Keywords

1 Introduction

Over the last two decades, simulation based medical trainings have been widely used in nursing trainings in order to improve patient safety and self confidence levels of nursing students and to meet today’s demands in the healthcare services [1,2,3].

Serious gaming is becoming an important modality among other simulation modalities used for undergraduate and post graduate levels of nursing trainings [4,5,6]. Serious gaming provides interactivity and multiple gaming environments thus actively engaging and motivating the learners to in the process of learning [6]. Another advantage of serious gaming is that it provides a location and time independent learning opportunity for learners [5]. Serious gaming modules with various learning contents like advanced life support, intravenous (I.V.) catheterization, basic life support or patient encounter scenarios are nowadays commonly used for undergraduate and post graduate level of healthcare training [7].

Integrated scoring systems of simulators or observational analysis based scoring criteria prepared by senior nursing educators are nowadays the most commonly tools to evaluate the outcome of the simulation trainings.

Due to the limitations of the traditional assessment techniques in terms of development of expertise during practice of complex cognitive and visuomotor tasks, educators are looking for new supportive assessment techniques [8]. As learning is associated with complex processes of the human brain, measuring cognitive and mental workload of trainees is crucial while performing the critical tasks [8, 9].

It is known that specific regions of the human brain are activated during motor execution, verbalization and observation [10,11,12]. In parallel to this, oxygen consumption of these specific areas of the brain varies due to the hemodynamic changes which are characterized by the alterations of oxygenated hemoglobin (HbO2) and cerebral hemoglobin (HHb) chromophores [13].

Performing psychomotor skills affect the amount of hemodynamic response in different parts of brain. Measuring the alterations of hemodynamic changes in prefrontal cortex (PFC) of the human brain provides valuable data about novel motor skill acquisition, attention, working memory and learning [14, 15]. Electroencephalography (EEG), functional Magnetic Resonance Imaging (fMRI), Magnetoencephalography (MEG), Positron Emission Tomography (PET) and functional Near-Infrared Spectroscopy (fNIRS) are neuroimaging techniques commonly used for monitoring human brain activation in response to a given specific task. fNIRS system, which measures neuronal activities in human brain by using near-infrared light, has been chosen as the neuroimaging technique for this study as it is a non-invasive, affordable and practical cerebral hemodynamic monitoring system [15,16,17,18,19,20].

fNIRS imaging technique has already been used to measure cognitive and mental workload in various studies about task specific training procedures such as open surgery, laparoscopic surgery, and robot assisted surgery trainings [14, 15, 19, 22,23,24].

The aim of this study is to investigate whether fNIRS technology can be used as an additional assessment tool for I.V. catheterization training of nursing students by measuring hemodynamic responses induced by the task-specific cognitive workload in the PFC regions of the participants.

2 Materials and Methods

2.1 Participants

Twenty three participants were recruited for this study. All twenty three participants were provided written informed consent, which has been reviewed and approved by the Ethical Committee of Acıbadem Mehmet Ali Aydinlar University. Participants were divided into two groups as novices and experts. The novice group consisted of fifteen untrained nursing students and the expert group had eight senior nurses (Table 1).

Table 1. Distribution of the participants
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2.2 Experimental Protocol

The protocol was run for 30 days and data acquisition occurred on 1st, 2nd, 7th and 30th days. The novice group attended all 4 days of the data acquisition sessions. Initial stage of the protocol, novice participants took a pretest on the theoretical knowledge level about the I.V. catheterization procedure. Following the pretest, novice group continued the experimental protocol by applying intravenous catheterization on the task trainer module and as the last task of the day 1, novice group participants completed the serious gaming intravenous catheterization training module. The Virtual I.V. Simulator (Laerdal; Norway; www.laerdal.com) was used as the I.V. training module. On the second and third sessions, participants of the novice group completed only the Virtual I.V. Simulator module. On the 30th day of the experiment, novice group started the session with the Virtual I.V. simulator training module and the task trainer module followed. After the final session of the protocol, a posttest was given to novice group in order to measure the differences of theoretical knowledge level between day 1 and day 30. The expert group completed the protocol in two sessions, on day 1 and on day 30, only by using the task trainer (see Fig. 1).

Fig. 1.
figure 1

Timeline of the experimental protocol and data acquisition sessions of 1st, 2nd, 7th and 30th days for both groups.

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Three types of measurements, theoretical test scores, I.V. Virtual Simulator scores and cortical oxygenation changes from the prefrontal cortex via fNIRS, were captured during the experiment (see Fig. 2). In addition to the scores, participants were camera recorded during performing on the task trainer modules and screen recordings of the computer running the I.V. Virtual Simulator module were also gathered.

Fig. 2.
figure 2

Types of data acquired on sessions.

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Pretest and Posttest.

A theoretical test were given to the participants of the novice group to compare their knowledge levels about the I.V. catheterization process at the beginning and at the end of the study. The theoretical test was prepared by the faculty of School of Nursing of Acıbadem Mehmet Ali Aydinlar University and it is a part of the standard curriculum for the evaluation of I.V. catheterization training classes. In total there are 17 questions in the test and it consists of 2 multiple choice scenario analysis questions and 15 true/false survey questions (See Appendix for the short version example of the test).

Task Trainer Module.

A manikin arm designed for intravenous catheterization practice. Task trainers, utilized in most clinical courses of the nursing schools, has been described as the traditional method for teaching peripheral vascular access [25, 26]. During the task trainer sessions of the protocol, participants of both groups wore the fNIR headband, which recorded the hemodynamic responses (see Fig. 3.a).

Fig. 3.
figure 3

a. A participant is performing I.V. catheterization on the task trainer. b. A participant using Virtual I.V. Simulation Module

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Virtual I.V. Simulator Module were utilized in this study as the intravenous catheterization training simulator module. It presents a fully interactive platform for self-directed learning of trainees during performing of intravenous catheterization skills [27]. The Virtual I.V. simulator module has haptic features and feedback mechanism that provides feeling of skin stretch, palpation, size, and insertion forces alongside an assessment tool that stores performance scores of trainees (see Fig. 3.b). Data acquired from this modality were not included in the analysis. The aim of using this modality was to train the participants and to increase their knowledge on I.V. catheterization procedure.

Functional Near-Infrared Spectroscopy.

fNIRS is safe, portable and a non-invasive optical brain imaging modality. Continuous wave fNIRS Imager 1200 system (fNIRS Devices LLC, Potomac, MD) was used to record the hemodynamic response from the prefrontal cortex. The system has three components: a headband that carries the 16 channel sensor pad, a control box and a computer for acquiring and recording fNIRS data. The sensor pad has 4 light emitting diodes (LED) as light sources and 10 detectors. The 2.5 cm of light source and detector separation was designed to monitor anterior PFC underlying the forehead [18].

2.3 Data Analysis

fNIRS Data.

The raw (light intensity) data recorded through fNIRs were filtered using a low pass finite impulse hamming filter. Sliding window motion artifact rejection filter was applied in order to exclude noise from the data, which were caused by the motion artifacts [28]. Oxygenation values for each of the 16 channels were calculated by applying The Modified Beer Lambert Law [8]. We have selected Oxy marker- difference between the oxyHb and deoxyHb – for the statistical analysis and channels of the left hemisphere as the regions of interest, which is an area known to be associated with working memory during learning and training studies [8, 22, 29].

Statistical Analysis.

The normality of continuous variables were investigated by Shapiro-Wilk’s test. Descriptive statistics were presented using mean and standard deviation for normally distributed variables and median (and minimum-maximum) for the non-normally distributed variables. For comparison of two non-normally distributed dependent groups Wilcoxon Signed Rank test was used. For comparison of two non-normally distributed independent groups Mann Whitney U test was used. Non-parametric statistical methods were utilized for values with skewed distribution. Statistical significance was accepted when two-sided p value was lower than 0.05. Statistical analysis was performed using the MedCalc Statistical Software version 12.7.7 (MedCalc Software, Ostend, Belgium, www.medcalc.org). Virtual I.V. Simulator scores excluded from statistical analysis of this study.

3 Results

In this study, the differences between the pretest and posttest scores of the novice group, changes of oxy values of the novice group between the initial and final sessions, the differences of oxy values between novice and expert groups were investigated.

There is a statistically significant difference between pretest and posttest test values (Wilcoxon test p < 0.05). Novice group scored significantly higher (P = 0.007) on the posttest when compared with the pretest (see Table 2).

Table 2. Pretest and Posttest Scores of the Novice Group
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The average oxygen consumption of the novice group on the left PFC were significantly higher during the first task trainer session when compared to the final (day 30) task trainer session (Wilcoxon test p < 0.05, p = 0.002). Average oxygen consumption of the novice group were significantly higher during the first task trainer session when comparing to the expert group (Mann-Whitney U test p < 0.05, p = 0.004). There are no significant differences of the left PFC oxygen consumption between groups during the day 30 task trainer session (see Table 3).

Table 3. Novice vs. Expert, Day 1 vs. Day 30, Task Trainer- Oxy Comparison
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These results indicate that within 30 days of the protocol; oxygen consumption of the novice group significantly decreased while performing I.V. catheterization on a task trainer. Between the beginning and end of the protocol, novice group managed to significantly increase their scores on the theoretical test (See Fig. 4).

Fig. 4.
figure 4

Oxy values and test scores comparison of the novice group, first day vs. last day of the experimental protocol.

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Oxygen consumption of the expert group slightly dropped, as expected there is no statistical significance of this minor shift. On the first day of the experimental protocol, novice groups’ oxy values were significantly higher than the experts. However, on day 30, novice group oxy values arrived at a similar level of the oxy values expert group (see Fig. 5).

Fig. 5.
figure 5

Comparison of novice and expert groups’ oxy values on day 1 and day 30

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4 Discussion and Conclusion

Regarding the patient safety, simulation based training has a crucial role for education of nursing students before they work on the real patient in clinical setting. In the field of simulation, it was shown that repetitive simulation sessions increase the performance and self-confidence levels of nursing students in several clinical practices [30]. Simulation based education has been integrated into the curriculum of our university’s nursing school as a learning and assessment tool in the last seven years. Task trainers and different simulation modalities like serious game based modalities and mannequin based simulators are used for this purpose at our university. In the last 18 months, we have been focusing on revealing the efficiency of using fNIRS measurements for monitoring the improvement of learners’ cognitive and mental workloads during simulation based trainings [31].

As it was revealed in the prior similar studies, using fNIRS technology in the brain-based learning approach may serve as an objective and complementary assessment tool to generate indicators or benchmarks to assess the outcome of the simulation based sessions [14, 15, 19, 22,23,24]. In this study, the evaluation of the oxygenation (OXY values) at the left PFC regions of the novice group revealed statistically significant changes between first and last sessions of the study indicated less oxygen use on the left PFC regions during the last session of the study. The OXY levels of the expert group were statistically similar on day 1 and day 30. Similar OXY values were obtained from the experts and the novices in their left PFC regions during the last (30th day) task trainer session. Pre and Posttest scores of novice group have a correlation with fNIRs measurements associated with hemodynamic responses of the PFC. These data clearly indicate that novice group had almost reached similar levels of oxygen consumption with expert group in their left PFC at the end of the training protocol.

Further studies are required in-depth analysis for the fNIRS measurements can be used in combination with the existing scoring systems currently utilized for simulation based trainings. With the help of the new generation fNIRS devices, potential to portable and wireless, the measurements will be much easier and ecologically-valid for the educators and learners.

Disclosure.

fNIR Devices, LLC manufactures the optical brain imaging instrument and licensed IP and know-how from Drexel University. Dr. K. Izzetoglu was involved in the technology development and thus offered a minor share in the startup firm, fNIR Devices, LLC.