Needle Insertion Force Research Articles

Behavior of Tip-Steerable Needles in Ex Vivo and In Vivo Tissue

Robotic needle steering is a promising technique to improve the effectiveness of needle-based clinical procedures, such as biopsies and ablation, by computer-controlled, curved insertions of needles within solid organs. In this paper, we explore the capabilities, challenges, and clinical relevance of asymmetric-tip needle steering through experiments in ex vivo and in vivo tissue. We evaluate the repeatability of needle insertion in inhomogeneous biological tissue and compare ex vivo and in vivo needle curvature and insertion forces. Steerable needles curved more in kidney than in liver and prostate, likely due to differences in tissue properties. Pre-bent needles produced higher insertion forces in liver and more curvature in vivo than ex vivo. When compared to straight stainless steel needles, steerable needles did not cause a measurable increase in tissue damage and did not exert more force during insertion. The minimum radius of curvature achieved by prebent needles was 5.23 cm in ex vivo tissue, and 10.4 cm in in vivo tissue. The curvatures achieved by bevel tip needles were negligible for in vivo tissue. The minimum radius of curvature for bevel tip needles in ex vivo tissue was 16.4 cm; however, about half of the bevel tip needles had negligible curvatures. We also demonstrate a potential clinical application of needle steering by targeting and ablating overlapping regions of cadaveric canine liver.

A realistic deformable prostate phantom for multimodal imaging and needle‐insertion procedures

Phantoms are a vital step for the preliminary validation of new image-guided procedures. In this paper, the authors present a deformable prostate phantom for use with multimodal imaging (end-fire or side-fire ultrasound, CT and MRI) and more specifically for transperineal or transrectal needle-insertion procedures. It is made of soft polyvinyl chloride (PVC) plastic and includes a prostate, a perineum, a rectum, a soft periprostatic surrounding and embedded targets for image registration and needle-targeting. Its main particularity is its realistic deformability upon manipulation. After a detailed manufacturing description, the imaging and mechanical characteristics of the phantom are described and evaluated. First, the speed of sound and stress-strain relationship of the PVC material used in the phantom are described, followed by an analysis of its storage, imaging, needle-insertion force, and deformability characteristics. The average speed of sound in the phantom was measured to be 1380 ± 20 m/s, while the stress-strain relationship was found to be viscoelastic and in the range of typical prostatic tissues. The mechanical and imaging characteristics of the phantom were found to remain stable at cooler storage temperatures. The phantom had clearly distinguishable morphology in all three imaging modalities, with embedded targets that could be precisely segmented, resulting in an average US-CT rigid registration error of 0.66 mm. The mobility of the phantom prostate upon needle insertion was between 2 and 4 mm, with rotations between 0° and 2°, about the US probe head. The phantom's characteristics compare favorably with in vitro and in vivo measurements found in the literature. The authors believe that this realistic phantom could be of use to researchers studying new needle-based prostate diagnosis and therapy techniques.

햅틱 기반 정맥주사 시뮬레이터를 위한 생체조직 바늘 삽입력

Haptics and virtual reality are rapidly growing technologies in medical fields. Physicians and nurses can benefit from medical simulation via training and acquire surgical and clinical techniques. In this paper, the research on needle insertion force of biological tissue for haptic based intravenous injection simulator was carried out. We built the setup for needle insertion (intravenous injection) experiments and performed the experiments on live pigs. The force responses against needle insertion were measured using the experimental setup. In addition, the modeling of needle insertion force was carried out with the experimental results and numerical models via nonlinear least-squares method. The results presented in this paper indicate that the developed models can be applied not only to estimate the force feedback during intravenous injection procedure but also to improve the overall training quality of the medical simulator.

Modeling cutting edge geometry for plane and curved needle tips

Hollow needles are commonly used in many areas of medicine, yet there has been limited research on needle tip geometry. A better understanding of needle tip geometry can lead to the creation of an optimized needle tip geometry design which would greatly benefit the procedure of biopsy, where a needle is used to cut and remove tissue from the body. The present research develops mathematical models to calculate the inclination and rake angle along the cutting edges of needle tips generated by curved surfaces. The parameters of needle insertion length and inner needle tip surface area are also examined. Needle insertion force is predicted based on needle geometry and calculated for curved and flat plane tip needles. A concave needle produced lower cutting forces than the convex and bias bevel needles. It is found that utilizing curved surface needle tip geometry, as opposed to flat plane geometry, allows for greater control in varying rake and inclination angles on the needle. This greater flexibility allows for more control in designing an optimized needle tip.

Insertion force in manual and robotic corneal suturing

Due to differences in corneal grafting microsurgery between manual and robotic suturing, new challenges have arisen in testing the insertion force and torque of corneal tissue acting on suturing needles in order to guarantee successful completion of surgical procedures. In order to measure the force during the insertion operation, from the needle entering the cornea through the entry point until the puncturing of the exit point along the circular trajectory, a force measurement system was established, including fresh porcine cornea, a corneal-suturing robot, a circular needle, a micro-forceps manipulator with a force transducer, a computer with a data acquisition board and a medical microscope. The force values in the needle coordinate frames were obtained on the basis of a sensor coordinate frame through D-H coordinate transformation, and an index is proposed here to evaluate the insertion performance. Experiments on both manual and robotic suturing were carried out for comparison. The scale and changes of the needle insertion force were obtained using two different suturing methods. The maximal tangent force in robotic suturing is a little larger than in manual suturing, and the maximal resultant force in robotic suturing is somewhat smaller. Although the difference is not very significant, robotic suturing performs in a more stable way. Moreover, the performance evaluation index M(dmax) (the maximum of square root of the quadratic sum of torque components M(OX) and M(OY)) in robotic suturing is much smaller than that in manual suturing. The force measurement system has been verified to be feasible through experimentation. Compared with conventional manual surgery, robotic suturing has some advantages: more stable suturing, smaller distortion torque and fewer invasions to the corneal tissue, showing that its application in minimally invasive surgery is practical.

MO‐G‐BRA‐03: The Study of Needle Insertion Force and Its Effect on Deflection in Brachytherapy

Purpose:To quantify needle deflection and study the relationship between the deflection and the force that is produced during insertion into a homogeneous phantom. A proposed model can be used to estimate needle deflection using the force that occurs on the needle during insertion into the phantom. Methods: A model was developed that correlates needle insertion force to needle deflection. Experiments were performed to validate this model. Using a needle grid, a 30° bevel trocar was inserted bevel up and then bevel right into two separate areas within a homogeneous phantom. During and after needle insertion, a force dynamometer was used to measure the y‐directional force data. After insertion and obtaining force data, needle deflection was quantified using a measurement apparatus that consisted of a digital depth gauge and two datum surfaces. A second experiment used a linear stage to bend a trocar inside the phantom, while force and needle deflection were measured. Using Matlab, the y‐force directional data of the bevel up and bevel right were analyzed. After matching up peeks of both data sets, the force of interest was obtained via bevel up data minus bevel right data. Results: With a sample size of n = 3 for the bevel up and bevel right experiments, a force reading of 0.23 ± 0.04 N and trocar deflection of 3.63 ± 0.5 mm were obtained. Similarly, the linear stage experiment was performed to obtain the Youngˈs modulus of the needle and phantom system. The deflection and force results validate the model created, providing the experimentally determined Youngˈs modulus of the needle and phantom system. Conclusions: Two sets of experimental apparatus was constructed to obtain force and deflection data. A model was developed to correlate the needle force to needle deflection and validated with experimental data.

High-field MRI-compatible needle placement robot for prostate interventions.

This paper presents the design of a magnetic resonance imaging (MRI) compatible needle placement system actuated by piezoelectric actuators for prostate brachytherapy and biopsy. An MRI-compatible modular 3 degree-of-freedom (DOF) needle driver module coupled with a 3-DOF x-y-z stage is proposed as a slave robot to precisely deliver radioactive brachytherapy seeds under interactive MRI guidance. The needle driver module provides for needle cannula rotation, needle insertion and cannula retraction to enable the brachytherapy procedure with the preloaded needles. The device mimics the manual physician gesture by two point grasping (hub and base) and provides direct force measurement of needle insertion force by fiber optic force sensors. The fabricated prototype is presented and an experiment with phantom trials in 3T MRI is analyzed to demonstrate the system compatibility.

Hollow needle tissue insertion force model

In this study, a mechanistic approach using elementary cutting tool (ECT) edges of varying inclination and normal rake angles is demonstrated to be capable to predict hollow needle insertion force. A needle force model is developed and validated for the specific case of 11 gauge two-plane symmetric needles. Blades of varying inclination and rake angles are inserted into bovine liver to determine the specific force of initial tissue cutting for the given edge geometry; this information is applied to the ECT force model which is validated against experimental force results of hollow needles inserted into bovine liver.

A real‐time prostate cancer detection technique using needle insertion force and patient‐specific criteria during percutaneous intervention

In this article, the authors present a novel real-time cancer detection technique by using needle insertion forces in conjunction with patient-specific criteria during percutaneous interventions. Needle insertion experiments and pathological analysis were performed for developing a computer-aided detection (CAD) model. Backward stepwise regression method was performed to identify the statistically significant patient-specific factors. A baseline force model was then developed using these significant factors. The threshold force model that estimated the lower bound of the cancerous tissue forces was formulated by adding an adjustable classifier to the baseline force model. Tradeoff between sensitivity and specificity was obtained by varying the threshold value of the classifier, from which the receiver-operating characteristic (ROC) curve was generated. Sequential quadratic programming was used to optimize the CAD model by maximizing the area under the ROC curve (AUC) using a set of model-training patient data. When the CAD model was evaluated using an independent set of model-validation patient data, an AUC of 0.90 was achieved. The feasibility of cancer detection in real time during percutaneous interventions was established.

A real‐time prostate cancer detection technique using needle insertion force and patient‐specific criteria during percutaneous intervention

In this article, the authors present a novel real-time cancer detection technique by using needle insertion forces in conjunction with patient-specific criteria during percutaneous interventions. Needle insertion experiments and pathological analysis were performed for developing a computer-aided detection (CAD) model. Backward stepwise regression method was performed to identify the statistically significant patient-specific factors. A baseline force model was then developed using these significant factors. The threshold force model that estimated the lower bound of the cancerous tissue forces was formulated by adding an adjustable classifier to the baseline force model. Trade-off between sensitivity and specificity was obtained by varying the threshold value of the classifier, from which the receiver-operating characteristic (ROC) curve was generated. Sequential quadratic programming was used to optimize the CAD model by maximizing the area under the ROC curve (AUC) using a set of model-training patient data. When the CAD model was evaluated using an independent set of model-validation patient data, an AUC of 0.90 was achieved. The feasibility of cancer detection in real time during percutaneous interventions was established.

A Real-time Cancer Sensing Technique using Needle Insertion Forces and Patient-specific Criteria during Percutaneous Intervention

A Real-time Cancer Sensing Technique using Needle Insertion Forces and Patient-specific Criteria during Percutaneous Intervention

Analysis for the epidural needle insertion force against porcine bone

Analysis for the epidural needle insertion force against porcine bone

Needle insertion into soft tissue: A survey

Needle insertion in soft tissue has attracted considerable attention in recent years due to its application in minimally invasive percutaneous procedures such as biopsies and brachytherapy. This paper presents a survey of the current state of research on needle insertion in soft tissue. It examines the topic from several aspects, e.g. modeling needle insertion forces, modeling tissue deformation and needle deflection during insertion, robot-assisted needle insertion, and the effect of different trajectories on tissue deformation. All studies show that the axial force of a needle during insertion in soft tissue is the summation of different forces distributed along the needle shaft such as stiffness force, frictional force and cutting force. Some studies have modeled these forces. The force data in some procedures is used for identifying tissue layers as the needle is inserted or for path planning. Needle deflection and tissue deformation are major problems for accurate needle insertion and attempts have been made to model them. Using current models several insertion techniques have been developed which are briefly reviewed in this paper.

In vivo motion and force measurement of surgical needle intervention during prostate brachytherapy

In this paper, we present needle insertion forces and motion trajectories measured during actual brachytherapy needle insertion while implanting radioactive seeds in the prostate glands of 20 different patients. The needle motion was captured using ultrasound images and a 6 degree-of-freedom electromagnetic-based position sensor. Needle velocity was computed from the position information and the corresponding time stamps. From in vivo data we found the maximum needle insertion forces to be about 15.6 and 8.9 N for 17 gauge (1.47 mm) and 18 gauge (1.27 mm) needles, respectively. Part of this difference in insertion forces is due to the needle size difference (17G and 18G) and the other part is due to the difference in tissue properties that are specific to the individual patient. Some transverse forces were observed, which are attributed to several factors such as tissue heterogeneity, organ movement, human factors in surgery, and the interaction between the template and the needle. However, theses insertion forces are significantly responsible for needle deviation from the desired trajectory and target movement. Therefore, a proper selection of needle and modulated velocity (translational and rotational) may reduce the tissue deformation and target movement by reducing insertion forces and thereby improve the seed delivery accuracy. The knowledge gleaned from this study promises to be useful for not only designing mechanical/robotic systems but also developing a predictive deformation model of the prostate and real-time adaptive controlling of the needle.

Interactive Simulation of Needle Insertion Models

A novel interactive virtual needle insertion simulation is presented. The simulation models are based on measured planar tissue deformations and needle insertion forces. Since the force-displacement relationship is only of interest along the needle shaft, a condensation technique is shown to reduce the computational complexity of linear simulation models significantly. As the needle penetrates or is withdrawn from the tissue model, the boundary conditions that determine the tissue and needle motion change. Boundary condition and local material coordinate changes are facilitated by fast low-rank matrix updates. A large-strain elastic needle model is coupled to the tissue models to account for needle deflection and bending during simulated insertion. A haptic environment, based on these novel interactive simulation techniques, allows users to manipulate a three-degree-of-freedom virtual needle as it penetrates virtual tissue models, while experiencing steering torques and lateral needle forces through a planar haptic interface.

SU‐FF‐T‐204: In Vivo Force‐Torque Measurement During Prostate Brachytherapy

Purpose: The main goal of this study is to measure the needle insertion force/torque (F/T), velocity/ acceleration (V/A), and tissue/organ deformation during actual brachytherapy procedures in the operating room (OR). These in vivo data will guide the design of a Robot‐Assisted Platform for Intratumoral Delivery (RAPID) system. Method and Materials: We have acquired F/T and V/A data from actual patients and a single surgeon placing brachytherapy needles in the OR using a hand‐held adapter equipped with a 6 degree‐of‐freedom (DOF) F/T sensor (Nano25™). During this in vivo measurement, the needle progression into the soft tissue was registered using ultrasound (US) imaging technique. A 6 DOF electromagnetic (EM)‐based position sensor (miniBIRD®) was attached to the hand‐held adapter to measure 3D position and orientation of the hand‐held adapter. Results: The in vivo data reveals that maximum needle insertion force is about 18N, velocity is about 72cm/s, and acceleration is about 3000cm/s2. This relatively high acceleration may have some implications on the inertia force, which may help the surgeon in needle insertion. We observed significant transverse force (about 1.7N). From in vitro data it was observed that the force and torque during robotic needle insertion in animal soft tissues were significantly smaller as compared to that for humans. Conclusion: Additional in vivo data are being collected from different patients to study the effects of patient specific criteria such as age, height, ethnicity, body mass index (BMI), prostate specific agent (PSA) value, special anatomy, previous treatment, etc. on needle insertion force/torque and tissue deformation. Since frequent in vivo data collection and experimentation are impractical, we will use these data to determine the soft animal tissues and soft materials which have close resemblance to human tissues.

An investigation of the force-time characteristics of needle insertions into Isobutene-Isoprene (Butyl) rubber bungs used in the pharmaceutical industry

For reasons of hygiene, the preparation and parenteral administration of drugs utilises a fresh sterile needle for each injection. Automated systems, where the drug is prepared for later administration, are not likely to suffer from biological cross-contamination and thus needles may be utilised for multiple insertions, providing enhanced cost efficiency. In order to assess the optimum needle life, an experiment was conducted to investigate the change in the force required to effect penetration, into isobutene-isoprene rubber bungs, over a number of insertions. Similarities between the injection process and that of metal die blanking have been noted, extending to the design of the needle. The experiments were conducted in an automated manner; a traversing mechanism provided the means of needle insertion and resultant forces were measured using a load cell. Force-time signatures, captured on a Digital Storage Oscilloscope, were transmitted to a microcomputer for incorporation into result documentation and disk storage. The characteristic signatures have been shown to demonstrate similarities to those of die blanking, thus vindicating the chosen model. Analysis of the insertion impulse, or change in momentum, as it varied with the number of insertions was expected to provide a measure of 'bluntness'. This is confirmed in the analysis of the initial small scale test results.