Palpation Simulator Research Articles

Difficulties in using simulation to assess abdominal palpation skills

ObjectivesAbdominal palpation is an essential examination to diagnose various digestive system diseases. This study aimed to develop an objective and standardized test based on abdominal palpation simulators, and establish a credible pass/fail standard of basic competency.MethodsTwo tests were designed using the newly developed Jucheng abdominal palpation simulator (test 1) and the AbSim simulator (test 2), respectively. Validity evidence for both tests was gathered according to Messick’s contemporary framework by using experts to define test content and then administering the tests in a highly standardized way to participants of different experience. Different simulator setups modified by the built-in software were selected from hepatomegaly, splenomegaly, positive McBurney’s sign plus rebound tenderness, gallbladder tenderness (Murphy’s sign), pancreas tenderness, and a normal setup without pathologies, with six sets used in test 1 and five sets used in test 2. Different novices and experienced were included in the tests, and test 1 was also administered to an intermediate group. Scores and test time were collected and analyzed statistically.ResultsThe internal consistency reliability of test 1 and test 2 showed low Cronbach’s alphas of 0.35 and -0.41, respectively. Cronbach’s alpha for palpation time across cases were 0.65 for test 1 and 0.76 for test 2. There was no statistical difference in total time spent and total scores among the three groups in test 1 (P-values (ANOVA) were 0.53 and 0.35 respectively), nor between novices and experienced groups in test 2 (P-values (t-test) were 0.13 and 1.0 respectively). It was not relevant to try to establish pass/fail standards due to the low reliability and lack of discriminatory ability of the tests.ConclusionsIt was not possible to measure abdominal palpation skills in a valid way using either of the two standardized, simulation-based tests in our study. Assessment of the patient’s abdomen using palpation is a challenging clinical skill that is difficult to simulate as it highly relies on tactile sensations and adequate responsiveness from the patients.

Modeling and Simulation of Robotic Palpation to Detect Subsurface Soft Tissue Anomaly for Presurgical Assessment

Abstract Surgical Haptics is an emergent field of research to integrate and advance the sense of robotic touch in laparoscopic tools in robot-assisted minimally invasive surgery. Haptic feedback from the tooltip and soft tissue surface interaction during robotic palpation can be leveraged to detect the texture and contour of subsurface geometry. However, precise force modulation of the robotic palpating probe is necessary to determine stiff inclusions of the anatomy and maneuver successive manipulation tasks during surgery. This paper focuses on investigating the layered deformations associated with different force profiles involved in manipulating the superficial anatomy of soft tissues during dynamic robotic palpation to determine the underlying anomaly. A realistic three-dimensional (3D) cross-sectional soft tissue phantom with anatomical layers and tumor, as an anomaly, is designed, modeled, and analyzed to examine the effects of oriented palpating forces (0–5 N) of a 7 DOF robot arm equipped with a contoured palpation probe. Finite element static structural analysis of oriented robotic palpation on the developed 3D soft tissue phantoms (with and without anomaly) reveals the soft tissue layer deformations and associated strains needed to identify presence of stiffer inclusions or anomaly during Robotic palpation. The finite element analysis study shows that the difference in deformations of soft tissue layers (e.g., underlying myofascial layers) under stiffer inclusions at different force levels can facilitate haptic feedback to acquire information about subsurface tumors. The deformation variations are further compared to assess better palpation orientations for subsurface anomaly detection.

Augmented Reality Application for Simulation of Mamma Palpation

Abstract The teaching of medicine is in a state of flux. New technologies enable students to learn faster and more efficiently than ever before. Especially the possibilities that augmented reality brings with it can be applied very well in this field. The possibility to project additional information directly into the user’s field of vision allows him to perceive additional knowledge without being distracted from the actual work. In this paper, a possibility of training Mamma Palpation is presented, which teaches students the course of action and the detection of possible tumors through virtual points. Through guideline-based interviews, added value for teaching could be highlighted.

73 Engaging youth through bovine reproductive practices

Abstract Two programs have been established at Virginia Tech with the purpose of engaging youth and showcasing agriculture. The Governor’s School for Agriculture (GSA) program began in 2001, and has over 1,850 graduates. High school juniors and seniors from different areas of the Commonwealth’s schools spend time on campus exploring the life sciences. The Virginia 4-H State Congress (4HC) is the premier, statewide annual 4-H event for outstanding teens, providing educational experiences to Virginia teens and helping them develop life skills and leadership abilities. Our extension group has focused on exposing teens enrolled in the GSA and 4HC to beef production, particularly bovine reproduction and reproductive biotechnologies. The 4-hr workshop, titled “Do it yourself cows”, consists of a mixture of in-class presentations and hands-on laboratories relating to bovine reproductive anatomy and physiology and reproductive biotechnologies. The wet-laboratory consists of bovine female reproductive tracts anatomy dissection and artificial insemination and rectal palpation simulation with a mannequin, as well as demonstrations of equipment used in the field including, nitrogen tank for semen storage, ultrasound and microscope visualization of bovine embryos. The GSA “Bovine Reproduction” course is 4 days long and allows for in-depth discussion of factors influencing fertility and case discussions on beef reproductive management. The hands-on portion of this course is similar to the 4HC workshop, however students are able to perform rectal palpation and ultrasonography in cattle. So far, 40 students from the GSA and 80 students from the 4HC (2 GSA, and 4 4HC programs) have graduated in the course. At the completion of both programs, a survey was performed and 100% of the students considered the program positive and gained knowledge and interest in bovine reproduction. Furthermore, 20% of students from the GSA program developed a desire to pursue a career in livestock production, and 92% of 4HC students claimed to have learned information they can apply in their communities. Our data indicate that we were successful in engaging youth in animal agriculture, specifically beef production.

Force quantification and simulation of pedicle screw tract palpation using direct visuo-haptic volume rendering

PurposeWe present a feasibility study for the visuo-haptic simulation of pedicle screw tract palpation in virtual reality, using an approach that requires no manual processing or segmentation of the volumetric medical data set.MethodsIn a first experiment, we quantified the forces and torques present during the palpation of a pedicle screw tract in a real boar vertebra. We equipped a ball-tipped pedicle probe with a 6-axis force/torque sensor and a motion capture marker cluster. We simultaneously recorded the pose of the probe relative to the vertebra and measured the generated forces and torques during palpation. This allowed us replaying the recorded palpation movements in our simulator and to fine-tune the haptic rendering to approximate the measured forces and torques. In a second experiment, we asked two neurosurgeons to palpate a virtual version of the same vertebra in our simulator, while we logged the forces and torques sent to the haptic device.ResultsIn the experiments with the real vertebra, the maximum measured force along the longitudinal axis of the probe was 7.78 N and the maximum measured bending torque was 0.13 Nm. In an offline simulation of the motion of the pedicle probe recorded during the palpation of a real pedicle screw tract, our approach generated forces and torques that were similar in magnitude and progression to the measured ones. When surgeons tested our simulator, the distributions of the computed forces and torques were similar to the measured ones; however, higher forces and torques occurred more frequently.ConclusionsWe demonstrated the suitability of direct visual and haptic volume rendering to simulate a specific surgical procedure. Our approach of fine-tuning the simulation by measuring the forces and torques that are prevalent while palpating a real vertebra produced promising results.

106 Virginia Tech Graduate Extension Scholars program: Artificial insemination course for inmates

Abstract The Graduate Extension Scholar program has the purpose of providing graduate students a unique professional development opportunity to develop high quality outreach programs, where the students actively participate extension and outreach. Weekly seminars are held by the program director and the graduate assistants, where program development and engagement strategies are presented to prepare the scholar. The program has existed since 2014, with 14 scholars participating. The present report is related to a single program during the fall of 2018. An artificial insemination course was taught for inmates with the Virginia Department of Corrections (VDOC). A total of 16 students were taught, being 4 farm employees and 12 inmates from two locations within VDOC. Inmates with minor offenses and good behavior get the opportunity to often work in the prison farms and learn farming as a skill. The objective of the present work was to provide inmates with an extra valuable skill in the farm and improve their work experience. The course was held in the Greenville correction facility for 2 days in the fall of 2018 and consisted of two portions: Hands-on theoretical, and live animal interaction. The theoretical portion was planned to provide students basic knowledge of reproductive anatomy and physiology of the cow, the artificial insemination (AI) technique, and proper semen handling. This portion consisted of a power point presentation and practice of technique on tracts from slaughter animals and simulation of rectal palpation with a mannequin (Breed’n Betsy). During the animal interaction portion of the class, students were able to practice the technique on culled cows and were asked to perform the technique correctly on 3 different animals. At the completion of the program, a survey was performed and all students considered the program positive and claimed to have gained knowledge and become confident with the technique.

140 Virginia Tech Graduate Extension Scholars program: Report of a scholar

Abstract The Graduate Extension Scholar program has the purpose of providing graduate students a unique professional development opportunity to develop high quality outreach programs, where the students actively participate in youth and adult education. The graduate scholar is assigned to an extension agent and a high school teacher. The program director and the graduate assistants hold weekly seminars, where program development and engagement strategies are presented to prepare the scholar for the task. The program has existed since 2014, with 14 scholars participating. The present report is related to a single program during the fall of 2017. A beef cattle reproduction symposium of a total of 5 lectures were taught for juniors and seniors in the Holston High School’s (Damascus, VA) agricultural class. The lectures were planned to provide the students both theoretical and hands-on activities on the topic of beef cattle reproduction. The theoretical portion of the class consisted of PowerPoint presentations on anatomy and physiology, as well as applied topics, such as factors influencing fertility and discussion case studies. The hands-on portion of the class consisted of activities related to reproduction, such as bovine female reproductive tracts anatomy and artificial insemination, simulation of rectal palpation with a mannequin (Breed’n Betsy) and demonstration of materials and technologies used in the field (nitrogen tank for semen storing and ultrasound). In addition, student assessment of knowledge was conducted and scores were used for the agricultural class final grade. Final grade mean for the class was 95. Finally, a field trip was organized to a local farm where students were able to perform rectal palpation and ultrasound in cattle. At the completion of the program, a survey was performed and all students considered the program positive and claimed to have gained knowledge of the subject.

A tumour perception system based on a multi-layer mass-spring model

The virtual reality (VR) has been utilised in the preoperative planning of tumour surgery because it enables surgeons to touch and operate on tumour in a virtual environment. This paper proposes a virtual tumour perception system for preoperative tumour surgery planning. The system is based on a novel multi-layer mass-spring model, which consists of connected springs in series. The basic parameters of springs are equal ratio sequence. The core parameter shear modulus of springs can be dynamically adjusted according to the biological properties of soft tissue in clinical applications to simulate tissue heterogeneity. A palpation simulation algorithm is designed to help users to perceive the tumours. Two validation experiments are carried out: model accuracy experiment and practical perception experiment. Experiments indicate that the proposed model faithfully mimics actual clinical tumour, which is more accurate compared with models simulated by other systems.

A tumour perception system based on a multi-layer mass-spring model

The virtual reality (VR) has been utilised in the preoperative planning of tumour surgery because it enables surgeons to touch and operate on tumour in a virtual environment. This paper proposes a virtual tumour perception system for preoperative tumour surgery planning. The system is based on a novel multi-layer mass-spring model, which consists of connected springs in series. The basic parameters of springs are equal ratio sequence. The core parameter shear modulus of springs can be dynamically adjusted according to the biological properties of soft tissue in clinical applications to simulate tissue heterogeneity. A palpation simulation algorithm is designed to help users to perceive the tumours. Two validation experiments are carried out: model accuracy experiment and practical perception experiment. Experiments indicate that the proposed model faithfully mimics actual clinical tumour, which is more accurate compared with models simulated by other systems.

ЗАСТОСУВАННЯ МЕДИЧНОГО НАВЧАЛЬНОГО ТРЕНАЖЕРА ПРИ ЗАСВОЄННІ ПРАКТИЧНИХ НАВИЧОК ІЗ ДИСЦИПЛІНИ “ХІРУРГІЯ”

Мета дослідження – покращити оволодіння практичними навичками та методиками студентів медичних факультетів вищих медичних навчальних закладів ІV рівня акредитації при вивченні дисципліни “Хірургія”.Матеріали та методи дослідження. Згідно з Тимчасовою наскрізною робочою програмою для підготовки студентів медичних факультетів вищих медичних навчальних закладів ІV рівня акредитації та підготовки фахівців освітньо-кваліфікаційного рівня “Спеціаліст” (Київ, 2015), для оволодіння практичними навичками та методиками, в переліку практичних навичок, якими повинні оволодіти студенти ІV–VI курсів медичного факультету при вивченні дисципліни “Хірургія” зазначено, що, вони повинні засвоїти та вивчити практичні методики та навички з “Проктології”.Результати й обговорення. З метою оволодіння зазначеними практичними навичками на кафедрі хірургії № 2 та кардіохірургії на базі віварію створено навчально-тренувальний центр з “Хірургії” для навчання студентів ІV–VI курсів медичного факультету. Прослідковані переваги використання навчального тренажера в якісному засвоєнні студентами пальцевого обстеження прямої кишки. При виконанні пальпації на тренажері зі вставкою нормальної слизової оболонки у чоловіків та жінок, студенти змогли краще зрозуміти та відчути тактильну різницю під час виконання методики в порівняльному аспекті.Висновки. Застосування медичного навчального тренажеру пальпації пухлин прямої кишки дає можливість студентам набути практичні навики з проктології та систематично їх удосконалювати. З нашого досвіду, відпрацювання практичних навиків на медичному навчальному тренажері викликає надзвичайно живий інтерес, збільшує мотивацію студентів до поглиблення знань з хірургії, дає можливість кожному проявити свої знання та навички.

Techniques and Devices Used in Palpation Simulation with Haptic Feedback

Palpation exam is a procedure in which a healthcare professional presses a specific region of a patient’s body with the fingers in order to detect the presence of features and abnormalities under the skin. A simulator that aids the training of this procedure may contribute to the learning of the technique and the improvement of its implementation in real patients. This article presents a systematic review conducted in order to assess the state of the art of the simulation of the palpation procedure, providing a categorization of techniques and approaches used in systems with haptic feedback. The results indicate that there are existing gaps concerning the accessibility of the haptic devices, innovative methods to calculate force feedback and deformation caused by haptic devices, and user experience improvement, since most of the studies consider only one point of contact, which can limit the simulation realism.

Canine Prostate Palpation Simulator as a Teaching Tool in Veterinary Education.

Adult dogs, especially elderly ones, are commonly affected by prostate diseases. Performing rectal palpation during physical examination in dogs is important in small animal clinical diagnosis. Prostate palpation training allows students to learn how to correctly introduce the finger into the rectum and identify the location, size, symmetry, and consistency of the prostate. Alternative methods are needed to teach this technique without using live dogs. Thus, our aim was to develop a canine prostate palpation simulator to provide students with the opportunity to learn the prostate palpation technique in dogs and to assess their opinion of this simulator as a teaching tool. The inner part of the canine mannequin contains a rotation system with three types of prostates that can be exchanged during the exam. Of the 64 participating students, 81% had never used alternative methods and 92.2% had never performed any prostatic palpation. According to the students' opinions, performing a clinical examination on a simulator allowed them to be prepared and familiarized with the palpation technique. They felt satisfied learning a practical method in a harmless way. Both the 3R (replacement, reduction, and refinement) and dog welfare principles were present in most of the students' concerns. We conclude that the simulator can help students to develop clinical skills for prostate palpation in dogs.

2A2-K05 空気式多自由度アクチュエータを用いた乳がん触診シミュレータ

Among the Japanese women, the disease rate of breast cancer became the most highest one, over ahead of that of stomach cancer around 1997. However, if the cancer is still remained at a small part of breast, thr existence rate is reported to be 92 % that is pretty higher than that of another cancer. It also shows the importance of early detection. Detection of breast cancer is implemented by both palpation diagnosis and Mammography (X-ray photograph of breast). We focused on a palpation diagnosis which requires for a medical doctor to have a highly skilled technique. From a view of medical education, there is strong need for palpation simulator and some equipment using robot technology or VR one are being developed. Actually, some palpation simulators has already come onto the market, but they don't have function to adjust size of position or magnitude of stiffness of lump. In this study, we aim at developing a palpation simulator which has pneumatic cylinder placed in orthogonal axis and realizing high functional palpation diagnosis.

Palpation simulator with stable haptic feedback

Background: The main difficulty in constructing palpation simulators is to compute and to generate stable and realistic haptic feedback without vibration. When a user haptically interacts with highly non-homogeneous soft tissues through a palpation simulator, a sudden change of stiffness in target tissues causes unstable interaction with the object. Material and methods: We propose a model consisting of a virtual adjustable damper and an energy measuring element. The energy measuring element gauges energy which is stored in a palpation simulator and the virtual adjustable damper dissipates the energy to achieve stable haptic interaction. Results: To investigate the haptic behavior of the proposed method, impulse and continuous inputs are provided to target tissues. If a haptic interface point meets with the hardest portion in the target tissues modeled with a conventional method, we observe unstable motion and feedback force. However, when the target tissues are modeled with the proposed method, a palpation simulator provides stable interaction without vibration. Conclusion: The proposed method overcomes a problem in conventional haptic palpation simulators where unstable force or vibration can be generated if there is a big discrepancy in material property between an element and its neighboring elements in target tissues.

Multi-fingered haptic palpation using pneumatic feedback actuators

This paper proposes a multi-fingered palpation method which employs pneumatic haptic feedback actuators allowing users to experience haptic sensations at multiple fingers while carrying out remote soft tissue palpation. Pneumatic actuators are used to vary the stress on the user's fingertips in accordance with the tissue stiffness, experienced during manual palpation. The proposed method reduces actuator elements compared to tactile actuators and provides more information than single-point force feedback. The results of our finite element analysis have proven that our pneumatic haptic feedback device can recreate the contact stress between fingertip and soft tissue during palpation. The accuracy (96.8% vs. 93.3%) and time-efficiency (4.6s vs. 8.3s) advantages of using three-fingered over single-fingered palpation have been confirmed in our user study results of stiffness levels discrimination. Relatively good tumor detection sensitivities have been demonstrated by the palpation user study which has showed a direct correlation between tumor size and detection sensitivity and has further proven the efficiency of the proposed actuator and multi-fingered palpation method for tumor detection in palpation simulation.

Use of Breast Simulators Compared with Standardized Patients in Teaching the Clinical Breast Examination to Medical Students

Simulators have replaced some standardized patients in medical student teaching, and their use seems to decrease anxiety related to the clinical breast examination (CBE). We compared learning the CBE on a breast palpation simulator with learning on a standardized patient with respect to skill acquisition and comfort level. At Penn State College of Medicine, the class of 2008 (historical control group, n = 113) learned the CBE on a standardized patient, whereas the class of 2009 (experimental group, n = 131) learned on the breast palpation simulator. We used measures of the process (conducting the CBE) and measures of the outcome (examination scores and detection of abnormal findings). During their third-year surgical clerkship, students in both groups completed a questionnaire reporting the number of CBEs performed and confidence in performing the CBE. The students then performed an observed examination on the simulator, and the number of positive findings detected was recorded. The mean number of positive findings was compared between groups, and an economic analysis was conducted. The experimental group had a significantly higher mean examination score than the historical control. In subgroups, this difference was significant for those who reported performing 0-5 clinical examinations but for not those who had performed >6 examinations. On individual items, the experimental group scored significantly higher in examining for neck nodes, nipple retraction, skin changes, and axillary evaluation. The 2 groups did not differ significantly in the mean number of positive findings detected or in ratings of comfort level. Medical students who learned the CBE on breast palpation simulators performed as well or better than those who learned on standardized patients; however, a subgroup analysis revealed that the benefit was limited to students with less clinical experience.

Teaching bovine abdominal anatomy: Use of a haptic simulator

Traditional methods of teaching anatomy to undergraduate medical and veterinary students are being challenged and need to adapt to modern concerns and requirements. There is a move away from the use of cadavers to new technologies as a way of complementing the traditional approaches and addressing resource and ethical problems. Haptic (touch) technology, which allows the student to feel a 3D computer-generated virtual environment, provides a novel way to address some of these challenges. To evaluate the practicalities and usefulness of a haptic simulator, first year veterinary students at the Royal Veterinary College, University of London, were taught basic bovine abdominal anatomy using a rectal palpation simulator: "The Haptic Cow." Over two days, 186 students were taught in small groups and 184 provided feedback via a questionnaire. The results were positive; the majority of students considered that the simulator had been useful for appreciating both the feel and location of key internal anatomical structures, had helped with their understanding of bovine abdominal anatomy and 3D visualization, and the tutorial had been enjoyable. The students were mostly in favor of the small group tutorial format, but some requested more time on the simulator. The findings indicate that the haptic simulator is an engaging way of teaching bovine abdominal anatomy to a large number of students in an efficient manner without using cadavers, thereby addressing some of the current challenges in anatomy teaching.

Real-time deformable models of non-linear tissues by model reduction techniques

In this paper we introduce a new technique for the real-time simulation of non-linear tissue behavior based on a model reduction technique known as proper orthogonal (POD) or Karhunen–Loève decompositions. The technique is based upon the construction of a complete model (using finite element modelling or other numerical technique, for instance, but possibly from experimental data) and the extraction and storage of the relevant information in order to construct a model with very few degrees of freedom, but that takes into account the highly non-linear response of most living tissues. We present its application to the simulation of palpation a human cornea and study the limitations and future needs of the proposed technique.

A new soft-tissue indentation model for estimating circular indenter ‘force—displacement’ characteristics

Models that predict soft-tissue indentation forces have many important applications including estimation of interaction forces, palpation simulation, disease diagnosis, and robotic assistance. In many medical applications such as rehabilitation, clinical palpation, and manipulation of organs, characterizing soft-tissue properties mainly depends on the accurate estimation of indentation forces. A new indentation model for estimating circular indenter 'force-displacement' characteristics is presented in this paper. The proposed model is motivated by a 'force-displacement' soil-tool model and is computationally efficient. The main feature of the proposed model is that it can be used to predict the force variations for a variety of tools without the need for retuning the model parameters for each tool. A six-degree-of-freedom robot manipulator with force and position sensors is used to validate the indentation model. Measured force versus tool displacement data for lamb liver and kidney, for a variety of tool diameters, are presented and compared with the forces predicted by the model, showing good agreement (RMS error < 8 per cent).

Real-time area-based haptic rendering and the augmented tactile display device for a palpation simulator

Although people usually contact a surface with some area rather than a point, most haptic devices allow a user to interact with a virtual object at one point at a time and likewise most haptic rendering algorithms deal with such situations only. In a palpation procedure, medical doctors push and rub the organ's surface, and are provided the sensation of distributed pressure and contact force (reflecting force) for discerning doubtable areas of the organ. In this paper, we suggest real-time area-based haptic rendering to describe distributed pressure and contact force simultaneously, and present a haptic interface system to generate surface properties in accordance with the haptic rendering algorithm. We represent the haptic model using the shape-retaining chain link (S-chain) framework for a fast and stable computation of the contact force and distributed pressure from a volumetric virtual object. In addition, we developed a compact pin-array-type tactile display unit and attached it to the PHANToMTM haptic device to complement each other. For the evaluation, experiments were conducted with non-homogenous volumetric cubic objects consisting of approximately 500 000 volume elements. The experimental results show that compared to the point contact, the area contact provides the user with more precise perception of the shape and softness of the object's composition, and that our proposed system satisfies the real-time and realism constraints to be useful for a virtual reality application.