Medical Needle Research Articles

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver.

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip's spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip's spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.

Geometry-Based Model for U-Shaped Strain Gauges on Medical Needles.

The knowledge of needle location during insertions is essential for the success of interventional radiology procedures. As the needle is susceptible to undergo deformations during its insertion into tissues, several methods have been proposed to monitor the needle deformed shape. Thus, instrumented needles with U-shaped strain gauges are currently being developed to reconstruct the shape of the needle from gauge acquisitions. These acquisitions are used in combination with gauge model to obtain estimate of the strain of the needle. The current modeling is limited as it does not consider the geometry of the gauge. This paper introduces a more complete model for U-shaped strain gauge which, unlike the current model, takes into account the width of the gauge. Thus, the impact of width modeling on the strain estimate can be measured and used to improve strain estimation accuracy. Results with real characteristics of instrumented needle devices show that the differences of strain estimate are around few percents. Finally, by taking into account the width and the length of the gauge our model includes the effets of the gauge size on the strain estimation and makes the miniaturization of the gauge less necessary.

Cylinder-type fiber-optic Vernier probe based on cascaded Fabry-Perot interferometers with a controlled FSR ratio.

We designed a cylinder-type fiber-optic Vernier probe based on cascaded Fabry-Perot interferometers (FPIs) in this paper. It is fabricated by inserting a short single-mode fiber (SMF) column into a large-aperture hollow-core fiber (LA-HCF) with an internal diameter of 150µm, which structures a length adjusted air microcavity with the lead-in SMF inserted into the LA-HCF from the other end. The length of the SMF column is 537.9µm. By adjusting the distance between the SMF column and the lead-in SMF, the spectral change is displayed intuitively, and the Vernier spectra are recorded and analyzed. In sensitivity analysis, the probe is encapsulated in the medical needle by ultraviolet glue as a small body thermometer when the length of the air microcavity is 715.5µm. The experiment shows that the sensitivity of the Vernier envelope is 12.55 times higher than that of the high-frequency comb. This design can effectively reduce the preparation difficulty of the optical fiber Vernier sensor based on cascaded FPIs, and can expand the applied fields by using different fibers and materials.

Piezoresistif microsensors for an instrumented medical needle for its real time monitoring in a microlocalization tool

Because today a physician has no reliable tool to monitor a medical needle, when he inserted it into the human body, this paper deals with an instrumented medical needle, which can be monitored in real time during its insertion in a human body. The final goal of this work is to fabricate a prototype to integrate it into a microlocalization tool. After an introduction, the current practices are given in the domain of the interventional radiology. Then, a summary report of the previous works is presented to give the context. The last microfabrication is described with the results of the experimentations of the new prototype. Then, the connecting tracks are designed and fabricated, in the way to connect the microgauges at the proximal extremity of the needle. So, a microconnector is designed to connect the microgauges to a microlocalization system. At the end of the paper, the short-term perspectives are given. The novelty in this work is that the microfabrications are processed on an unconventional substrate in a clean room (curved surface and stainless steel).

Effect of working gas composition in medical needle sharpening by ion beam sputtering

The sharpness of cutting edges and apexes is crucial in the performance of various medical devices. A method of medical needle finishing, consisting of large area ion beam sputtering, is introduced and studied. Significant deburring, edge sharpening and surface modification of the needles is demonstrated by an experiment. The influences of working gas composition and total ion fluence on the resulting needle properties are emphasized. It was shown that the utilization of an Ar/dry air mixture (37/6) resulted in a significant improvement in surface morphology, compared to pure Ar sputtering. The effect of gas composition is discussed in terms of concurrent material sputtering and chemisorption of reactive species. Needle sharpening aspects studied using microscopy techniques were confirmed by measuring the force required to push a needle through a plastic film. The puncture force of an as-grinded needle was reduced by ∼50% by means of the reported method.

Investigations into insertion force of electrochemically micro-textured hypodermic needles

Electrochemical micro-machining (ECMM) is being a widely used process for replicating multiple micro-structures for micro-texturing due to its heat-free and zero tool wear processing. This paper outlines an experimental study of the tribological behavior of medical hypodermic needles. The real surface contact area of textured needles is calculated and related to insertion force. Insertion force of textured needles is investigated by puncturing and inserting in a hydrogel sample with and without castor oil. An electrochemical micro-machining process is extended for machining of micro-dimples, circular micro-grooves, and linear micro-channels on curved metallic surfaces for creating micro-textures. Insertion force of micro-textured needle is recorded using a load cell, and comparison of it with untextured needles shows the significance of micro-textures. From the experimental study, it is witnessed that micro-textures developed on the needle decreased the insertion force and changed the behavior of fracturing of the hydrogel as compared to the needle without textures. The needle with circular micro-channels (grooves) confirmed the minimum insertion force compared to other micro-textured needles. Reduction in insertion force with respect to micro-dimples, parallel micro-channels, and circular micro-channels are 5.6, 25.5, and 37.8%, respectively. Calculation and analysis of surface area in all the three micro-textured needles support the reason of reducing the force in the case of circular micro-channels. In the case of circular micro-channels, contact area decreases more and fracture in the lateral direction is minimal; hence, insertion force recorded is minimum.

A new method for evaluating the normal rake angle and inclination angle on medical needles.

Hollow needles are the most frequently used medical equipment. The design of a hollow needle that best enables medical procedures requires a better understanding of needle tip geometry. Calculating the cutting angles of a needle for a complex surface topology is difficult. This article proposes a new method based on non-Euclidean geometry for the analysis of biopsy needle tip. The method can be used to calculate the cutting angles on any pipe needle. To verify the validity of this method, the normal rake angle and inclination angle on four types of needles (bias bevel needle, cylinder surface needle, curved surface needle and Cournand-type needle) were investigated. It was found that calculation of the cutting angles was simple and convenient using this method, especially for the curved surface needles. Images of the cutting angles from the Cournand-type needles revealed that the smaller bevel angle [Formula: see text] resulted in a higher normal rake angle [Formula: see text] and inclination angle [Formula: see text]. As [Formula: see text] increased, the range of the normal rake angle [Formula: see text] became larger at first and then became smaller.

Current status of and strategies for hepatitis C control in South Korea.

Chronic hepatitis C (CHC) is caused by hepatitis C virus (HCV) infection. HCV infection causes acute hepatitis, and the majority of those infected progress to chronic hepatitis, and some of them develop cirrhosis and hepatocellular carcinoma. Transmission of HCV is parenteral, and the major transmission routes include drug abuse, insecure injections or medical procedures, contaminated syringes or needles, sexual contact with an HCV-infected person, vertical infection of newborns by infected mothers, the transfusion of blood or blood products contaminated with viruses, and organ transplants. As no vaccine against HCV is available, HCV management involves blocking routes of transmission transmission, screening for HCV infection, and protecting liver disease progression by treatment. Highly potent oral direct antiviral agents are now available. Therefore, early detection through nation-wide screening program and appropriate treatment should be implemented to improve the quality of life of patients with HCV. Furthermore, for the effective HCV control in South Korea, The organization of an ‘integrated national viral hepatitis control system’ is desirable.

Optical Guidance Systems for Epidural Space Identification

Epidurals are the most diffused loco-regional techniques for the relief of operative, postoperative, and chronic pain and are used for about 50% of deliveries. Currently, doctors still identify epidural space relying on subjective perception, by using “blind” manual techniques to which are associated failure rate up to 7%. In the last years, many systems aimed at assisting and guiding the placement of epidural needle have been proposed. In particular, optical systems basically rely on the integration inside the epidural needle lumen of optical fiber probes providing real-time discrimination of differing tissue types during needle penetration. In this study, aside of providing an exhaustive overview on the systems proposed so far, we also report on a novel sensorized medical needle, based on the judicious integration of a fiber Bragg grating sensor inside the epidural needle lumen. Our device, by providing continuous and real-time measurements of the pressure experienced by the needle tip during its advancement, is able to effectively detect the needle passage from one tissue to the other. A pilot study carried out on an epidural training phantom demonstrates the validity of our approach for making the needle placement into the epidural space easier and safer.

Auditory feedback to support image-guided medical needle placement.

During medical needle placement using image-guided navigation systems, the clinician must concentrate on a screen. To reduce the clinician's visual reliance on the screen, this work proposes an auditory feedback method as a stand-alone method or to support visual feedback for placing the navigated medical instrument, in this case a needle. An auditory synthesis model using pitch comparison and stereo panning parameter mapping was developed to augment or replace visual feedback for navigated needle placement. In contrast to existing approaches which augment but still require a visual display, this method allows view-free needle placement. An evaluation with 12 novice participants compared both auditory and combined audiovisual feedback against existing visual methods. Using combined audiovisual display, participants show similar task completion times and report similar subjective workload and accuracy while viewing the screen less compared to using the conventional visual method. The auditory feedback leads to higher task completion times and subjective workload compared to both combined and visual feedback. Audiovisual feedback shows promising results and establishes a basis for applying auditory feedback as a supplement to visual information to other navigated interventions, especially those for which viewing a patient is beneficial or necessary.

On the use of an optoacoustic and laser ultrasonic imaging system for assessing peripheral intravenous access

We describe a universal system for research in combined real-time optoacoustic (OA) and laser-ultrasonic (LU) imaging. The results of its testing on the task of needle insertion into the blood vessel model diagnostics are presented. In OA mode, where laser light is absorbed directly in the sample, the contents of blood vessel model is clearly visible. In LU mode, where the short ultrasonic probe pulse scattered on the sample is detected, the needle is clearly visible. The developed solution combining OA and LU imaging modalities due to the common detection system allowed real-time diagnostics of the position of medical needles (0.63mm and 0.7mm in diameter) inside blood vessel models (1.6mm and 2.4mm in diameter). Frame rate was 10Hz. High longitudinal spatial resolution of the system − 0.1mm − allows distinguishing the two walls of the vessel model and the position of the needle inside.

Ultrasonic Needle Tracking with a Fibre-Optic Ultrasound Transmitter for Guidance of Minimally Invasive Fetal Surgery.

Ultrasound imaging is widely used for guiding minimally invasive procedures, including fetal surgery. Visualisation of medical devices such as medical needles is critically important and it remains challenging in many clinical contexts. During in-plane insertions, a needle can have poor visibility at steep insertion angles and at large insertion depths. During out-of-plane insertions, the needle tip can have a similar ultrasonic appearance to the needle shaft when it intersects with the ultrasound imaging plane. When the needle tip is not accurately identified, it can damage critical structures, with potentially severe consequences, including loss of pregnancy. In this paper, we present a tracking system to directly visualise the needle tip with an ultrasonic beacon. The waves transmitted by the beacon were received by an external ultrasound imaging probe. Pairs of co-registered images were acquired in rapid succession with this probe: a photoacoustic image obtained with the system in receive-only mode, and a conventional B-mode ultrasound image. The beacon comprised a custom elastomeric nanocomposite coating at the distal end of an optical fibre, which was positioned within the lumen of a commercial 22 gauge needle. Delivery of pulsed light to the coating resulted in the photoacoustic generation of ultrasonic waves. The measured tracking accuracies in water in the axial and lateral dimensions were 0.39±0.19 mm and 1.85±0.29 mm, respectively. To obtain a preliminary indication of the clinical potential of this ultrasonic needle tracking system, needle insertions were performed in an in vivo fetal sheep model. The results demonstrate that ultrasonic needle tracking with a fibre-optic transmitter is feasible in a clinically realistic fetal surgery environment, and that it could be useful to guide minimally invasive procedures by providing accurate visualisation of the medical device tip.

Thin-slots Machining of Compliant Needles for Vibration-assisted Medical Insertion

This paper presents a geometric analysis modeling and control of micro-slots manufacturing for compliant needles fabrication and biomedical applications. In medical applications, the insertion accuracy of medical needles is closely related with the insertion forces encountered during the relative motion between needle and tissue. This paper presents a new design of compliant needle featured by 4-bevel tip and shaft slots for vibratory needle insertion, whose capability in reducing insertion force has been demonstrated in our earlier works. The effects of the design variables of the slots on needle tip vibration pattern are studied using harmonic analysis with a focus on slot width and slot depth. This paper presents a method of using harmonic analysis to identify the effects of the design variables of the slots on needle tip vibration pattern with a focus on slot width and slot depth. Based on the analysis results, an analytical model is presented and validated for accurate calculation of slot depth in the EDM-based (electrical discharge machining) fabrication process. To use slot width to fine tune the tip vibration, a methodology involving additional electrode motions after initial slot cutting is proposed to increase slot width. This paper provides practical design and manufacturing guidance for vibration-assisted medical insertion devices. Examples and experimental results are presented in the paper for demonstration and validation. The presented geometric analysis model and manufacturing techniques can be used for micro-slots fabrication and biomedical applications.

Development of a Biocompatible In-Tube Solid-Phase Microextraction Device: A Sensitive Approach for Direct Analysis of Single Drops of Complex Matrixes.

The aim of the current study is to develop a sensitive solid-phase microextraction (SPME) device for direct and rapid analysis of untreated complex matrixes (i.e., single drop of the samples, V ≤ 2 μL). A thin layer of a biocompatible nanostructured polypyrrole (PPy) was electrochemically deposited inside a medical grade spinal needle, minimizing the matrix effect. Microsampling was facilitated by loading the sample inside the in-tube SPME device (withdraw of sample via plunger), where extraction was performed under static conditions. Two strategies were used for analysis of the compounds including offline desorption and running the extract to the liquid chromatograph-tandem mass spectrometer (LC-MS/MS) or direct coupling of the in-tube SPME device to the MS. Given the high surface-area-to-volume ratio of the coating, a short equilibrium time (i.e., t ≤ 2 min) was obtained. The whole analytical procedure (i.e., extraction, rinsing, desorption, and LC-MS/MS analysis) was performed within 10 min by LC-MS/MS, and 3 min by in-tube-MS/MS. Possible matrix effects for the prepared device were evaluated in whole blood samples at three levels of concentration, and encouraging results were achieved in the range of 83-120%. The obtained results, no matrix effect, are attributed to the smooth surface and small pore size of the biocompatible PPy coating, which was prepared in the presence of cetyltrimethylammonium bromide (CTAB) surfactant. The in-tube SPME device was shown to be very sensitive, with high total recoveries obtained for all compounds in phosphate-buffered saline (PBS) and urine samples owing to the large volume and capacity of the coating. Subnanogram per milliliter levels of detection were achieved for urine samples, and low nanogram per milliliter levels were found in whole blood samples for all studied compounds with a high protein binding index. Rapid analysis of whole blood samples was achieved without need of any pretreatment or manipulation of sample, revealing the developed in-tube SPME device as an ideal probe for forensic application, drug monitoring, and point-of care-diagnosis.

Modeling of machined depth in laser surface texturing of medical needles

The present paper addresses the experimental modeling of process parameters in laser surface texturing (LST) of medical needles. First, experiments were carried out based on Taguchi methodology. The laser process parameters considered during LST were the circumferential overlap, axial overlap and the overscan number. A second-order regression model of the machined depth for LST was developed based on the experimental results. Second, a predictive model for the machined depth based on least squares support vector machines (LS-SVM) with radial basis functions was constructed using the same experimental swatches. Grid search and leave-one-out cross-validation were used to determine the optimal parameters of the LS-SVM model. The comparison between the second-order regression model and the LS-SVM model was carried out. The experiments indicated that the LS-SVM model is capable of better predictions of the machined depth than the second-order regression model. The validity of the LS-SVM model has been checked through the creation of micro-channels with blended edges. It was found that the predicted profile was in a good agreement with the experimental profiles. The LS-SVM model can be used to predict machined geometry of the micro-channels on medical needles.

Surface-blended texturing of medical needles for friction reduction using a picosecond laser

The success of percutaneous procedures depends on the accuracy of the medical needle insertion. Reducing the insertion force and using better needle visualization during needle insertion can reduce needle placement errors. Surface texturing is frequently used to create micro-features on medical needle’s tip portion to improve the visibility in ultrasound-guided percutaneous procedures. However, these micro-features usually increase the friction between the needle and tissue because of stress concentrations. This paper explores a method for creating micro-features with blended edges on echogenic needles and studies the friction behavior between textured echogenic needles and phantom tissue to identify blended texture patterns that would minimize the friction during needle insertion. Laser surface texturing was used to create regular micro-circumferential channels and micro-corner-cube-like dimples along the needle’s axial direction. Variations of the overlap in the feed direction were used to blend the edges of micro-channels and micro-dimples with different fillet radii. Both needles with regular and blended surface textures were experimentally investigated through needle extraction experiments from phantom tissue. It was found that the blended textured needles with large fillet radii exhibit a much better friction behavior.

Combined puncture/cutting of elastomer membranes by pointed blades: An alternative approach of fracture energy

Resistance to combined puncture and cutting is controlled by two energies, one is the fracture energy or the intrinsic strength of the material, the other reflects the friction energy between a pointed blade and the material. The purpose of this study is to propose an alternative approach derived from the fracture mechanics theory to calculate the fracture energy associated to the puncture/cutting of neoprene rubber by pointed blades. The proposed approach is also based on the application of a sample pre-strained during the puncture/cutting test in order to remove the contribution of friction. It was validated with two different pointed blade angles of 22.5° and 35°. Results show that for an applied pre-strain energy (or tearing energy) of high value, the friction between pointed blade and material is completely removed. Without friction, the total fracture energy is constant. In that case, the crack growth contribution of the applied pre-strain energy is marginal. Growth of the crack is thus completely caused by the puncture/cutting by a pointed blade. Finally, results suggest that the value of the fracture energy corresponding to puncture/cutting by pointed blades is obtained at a frictional contribution of zero, but not at tearing energy value of zero. The value obtained is three times higher than the cutting energy corresponding to a cut by razor blade and also larger than that obtained from puncture by medical needles.

Stochastic Extended LQR for Optimization-based Motion Planning Under Uncertainty.

We introduce a novel optimization-based motion planner, Stochastic Extended LQR (SELQR), which computes a trajectory and associated linear control policy with the objective of minimizing the expected value of a user-defined cost function. SELQR applies to robotic systems that have stochastic non-linear dynamics with motion uncertainty modeled by Gaussian distributions that can be state- and control-dependent. In each iteration, SELQR uses a combination of forward and backward value iteration to estimate the cost-to-come and the cost-to-go for each state along a trajectory. SELQR then locally optimizes each state along the trajectory at each iteration to minimize the expected total cost, which results in smoothed states that are used for dynamics linearization and cost function quadratization. SELQR progressively improves the approximation of the expected total cost, resulting in higher quality plans. For applications with imperfect sensing, we extend SELQR to plan in the robot's belief space. We show that our iterative approach achieves fast and reliable convergence to high-quality plans in multiple simulated scenarios involving a car-like robot, a quadrotor, and a medical steerable needle performing a liver biopsy procedure.

Mechanics-Based Interactive Modeling for Medical Flexible Needle Insertion in Consideration of Nonlinear Factors

A mechanics-based model of flexible needle insertion into soft tissue is presented in this paper. Different from the existing kinematic model, a new model has been established based on the quasi-static principle, which also incorporates the dynamics of needle motions. In order to increase the accuracy of the model, nonlinear characteristics of the flexible needle and the soft tissue are both taken into account. The nonlinear Winkler foundation model and the modified Euler–Bernoulli theory are applied in this study, providing a theoretical framework to study insertion and deformation of needles. Galerkin method and iteration cycle analysis are applied in solving a series of deformation control equations to obtain the needle deflection. The parameters used in the mechanics-based model are obtained from the needle force and needle insertion experiment. Sensitivity studies show that the model can respond reasonably to changes in response to variations in different parameters. A 50 mm needle insertion simulation and a 50 mm corresponding needle insertion experiment are conducted to prove the validity of the model. At last, a study on different needle tip bevel demonstrates that the mechanics-based model can precisely predict the needle deflection when more than one parameter is changed. The solution can also be used in optimizing trajectory of the needle tip, enabling the needle to reach the target without touching important physiological structures such as blood vessels with the help of dynamic trajectory planning.