Haptic Telerobotic Cardiovascular Intervention: A Review of Approaches, Methods, and Future Perspectives.

Cardiac diseases are recognized as the leading cause of mortality, hospitalization, and medical prescription globally. The gold standard for the treatment of coronary artery stenosis is the percutaneous cardiac intervention that is performed under live X-ray imaging. Substantial clinical evidence shows that the surgeon and staff are prone to serious health problems due to X-ray exposure and occupational hazards. Telerobotic vascular intervention systems with a master-slave architecture reduced the X-ray exposure and enhanced the clinical outcomes; however, the loss of haptic feedback during surgery has been the main limitation of such systems. This paper is a review of the state of the art for haptic telerobotic cardiovascular interventions. A survey on the literature published between 2000 and 2019 was performed. Results of the survey were screened based on their relevance to this paper. Also, the leading research disciplines were identified based on the results of the survey. Furthermore, different approaches for sensor-based and model-based haptic telerobotic cardiovascular intervention, haptic rendering and actuation, and the pertinent methods were critically reviewed and compared. In the end, the current limitations of the state of the art, unexplored research areas as well as the future perspective of the research on this technology were laid out.

Design and finite element analysis of a novel smart clamper for aortic cross-clamping in minimally invasive surgery.

Aortic cross-clamping is a critical action during heart surgeries which may cause some injuries to the wall of the artery. These injuries may have both short-term and long-term adverse effects on the artery function. Appropriate clampers can properly occlude the artery and decrease the extent of injury. Thus, developing a model for evaluation of such clampers is inevitable. In this paper, a finite element model of the aorta is presented; then, different mechanisms of clamping are investigated. In this regard, a numerical model of aortic cross-clamping by three types of clampers has been implemented with consideration of nonlinear behavior of two-layer artery, residual stress in aorta, and calcification. These three clamper models are commercial Chitwood clamper and linear mechanism clamper with and without balloon. Using the obtained results, comparative analysis was performed between the proposed clamper design and the commercial one. Based upon the analysis, it was concluded that the designed clamper, linear mechanism clamper with balloon, helps to distribute the stress uniformly in different layers of the aorta, which results in better performance of the clamping procedure and causes less injury in the aorta, especially when there is calcification.

A proof-of-principle robot with potential for the development of a hand-held tactile instrument for minimally-invasive artery cross-clamping.

One of the most common diseases of the vascular system is abdominal aortic aneurysm (AAA), for which the most definitive treatment is surgery. Minimally invasive aorta surgery is a novel method of surgery performed through small incisions and offers significant advantages including less pain, shorter hospital stay, faster patient recovery, less possibility of infection, etc. However, lack of sense of touch is the main drawback of this type of aorta surgery that would incapacitate the surgeon to exactly distinguish the aorta from its surrounding tissues which could cause various problems during the aorta cross-clamping process. One of the most important drawbacks is that it makes the aorta cross-clamping process the most time-consuming process of aortic repair surgery. The artificial tactile sensing approach is a novel method that can be used in various fields of medicine and, more specifically, in minimally invasive surgeries, where using the 'tactile sense' is not possible. In this paper, considering the present problems during aortic-repair-laparoscopy and imitating the movement of surgeons' fingers during aorta cross-clamping, a novel tactile-based artery cross-clamping robot is introduced and its function is evaluated experimentally. It is illustrated that this new tactile-based artery cross-clamping robot is well capable of dissecting an artery from its adjacent tissues in a short time with an acceptable accuracy.

A novel haemostatic powder delivery device applicable in minimally invasive surgery.

Haemostatic powder is an effective solution commonly used in various open surgeries. However, there is no specific intra-abdominal delivery device for application of haemostatic powder at the bleeding site during minimally invasive surgery (MIS). In this study, design, construction and test of a novel powder delivery device were carried out. The device uses pressurized gas to deliver the haemostatic powder to the bleeding point. The effect of the gas pressure and the spraying distance on the geometry of the powder dispersion surface area was investigated and found to be significant. The findings indicate that the driving gas pressure range of 60-80 mmHg and the spraying distance range of 2-5 cm achieve the most concentrated powder dispersion surface area. Additionally, in vivo experiments confirmed the effectiveness of the device in live tissue.

Artery cross-clamping during laparoscopic vascular surgeries; a computational tactile sensing approach.

Artificial palpation is one of the most valuable achievements of artificial tactile sensing approach that can be used in various fields of medicine and more specifically in surgery. These techniques cause different surgical maneuvers to be done more precisely and noninvasively. In this study, considering the present problems and limitations of cross-clamping an artery during laparoscopic vascular surgeries, a new tactile sensory system will be introduced.Having imitated surgeon's palpation during open vascular surgeries and modeled it conceptually, the optimal amount of the total angular displacement of each robot joint in order to cross-clamping an artery without damaging to the artery surrounding tissues will be calculated. The elastic governing equation of contact occurred between the tactile sensor placed on the first link of the robot and the surrounding tissues around the artery were developed. A finite element model is coupled with genetic algorithm optimization method so that the normal stress and displacements in contact surface of the robot and artery's surrounding tissues would be minimized. Thus, reliability and accuracy of artificial tactile sensing method in artery cross-clamping will be demonstrated. Finally, the functional principles of the new tactile system capable of cross-clamping an artery during laparoscopic surgeries will be presented.

A novel robotic tactile mass detector with application in clinical breast examination.

This paper presents a novel tactile sensing robot designed to detect breast lesions with minimum invasiveness to the tissue while providing exact documentation to make therapeutic and surgical decisions. The robot named "Robotic Tactile Breast Mass Identifier (Robo-Tac-BMI) consists of an indentation probe controlled by a robotic system and a visualization interface to manipulate the end-effecter. Geometrical maps of the test points with related tension-relaxation curves are provided during clinical examinations. Utilizing the curves, three functional stiffness parameters are extracted locally for each test point. These parameters are employed to provide objective information to facilitate the surgeon's task in the diagnostic procedure. Computational analysis is proposed for a real breast tissue model to study the capability of artificial tactile sensing in the mass detection. Indications of the mass existence are determined and employed as the basis of the Robo-Tac-BMI design and construction. Clinical trials are executed by the Robo-Tac-BMI on 161 cases. The results show that the robot has the potential to provide tissue mechanical properties unlike the conventional screening modalities carried out either by the surgeon or the imaging techniques which are not quantitative and lack documentation. Sonography with and without mammography is chosen as the "gold standard" tests.

The study of collagen immobilization on a novel nanocomposite to enhance cell adhesion and growth.

BACKGROUND: Surface properties of a biomaterial could be critical in determining biomaterial's biocompatibility due to the fact that the first interactions between the biological environment and artificial materials are most likely occurred at material's surface. In this study, the surface properties of a new nanocomposite (NC) polymeric material were modified by combining plasma treatment and collagen immobilization in order to enhance cell adhesion and growth. METHODS: NC films were plasma treated in reactive O2 plasma at 60 W for 120 s. Afterward, type I collagen was immobilized on the activated NC by a safe, easy, and effective one-step process. The modified surfaces of NC were characterized by water contact angle measurement, water uptake, scanning electron microscopy (SEM), and Fourier transformed infrared spectroscopy in attenuated total reflection mode (ATR-FTIR). Furthermore, the cellular behaviors of human umbilical vascular endothelial cells (HUVEC) such as attachment, growth and proliferation on the surface of the NC were also evaluated in vitro by optical microscopy and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. RESULTS: The outcomes indicated that plasma treatment and collagen immobilization could improve hydrophilicity of NC. SEM micrograph of the grafted film showed a confluent layer of collagen with about 3-5 mum thicknesses. In vitro tests showed that collagen-grafted and plasma-treated surfaces both resulted in higher cell adhesion and growth state compared with untreated ones. CONCLUSION: Plasma surface modification and collagen immobilization could enhance the attachment and proliferation of HUVEC onto NC, and the method would be usefully applied to enhance its biocompatibility.

Surface modification of POSS-nanocomposite biomaterials using reactive oxygen plasma treatment for cardiovascular surgical implant applications.

In this study, central composite design (CCD) was used to develop predictive models to optimize operating conditions of plasma surface modification. It was concluded that out of the two process variables, power and duration of plasma exposure, the latter was significantly affecting the surface energy (γ(s) ), chemistry, and topography of polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU) films. On the basis of experimental data, CCD was used to model the γ(s) using a quadratic modeling of the process variables to achieve optimum surface energy to improve the interaction between endothelial cells (ECs). It was found that optimal water θ for EC adhesion and retention, which was reported 55° from supporting literature (equivalent to γ(s) = 51 mN/m), was easily achievable using the following experimental conditions: (1) power output at 30 W for 75 Sec, (2) 90 W for 40 Sec, and (3) 90 W for 55 Sec in oxygen. In vitro cell culture and metabolic activity studies on optimized films [as in (1)] demonstrate increased adhesion, coverage, and growth of human umbilical vein endothelial cells that were confluent over a shorter time period (<24 H) than controls. Such materials enhanced the EC response and promoted endothelialization on optimized films, thus demonstrating their use as bypass graft materials.

A novel haptic robotic viscogram for characterizing the viscoelastic behaviour of breast tissue in clinical examinations.

BACKGROUND: This paper presents a novel tactile sensing robot designed to characterize the viscoelastic behaviour of breast tissue during clinical breast examination (CBE). The robot, named the 'robotic tactile breast mass identifier' (Robo-Tac-BMI), mainly consists of an indentation probe controlled by a robotic system and a visualization interface to manipulate the end-effector. Major high order mechanical parameters are extracted to characterize the viscoelastic behaviour of the tissue in order to certify mass detection and judge the mass type. By fusing the measurements over both breasts, the probe can generalize a mechanical image to visualize the viscoelastic distribution within the internal tissue. The viscoelastic properties provide additional and objective information to facilitate the surgeon's task in the decision-making process. METHODS: A new computational method is presented for characterizing mass existence in a real breast model. The effect of the strain rate on the mechanical properties is considered to study the viscoelastic behaviour of different mass types. A creative method is proposed to find the optimum strain rate for different mass positions and consistencies, which improves nodule detection. The computational results would be used as the basis for the design and set-up of the Robo-Tac-BMI. Clinical tests with statistical analyses were performed on 161 cases, using the Robo-Tac-BMI. RESULTS: The results include analysis of two high-order mechanical properties. Robo-Tac-BMI's capability of nodule detection and differentiation between benign and malignant mass types are investigated. The results were validated by 'gold standard' tests. CONCLUSION: The results show that Robo-Tac-BMI has the potential to provide high-order mechanical parameters, unlike the conventional screening modality carried out by the surgeon, which is not inclusive or quantitative and lacks effectiveness and documentation. The nodule detection ability of this device is confirmed statistically in clinical breast examinations. Differentiation between different mass types is reported as the preliminary result of Robo-Tac-BMI utilization.

Design and fabrication of a novel tactile sensory system applicable in artificial palpation.

Force and position feedback are the two important parameters that are employed in different medical diagnoses and more specifically surgical operations. Furthermore, during different minimally invasive procedures, the ability of touch and force and position feedback are absent. In this regard, artificial palpation is a new technology that is employed to obtain tactile data in situations where physicians/surgeons cannot use their tactile sense. One of the most valuable achievements of artificial palpation are tactile sensory systems that have various applications in the detection of hard objects inside the soft tissue. Considering the present problems and limitations of kidney stone removal laparoscopy, the aim of this research is to design and fabricate a novel tactile sensory system capable of determining the exact location of stones during laparoscopy. This new tactile sensory system consists of four main parts: The sensory part, the mechanical part, the electrical part, and the display part. In this new system, due to the use of both displacement and force sensors, the usage limitations of previous tactile sensory systems are eliminated. The new tactile sensory system is well capable of finding the stone in the laboratory models through physical contact with the model's surface.

Application of artificial tactile sensing approach in kidney-stone-removal laparoscopy.

Artificial tactile sensing is a novel method for obtaining different characteristics of a hard object embedded in a soft tissue. In this regard, artificial palpation is one of the most valuable achievements of artificial tactile sensing that can be used in various fields of medicine and more specifically in surgery. In this study, considering the present problems and limitations in kidney-stone-removal laparoscopy, a new application will be presented for artificial tactile sensing approach. Having imitated surgeon's palpation during open surgery and modeled it conceptually, indications of stone existence that appear on the surface of kidney (due to exerting mechanical load) were determined. A number of different cases were created and solved by the software. Using stress distribution contours and stress graphs, it is illustrated that the created stress patterns on the surface of kidney not only show the existence of stone inside, but also its exact location. In fact, the reliability and accuracy of artificial tactile sensing method in detection of kidney stone during laparoscopy is demonstrated by means of finite element analysis. Also, in this paper, the functional principles of tactile system capable of determining the exact location of stone during laparoscopy will be presented.

Effects of mass and momentum of inertia alternation on individual muscle forces during swing phase of transtibial amputee gait.

A computer simulation was carried out to investigate the forces of lower extremity muscles in the swing phase of a transtibial amputee gait. With each muscle as an ideal force generator, the lower extremity was simulated as a two-degrees of freedom linkage with the hip and knee as its joints. Kinematic data of hip and knee joints were recorded by a motion analysis system. Through a static optimization approach, the forces exerted by muscles were determined so that recorded hip and knee joint angles were produced. Simulation results showed that when the mass of prosthetic foot is increased, muscle forces increase, too. This result is in accord with experimental and theoretical studies that reported an increase in leg mass lead to higher electromyography activity of muscles, and energetic of walking. However, since prosthetic foot moment of inertia is smaller than that of thigh and prosthetic shank, its alternation does not have noticeable effect on muscle forces.

Mathematical modeling of CSF pulsatile hydrodynamics based on fluid-solid interaction.

Intracranial pressure (ICP) is derived from cerebral blood pressure and cerebrospinal fluid (CSF) circulatory dynamics and can be affected in the course of many diseases. Computer analysis of the ICP time pattern plays a crucial role in the diagnosis and treatment of those diseases. This study proposes the application of Linninger et al.'s [IEEE Trans. Biomed. Eng., vol. 52, no. 4, pp. 557-565, Apr. 2005] fluid-solid interaction model of CSF hydrodynamic in ventricular system based on our clinical data from a group of patients with brain parenchyma tumor. The clinical experiments include the arterial blood pressure (ABP), venous blood pressure, and ICP in the subarachnoid space (SAS). These data were used as inputs to the model that predicts the intracranial dynamic phenomena. In addition, the model has been modified by considering CSF pulsatile production rate as the major factor of CSF motion. The approximations of ventricle enlargement, CSF pressure distribution in the ventricular system and CSF velocity magnitude in the aqueduct and foramina were obtained in this study. The observation of reversal flow in the CSF flow pattern due to brain tissue compression is another finding in our investigation. Based on the experimental results, no existence of large transmural pressure differences were found in the brain system. The measured pressure drop in the ventricular system was less than 5 Pa. Moreover, the CSF flow pattern, ICP distribution, and velocity magnitude were in good agreement with the published models and CINE (phase-contrast magnetic resonance imaging) experiments, respectively.

Differences in center of pressure trajectory between normal and steppage gait.

BACKGROUND: This pilot study aimed to assess the differences in center of pressure trajectory in neuropathic patients with steppage gait. Steppage gait has previously been evaluated by several biomechanical methods, but plantar pressure distribution has been much less studied. The purpose of this study was to analyze the changes in center of pressure trajectory using a force plate. METHODS: The steppage gait group was selected from the patients using drop foot brace (25 male) and the control group was selected from Isfahan university students (20 male). They walked at self- selected speed at a mean of ten trials (+2) to collect the center of pressure using a force plate. Center of pressure patterns were categorized into four patterns based on the center of pressure displacement magnitude (spatial features) through time (temporal features) when the longitudinal axis of the insole was plotted as the Y- axis and the transverse axis of the insole as X- axis during stance phase. RESULTS: The horizontal angle measured from center of pressure linear regression was positive in the control group (4.6 ± 2.4) (p < 0.005), but negative in the patient group (- 2.3 ± 1.6) (p < 0.005). CONCLUSIONS: The finding of this research measured center of pressure trajectory in steppage gait over time, which is useful for designing better shoe sole and also orthopaedic device and better understanding of stability in patients with drop foot.

Dosimetric evaluation of a novel high dose rate (HDR) intraluminal / interstitial brachytherapy applicator for gastrointestinal and bladder cancers.

High dose rate (HDR) brachytherapy is one of the accepted treatment modalities in gastro-intestinal tract and bladder carcinomas. Considering the shortcoming of contact brachytherapy routinely used in gastrointestinal tract in treatment of big tumors or invasive method of bladder treatment, an intraluminal applicator with the capability of insertion into the tumor depth seems to be useful. This study presents some dosimetric evaluations to introduce this applicator to the clinical use. The radiation attenuation characteristics of the applicator were evaluated by means of two dosimetric methods including well-type chamber and radiochromic film. The proposed 110 cm long applicator has a flexible structure made of stainless steel for easy passage through lumens and a needle tip to drill into big tumors. The 2mm diameter of the applicator is thick enough for source transition, while easy passage through any narrow lumen such as endoscope or cystoscope working channel is ensured. Well-chamber results showed an acceptably low attenuation of this steel springy applicator. Performing absolute dosimetry resulted in a correlation coefficient of R = 0.9916 (p-value ≈ 10-7) between standard interstitial applicator and the one proposed in this article. This study not only introduces a novel applicator with acceptable attenuation but also proves the response independency of the GAFCHROMIC EBT films to energy. By applying the dose response of the applicator in the treatment planning software, it can be used as a new intraluminal / interstitial applicator.

A medical tactile sensing instrument for detecting embedded objects, with specific application for breast examination.

BACKGROUND: In this paper, having considered the tactile sensing and palpation of a physician in order to detect abnormal masses in the breast, we simplified and then modelled the tissue containing a mass and used contact elements to analyse the tactile sensor function. METHODS: By using the finite element method, the effects of the mass existence appeared on the surface of the tissue. This was due to exerting mechanical load on the modelled tissue surface. Following this, a tactile sensing instrument called the 'tactile tumour detector' (TTD) was designed and constructed. This device is able to detect abnormal objects in the simulated models by making contact with model surfaces. In order to perform a series of precise experiments, a robot that could hold the tactile probe was used. The velocity of the linear movement of the probe is low enough to ensure that the tissue behaves in the linear elastic range, so that dynamic effects can be neglected. RESULTS AND DISCUSSION: The maximum value of stresses was chosen as the comparison criterion. The variation of this criterion vs. the mass parameter changes was investigated and good agreements between numerical and experimental results were obtained. Moreover, the sensitivity and specificity of TTD and clinical breast examination (CBE) in the detection of breast masses, in comparison to sonography as the 'gold standard', were calculated by performing clinical trials on 55 cases.

Can surgeon's hand be replaced with a smart surgical instrument in esophagectomy?

Esophageal cancer is the eighth most common cancer in the world. The most common surgical procedures for esophageal cancer are transhiatal esophagectomy and transthoracic esophagectomy. Thoracic esophagectomy involves an abdominal incision and a thoracotomy, but transhiatal esophagectomy involves both an abdominal incision and a cervical incision. It can reduce postoperative morbidities and fast recovery. In transhiatal esophagectomy, part of dissection is blind and lack of sufficient vision during operation increases the dangers of this kind of surgery. In this paper, we propose a hypothesis about replacing surgeon's hand with surgical instrument in esophagectomy. The proposed instrument is one-forth of surgeon's hand volume and it can surround the esophagus radially. So, it would be able to sheer and dissect all the adhesive tissues around the esophagus. For determining possible threshold of causing traumas in delicate tissues during esophagectomy, various tactile sensors can be incorporated into the surgical instrument to detect and control the contact force of the instrument with delicate biological structures. For evaluating the proposed hypothesis, we analyzed the function of the instrument with finite element method and finally we constructed an initial prototype of the designed instrument.

Modeling and simulation of blood flow in a sac-type left ventricular assist device.

Left ventricular assist devices (LVADs) are among the most important mechanical artificial hearts in medical equipment industry. Since the need for heart transplantation is on the rise, there is a requirement for implantable LVADs, which can be safely used for long-term purposes. One of the most promising kinds of these devices is the sac-type LVAD (ST-LVAD) that has the ability to generate pulsatile flow. In this study and for the first time, three different models of ST-LVAD are analyzed numerically. In the first model, the motion of the elastic membrane wall is simplified, while in the second model, the motion is assumed to be wavy. The pressure boundary conditions are added to the second model to allocate for the effect of pressure on the flow pattern, and hence, form the third model. The simulation results of the analyzed models show that in this particular type of LVAD, the viscous term of the applied stress from the fluid on the moving wall is negligible, compared with the pressure term. Additionally, it can be concluded that the motion pattern of the moving wall does not affect the blood flow pattern in a great deal. Furthermore, the inclusion of the fluid pressure in the boundary conditions does not have a major influence on the blood flow pattern.

Elastodynamic analysis of the human aorta and the effect of biomechanical parameters on its behavior.

In this work, a finite element formulation for the analysis of the elastodynamic behavior of the human aorta is presented. In this formulation, a one-dimensional approach was adopted and a comprehensive computer program was written and employed in the mathematical analysis. All the necessary material and geometrical parameters were appropriately incorporated in the simulation. A comparison was made between the simplified elasticity theory and the one proposed in this study using the poroelasticity theory. The effects of certain parameters including the fluid density and the material permeability of the matrix on the behavior of the aortic tissue were investigated. According to these findings, the higher the density of the liquid in the tissue, the more delay will be observed in the resonance frequencies. It was also concluded that in the poroelasticity theory, the resonance frequencies occur at a later stage compared with the elasticity theory. The permeability of liquid into the pores and its damping effect are the two factors that contributed to the delay in the resonance. It was observed that at a frequency of 10 Hz, up to a permeability of about 10(-8) m(4)/N.s, the effect on the magnitude of the amplitude is negligible. However, from this threshold value up to a point at which the permeability is equal to 10(-5) m(4)/N.s, there is a corresponding increase in the amplitude.

Application of artificial neural networks for the estimation of tumour characteristics in biological tissues.

BACKGROUND: Artificial tactile sensing is a method in which the existence of tumours in biological tissues can be detected and computerized inverse analyses used to produce 'forward results'. METHODS: Three feed-forward neural networks (FFNN) have been developed for the estimation of tumour characteristics. Each network provides one of the three parameters of the tumour, i.e. diameter, depth and tumour:tissue stiffness ratio. A resilient back-propagation (RP) algorithm with a leave-one-out (LOO) cross-validation approach is used for training purposes. RESULTS: The proposed inverse approach based on neural networks is a reliable and efficient tool for diagnostic tests in order to accurately estimate the basic parameters of the tumour in the tissue. CONCLUSION: There is a non-linear correlation between the tumour characteristics and their effects on the extracted features. In general, reliable estimation of tumour stiffness is obtained when the depth of tumour is small.