Masanao Segawa

Development of the evaluation system for the Airway Management Training System WKA-1R

The emerging field of medical robotics is aiming in introducing intelligent tools. More recently, thanks to the innovations on robot technology (RT), advanced medical training systems have been introduced to improve the skills of trainees. The principal challenges of developing efficient medical training systems are simulating real-world conditions and assuring their effectiveness. Up to now, different kinds of medical training devices have been developed which are designed to reproduce with high fidelity the human anatomy. Due to their design concept, the evaluation of progress of the trainees is based on subjective assessments limiting the understanding of their effectiveness. In this paper, we are presenting our research towards developing a patient robot designed to simulate the real-world task conditions and providing objective assessments of the training achievements. Due to its complexity; in this paper, we are presenting as a first approach the development of the Waseda-Kyotokagaku Airway No. 1R (WKA-1R) which includes a human patient model with embedded sensors in order to provide objective assessments of the training progress. In particular, we have proposed an evaluation function to quantitatively evaluate the task performance by determining the weighting of coefficients. In order to determine the weighting of coefficients, we applied discriminant analysis. In order to determine the effectiveness of the proposed evaluation function to detect differences among different levels of expertise, an experimental setup was carried out. From the experimental results, we could find a significant difference between both groups (P < 0.05).

Development of a robot which can simulate swallowing of food boluses with various properties for the study of rehabilitation of swallowing disorders

Many patients suffer from swallowing disorders (dysphagia). There are many treatments for these disorders, such as swallowing therapy, surgery, and dietary modification. In our study, we focuse on dietary modification, a common approach. Normally, the swallowing is affected by food bolus properties such as hardness, stickiness and rheological characteristics, and dietary modifications can prevent swallowing disorder patients from suffering dysphagia (aspiration), as well as promote good nutrition. Based on these facts, our goal is to find foods which do not cause dysphagia, and develop food for swallowing disorder patients accordingly. Therefore, we are proposing an in-vitro Dynamic VFSS (Video Fluorographic Swallowing Study) simulation system which uses advanced robotics technology to mimic the dynamic process of swallowing and monitors the status and movement of the food bolus inside the system, for objective evaluation of the swallowing process. The dynamic VFSS simulation system consists of a head, mandible, neck, tongue, pharynx, and larynx which reproduce human anatomy. It is driven by 16 actuators with wire driving mechanisms. In this paper, we will present the dynamic VFSS simulation unit in detail. In addition, we will detail a set of the experiments carried out to determine whether food bolus properties can affect dysphagia or not. To observe the movement of the food bolus, we use a Video Fluoroscopy (VF) unit. The results of the experiments show that thickened boluses have a tendency to leave residue in the epiglottic vallecula. In contrast, liquids cause less residue, and increase the risk of dysphagia (aspiration). Moreover, this study shows that the frontal image, as well as the lateral image, is important for evaluating residual food in the oral- pharyngeal space.

Development of Patient Scenario Generation which can reproduce characteristics of the patient for simulating real-world conditions of task for airway management training system WKA-3

Recently, in medical field, different training methods for medical staff have been proposed. However, the lack of knowledge on the real improvements of trainees makes difficult the real effectiveness of those proposed methods. Therefore, we are proposing an Active Training system for the effective medical training. The Active training system is characterized by providing quantitative information of the trainees performance of the task to the trainee, simulating real-world conditions of the task, and assuring training effectiveness. In order to fulfill each of these characteristics, we have developed Waseda Kyotokagaku Airway No.3 (WKA-3) which makes it possible to obtain quantitative information for the trainees performance and reproduce the various cases, individual differences for the airway difficulties for the simulating real-world conditions of the task. In this paper, we are proposing a patient scenario generation which can reproduce the characteristics of the patient simulating real-world conditions of the task for WKA-3. In emergent situation or surgical operation, the characteristics of patients are presented in the three parameters such as: patient initial conditions, time variant status change, and reflex action. By adjusting, and combining each of the three parameters, we can reproduce the various patient scenarios. In this paper, we also state how to generate the Patient Scenario Generation using the position control and virtual compliance control. Finally, a set of experiments has been carried out to the doctor subjects in order to verify effectiveness of the proposed Patient Scenario Generation, and discuss the doctors about the result of the experiments.

Development of the airway management training system WKA-2 designed to reproduce different cases of difficult airway

The emerging field of medical robotics aims to introduce intelligent tools to assist a physician. The main challenges for developing efficient medical robotic training systems are simulating real-world conditions of the task and assuring training effectiveness. High anatomic fidelity has been achieved in current systems. However, those training systems are designed to reproduce specific conditions of the task (passive training). In this research, we are focusing in developing an airway management training systems designed to reproduce various cases of difficult airway. Such difficulties (i.e. restricted mouth opening, various shapes of oral cavity including tongue swallowing, etc) may provoke traumas on different organs of the patient during an emergency situation. For this purpose, the authors have proposed the development of more advanced training tools. For this purpose, we have focused in embedding sensors and actuators to a conventional patient model towards the development of a patient robot (in previous research, authors have presented the evaluation model which embeds sensors). In this paper, we present an airway training system which embeds actuators into a mannequin. In particular, the mechanism design of the Waseda Kyotokagaku Airway No.2 (WKA-2) is detailed. The WKA-2 is composed of twelve active and one passive degrees of freedom; which are designed to reproduce the various cases of difficult airway. For this purpose, the WKA-2 reproduces the human muscles around the upper airway based on a wire driving mechanisms (a total of sixteen wires are used). In particular, the head of the model is composed of a tongue and mandible with translational and rotational movements around kinematic axis. In addition, we present the details of the kinematic model of WKA-2 which enable the robot to reproduce the airway difficulties. Finally, we presented the design of a tension sensor designed to measure the applied tension on each of the wire driving mechanism of WKA-2. As preliminary experiments, we reproduce several cases of difficult airways using WKA-2.

Development of the airway management training system WKA-4: For improved high-fidelity reproduction of real patient conditions, and improved tongue and mandible mechanisms

In recent years advanced robotic technology has seen more use in the medical field to assist in the development of efficient training systems. Such training systems must fulfill the following criteria: they must provide quantitative information, must simulate the real-world conditions of the task, and assure training effectiveness. We developed Waseda Kyotokagaku Airway series to fulfill all of those requirements. The WKA series we had developed does not consider external appearance such as patient skin, or internal appearance such as the pharynx, larynx, and esophagus. Moreover, the tongue mechanism of the previous system can not precisely measure the force applied by medical devices and cannot simulate muscle stiffness. In addition, the mandible mechanism of the previous system could not adequately reproduce various airway difficulties or apply force control. For these reasons, we propose the WKA-4, which has high-fidelity simulated human anatomy, and we have improved the mechanism over the previous system. We have also attached a lung to the proposed system to improve simulation of the real-world conditions of the task. In this paper, we present how to design several organs with various embedded sensors and actuators, for a conventional patient model with high-fidelity simulated human anatomy. We also present the control system for the WKA-4. Finally, we present a set of experiments carried out using doctors as subjects, and they gave their valuable opinions about our system.

Development of the airway management training system WKA-3: Integration of evaluation module to provide assessment of clinical competence and feedback module to reproduce different cases of airway difficulties

An active training system is characterized by providing quantitative information of the trainees performance of the task to the trainee, simulating real-world conditions of the task, and assuring training effectiveness. For this purpose, the authors have been developing an Airway management training system. In particular, we have previously presented an evaluation model system to acquire quantitative information for the trainees performance, and an actuated model system for real-world conditions of the task. In order to fulfill all of the characteristics of the active training system; in this paper, we would like to propose an integrated system, W̲aseda K̲yotokagaku A̲irway No.3 (WKA-3) which integrates the function of both system models. For this reason, we have focused on embedding sensors and actuators with the link drive mechanism and the wire drive mechanism to a conventional patient model towards the development of a patient robot. In this paper, we present WKA-3 how to design the mechanism and how to redesign several organs to embed the sensors for the measurement of the trainees performance. A set of experiment have been carried out to doctor subjects using the WKA-3 to verify the effectiveness of the proposed system by asking doctors to evaluate the proposed system.

Reproducing Difficulties of Airway Management on Patients with Restricted Mouth Opening using the WKA-1

Airway management is provided by emergency medical technicians or anesthetists in order to save unconscious patients under emergency situations. Even though airway management is basic skill, there may be some difficulties while performing airway management to patients with abnormalities. Therefore, it is important to train medical students to perform such a task on patients with abnormalities. Recently, many companies are developing airway training mannequins designed to reproduce the conditions of the airway management procedure. However, such training devices cannot provide any quantitative information of the training progress so that few amount of feedback can be provided to trainees. For this purpose, we have proposed the development of an airway management training system which has been designed to embed sensors into a conventional mannequin. As a result, we have developed the Waseda-Kyotokagaku airway No. 1 (WKA-1). In this paper, the WKA-1 was used to reproduce the airway management on patients with abnormalities on jaw opening. For this purpose, we have added an array of springs to simulate those abnormalities. Then, we proposed an experiment to detect the differences on performances among doctors (anesthetist) while performing the airway management in patients with and without abnormalities on the jaw opening. Both cases were analyzed quantitatively by using the functionalities of the WKA-1. From the experimental results, we could find a statistically significant difference between both cases.

Mechanism Design Improvements of the Airway Management Training System WKA-3

This paper reports on the development of an Airway Management Training System. Airway management is a standard operation executed in emergency and operating rooms. However, medical accidents occur due to unskilled operations. In order to avoid accidents, medical doctors undergo to mannequin-based training. However, traditional training techniques do not provide quantitative information on the trainee’s performance and are not capable to assess the trainee’s performance based on the quantitative information. In this context, we proposed a novel airway management training system, dubbed WKA-3. This work presents both the electromechanical and the control sub-systems of the WKA-3. The results of preliminary experiments carried out by medical doctors to doctors to verify the training system are also provided.