Optimal needle design for minimal insertion force and bevel length

Effect of a thin-tipped short bevel needle for peripheral intravenous access on the compressive deformation and displacement of the vein: A preclinical study

BACKGROUND

Peripheral intravenous catheter (PIVC) insertion often fails on the first attempt. Risk factors include small vein size and dehydration, causing vein deformation and displacement due to puncture resistance of the vessel. The authors developed a short, thin-tipped bevel needle and compared its puncture performance with needles of four available PIVCs using an ex vivo model.

METHODS

The PIVC with the thin-tipped short bevel needle was compared to four available PIVCs using an ex vivo model which simulated the cephalic vein of the human forearm. The ex vivo model consisted of a porcine shoulder and porcine internal jugular vein, and was used for evaluation of the rate of vein deformation and vessel displacement during needle insertion.

RESULTS

An ex vivo model was created with a vessel diameter of 2.7-3.7 mm and a depth of 2-5 mm. The thin-tipped short bevel PIVC needle was associated with a significantly lower compressive deformation rate and venous displacement compared to the needles of the other four PIVCs.

CONCLUSION

The thin-tipped short bevel needle induced lower compressive deformation and displacement of the vein than the conventional needles. This needle has the potential to improve the first-attempt success rate of peripheral intravenous catheterization in patients with difficult venous access.

Needle bevel geometry influences the flexural deflection magnitude in ultrasound-enhanced fine-needle biopsy

It has been recently demonstrated that use of ultrasound increases the tissue yield in ultrasound-enhanced fine-needle aspiration biopsy (USeFNAB) as compared to conventional fine-needle aspiration biopsy (FNAB). To date, the association between bevel geometry and needle tip action has not been widely explored. In this study, we studied the needle resonance characteristics and deflection magnitude of various needle bevel geometries with varying bevel lengths. With a conventional lancet, having a 3.9 mm long bevel, the tip deflection-to-power ratio (DPR) in air and water was 220 and 105 µm/W, respectively. This was higher in comparison to an axi-symmetric tip, having a bevel length of 4 mm, which achieved a DPR of 180 and 80 µm/W in air and water, respectively. This study emphasised the importance of relationship between flexural stiffness of bevel geometry in the context of various insertion media and, thus, could provide understanding on approaches to control post-puncture cutting action by modifying the needle bevel geometry, essential for the USeFNAB application.

Microneedles: One-Plane Bevel-Tipped Fabrication by 3D-Printing Processes

This article presents microneedles analyses where the design parameters studied included length and inner and outer diameter ranges. A mathematical model was also used to generalize outer and inner diameter ratios in the obtained ranges. Following this, the range of inner and outer diameters was completed by mechanical simulations, ranging from 30 μm to 134 μm as the inner diameter range and 208 μm to 250 μm as the outer diameter range. With these ranges, a mathematical model was made using fourth-order polynomial regressions with a correlation of 0.9993, ensuring a safety factor of four in which von Misses forces of the microneedle are around 17.931 MPa; the ANSYS software was used to analyze the mechanical behavior of the microneedles. In addition, the microneedle concept was made by 3D printing using a bio-compatible resin of class 1. The features presented by the microneedle designed in this study make it a promising option for implementation in a transdermal drug-delivery device.

Effect of Transcodent painless needles on injection pain in maxillary anterior infiltration: a split-mouth controlled randomized clinical trial

Objectives

The present study aimed to determine the pain perceived during supraperiosteal (infiltration) injection in anterior maxillary region by Transcodent painless needle tips in comparison to the regular needle tips.

Material and methods

In this split‐mouth controlled randomised clinical trial, 30 patients were selected as candidates for cosmetic treatment who needed infiltration injections on both sides of canine area. They were each administered 0.9 mL of Lidocaine HCl 2% with epinephrine 1:100,000 in the buccal vestibules using two types of needle tips, Transcodent painless needle tip or regular needle tip. Immediately after the injection, the pain was measured using a 100 mm visual analog scale. The level of pain was statistically analyzed in the two groups using the parametric paired t‐test. A 5% significance level was considered for statically significant difference between two means.

Results

In accordance with the results, the patients' level of pain were estimated as 18.3 ± 10.7 mm with Transcodent painless needle tips and 43.1 ± 13.1 mm in regular needle tip (p < 0.05).

Conclusion

The Transcodent painless needle showed considerable reduction of pain in the anterior maxillary infiltration when compared to the regular needle tips.

A short bevel needle with a very thin tip improves vein puncture performance of peripheral intravenous catheters: An experimental study

BACKGROUND

Peripheral intravenous catheter placement is frequently unsuccessful at the first attempt. One suggested risk factor is a small vein size, because of the consequences of mechanical forces generated by the needle tip. We developed short bevel needles with a very thin tip and evaluated their puncture performance in two in vitro models.

METHODS

Peripheral intravenous catheters with a new needle ground using the lancet method (experimental catheter (L)) or backcut method (experimental catheter (B)) were compared with a conventional peripheral intravenous catheter (Surshield Surflo®) in a penetration force test and a tube puncture test. Penetration forces were measured when peripheral intravenous catheters penetrated a polyethylene sheet. The tube puncture test was used to evaluate whether the peripheral intravenous catheters could puncture a polyvinyl chloride tube at two positions, at the center and at 0.5 mm from the center of the tube.

RESULTS

Mean penetration forces at the needle tip produced by experimental catheters (L) (0.05 N) and (B) (0.04 N) were significantly lower than those produced by the conventional catheter (0.09 N) (p < 0.01). At the catheter tip, mean forces produced by experimental catheter (B) and the conventional catheter were 0.16 N and 0.26 N, respectively (p < 0.05). In the tube puncture test, the frequency at which the conventional catheter punctured the center-shifted site on the tube at an angle of 20° and speed of 50 mm/min was low (40%). In contrast, experimental catheters (L) and (B) were 100% successful at puncturing both the center and center-shifted sites at 20°.

CONCLUSION

Puncture performance was comparable between the lancet-ground and backcut-ground needles except for penetration forces at the catheter tip. The experimental catheters produced lower penetration forces and induced puncture without target displacement at smaller angles compared with the conventional catheter. Therefore, optimization of the needle can prevent vein deformation and movement, which may increase the first-attempt success rate.

Design Optimization of Nonrotational and Rotational Needle Insertion for Minimal Cutting Forces

The needle insertion is widely used in many medical procedures, particularly in the needle biopsy. The cutting force occurred during the insertion process has a significant effect on the cutting outcome. This paper focuses on minimizing the cutting force for two conventional needle insertion methods, the nonrotational and rotational needle insertion. For the nonrotational needle insertion, the secondary bevel angle and angle of rotation, which are two used for grinding the back-bevel and lancet needles, are considered. For the rotational needles, the effects of the insertion speed and the slice-push ratio on the cutting force are investigated. Levels of these design variables are defined using practical needle design configurations found in the literature. A clear trend of the cutting force decreases as the increase of the inclination angle was observed. The optimal cutting force of nonrotational needles was found as 0.242 N with inclination angle of 69.25 deg for the lancet needle and 0.254 N with inclination angle of 66.24 deg for the back-bevel needle. The optimization of rotational needles yielded a configuration of slice-push ratio as 4.66 and insertion speed as 2.01, which resulted in a minimal cutting force of 0.22 N. Besides, the main effects of and the interaction between the design variables on the cutting force are obtained and discussed. These results provide essential information for selecting geometric and cutting speed parameters for the design of nonrotational and rotational needles.

Modeling of geometry and insertion force of a new lancet medical needle

Lancet needle is a typical medical treatment device. Its tip consists of two lancet planes and one bevel plane. When the lancet needle is inserted into soft organ tissue, the insertion force may influence the needle cutting direction and treatment effect and increase the pain. One of the main factors affecting this insertion force is the geometry of the needle tip. Based on the research on the shape and processing method of the conventional lancet needle, a new lancet needle tip geometry was obtained by adjusting the relative position of the grinding wheel to the needle. A mathematical model of this new lancet needle was established. The relationship between processing parameters and needle shape was analyzed, and the needle insertion force was predicted. Compared with the conventional lancet needle, the new lancet needle is sharper, and the insertion force on the cutting edge is smaller. However, this change in the grinding position of the needle lancet plane has a great influence on the shape of needle tip near the intersection of the bevel plane and the lancet plane. Some special second bevel angle and rotated angle will cause a large change in the specific force at the intersection place, which is not conducive to reducing the insertion force.

Needle Biopsy Adequacy in the Era of Precision Medicine and Value-Based Health Care

CONTEXT.—

Needle biopsy of diseased tissue is an essential diagnostic tool that is becoming even more important as precision medicine develops. However, the capability of this modality to efficiently provide samples adequate for diagnostic and prognostic analysis remains quite limited relative to current diagnostic needs. For physicians and patients, inadequate biopsy frequently leads to diagnostic delay, procedure duplication, or insufficient information about tumor biology leading to delay in treatment; for health systems, this results in substantial incremental costs and inefficient use of scarce specialized diagnostic resources.

OBJECTIVE.—

To review current needle biopsy technology, devices, and practice with a perspective to identify current limitations and opportunities for improvement in the context of advancing precision medicine.

DATA SOURCES.—

PubMed searches of fine-needle aspiration and core needle biopsy devices and similar technologies were made generally, by tissue site, and by adequacy as well as by health economics of these technologies.

CONCLUSIONS.—

Needle biopsy adequacy can be improved by recognizing the importance of this diagnostic tool by promoting common criteria for needle biopsy adequacy; by optimizing needle biopsy procedural technique, technologies, clinical practice, professional education, and quality assurance; and by bundling biopsy procedure costs with downstream diagnostic modalities to provide better accountability and incentives to improve the diagnostic process.

FORCE CHARACTERISTICS AND EFFECTIVE STOPPING UPON THE ABDOMINAL WALL IS PENETRATED OUT BY TROCAR DURING LAPAROSCOPIC SURGERY

Overshooting during trocar insertion may injury patient viscera and arteries or even lead to death. It has been extensively cited as a kind of common medical negligence. Hence, this paper investigated the force characteristics during a trocar inserted into the abdominal wall and developed strategies for effective stopping upon the trocar penetrated out of the abdominal wall. First, an experimental platform with two degrees of freedom was assembled. Second, two insertion methods were compared and the insertion forces using three types of trocars were measured respectively. Subsequently, we interpreted the force characteristics in terms of insertion principle and the abdominal structure. And based on the force characteristics, we generated two algorithms for the two insertion methods, which can be utilized to stop inserting effectively upon the trocar penetrated out of the abdominal wall. Finally, we evaluated the merits and demerits of the two algorithms. This paper proposed the interpretation of force characteristics during trocar insertion and achieved effective stopping to avoid overshooting. It provides foundations for the development of automatic trocar insertion device in the future.

Force Modeling, Identification, and Feedback Control of Robot-Assisted Needle Insertion: A Survey of the Literature

Robot-assisted surgery is of growing interest in the surgical and engineering communities. The use of robots allows surgery to be performed with precision using smaller instruments and incisions, resulting in shorter healing times. However, using current technology, an operator cannot directly feel the operation because the surgeon-instrument and instrument-tissue interaction force feedbacks are lost during needle insertion. Advancements in force feedback and control not only help reduce tissue deformation and needle deflection but also provide the surgeon with better control over the surgical instruments. The goal of this review is to summarize the key components surrounding the force feedback and control during robot-assisted needle insertion. The literature search was conducted during the middle months of 2017 using mainstream academic search engines with a combination of keywords relevant to the field. In total, 166 articles with valuable contents were analyzed and grouped into five related topics. This survey systemically summarizes the state-of-the-art force control technologies for robot-assisted needle insertion, such as force modeling, measurement, the factors that influence the interaction force, parameter identification, and force control algorithms. All studies show force control is still at its initial stage. The influence factors, needle deflection or planning remain open for investigation in future.

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.

A feature study of innovative high-speed lancing device and safety lancet

The study developed two models of an innovative high-speed lancing device and safety lancet, where the specially designed structure causes high-speed motion of the lancet, resulting in only one puncture of the skin. The two experimental models and other lancing devices sold on market were compared in order to: (1) measure the forces of lancets piercing animal skin by a load cell; (2) observe the wound areas caused by lancing devices under a microscope. The experimental results showed that, after using this innovative high-speed lancing device, the maximum force of a lancet piercing skin is only 1/3 of the force of conventional lancing devices, and the duration of the former under the skin is 1/6 of the latter. In addition, the wound area caused by the innovative lancing device is 20 % smaller than those of the conventional lancing devices. Usage of this innovative high-speed safety lancet shows that its maximum skin-piercing force is only 2/3 of conventional safety lancets, its duration under the skin is 1/4 of conventional safety lancets, and the wound area is 12 % smaller. In conclusion, both the innovative high-speed lancing device and safety lancet are proved effective in alleviating pain for diabetics and shortening the recovering time for wounds, thus, providing a more comfortable process for the self-monitoring of blood glucose.