A Review of Pneumatic Actuators Used for the Design of Medical Simulators and Medical Tools

International audienc

PériSIM : an haptic simulator to learn the epidural anaesthesia procedure

L’anesthésie péridurale est un geste médical commun consistant à réaliser une anesthésie locale du bas du corps. Généralement pratiqué lors d’accouchements afin de limiter les douleurs de la future maman, le geste reste relativement simple mais requiert un long entraînement afin d’être suffisamment maîtrisé. Les moyens de formations actuels tels que des mannequins ne permettant pas de proposer un apprentissage suffisant, la plupart du temps la première péridurale est réalisée directement sur le patient. Cela augmente les risques de réaliser une mauvaise anesthésie mais aussi le stress des médecins novices. Cette thèse propose un simulateur haptique utilisant une interface haptique électrique couplée à un vérin pneumatique afin de proposer une simulation complète et réaliste de la procédure. Les travaux proposent une commande de vérin pneumatique visant à simuler le comportement d’une seringue. Le contrôle du vérin pneumatique est réalisée à l'aide d'une servovalve par une approche par backstepping et permet d'accroître grandement le réalisme de la simulation. Le contrôle de l’interface haptique électrique a, lui, pour but de représenter l’insertion d’une aiguille dans le dos d’un patient. L’ensemble vise à mettre à disposition une simulation étoffée et réaliste de différents types de patients. Les travaux de thèses ont donc pu aboutir à la présentation d'un simulateur complet dédié à la simulation du geste de l'anesthésie péridurale. Le simulateur développé a pu être testé au cours d'une campagne de mesure auprès de médecins novices et expérimentés. Cette campagne a permis de récolter suffisamment de données pour entreprendre le développement d'une méthode d’évaluation du geste.The epidural anesthesia is a common medical gesture that consists in a local anesthesia of the lower part of the body. It is usually performed at childbirth to relieve the future mother from birthing pain. Although the gesture itself is simple, it requires a long training to be mastered by anyone. Current training tools however do not provide sufficient training quality, and most of the time the first epidural anesthesia is performed directly on a patient. This, not only increase the risk of an error happening during the procedure but it also increases the level of stress for the novices.This thesis propose a haptic simulator composed of an electrical haptic interface coupled with a pneumatic cylinder to create a complete a realistic simulation of the procedure. In this work, we propose control laws to use a pneumatic cylinder as a syringe emulator. The control of the cylinder is achieved using a servovalve and a backstepping approach to greatly increase the realism of the simulation. The electrical haptic interface is used to reproduce a needle insertion through tissues in the back of a patient. The overall objective is to put together a complete a realistic simulation of different patient types. This project has lead to the development of a complete haptic simulator dedicated to reproduce the epidural anesthesia gesture. The simulator has been tested in a test campaign involving both novices and experts. This campaign allowed to get enough data points to undertake the implementation of a gesture evaluation metho

PériSIM : un simulateur haptique d'apprentissage du geste de l'anesthésie péridurale

The epidural anesthesia is a common medical gesture that consists in a local anesthesia of the lower part of the body. It is usually performed at childbirth to relieve the future mother from birthing pain. Although the gesture itself is simple, it requires a long training to be mastered by anyone. Current training tools however do not provide sufficient training quality, and most of the time the first epidural anesthesia is performed directly on a patient. This, not only increase the risk of an error happening during the procedure but it also increases the level of stress for the novices.This thesis propose a haptic simulator composed of an electrical haptic interface coupled with a pneumatic cylinder to create a complete a realistic simulation of the procedure. In this work, we propose control laws to use a pneumatic cylinder as a syringe emulator. The control of the cylinder is achieved using a servovalve and a backstepping approach to greatly increase the realism of the simulation. The electrical haptic interface is used to reproduce a needle insertion through tissues in the back of a patient. The overall objective is to put together a complete a realistic simulation of different patient types. This project has lead to the development of a complete haptic simulator dedicated to reproduce the epidural anesthesia gesture. The simulator has been tested in a test campaign involving both novices and experts. This campaign allowed to get enough data points to undertake the implementation of a gesture evaluation methodL’anesthésie péridurale est un geste médical commun consistant à réaliser une anesthésie locale du bas du corps. Généralement pratiqué lors d’accouchements afin de limiter les douleurs de la future maman, le geste reste relativement simple mais requiert un long entraînement afin d’être suffisamment maîtrisé. Les moyens de formations actuels tels que des mannequins ne permettant pas de proposer un apprentissage suffisant, la plupart du temps la première péridurale est réalisée directement sur le patient. Cela augmente les risques de réaliser une mauvaise anesthésie mais aussi le stress des médecins novices. Cette thèse propose un simulateur haptique utilisant une interface haptique électrique couplée à un vérin pneumatique afin de proposer une simulation complète et réaliste de la procédure. Les travaux proposent une commande de vérin pneumatique visant à simuler le comportement d’une seringue. Le contrôle du vérin pneumatique est réalisée à l'aide d'une servovalve par une approche par backstepping et permet d'accroître grandement le réalisme de la simulation. Le contrôle de l’interface haptique électrique a, lui, pour but de représenter l’insertion d’une aiguille dans le dos d’un patient. L’ensemble vise à mettre à disposition une simulation étoffée et réaliste de différents types de patients. Les travaux de thèses ont donc pu aboutir à la présentation d'un simulateur complet dédié à la simulation du geste de l'anesthésie péridurale. Le simulateur développé a pu être testé au cours d'une campagne de mesure auprès de médecins novices et expérimentés. Cette campagne a permis de récolter suffisamment de données pour entreprendre le développement d'une méthode d’évaluation du geste

Control laws for pneumatic cylinder in order to emulate the Loss Of Resistance principle

International audienceMedicine requires advanced teaching methods in order to reach an efficient student training without having to train them directly on patients. In France, the Haute Autorité de la Santé (H.A.S.) has stated to "never [do] the first time with a patient" as a requirement for the training of new doctors. The goal of this work is to other a novel robotic solution to teach students how to perform an epidural anaesthesia. This medical operation can be divided intotwo different gestures: First the insertion of a needle between two vertebrae and second the application of pressure on the plunger all along the insertion of the needle. This works aims at simulating this second part as it has already been done on the first part in previous studies. We introduce a way to emulate the principle of loss of resistance felt by the anaesthetist when the needle reaches the appropriate depth

Skill assessment of an epidural anesthesia using the PeriSIM simulator

International audienceCurrently, the training in the lumbar epidural anesthesia procedure, a very common procedure, is mainly performed on patients under the supervision of experts. The reason for this situation is that the simulators that exist on the market are not realistic enough to efficiently learn this particularly haptic-sense-based gesture. To avoid this ethical issue and provide an efficient, repeatable, and affordable way of safely learning this gesture, the Ampére laboratory designed PeriSIM: a haptic training computer-based simulator. In this article, the trainees’ skill assessment is tackled. This work presents various machine learning approaches to the evaluation of trainees and introduces a complete skill assessment algorithm to use in conjunction with the PeriSIM simulator. This work also aims to determine the important variables of an lumbar epidural anesthesia procedure for objective assessment purpose

Simulating a Syringe Behaviour Using a Pneumatic Cylinder Haptic Interface

International audienceMastering medical gestures, such as epidural needle insertion, requires much practice. Haptic interfaces can be efficient training solutions. Nevertheless, they must provide users with an accurate experience for an effective training. This article introduces a control framework that turns a pneumatic cylinder into a haptic interface able to simulate a syringe and more specifically the loss of resistance phenomenon encountered during an epidural needle insertion. To achieve this, the framework switches between two control laws (position and force tracking) according to the system state. Experiments involving two anesthetists confirm the practicality of this system for hands-on training or rehearsal purposes

Designing an accurate and customizable epiduralanesthesia haptic simulator

International audienceEpidural anesthesia, despite being a relatively common medical procedure, remains quite demanding in terms of skills as it is mostly blind and thus heavily reliant on the haptic sensations. Although some training support solutions exist, anesthetists consider them mostly inefficient or impractical. A few attempts at creating a simulator for this particular procedure exist but each one lacks one of the important requirements of the procedure. This article introduces a haptic simulator featuring a more complete and realistic simulation of the procedure than we could observe in existing simulators. The simulator is composed of a generic electrical haptic interface coupled with a pneumatic cylinder

Introducing Pneumatic Actuators in HapticTraining Simulators and Medical Tools

International audienceSimulators have been traditionally used for centuries dur-ing medical training as the trainees have to improve their skills beforepracticing on a real patient. Nowadays mechatronic technology has openthe way to more evolved solutions enabling objective assessment anddedicated pedagogic scenarios. Trainees can now practice in virtual en-vironments on various body parts, with current and rare pathologies, forany kind of patient (slim, elderly ...). But medical students need kines-thetic feedback in order to get significant learning. Gestures to acquirevary according to medical specialties: needle insertion in rheumatologyor anesthesia, forceps installation during difficult births ... Simulatorsreproducing such gestures require haptic interfaces with a variable ren-dered stiffness, featuring commonly called Variable Stiffness Actuators(VSA) which are difficult to embed with off-the-shelf devices. Existingsolutions do not always fit the requirements because of their significantsize. In contrast, pneumatic technology is low-cost, available off-the-shelfand has a better mass-power ratio. Its main drawback is its non-lineardynamics, which implies more complex control laws than with electri-cal motors. It also requires a compressed air supply. Ampère researchlaboratory has developed during the last decade haptic solutions basedon pneumatic actuation, applied on a birth simulator, an epidural nee-dle insertion simulator, a pneumatic master for remote ultrasonography,and more recently a needle insertion under ultrasonography simulator.This paper recalls the scientific approaches in the literature about pneu-matic actuation for simulation and tools in the medical context. It isillustrated with the aforementioned applications to highlight the bene-fits of this technology as a replacement or for an hybrid use with classicalelectric actuators

Introducing Pneumatic Actuators in HapticTraining Simulators and Medical Tools

International audienceSimulators have been traditionally used for centuries dur-ing medical training as the trainees have to improve their skills beforepracticing on a real patient. Nowadays mechatronic technology has openthe way to more evolved solutions enabling objective assessment anddedicated pedagogic scenarios. Trainees can now practice in virtual en-vironments on various body parts, with current and rare pathologies, forany kind of patient (slim, elderly ...). But medical students need kines-thetic feedback in order to get significant learning. Gestures to acquirevary according to medical specialties: needle insertion in rheumatologyor anesthesia, forceps installation during difficult births ... Simulatorsreproducing such gestures require haptic interfaces with a variable ren-dered stiffness, featuring commonly called Variable Stiffness Actuators(VSA) which are difficult to embed with off-the-shelf devices. Existingsolutions do not always fit the requirements because of their significantsize. In contrast, pneumatic technology is low-cost, available off-the-shelfand has a better mass-power ratio. Its main drawback is its non-lineardynamics, which implies more complex control laws than with electri-cal motors. It also requires a compressed air supply. Ampère researchlaboratory has developed during the last decade haptic solutions basedon pneumatic actuation, applied on a birth simulator, an epidural nee-dle insertion simulator, a pneumatic master for remote ultrasonography,and more recently a needle insertion under ultrasonography simulator.This paper recalls the scientific approaches in the literature about pneu-matic actuation for simulation and tools in the medical context. It isillustrated with the aforementioned applications to highlight the bene-fits of this technology as a replacement or for an hybrid use with classicalelectric actuators