CIN: Computers, Informatics, Nursing
March/April 2009 
Volume 27 Number 2
Pages 105 - 113


The nursing faculty shortage has created the need for more innovative and effective ways to better stimulate nursing students. Simulation technology is one way to increase the effectiveness of teaching faculty. In this article, a collaborative project between the College of Nursing and College of Engineering at the University of South Florida to develop and evaluate a PC-based software simulator based on videogame technologies for nursing skill acquisition is discussed. A software simulator for teaching and assessing mastery of the procedure for nasogastric tube insertion is described. The purpose of the simulator is to complement the standard training of nasogastric tube insertion that uses static mannequins and instruction/assessment by nursing instructors. The simulator was used in a fundamentals of nursing class at the University of South Florida, with 75 students enrolled. Evaluation showed that the simulator significantly increased the confidence of the students in their ability to perform nasogastric tube insertion.

Nursing faculty have become increasingly aware of the need to provide more realistic and varied experiences to acquire basic nursing skills. The literature suggests1-3 that skill acquisition in nursing is better facilitated with the use of simulation in conjunction with didactic education. Clearly, practice and reflective learning are critical to skill acquisition. However, simulation technology offers advantages such as a safe environment with no threat to a human patient, sophisticated scenarios, and opportunities for debriefing.1 In today's nursing schools, it is commonplace to have static mannequins and also some type of dynamic patient simulator such as a Laerdal SimMan (Laerdal Medical Corporation [USA Headquarters] Wappingers Falls, NY) or METI Stan (Medical Education Technologies, Inc., Sarasota, FL). Mannequins and patient simulators require an instructor to operate them and manually assess student performance. This instructor-centric approach limits the amount of time that a student can spend learning and mastering a procedure or skill. Computer-based software simulation can make learning possible on readily available commodity PCs and automatically teach and assess student performance. As such, software simulation could complement the use of physical mannequins and patient simulators and increase the effectiveness of instruction by nursing faculty.

During the spring of 2005, with an interdisciplinary internal (university) grant from the University of South Florida, a collaborative effort between the College of Nursing and the College of Engineering was set in motion. The grant program was established by the university with the objective of fostering greater collaboration between the College of Nursing and the College of Engineering. The goal of the grant was to develop a prototype nursing skills acquisition simulator that could be piloted by the students from the College of Nursing. The development of an interactive computer-based nursing skills acquisition simulator would allow for widespread use without the need for continuous instructor supervision. The development of this simulator prototype was a research project of two graduate students, one from the College of Nursing and the other from the College of Engineering. This initial investment of time and talent proved to be beneficial to the student body at the College of Nursing.


Today's nursing students are required to be proficient in many tasks, but opportunities to enhance proficiency are limited. The increasing number of students, coupled with a reduction of faculty and staff, makes supervision in the clinical setting difficult. Current students are also at a disadvantage because there is less contact time with patients due to reduced length of stay, higher acuity, and staff shortages.1 These factors place pressure on nursing programs to develop a curriculum that maximizes faculty instruction time. Despite a reduction in overall patient contact, performance standards must remain in place to ensure that the quality of nursing education is not diminished.4

Research has demonstrated that larger class sizes with a traditional lecture format are not conducive to student-teacher interaction. In fact, students are forced to learn at the style and pace of the lecturer and can often fall behind when difficult information is delivered in a short amount of time. The rigid structure of lecture alone does not allow for flexibility to meet the many different learning styles of students.2,4,5 Computer-based simulation allows students to be active participants in their learning with an anytime, anywhere modality. With simulation, students are able to explore a topic or skill of their choice in a flexible environment, which can ultimately lead to increased confidence and enthusiasm about learning.2,3

Faculty cooperation and support are essential for successful implementation of a computer-based simulation. Unless faculty are given enough time and support to adjust traditional pedagogies so that computer simulation can supplement the lecture material, opportunities will be lost for students.1,4,6 Instructor goals for teaching with computer-based simulation should include appropriate content, specific objectives, and replication of reality when possible.1 As students begin to take control of their learning using simulation technology, they are more likely to gain confidence and be better prepared for the clinical environment.


Teaching Nasogastric Tube Insertion

In a traditional setting, skills such as nasogastric tube (NGT) insertion are taught using a three-step approach. First, students are presented with information pertaining to the rationale for a procedure, a brief review of relevant anatomy and physiology, as well as the correlating nursing diagnoses, interventions, and outcomes. The students then observe the instructor performing the skill in a step-by-step manner with explanations throughout the process. Lastly, the students are able to practice on the mannequins provided in the nursing laboratory. Using this approach, students are expected to have reviewed the information prior to the initial lecture and to use the nursing laboratory, when it is available, to practice their skills prior to an end-of-semester competency evaluation.

Existing Simulators

There is a burgeoning amount of simulation literature and research to demonstrate the importance of this emerging technology. To date, numerous simulators are used widely throughout nursing education, such as the Cath Sim (Immersion Medical, Gaithersburg, MD), which allows for intravenous catheter insertion, and the Noelle (Gaumard, Scientific, Miami, FL), which is used by obstetric nursing faculty to demonstrate vaginal births. Nursing faculty frequently incorporate the use of supplemental materials such as DVDs, VHS tapes, and CD-ROMs, which often accompany course textbooks. Although these resources are useful, they limit student interaction and foster a passive learning environment.


The initial task was to identify what was currently available both commercially and academically in simulation technology and then to create a software-based simulator expanding on the current technology. The intent was to augment existing procedural skill training done on static mannequins using a "live" nursing instructor. The skill selected for simulation was NGT insertion as a procedure of interest. The decision to use NGT insertion was based on the skill complexity and its overall importance in the repertoire of basic nursing skills. The instructional requirements that drove the design of the simulator were to build and implement a simulator that would teach and assess a procedural skill consisting of sequence of steps, would emphasize active learning over static learning, could be used independently of teaching or laboratory facilities and include automatic assessment of student performance.

1. Would run on commodity Microsoft Windows PCs with no special requirements for additional hardware or software, could be downloaded from a Web site and be used on a home PC (ie, not to be constrained to use on laboratory PCs), and would allow users to log and automatically report to a server the hours of use and assessment grades of an individual student.

As a first step, a storyboard was developed using the critical elements outlined in Smith et al.7 Subsequently, a static mannequin was digitally photographed in various stages of NGT insertion. Several steps were highlighted, such as measurement of NGT, hand washing, and placement verification using the "whoosh" and litmus paper techniques. Each sequence of pictures-which could be assembled and played as a video sequence-represented about 6 seconds of each procedural step. This corresponded to the amount of time needed to actually complete a given step. The picture sequences were taken from the perspective of the nurse doing the procedural step. This first-person perspective is a new aspect of the developed simulator. The final result was that, using a user-directed stop-and-go technique, we were able to bring the student in as an active learner for the NGT insertion skill. Another perceived need was the opportunity for faculty to monitor student progress, performance, and use of these educational resources. Incorporating a Web-based log into the simulator became a priority.

The Allegro Game Engine

The Allegro videogame programming library, or "game engine," was used to implement the simulator ( ). Originally created by Shawn Hargreaves, Allegro is a freely distributed function library for C/C++ developers that supports Microsoft Windows (Microsoft, Redmond, WA), Linux (Linux Foundation, San Francisco, CA), and MacOS (Apple Computer, Cupertino, CA) operating systems. Allegro provides functions for graphics, sounds, player input (keyboard, mouse, and joystick), and timers. It also provides file management functions. Other more advanced graphics environments, such as Direct-X, support more sophisticated features such as three-dimensional graphics (not needed, in any case, for this simulator) and have a much steeper learning curve. Allegro assumes knowledge of C programming, as do most game engines. One of the most used Allegro functions for this project was sprites. A sprite describes the display of images in a window with the capability of managing properties such as image size, position, and stretch. This, combined with the managing of time, was used to create video-like sequences out of a series of still images.

Implementation of the Simulator

The six instructional requirements were addressed in the design and implementation of the software simulator. The simulator was designed to display a group of pictures as a video sequence and to display text boxes in response to the selection of an on-screen button. Figure 1 shows the simulator user interface. The user interface has the following elements:

Figure 1 - Click to enlarge in new window FIGURE 1. Screenshot of the simulator user interface.

* Video frame: a 700x525-pixel frame in which the video sequence is displayed.

* Text frame: a 300x526-pixel frame in which the descriptive files for each step are displayed.

* Tool buttons frame: a 770x120-pixel frame in which images representing all the tools necessary for the procedure plus the control buttons (go, stop, exit, back) are shown.

* Special messages frame: a 300x120-pixel frame for displaying special messages such as the mode the software is running (testing or training) and a message explaining if the step selected is correct or incorrect.

Each control button was designed to be an icon representing a procedural step.

The simulator was implemented using the storyboard, collected picture sequences, designed user interface, and the Allegro game engine. The pictures taken for the steps of the NGT insertion procedure were placed into folders named "1" to "17" (corresponding to the step number). A key function called show_tools_sprite() displays the video sequences in the video frame. The images, stored as bitmaps, have been previously loaded into memory. First, the sprite (image) is enlarged from its original size (400x300 pixels) to the size of the video frame. Then it is positioned in the window and displayed. The image enlarging and displaying action is inserted in a loop, which loads all the pictures for a video sequence. Between displayed images, a "sleep time" is inserted to produce the effect of animation (with realistic human motion). The information for a sequence step is loaded from a text file stored with the corresponding video sequence and shown in the text frame.

The programmatic flow of the simulator is shown in Figure 2. The separate paths for the training and testing modes are depicted. For the training mode (the left branch in Figure 2), a help text is always displayed in the text frame. Only when the correct step is selected is the corresponding help text displayed. During the entire session, the button necessary for the following step is highlighted in green to give the user a clear direction as to what step follows. When a button is selected, a message is displayed in the special messages frame stating whether the step selected was the correct one or not. If the correct step is selected, then the step is shown, whereas if the user selects an incorrect step while in the training mode, the procedure does not advance and awaits the correct response. At the end of a training mode session, the "solution" (listing of all steps in correct sequence) is presented in the text frame.

Figure 2 - Click to enlarge in new window FIGURE 2. Programmatic flow of the simulator.

In the testing mode (the right branch in Figure 2), there is a more specific distinction between incorrect and correct steps selected. The program shows the selected step whether it is in the correct sequence or not. A log is maintained to track the user-selected steps. Although in the testing mode, the simulator can be stopped at any time by clicking the "Stop" button. This button finishes the session and shows the log that displays the student's grade and critique of the session. The log is viewable by either the student alone or with faculty input. The log shows the student's choice, expected selection, and a total grade for each step of the NGT insertion process. In the testing mode, the benefit of allowing the students to progress while making errors is twofold. First, they are encouraged to master the correct sequence; second, they are discouraged from blindly selecting steps. The anticipated outcome is that with the use of the simulator, students will demonstrate mastery of NGT insertion, with the expectation that they will experience less anxiety in a real-life environment.

Automatic Grading and Reporting

An important capability of the simulator is the ability to grade the student without the presence of an instructor. The grading system is based on assigning weights to each of the steps from the procedure. This was done based on the importance of each step (ie, considering the consequences of performing the step or not). The critical elements of the procedure are those related to the NGT insertion itself, such as order verification, patient identification, and NGT placement confirmation. A log file is created each time a person runs the software. This log file contains student name, time of session start and end, and a time stamp and grade for each step.

A registration interface was developed to be displayed at program start-up. This registration interface prompts the user for "first name" and "last name." This information is then used for tracking student performance. With the completion of a session and after the grading is complete, the log file containing student results is automatically sent to a repository in a Web server computer hosted in the Department of Computer Science and Engineering. An HTTP POST command is used to send the data to the designated Web server. This Web server stores the results for each student and each simulation session completed. The results are available to the class instructor via a Web interface, which displays the results ordered by criteria such as student name, session, and date and time. Figure 3 shows a user log file viewed from a Web browser. It can be seen that the student failed to perform steps 12, 13, and 14 (which are "Listen for Whoosh with Stethoscope," "Test PH," and "Secure Tube," respectively).

Figure 3 - Click to enlarge in new window FIGURE 3. Example grading log from the simulator.

Beta Testing With Nursing Students

Two rounds of prerelease evaluation, or beta testing, were completed with student nurse volunteers to evaluate the simulator before final release. Nineteen student nurses, at various stages of the nursing program, were asked to participate in the beta testing. Participation was voluntary; students were assured that the decision to participate would not affect grades positively or negatively. In addition, students were informed that they could opt out at any time without penalty. Students were asked to attend a session to test the simulator. The students were given a brief overview and were allowed to experiment with the simulator and encouraged to explore both testing and training modes. Students were asked to complete an anonymous evaluation form that asked four Likert-style questions and two short-answer questions such as "What did you like about the program?" and "What did you dislike about the program?" and that solicited open comments.

The purpose of the beta testing was to identify shortcomings in the user interface. For example, several students noted that some of the text boxes were not displayed for a sufficient amount of time and that the size of the text was too small to read clearly. Suggestions for possible future revisions of the simulator included the use of a voice-over to augment the text boxes.


The simulator was evaluated within the scope of a fundamental nursing course as an additional teaching aid. It was intended to augment current resources and limit actual time spent by the instructor teaching NGT insertion. It was also meant to enhance student confidence. In light of these goals, student feedback was essential. The findings, although minimally rigorous, formed the basis for future consideration.

All nursing students learn NGT insertion within the fundamental curriculum. Students received traditional in-service followed by laboratory time by midsemester. Students were then instructed on how to gain access to the simulator and were expected to use it during their course work with the understanding that during finals week, they must demonstrate successful NGT insertion. Because specific teaching techniques were individual to each clinical team, NGT instruction differed among clinical teams. However, all instructions were based on the same performance standards as outlined in Smith et al.7 In addition to the laboratory and didactic component, all students were introduced to the computer-based NGT insertion simulator in the school's computer laboratory and were provided information on access, basic verbal and written instructions for use, and hardware requirements for home installation. During the orientation process, it was made clear to students that the use of the simulator was not counted as part of their grade and was not a requirement for the course; rather, it was an available resource to supplement their current learning. At this time, students were also given a survey inquiring about their previous use of a computer, current comfort level with learning on a computer, and their anxiety and comfort level with performing hands-on nursing skills.

At the end of the semester and consistent with previous semesters, students were expected to select, at random, one clinical nursing skill to perform, along with NGT insertion, during the final examination checkoff period. Clinical instructors were provided with a checklist of the required element for successful NGT insertion. The elements that were evaluated mirrored the instruction provided on the NGT insertion simulator. Students were asked to complete a final survey that had three distinct parts. The first, using a Likert scale, queried their end-of-semester levels of anxiety and comfort related to NGT insertion. The second section asked them to report their use of the simulator, frequency of use, and location of use, and the final section used a five-question Likert scale regarding the functionality of the software.

Theoretical Framework

The evaluation of the learning effectiveness of the simulator was based on the framework recently developed by Jefferies,8 which indicates that successful implementation of simulation requires integration between teachers, students, and educational practice. Students who use a simulator as a supplemental learning method should be expected to be self-directed and motivated. Key to skills acquisition is an active learning environment that provides direct engagement, immediate feedback, and reinforcement of learning. The feedback provided to a student by the learning environment should be helpful, informative, and encouraging.

The development of the nursing skill acquisition simulator was done with consideration of five variables8: objectives, fidelity, complexity, cues, and debriefing. The developed simulator clearly presents the learning objective as successful insertion of an NGT. Digital pictures of a nurse performing the procedure were used to increase the fidelity of the simulator. The exercises developed for the simulator were intentionally simplistic to allow for focused learning. Within the training mode, students are provided cues and rationales for successful insertion of an NGT. With the procedural quality of NGT insertion, it is imperative that the student master the correct sequence from memory rather than be prompted for the next step. The simulator in the testing mode is designed to allow students to progress while making mistakes and does not cue them to the correct answer. Last, debriefing occurs when the student has completed NGT insertion. A log of the student's choice, along with the correct sequence and corresponding rationales, provides immediate feedback to the students.

Using the framework of Jefferies, skill performance for NGT insertion was examined. The aim was to identify whether students who chose to access the simulator and enhanced their exposure to the specific skill perform better on their required competency than students who chose not to use the additional teaching resource. Student feedback on satisfaction and perceived value to learning and reasons for nonuse, if applicable, of the simulator were obtained anecdotally.

Evaluation and Results

At the end of the semester, student evaluation included hands-on demonstration for the NGT insertion skill. Using a standardized evaluation tool, each student in the class successfully completed this skill. Because there is no correlation between simulation use and competency, the remainder of the discussion focuses on the use of the simulator and the impact that the simulator had on learning.

To evaluate the NGT insertion simulator, presemester and postsemester surveys were used. In addition to the surveys, free-form comments were solicited at the end of the semester and the server logs were used to measure the use of the simulator. At the beginning of the semester, 75 students were surveyed, and at the end of the semester, 65 students were surveyed (a smaller number at the end because of class withdrawals). From the survey data, it was found that 87% of the students voluntarily tried the simulator at least once during the semester and 70% used it between one and three times. Based on the logs on the Web server, the average amount of time per session was 3 minutes, with a minimum of 1 minute and maximum of 7 minutes. Tables 1 and 2 show some of the key results from the surveys. Table 1 shows the general characteristics of the students, including basic demographic information. Table 2 summarizes the answers to key questions in comfort, confidence, and amount of learning. Table 1 shows that the students were mostly women and generally young. Most students already had some experience with computer-based learning but clearly preferred hands-on learning. Although this was an unexpected finding given this generation's exposure to computer-based software, the type of software developed allows for the combination of visual instruction with a user-driven interface. The portability and flexibility of computer-based learning provide a diverse educational environment that meets the needs of a variety of learning styles. Table 2 shows that the level of comfort in computer use did not remarkably change during the semester; however, the opinion on the use of computed-aided learning tools as a help to becoming an effective learner decreased. The confidence level of the NGT insertion skill learned significantly increased. The general opinion on the simulator (ease of use, help with studies, and desire to have more skills taught with a simulator) was very high.

Table 1 - Click to enlarge in new window Table 1 General Characteristics of the Surveyed Students

Table 2 - Click to enlarge in new window Table 2 Summary of Key Survey Questions (5 Is High, 1 Is Low)

General comments about the software were also recorded. Most of these comments suggest that the simulator was a useful tool to make learning easier. Several comments recommended that sound should be added, that other operating systems than Microsoft Windows should be supported, and that the same type of simulator be implemented for other nursing skills. Representative free-form comments (all from the end-of-semester survey) include the following:

* "The simulator was very useful."

* "Felt NG tube is self explanatory and had enough practice in lab."

* "NGT simulator really helped me understand the skill better."

* "Thank you for taking the time to make this software available-saved me a lot of work."

* "I wasn't able to get it to work. I became too frustrated. I practice better with hands on in the lab so I didn't worry about the program."

* "I just wanted to tell you how much I enjoyed the NGT simulator that you did! Excellent job. For your next project, may I recommend adding voice. It would give options to folks who prefer to listen to the rationale instead of reading it. Second, this would be wonderful for Foley insertions as well."

* "The CD was really helpful b/c it tested you the order on which you had to do next. It sorta make you remember what items you needed and which step you had to do next."

Discussion of Evaluation Results

Most of the students were relatively young, which may explain the high degree of comfort in using computers. It is interesting to note that the surveyed students preferred to learn a new skill by hands-on training than by using a computer as the learning tool. This preference for hands-on training may have predisposed some students against using the simulator. Thus, it is not a surprise that the number of hours of simulator use is generally low for most of the students. Overall, self-confidence on performing the NGT skill was low at the beginning and higher at the end, as expected. This increase in confidence may be the result of multiple factors including class completion, hands-on training, and use of the simulator. Despite these factors, anecdotal findings suggest that the use of the simulator for skill acquisition was useful in increasing student confidence level.


Several limitations were identified in this project. Limitations were identified during the development of the software, during the beta testing with the students, and when used in the class. As with any new technology, faculty buy-in is important. Personal faculty bias with regard to the value of the simulator as a viable resource may have inadvertently impacted student overall perception as well. This may have contributed to the lack of motivation exhibited by the students to use the simulator, as evidenced by the short amount of time dedicated to the use of the simulator. Likewise, the voluntary nature of this project may have impacted time spent with the simulator. Future studies would require greater commitment on the part of the student. Tracking the use of the simulator was based on direct communication of the software with a Web server. Some errors were encountered with the tracking, resulting in lost data. Clearly, these tracking problems need to be resolved. Although simulation as a teaching strategy has tremendous potential in the learning environment, faculty should not lose sight of the varied learning styles of its students. This strategy, coupled with current strategies, can better meet the needs of the hands-on learner, auditory learner, and visual learner.


The outcome of this project-a simulator for NGT insertion-will afford students another modality for acquiring nursing skills and enhancing their learning experience. Nursing students who are competent and confident in fundamental skills will be better prepared to care for patients in the clinical setting. The NGT insertion simulator can be viewed as an adjunct tool to help nursing students in their understanding of nursing procedures. The simulator still needs further evaluation to fully understand its impact on student learning and increased productivity of nursing instructors. The simulator design was made to be generic such that procedures other than NGT insertion could be implemented. The simulator is freely available from the authors.

A continuing goal of the project is to secure future funding so that the collaborative relationship between the College of Nursing and the College of Engineering can continue. The team also looks to expand the simulator to include other nursing skills, such as indwelling catheter insertion and wound care.


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