Keywords

1 Introduction

With the recent progress in computer technology and multimedia, it becomes possible to provide quantities of preserved visual or other sensory information to us. Particularly, some training systems for students using e-learning technologies have obtained much attention [1, 2]. Similarly in clinical medicine, systems using advanced technologies of both information and engineering to support have been taken into account [3].

A clinical engineer has to deal with a wide range of tasks such as the operation, management, and maintenance of medical machines which requires high levels of expertise and technical capabilities. It is very difficult to master such a large sum of knowledge and skill only in university within limited times, particularly in an environment being lack of repeated operation and trouble-shooting experience [4].

In order to solve these problems, we have been carried out a series of study for the construction of educational systems with operation skills [5–7]. In this study, for a high training efficiency for the student in clinical engineering, and aiming the goal of a computer-added training system with low cost, simulated experiences, and good repeatability, we proposed a training system for clinical engineer using the up-to-now technologies in our sequential researches on computer-added skill-training system. Special attention was paid to the training of medical operations in addition to the conventional e-learning for general knowledge [8–10].

The conventional e-learning method focuses mostly on the learning of knowledge like that from textbook, paying less attention to practical operations of medical machines. Obviously, the knowledge learnt only from textbook can hardly be comparative to that by experience (empirical knowledge), body movements (embodies knowledge), and explicit knowledge in addition to textbook [11, 12].

In this study, the training system for hemodialysis apparatus was taken as a training example. In more detail, a simulation circuit and an arm model for dialysis were firstly constructed. Operation data from experienced clinical engineers were quantified and taken as indicators for the evaluation of operation training effects. In addition, a camera and operation movement analysis software was used to construct the above training system.

2 Hemodialysis and Puncture Technique

Hemodialysis is such a medical operation to take out the blood of a patient with disabled kidney and to purify it through a dialyzer. The operation normally takes 4 h, repeated every 2 days.

The operation is accompanied firstly with a “puncture” to the blood vessel with needle. The puncture includes one to take out the blood and another to return the blood to vessel by putting needles into their special shunts prepared earlier in blood vessel. It is required to put the needle with a proper angle precisely into the shunt under the condition that the blood vessels are structurally complex and visually hidden under skin. As can be imaged, a correct puncture operation should be much difficult than a normal injection, because an erroneous puncturing may result in medical accidents such as heavy bleeding. Therefore, the puncture operation is among the most important techniques for hemodialysis.

Of course, high levels of precision and skill are required for such operation. However, it is impossible for a student to do practical puncture on a patient during his clinical training process. It can be imaged how anxiety he may be when the student faces a patient for the first time. Though, there has not yet been such a training system developed up to the present time. In order to solve the above problems, we proposed the following training system for “puncture” operation for hemodialysis.

3 Puncture Technique Training System

3.1 Construction of Simulation Circuit

The practical roller pump was used in the system. Simulated blood vessels were made, and the flow of blood was demonstrated with red-colored distilled water. The blood vessels were inserted into the arm model, further covered with silicone rubber sheet as an artificial skin. The schematic of simulation circuit was shown in Fig. 1.

Fig. 1.
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Simulation circuit (Color figure online)

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3.2 Determination of Teaching Data

It is necessary to prepare operation teaching data as the standard to judge student’s operation. For this purpose, operations from experienced clinical engineers were recorded, analyzed quantitatively, and taken as the judgement standards. The correct insertion angle, for example, should be between 12 to 15° after analyzing several expert’s operations. Textbook video was made based on the standard operations. As an example, a good holding of puncture needle is shown in Fig. 2, by which an unexpected reverse flow of blood can be viewed clearly.

Fig. 2.
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A good holding of puncture needle

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A teaching movie was made after recording a series of expert’s puncture movements with necessary analysis, and important points for puncture were extracted to construct a teaching movie, as shown in Fig. 3.

Fig. 3.
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Teaching video of dialysis puncture

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3.3 Configuration of the Puncture Training System

The system was constructed using the simulated circuit and teaching data. The configuration and flowchart for operation and information were shown in Fig. 4.

Fig. 4.
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Configuration of the puncture training system

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Series of operations were firstly provided to the students by electronic textbook for getting the basic knowledge. After that, the students carried out puncture operations upon the arm model, and the operation movements were recorded by camera and the data were transferred to a personal computer. The operations of students were analyzed with a video analysis software “kinover”, and their movements such as needle holding poses and puncture angles were superimposed and evaluated with those from the teaching data (Fig. 5). A display screen of puncture angles was shown in Fig. 6.

Fig. 5.
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A Superposition to the teaching data

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Fig. 6.
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Display of the puncture angle

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3.4 Verification of System

To verify the system, a comparison of training effect between students with and without the use of the proposed system was made upon the 4th grade student of our university using questionnaire. A verification experiment with training was displayed in Fig. 7. With all questions in the questionnaire, a 5 stage evaluation was made on the students. As the results, 90 % of the students gave positive answers with confidence for the use of the training system. The effectiveness of the system was proved with the questionnaire.

Fig. 7.
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Verification experiment

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4 Conclusions

In this study, a training system for puncture technique of hemodialysis was proposed. A simulation circuit and an arm model for dialysis were constructed. Operation data from experienced clinical engineers were quantified and taken as indicators for the evaluation of operation training effects together with video texts. The effectiveness of the system was proved with a questionnaire upon the 4th grade students in our university.

Further improvement on the system, such as the use of new materials to construct blood vessels with high reality, and trouble-shooting with blood vessels or shunt, will be included into the system. New sensors and analysis methods with high precisions are considered also for the development of more advanced training system.