Heliotrope Medical Devices - Case Study Example

? HELIOTROPE MEDICAL DEVICES (HMD) This report describes the preface testing of a tiny mobile robot device also known as Heartlander used in minimally invasive cardiac surgery in order to check the process capability of the primary piece of equipment in the process through two groups of samples, one having a smaller number and big size and the other one vice versa. During testing the Heartlander is placed on the heart surface via a port slotted in below the sternum. The robot adheres to the heart surface as the surgeon controls it as it navigates to any point to administer therapy. In comparison to the current-assisted cardiac surgery, the tiny mobile robot obviates control of the heart and reduces access limitations. In addition, the Mobile robot permits application of an insertion method that enables outpatient cardiac surgery. The models in these experiment used suction to sustain pretension of the heart while the locomotion was aided by a wire-driven actuation. Also a digitized fiber scope presents visual feedbacks to the general practitioner, who gearshift the heartlander through joystick interface in various samples to determine the control process. The original model exhibited progressive prehension , locomotion and turning on bare chest, thumping pig hearts having excess pericardiums .This work exhibits a control process for producing the heartlander component which requires special attention during production. Abstract Table of contents Background information …………………………………………………………………..4 Objective ………………………………………………………………………………….4 Literature review ………………………………………………………………………….6 Robot Assisted cardiac Surgery …………………………………………………………..6 Methodology ………………………………………………………………………………7 System requirements ………………………………………………………………………7 Design implementation…………………………………………………………………….9 Testing ………………………………………………………………………………………9 Findings and discussion …………………………………………………………………….12 Conclusion and recommendation ……………………………………………………………12 Reference …………………………………………………………………………..15 Appendix 1: Calculation to test one finding Appendix 2: Calculation to test two finding BACKGROUND INFORMATION Cardiac surgery is an intervention on the heart or other significant vessels carried out by cardiac surgeons, in most cases it is performed to treat issues related ischemic heart disease. In the recent past, application of minimally invasive methods has turn out to be the main objective in cardiothoracic surgery since there a need to do away with morbidity related to sternotomy. Sternotomy refers to the bisecting of the sternum in order to expose the ribcage which gives the surgeon easy access to the heart and it majorly obviated by use of endoscopic minimally invasive surgery(Tendick et al 2003). This practice employs minute cameras and tools placed at distal ends of rigid shafts placed through miniature incisions between the ribs (figure 1). By use of endoscopic tools, the surgeon is in a position to convey the equipments to the operative site instead of exposing the patient to render the operative site to the tools. These mainly reduce movement in surgical process since the major pain and disability witnessed by the patient is as result of accessibility rather than the process itself. Figure 1 Nevertheless, the initial handheld endoscopic equipments had various setbacks that limited the implementation of minimally invasive methods for most surgical procedures. These drawbacks included: decrease in dexterity, reduced visualization, reversed motion and increased fatigue among others. These issues were worsened by the restrained environment of minimally invasive surgery, and it resulted in invention of the mobile robotic solutions. OBJECTIVES The main objective of this report is to establish a control process for producing a component in mobile robotic device used in minimally invasive cardiac surgery To come up with a solution to limitations associated with robotic assisted cardiac surgery those have restricted application of minimally invasive techniques in cardiac procedures LITERATURE REVIEW ROBOT ASSISTED CARDIAC SURGERY According to Bowersox, (1998) advanced healthcare solutions in the past have been established to combat casualties using biomedical technologies, one of such technologies was development of a robotic surgical system that assisted the surgeon to carry out remote surgeries on injured soldiers in battlefield. This technology was approved and advanced into two distinct viable robotic surgical methods used in endoscopic surgery. Some of the merits for this technology included: Increase in dexterity Increase in resolution power for 3D stereo Restoration of hand-eye coordination Reduced motion reversing and etc For these merits mobile robotic devices have been widely used in cardiac surgery. THE TINY MOBILE ROBOT CONCEPT/ HEARTLANDER CONCEPT During surgical operation a tiny mobile robot device is passed through a minimally invasive port, fixed to the epicardial surface and moved to the required point for therapy. By so doing, it permits the cardiopulmonary bypass to be evaded without the need of mechanical balancing of the epicardium. The capacity of the crawl to travel to any location on the heart surface from a point limits the restriction of operative site limitations (Bowersox 1998). This concept allows direct accessibility to the heart chamber by a single opening on the sternum which is a major advantage of the subxiphoid approach which is associated with obviates sternotomy. Figure 2 METHODOLOGY DESIGN CONCEPT This section outlines formation of a wide theoretical design of the tiny mobile robot device system (Heartlander system). Particularly general listed methodology for the therapy, control, feedback, locomotion, actuation, prehension and insertion as reflected based on the design system requirements. System requirements The design system requirements for the tiny mobile robot device were as listed below: Insertion-it should in 20mm dia port Prehension-should be attached to epicardium Actuation –it should be flexible to move unrestrictedly Locomotion –must have locomotive abilities Feedback-should have enough visual feedback Control –should have standardized user interface and a joystick Therapy –it should exhibit intervention capability In the case of size restrictions, there was lack of quantitative guidelines. Previously measured figures/ values or automated parameters i.e e force and pressure produced by the heart action and pericardial coefficients of friction were absent .if these values could be present, the suction force needed to be sustained on the epicardium and force requisited tomove below the pericardium could have been approximated. As an alternative, prehensile forces were approximated from the surgical equalizer that hold on to the epicardium, and increased actuation pressures were delivered for analysis during intial testing DESIGN IMPLEMENTATION This section outlines the implementation information of the abstract design that was developed. The tiny mobile robot device system is composed of a crawling robot fixed to a tabletop instrument through a tether (Chen 2003). This tether transmits the function of the huge external instrument needed for prehension, actuation, vision, and control all the way to the crawler. The system design permits the therapeutic section of robot to be compact, passive, inexpensive and lightweight. As shown in the figure below TESTING Testing was essential to determine the control process of the component production. In this experiment prototype had to be tested first in order to validate the pressure readings from the sensors within the system and to approximate the prehensile force which can be obtained by the original prototype. In all the trials using samples in both scenarios, only the sample was supplied a vacuum pressure from the pump, this yield a vacuum pressure (FV) between the suction pads and the surface of the sample. In the first test using samples in group one, a normal force (FN) was forced up from below the 15 samples surface of 18 pieces, this normal force was expected to cut the suction contact of which it was recorded by taking reading from a digital force gauge. The mean and standard deviation were calculated. A relative comparison was made between the force recorded and predicted vacuum force (Fv) In the second test involving 26 samples of 5 pieces, a tangential force (Ft) was supplied to the surface of the specimen due to its size. The pressure/forced expected to fracture the suction contact recorded again by the digital force gauge. An equation; FT (prediction) = FV. R/h Where; h & r refers to the evaluations of the forces applied and the radius respectively. This was used to establish an equilibrium that could be used as a control process in the production of the heartlander component. FINDING AND DISCUSSION The table below represents results from test 1 of the experiment. A graph showing various samples versus the mean pressure (mm)(x-bar) and the range pressure(mm)( R-bar). Graph 1 The table (B) below represents results from the second test of the experiment A graph showing various samples versus the mean pressure (mm)(x-bar) and the range pressure(mm)( R-bar). ANALYSIS From the results computation of the mean and stardard deviation relating to the two distict scenario, anumber of conclusion have to be made In the first set of experiment, (15 samples and 18 observations) there was big gap between the variance and standard deviation which are significant variables of the control process, the variance standing at 18.3254 and stardard deviations at 4.25464, it means that much attentions should be put in consideration in producing the component when the mobile robot device is going to handle less sample with big size. It is like the efficiency of the deceive is not viable and in the long run the device is not economical. In the second test/ experiment,(26 samples and 5 observations) the gap between te variance and stardard deviation is small, there also some element of constistency in the figures as observed between the mean and range. In this case the variance is 9.165151 while the stardard deviation 7.79423 this small difference defines the sensitivity of the component and the control process in general. In this case the component is more efficient and viable, this means that less attention will be required during production and thus it more economical to target larger samples in number that requires less observations . Generally, sample size defines the intensity activity, that is the cardiac surgery procedure of which the tiny mobile robot is involved in. CONCLUSION AND RECOMMENDATION From the results obtained in this report exhibits the viability of applying a mobile robot devicein cardiac surgery this facilitates minimally invasive beating –hear intervention. In order to aid surgical procedures between the epicardium and pericardium the prototype sizemust be reduced and samples increased. In addition, an unconventional vision system should be employed to reduce severe impacts of fiber rigidity and at the same time facilitate imagine of the feedback channel to the surgeon (Chen 2003). This is likely to be achieved by use of camera’s and other tools that promote subxiphoid access. By use of a modular design in therapeutic end-effector fixed to the tiny mobile robot device, it will assist the device to carry out a number of surgical treatments. Previous , advancement in dedicated end-effectors , the 3.5mm route has been employed in various endoscopic equipments from the steady Heartlander platform. This report is a baseline for other research to be studied for more innovative procedures in cardiac surgery which may include; epicardial delivery of myoblast and others like regenaration of the stem cells as witnessed in failing myocardium. Eventually, we visualize to adopt the mobile robot device based intrapericadia therapies in intervention cardiologists and electrophysiologists practises as an addition area to minimally invasive cardiac surgeons. REFERANCES Bowersox jc, cordts PR, LaPoarta AJ. 1998. Use of an intuitive telemanipulator system for remote trauma surgery: an experimental study . J Am Coll Surg 186(6): 615-621 Cavusoglu,Mc, Williams, W, Tendick, F, Sastry, S.S. 2003. Roboticsfor telesurgery:second generation Berkeley/UCSF laparoscopic telesurgical workpstation and looking towards the future application: industrial Robot 30(1):22-29 Chen,I-M, Yeo, S.H. 2003. Locomotionof a 2D Walking-Climbing Robot Using Closed-loop Mechanism:From Gait Generation to Navigation. International Journal Robotics Research.22(1):21-40 Read More