THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY ORIGINAL Int J Med Robotics Comput Assist Surg 2015; 11: 448–457. Published online 14 October 2014 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/rcs.1628
ARTICLE
Mechanical chest compression with a medical parallel manipulator for cardiopulmonary resuscitation
G. Yedukondalu1,2* A. Srinath2 J. Suresh Kumar1 1
Department of Mechanical Engineering, Jawaharlal Nehru Technological University Hyderabad (JNTUH), India
2
Department of Mechanical Engineering, K. L. University Andhra Pradesh, India *Correspondence to: G. Yedukondalu, Department of Mechanical Engineering, K. L. University, Green Fields, Vaddeswaram, Guntur Dt., Andhra Pradesh, India. Email: [email protected]
Abstract Background Chest compression is the primary technique in emergency situations for resuscitating patients who have a cardiac arrest. Even for experienced personnel, it is difficult to perform chest compressions at the correct compression rate and depth. Methods We describe a new translational three-revolute–revolute–revolute (3-RRR) parallel manipulator designed for delivering chest compressions. The kinematic and chest analyses have been carried out analytically. The motion of the parallel manipulator while performing chest compressions was simulated under experimental conditions and the results were verified in MSC ADAMS software. Results Simulation and experimental results had more or less similar results. The proposed parallel manipulator was able to achieve 120 compressions/min (cpm) with a depth in the range 38–51 mm during cardio-pulmonary resuscitation (CPR). Conclusions The design of the manipulator makes it easy to deploy for performing chest compressions at the correct compression rate and depth, as outlined in the 2010 resuscitation guidelines. Copyright © 2014 John Wiley & Sons, Ltd. Keywords parallel manipulator; cardiopulmonary resuscitation; chest compression; mechanical chest
Introduction
Accepted: 15 September 2014
Copyright © 2014 John Wiley & Sons, Ltd.
For patients suffering from cardiac arrest, cardio-pulmonary resuscitation (CPR) is the basic technique used in emergency situations. The main aspects of CPR are chest compressions and rescue breathing, which are important manoeuvres used in hospitals, at home and at the site of an accident (1). The purpose of chest compressions during CPR is to stimulate blood flow and induce oxygen delivery to the myocardium and brain by increasing intrathoracic pressure by directly compressing the heart (2,3). Quality chest compressions are key elements in the chain of survival. According to the 2010 resuscitation guidelines, chest compressions must be delivered at a rate of 100–120 compressions/min with a depth of 38–51 mm
Mechanical chest compression for cardiopulmonary resuscitation
449
(3.8–5 cm), with the resuscitator’s hands placed on the middle of the lower half of the sternum to ensure the change of compression:ventilation ratio from 15:2 to 30:2 (4). Even for experienced medical practitioners, in emergency situations it is difficult to perform chest compressions at the correct compression rate and depth (1,5). The reported output achieved with manual chest compression during CPR is 20–30%, and the effectiveness is limited by the resuscitator’s endurance (6,7). In addition, the technique requires two physicians to execute chest compressions for at least 2 h in order to resuscitate a patient. In order to reduce the time, a dedicated skilled medical professional is needed to provide manual CPR. Therefore, a medical robot specifically designed for chest compression is required (8). A parallel manipulator typically consists of a moving platform that is connected to a fixed base through several limbs or legs that are parallel. Parallel manipulators are being widely used, as they have many inherent advantages, such as high speed, high accuracy, high stiffness and high load-carrying capacity, in contrast to their serial counterparts (8,9). In fact, parallel manipulators have several potential applications in the medical field, owing to their effective performance under conditions of high structural stiffness, motion accuracy and cases of compact structures (8). For instance, the design and development of a medical parallel robot for CPR, by utilizing a designed three-prismatic– universal–universal (3-PUU) translational parallel manipulator, has been reported throughout the literature (10,11). However, very few studies have investigated the use of parallel manipulators to assist in CPR (12,13). This paper describes a design for a parallel medical robot that can be deployed to execute chest compressions, perform kinematic analyses and record the outcomes of the chest compressions. The biomechanical analysis was subsequently correlated using MSC ADAMS software for chest compression. An experimental system with a schematic flow of the various operations is suggested for use in chest compression.
applied with the necessary force to depress the sternum by 38–51 mm for adults (Figure 1); this is independent of sex, body size and habitus (16,17). Today, most devices for mechanical chest compression that are in use have limitations, owing to the fact that they are too bulky to be accurately placed on the patient’s chest, cannot be properly positioned and controlled, are unsteady on the chest and are costly to install in public health centres (15). Therefore, there is no mechanical device for chest compression/decompression currently available for clinical implementation, despite the clear limitations associated with manual chest compressions (18).
Device description The structure of the proposed manipulator and its positioning for chest compression are illustrated in Figures 2 and 3, respectively. The patient is placed on a bed beside the CPR robot, which is mounted on a separate movable base using two supporting columns and is positioned above the patient’s head. The movable base can be positioned anywhere on the ground, and the supporting columns can be extended vertically. Thus, the robot can
Figure 1. Chest compression force and/or depth on cardiac arrest patient
Materials and methods Chest compression Recent clinical studies have shown that during CPR blood flow increases the compression force and/or depth increase (14). A chest compression force of 265–442 N (27–45 kg for adults) applied to the sternum is transmitted circumferentially around the chest. This force increases the pressure inside the chest (15). CPR guidelines recommend that chest compressions should be Copyright © 2014 John Wiley & Sons, Ltd.
Figure 2. The designed parallel manipulator for chest compression Int J Med Robotics Comput Assist Surg 2015; 11: 448–457. DOI: 10.1002/rcs
G. Yedukondalu et al.
450
Table 1. Architectural parameters of the manipulator S.No 1 2 3 4
Parameter
Value
Units
R r La Lb
200 160 180 180
mm mm mm mm
Kinematic modelling
Figure 3. Parallel manipulator arrangement for chest compression
be easily and comfortably positioned so that chest compressions can be started rapidly. The robot is also easy to reposition in case there is an operative malfunction, so that the patient is not put at risk. Moreover, because the CPR robot is located on only one side of the patient, there is ample space for a human rescuer to operate on the opposite side. The CPR manipulator uses a parallel construction in order to perform its function with high stiffness and high accuracy. This concept stems directly from manual CPR, where the rescuer uses two hands instead of one to deliver chest compressions, thereby creating a parallel configuration. The main disadvantage of parallel robots is their relatively limited range of motion. However, when properly designed, a parallel robot can satisfy the requirements and achieve a depth of 38–51 mm to administer effective CPR. Parallel robots with six degrees of freedom (6-DOF) are not suited to administer mechanical CPR. This is because they use complicated forward kinematics and highly coupled translation and rotation motions that present significant disadvantages. The literature has shown that three degrees of freedom (3-DOF) for a parallel manipulator with translation motion is best suited for mechanical CPR. In addition to a vertical translation, the proposed design also provides translations in other directions, which enables adjustments to be made to the manipulator’s moving platform, so that a suitable position can be found for performing chest compressions. According to the current literature, to date, parallel manipulators with
ARTICLE
Mechanical chest compression with a medical parallel manipulator for cardiopulmonary resuscitation
G. Yedukondalu1,2* A. Srinath2 J. Suresh Kumar1 1
Department of Mechanical Engineering, Jawaharlal Nehru Technological University Hyderabad (JNTUH), India
2
Department of Mechanical Engineering, K. L. University Andhra Pradesh, India *Correspondence to: G. Yedukondalu, Department of Mechanical Engineering, K. L. University, Green Fields, Vaddeswaram, Guntur Dt., Andhra Pradesh, India. Email: [email protected]
Abstract Background Chest compression is the primary technique in emergency situations for resuscitating patients who have a cardiac arrest. Even for experienced personnel, it is difficult to perform chest compressions at the correct compression rate and depth. Methods We describe a new translational three-revolute–revolute–revolute (3-RRR) parallel manipulator designed for delivering chest compressions. The kinematic and chest analyses have been carried out analytically. The motion of the parallel manipulator while performing chest compressions was simulated under experimental conditions and the results were verified in MSC ADAMS software. Results Simulation and experimental results had more or less similar results. The proposed parallel manipulator was able to achieve 120 compressions/min (cpm) with a depth in the range 38–51 mm during cardio-pulmonary resuscitation (CPR). Conclusions The design of the manipulator makes it easy to deploy for performing chest compressions at the correct compression rate and depth, as outlined in the 2010 resuscitation guidelines. Copyright © 2014 John Wiley & Sons, Ltd. Keywords parallel manipulator; cardiopulmonary resuscitation; chest compression; mechanical chest
Introduction
Accepted: 15 September 2014
Copyright © 2014 John Wiley & Sons, Ltd.
For patients suffering from cardiac arrest, cardio-pulmonary resuscitation (CPR) is the basic technique used in emergency situations. The main aspects of CPR are chest compressions and rescue breathing, which are important manoeuvres used in hospitals, at home and at the site of an accident (1). The purpose of chest compressions during CPR is to stimulate blood flow and induce oxygen delivery to the myocardium and brain by increasing intrathoracic pressure by directly compressing the heart (2,3). Quality chest compressions are key elements in the chain of survival. According to the 2010 resuscitation guidelines, chest compressions must be delivered at a rate of 100–120 compressions/min with a depth of 38–51 mm
Mechanical chest compression for cardiopulmonary resuscitation
449
(3.8–5 cm), with the resuscitator’s hands placed on the middle of the lower half of the sternum to ensure the change of compression:ventilation ratio from 15:2 to 30:2 (4). Even for experienced medical practitioners, in emergency situations it is difficult to perform chest compressions at the correct compression rate and depth (1,5). The reported output achieved with manual chest compression during CPR is 20–30%, and the effectiveness is limited by the resuscitator’s endurance (6,7). In addition, the technique requires two physicians to execute chest compressions for at least 2 h in order to resuscitate a patient. In order to reduce the time, a dedicated skilled medical professional is needed to provide manual CPR. Therefore, a medical robot specifically designed for chest compression is required (8). A parallel manipulator typically consists of a moving platform that is connected to a fixed base through several limbs or legs that are parallel. Parallel manipulators are being widely used, as they have many inherent advantages, such as high speed, high accuracy, high stiffness and high load-carrying capacity, in contrast to their serial counterparts (8,9). In fact, parallel manipulators have several potential applications in the medical field, owing to their effective performance under conditions of high structural stiffness, motion accuracy and cases of compact structures (8). For instance, the design and development of a medical parallel robot for CPR, by utilizing a designed three-prismatic– universal–universal (3-PUU) translational parallel manipulator, has been reported throughout the literature (10,11). However, very few studies have investigated the use of parallel manipulators to assist in CPR (12,13). This paper describes a design for a parallel medical robot that can be deployed to execute chest compressions, perform kinematic analyses and record the outcomes of the chest compressions. The biomechanical analysis was subsequently correlated using MSC ADAMS software for chest compression. An experimental system with a schematic flow of the various operations is suggested for use in chest compression.
applied with the necessary force to depress the sternum by 38–51 mm for adults (Figure 1); this is independent of sex, body size and habitus (16,17). Today, most devices for mechanical chest compression that are in use have limitations, owing to the fact that they are too bulky to be accurately placed on the patient’s chest, cannot be properly positioned and controlled, are unsteady on the chest and are costly to install in public health centres (15). Therefore, there is no mechanical device for chest compression/decompression currently available for clinical implementation, despite the clear limitations associated with manual chest compressions (18).
Device description The structure of the proposed manipulator and its positioning for chest compression are illustrated in Figures 2 and 3, respectively. The patient is placed on a bed beside the CPR robot, which is mounted on a separate movable base using two supporting columns and is positioned above the patient’s head. The movable base can be positioned anywhere on the ground, and the supporting columns can be extended vertically. Thus, the robot can
Figure 1. Chest compression force and/or depth on cardiac arrest patient
Materials and methods Chest compression Recent clinical studies have shown that during CPR blood flow increases the compression force and/or depth increase (14). A chest compression force of 265–442 N (27–45 kg for adults) applied to the sternum is transmitted circumferentially around the chest. This force increases the pressure inside the chest (15). CPR guidelines recommend that chest compressions should be Copyright © 2014 John Wiley & Sons, Ltd.
Figure 2. The designed parallel manipulator for chest compression Int J Med Robotics Comput Assist Surg 2015; 11: 448–457. DOI: 10.1002/rcs
G. Yedukondalu et al.
450
Table 1. Architectural parameters of the manipulator S.No 1 2 3 4
Parameter
Value
Units
R r La Lb
200 160 180 180
mm mm mm mm
Kinematic modelling
Figure 3. Parallel manipulator arrangement for chest compression
be easily and comfortably positioned so that chest compressions can be started rapidly. The robot is also easy to reposition in case there is an operative malfunction, so that the patient is not put at risk. Moreover, because the CPR robot is located on only one side of the patient, there is ample space for a human rescuer to operate on the opposite side. The CPR manipulator uses a parallel construction in order to perform its function with high stiffness and high accuracy. This concept stems directly from manual CPR, where the rescuer uses two hands instead of one to deliver chest compressions, thereby creating a parallel configuration. The main disadvantage of parallel robots is their relatively limited range of motion. However, when properly designed, a parallel robot can satisfy the requirements and achieve a depth of 38–51 mm to administer effective CPR. Parallel robots with six degrees of freedom (6-DOF) are not suited to administer mechanical CPR. This is because they use complicated forward kinematics and highly coupled translation and rotation motions that present significant disadvantages. The literature has shown that three degrees of freedom (3-DOF) for a parallel manipulator with translation motion is best suited for mechanical CPR. In addition to a vertical translation, the proposed design also provides translations in other directions, which enables adjustments to be made to the manipulator’s moving platform, so that a suitable position can be found for performing chest compressions. According to the current literature, to date, parallel manipulators with
