Jet Injection System Research Articles

Experimental investigation of the optimal driving pressure for a larger-volume controllable jet injection system.

Jet injection technology has become the alternative drug delivery method of conventional needle-based injection due to its obvious advantages. In order to meet the demand for larger volume injection, the pneumatic jet injection systems have efficiently administrated vaccine up to 1mL in human. Our recent study has also demonstrated that controlling the driving pressure enabled the pneumatic jet injection system to deliver larger volumes of drugs to target sites at desired rates and times. This work continues to explore the optimal two-phase driving pressure combination with better injection efficiency for typical larger-volume (1.0mL) jet injection with controllable pneumatic jet injection system. Under the combination of a first phase driving pressure of 1.00MPa and a second phase driving pressure ranging from 0.25 to 0.90MPa, dynamic characteristics, dispersion characteristics and pharmacokinetic characteristics of this controllable jet injection system were quantitatively analyzed. In all experiments, it was confirmed that the optimal driving pressure combination of 1.0mL ejection volume was close to (1.00-0.50) MPa. That is, the injection velocities of 151.85m/s and 102.01m/s for the first and second phase respectively facilitated better injection performance with a controlled release of 1.0mL ejection volume. This strategy is practical for facilitating the clinical application of large-volume controllable jet injection systems.

Conceptualisation of a novel electromechanical system for small-volume needle-free jet injection

Needle-free jet injectors are minimally invasive drug delivery systems that utilise high-velocity microjets (∼100 m/s) created by pressurising the liquid drug through a micronozzle (50–300 µm in diameter). Most of the current commercially available jet injectors use a mechanical power possessed by a compressed spring or air to pressurise the fluid inside the injection chamber to deliver the liquid drug (typically ∼100 µL in volume) into the skin matrix. However, they cannot be utilised for achieving shallow penetration depths as they lack dynamic control that can shape the real-time microjet characteristics. Recently, electrically or optically powered jet injection systems are being developed to achieve shallow penetration depth by small-volume (<5 μL) injections. However, they require complex system and have a limited injection frequency (maximum reported value is 16 Hz). Herein, we propose a novel electro-mechanical jet injection system, where a mechanically actuated source pressurises the fluid inside the injection chamber and an electrically actuated system controls the characteristics of the propelled microjet. A computational model was developed to prove the feasibility of the proposed system, and the obtained results showed that the proposed system could produce stable small-volume microjets at about 100 Hz frequency that could be utilised for drug delivery applications.

Case study of user experience-driven design in a new local anaesthetic dentistry jet injection device

ABSTRACT This case study explored how human-centred design methodologies can improve clinician experience and reduce patient treatment anxiety in the application of a new dental local anaesthetic jet-injection system. An initial embodiment of the prototype injector, dubbed the ‘Kiwi’ injector, was developed to better understand the user experience during dental-injection procedures. Further design development was undertaken in two distinct phases. Stage one entailed the initial non-functional Kiwi injector model being used as a design probe to explore clinician views on its aesthetics and ergonomics. The second stage explored the clinician and patient experiences of the functional Kiwi Injector while administering a local anaesthetic to the patient. Stage one findings highlighted clinician satisfaction with the aesthetics of the non-functional prototype device but expressed the desire to make the device smaller. Stage two clinical study results highlighted an issue with the functional jet injector configuration, where the participating dental clinicians speculated that a greater bend in the wand and change of trigger position would significantly improve the Kiwi injector ergonomic performance. This research has demonstrated the benefits of applying a structured and staged human-centred user experience design process to inform the design of a new dental anaesthetic delivery device.

A Needle-Free Jet Injection System for Controlled Release and Repeated Biopharmaceutical Delivery.

Swift vaccination is necessary as a response to disease outbreaks and pandemics; otherwise, the species under attack is at risk of a high fatality rate or even mass extinction. Statistics suggest that at least 16 billion injections are administered worldwide every year. Such a high rate of needle/syringe injection administration worldwide is alarming due to the risk of needle-stick injuries, disease spread due to cross-contamination and the reuse of needles, and the misuse of needles. In addition, there are production, handling, and disposal costs. Needle phobia is an additional issue faced by many recipients of injections with needles. In addition to a detailed literature review highlighting the need for needle-free injection systems, a compressed air-driven needle-free jet injection system with a hydro-pneumatic mechanism was designed and developed by employing an axiomatic design approach. The proposed injection system has higher flexibility, uninterrupted force generation, and provides the possibility of delivering repeated injections at different tissue depths from the dermis to the muscle (depending on the drug delivery requirements) by controlling the inlet compressed air pressure. The designed needle-free jet injector consists of two primary circuits: the pneumatic and the hydraulic circuit. The pneumatic circuit is responsible for driving, pressurizing, and repeatability. The hydraulic circuit precisely injects and contains the liquid jet, allowing us to control the volume of the liquid jet at elevated pressure by offering flexibility in the dose volume per injection. Finally, in this paper we report on the successful design and working model of an air-driven needle-free jet injector for 0.2–0.5 mL drug delivery by ex vivo experimental validation.

Laterally Dispersing Nozzles for Needle-assisted Jet Injection.

Most transdermal drug delivery systems are designed to inject drugs through the skin in a direction normal to the skin surface. However, in some applications, such as local anaesthesia, it is desirable to disperse the drug in a direction parallel to the surface of the skin. In this paper we present nozzles for needle-assisted jet injection that are designed to laterally disperse the fluid drug at a chosen depth in tissue. These nozzles were manufactured by laser machining holes in the walls of 0.57 mm (24 G) hypodermic needles, and sealing the ends of the needles. An existing controllable jet injection system was used to test the nozzles. High-speed video recordings were taken to examine the shape of the high-speed jets emitted from the orifices, and jet injections into post mortem porcine tissue were performed to evaluate the resulting dispersion pattern. These injections demonstrated the ability of these nozzles to achieve a widely spread dispersion at a depth of 3 mm to 4 mm in tissue. We observed that the widest dispersion occurred at the same depth as the orifices, and dispersion was greater in the direction of the jets. Further investigation, including an in vivo study, is now required to evaluate whether this technique can reduce the time, cost or pain associated with transdermal local anaesthetic delivery.

Large eddy simulation of transverse single/double jet in supersonic crossflow

In this paper, large eddy simulation of transverse sonic single/double hydrogen jets into supersonic Mach 2 crossflow have been carried out to investigate the complex flow structures and the mixing performance. Detailed turbulence characteristics, in terms of the instantaneous and mean flow fields, the vortex structures and their evolutions, the turbulence kinetic energy and the Reynolds shear stress distributions, the maximum hydrogen mass fraction and jet penetration, have been provided. Results of the two-dimensional and three-dimensional streamlines illustrate that the trailing counter-rotating vortex pairs (TCVP), the secondary TCVP of primary jet and the horseshoe vortex can merge and form a new horseshoe vortex. Three counter-rotating vortex pairs (CVP) are formed in the downstream of secondary jet: the CVP-B due to interactions between the supersonic crossflow and secondary jet; the CVP-C due to interactions between the supersonic crossflow, primary and secondary jets; and the CVP-D due to interactions of the supersonic crossflow and primary jet. The presence of primary jet flow alters the Reynolds shear stress distributions after the secondary injection with the influence of these large-scale structures. In addition, the two-stage jet injection system is proved to yield a better mixing performance than the single jet system.

Assessment of anesthetic properties and pain during needleless jet injection anesthesia: a randomized clinical trial.

Pain due to administration of local anesthetics is the primary reason for patients' fear and anxiety, and various methods are used to minimize it. This study aimed to measure the degree of pain during administration of anesthesia and determine the latency time and duration of pulpal anesthesia using two anesthetic methods in the maxilla.Materials and Methods:A randomized, single-blind, split-mouth clinical trial was conducted with 41 volunteers who required class I restorations in the maxillary first molars. Local anesthesia was administered with a needleless jet injection system (experimental group) or with a carpule syringe (control) using a 30-gauge short needle. The method of anesthesia and laterality of the maxilla were randomized. A pulp electric tester measured the latency time and duration of anesthesia in the second molar. Visual analogue scale (VAS) was used to measure the degree of pain during the anesthetic method. Data were tabulated and then analyzed by a statistician. The t-test was used to analyze the differences between the groups for basal electrical stimulation. Duration of anesthesia and degree of pain were compared using the Mann-Whitney test. A 5% significance level was considered.Results:There was no statistical difference in the basal electrical stimulation threshold (mA) and degree of pain between the two methods of anesthesia (p>0.05). Latency time was 2 minutes for all subjects. The duration of pulpal anesthesia showed no statistical difference (minutes) between the two methods (p<0.001), with a longer duration for the traditional method of anesthesia (median of 40 minutes).Conclusions:The two anesthetics methods did not differ concerning the pain experienced during anesthesia. Latency lasted 2 minutes for all subjects; the traditional infiltration anesthesia resulted in a longer anesthetic duration compared with the needleless jet injection.

A Randomized Double Blind Trial of Needle-free Injected Lidocaine Versus Topical Anesthesia for Infant Lumbar Puncture.

Lumbar punctures (LPs) are commonly performed in febrile infants to evaluate for meningitis, and local anesthesia increases the likelihood of LP success. Traditional methods of local anesthesia require injection that may be painful or topical application that is not effective immediately. Recent advances in needle-free jet injection may offer a rapid alternative to these modalities. We compared a needle-free jet-injection system (J-Tip) with 1% buffered lidocaine to topical anesthetic (TA) cream for local anesthesia in infant LPs. This was a single-center randomized double-blind trial of J-Tip versus TA for infant LPs in an urban tertiary care children's hospital emergency department. A computer randomization model was used to allocate patients to either intervention. Patients aged 0 to 4 months were randomized to J-Tip syringe containing 1% lidocaine and a placebo TA cream or J-Tip syringe containing saline and TA. The primary outcome was the difference between the Neonatal Faces Coding Scale (NFCS) before the procedure and during LP needle insertion. Secondary outcomes included changes in heart rate (HR) and NFCS throughout the procedure, difficulty with LP, number of LP attempts, provider impression of pain control, additional use of lidocaine, skin changes at LP site, and LP success. We enrolled 66 subjects; 32 were randomized to J-Tip with lidocaine and 34 to EMLA. Six participants were excluded from the final analysis due to age greater than 4 months, and the remaining 58 were analyzed in their respective groups (32 J-Tip, 34 TA). There was no difference detected in NFCS between the two treatment groups before the procedure and during needle insertion for the LP (p=0.58, p=0.37). Neither HR nor NCFS differed among the groups throughout the procedure. Median perception of pain control by the provider and the need for additional lidocaine were comparable across groups. LPs performed with a J-Tip were twice as likely to be successful compared to those performed using TA (relative risk= 2.0; 95% confidence interval= 1.01-3.93; p=0.04) with no difference in level of training or number of prior LPs performed by providers. In a randomized controlled trial of two modalities for local anesthesia in infant LPs, J-Tip was not superior to TA cream as measured by pain control or physiologic changes. Infant LPs performed with J-Tip were twice as likely to be successful.

Investigation of Hybrid Adaptive Control Schemes for Needle Free Jet Injection System

Investigation of Hybrid Adaptive Control Schemes for Needle Free Jet Injection System

Adaptive controller for a needle free jet-injector system.

A nonlinear, sliding mode adaptive controller was created for a needle-free jet injection system. The controller was based on a simplified lumped-sum parameter model of the jet-injection mechanics. The adaptive control scheme was compared to a currently-used Feed-forward+PID controller in both ejection of water into air, and injection of dye into ex-vivo porcine tissue. The adaptive controller was more successful in trajectory tracking and was more robust to the biological variations caused by a tissue load.

The use of the needle-free jet injection system with buffered lidocaine device does not change intravenous placement success in children in the emergency department.

The needle-free jet injection system with buffered lidocaine (J tip) has been shown to reduce pain for intravenous (IV) line insertion, but its relationship with successful IV placement has not been well studied. This study aimed to determine if J tip use is associated with improved first-attempt IV placement success in children. This was a retrospective cohort study of children ages 1 to 18 years with need for emergent IV placement. Approximately 300 children were selected from each of three separate age groups: 1 to 2, 3 to 6, and 7 to 18 years. The standard treatment group (no device) included children with IV insertions from January 2009 through January 2010 with no J tip. The J tip treatment group (device) included children with IV insertions from December 2010 through December 2011 who received J tips. Successful IV placement on first attempt was the primary outcome. A chi-square test was used to compare the proportion of first-attempt success and logistic regression was performed to assess the effect of device use and patient age, sex, and race on first-attempt success. A total of 958 children were identified, 501 in the no-device group and 457 in the device group. The most common diagnoses were vomiting or dehydration (30.3%), trauma or burn (20.0%), and infection (15.5%). Overall, first-attempt success was 69.0% and was similar between the no-device (68.7%) and device (69.4%) groups (p = 0.81). No difference in first-attempt success with the use of the device was found in any of the age groups. Multivariate analysis found that only age of 1 to 2 years was associated with lower odds of first-attempt success when controlling for patient characteristics and device use. The use of the J tip did not affect first-attempt success for IV placement in children.

A hantavirus pulmonary syndrome (HPS) DNA vaccine delivered using a spring-powered jet injector elicits a potent neutralizing antibody response in rabbits and nonhuman primates.

Sin Nombre virus (SNV) and Andes virus (ANDV) cause most of the hantavirus pulmonary syndrome (HPS) cases in North and South America, respectively. The chances of a patient surviving HPS are only two in three. Previously, we demonstrated that SNV and ANDV DNA vaccines encoding the virus envelope glycoproteins elicit high-titer neutralizing antibodies in laboratory animals, and (for ANDV) in nonhuman primates (NHPs). In those studies, the vaccines were delivered by gene gun or muscle electroporation. Here, we tested whether a combined SNV/ANDV DNA vaccine (HPS DNA vaccine) could be delivered effectively using a disposable syringe jet injection (DSJI) system (PharmaJet, Inc). PharmaJet intramuscular (IM) and intradermal (ID) needle-free devices are FDA 510(k)-cleared, simple to use, and do not require electricity or pressurized gas. First, we tested the SNV DNA vaccine delivered by PharmaJet IM or ID devices in rabbits and NHPs. Both IM and ID devices produced high-titer anti-SNV neutralizing antibody responses in rabbits and NHPs. However, the ID device required at least two vaccinations in NHP to detect neutralizing antibodies in most animals, whereas all animals vaccinated once with the IM device seroconverted. Because the IM device was more effective in NHP, the Stratis® (PharmaJet IM device) was selected for follow-up studies. We evaluated the HPS DNA vaccine delivered using Stratis® and found that it produced high-titer anti-SNV and anti-ANDV neutralizing antibodies in rabbits (n=8/group) as measured by a classic plaque reduction neutralization test and a new pseudovirion neutralization assay. We were interested in determining if the differences between DSJI delivery (e.g., high-velocity liquid penetration through tissue) and other methods of vaccine injection, such as needle/syringe, might result in a more immunogenic DNA vaccine. To accomplish this, we compared the HPS DNA vaccine delivered by DSJI versus needle/syringe in NHPs (n=8/group). We found that both the anti-SNV and anti-ANDV neutralizing antibody titers were significantly higher (p-value 0.0115) in the DSJI-vaccinated groups than the needle/syringe group. For example, the anti-SNV and anti-ANDV PRNT50 geometric mean titers (GMTs) were 1,974 and 349 in the DSJI-vaccinated group versus 87 and 42 in the needle/syringe group. These data demonstrate, for the first time, that a spring-powered DSJI device is capable of effectively delivering a DNA vaccine to NHPs. Whether this HPS DNA vaccine, or any DNA vaccine, delivered by spring-powered DSJI will elicit a strong immune response in humans, requires clinical trials.

A randomized controlled study to assess the immunogenicity and tolerability of a 2012 trivalent seasonal inactivated influenza vaccine administered via a disposable syringe jet injector device versus a traditional pre-filled syringe and needle

The Stratis® disposable syringe jet injection (DSJI) system (PharmaJet Inc., Denver, USA) delivers vaccine utilizing a spring powered energy source to create a fine high-velocity jet of liquid that directly penetrates the skin without using a needle. We performed a study to collect data on the effect of the Stratis DSJI device on influenza immunization in 46 predominantly elderly subjects (28M, 18F; mean age 61 years) who were randomized 1:1 to receive Fluvax 2012 trivalent inactivated influenza vaccine via prefilled N–S or Stratis DSJI. H1N1 seroprotection was not significantly different for vaccine delivered by DSJI (86.4%, 95% CI 72.1–100) or N–S (79.2%, 95% CI 63.0–95.4), and likewise for H3N2 and B strains. The DSJI had a ∼2-fold higher mean injection pain score (DSJI: 3.0 versus N–S 1.58, p = 0.045) plus increased rates of swelling and tenderness but this was offset by a lower rate of elicited systemic reactions, particularly the frequency of post-immunization headaches (DSJI: 9% vs N–S: 33.3%). This study suggests that subject to confirmation of non-inferiority in an appropriately powered study, the Stratis DSJI is a viable alternative strategy for the administration of seasonal influenza vaccines with particular appeal for individuals with needle phobia. Australia New Zealand Clinical Trials Register: ACTRN12612000709842.

주류유동에서 단일 및 이중 수직분사 분무특성

연소실 내의 주류 공기유동에 미치는 영향을 최소화하면서 미립화 및 혼합특성을 향상시키기 위한 방법으로 주류공기 유동에 대해 수직방향의 연료분사 방식이 실용 엔진에서 많이 사용되고 있고, 관련 연구도 활발히 보고되고 있다. 본 연구는 가스터빈이나 램젯 엔진에서 사용되고 있는 수직분사의 분무특성은 실험적으로 조사하고, 단일 및 이중 수직분사에 따른 침투길이를 측정함으로써 선행연구에 의해 보고된 결과와 비교하였다. 또한 압력과 모멘텀 플럭스비 변화에 따른 침투길이, 분무입경 등의 분무 특성을 연구하였다. 특히, 이중 수직분사의 침투길이는 단일 수직분사의 침투길이에 비해 전단의 수직분사의 영향으로 후단의 수직분사 길이가 약 20% (Lh=4mm) 증가함을 확인할 수 있었다.

Comparison and correction of the drop breakup models for stochastic dilute spray flow

Spray–gas interaction is common in many industrial applications that use a liquid jet injection system. Numerous liquid drops interact with the surrounding gas as they travel through the air. During such a travel, aerodynamic interaction between a drop and the surrounding gas flattens the drop and ultimately, breaks up the drop. The TAB (Taylor Analogy Breakup) model was proposed by O’Rourke and Amsden (1987) [6] for the KIVA spray code, but the use of this model has been controversial because the original paper that proposed this model has typographical errors. Another well-known drop breakup model, such as the DDB (Drop Deformation Breakup) model of Ibrahim et al. (1993) [8], has been widely used. However, although numerical solutions of the DDB model ostensibly make it appear superior to those of other previous breakup models, they contain errors that need to be amended. This paper aims to clarify the error controversies of both models; the typographical errors and the erroneous numerical solutions. The complete mathematical derivation of the TAB model is presented, and its correct numerical solutions are compared against the experimental data. We found that the TAB model was superior to other breakup models, such as Clark (1988) [7] and DDB.

Numerical studies on evaluation of smoke control system of underground metro rail transport system in India having jet injection system: A case study

The rail based urban transport system is being developed for national capital of India, New Delhi. The smoke control using ventilation in case of fire inside the tunnel, similar to Delhi Metro corridor has been investigated using computational fluid dynamics technique. A section of tunnel having dimensions 400 m long, 5.5 m wide and 6 m high is considered for simulation. The analysis has been carried out by assuming a variable fire source with a peak heat release rate (HRR) of 16 MW, located at the center of the tunnel. Ventilation ducts are located in the ceiling near the tunnel portals and are inclined at 10 degrees to the plane of the ceiling through which fans discharge air. The influence of the fire HRR curve slope on the smoke flow dynamics in a realistic tunnel model fitted with jet injection type longitudinal ventilation system has been investigated. In case of fire two cases are studied: (1) fans activated immediately after detection, (2) fans activated at delayed times to take into account the response time for the fans to achieve its maximum speed. The velocity of supply and exhaust fans necessary to remove smoke in 30 s from the upstream direction is determined. The velocities of fan required to produce desired critical velocity in the longitudinal direction for different HRR of fire is predicted.

Incidence and severity of Arcanobacterium pyogenes injection site abscesses with needle or needle-free injection methods (2009)

A total of 198 nursery age pigs were used to evaluate the difference in the occurrence of injection site abscesses between needle-free jet injection and conventional needle-and-syringe injection systems. Pigs were fed for 21 d prior to treatment administration to acclimate the pigs to the environment of the Kansas State University Segregated Early Weaning Unit. On d 21, each pig received 4 injections of aluminum hydroxide adjuvant, 1 in the neck and 1 in the ham by needle-free jet injection (Pulse Needle-Free Systems, Lenexa, KS) on 1 side and 1 in the neck and 1 in the ham on the opposite side by conventional needle-and-syringe injection. Immediately prior to injection, the external surface of the injection sites was contaminated with an inoculum of Arcanobacterium pyogenes. The pigs were then fed for a period of 27 and 28 d. On d 27 and 28, the pigs were humanely euthanized and sent to the Kansas State University Veterinary Diagnostics Laboratory, where necropsies were performed and the injection sites underwent histopathological evaluation. The needle-free jet injection system was associated with more injection site abscesses than the conventional needle-and-syringe injection method for both the neck (P = 0.06) and ham (P = 0.03) injection sites. Twelve abscesses were found at needle-free injection sites, whereas only 1 abscess was found where a conventional needle injection method was used. Five abscesses were found at the neck injection sites, and 8 abscesses were observed at the ham injection sites. Of the 13 abscesses found, 10 developed on the left side of the animal, and only 3 were on the right side. In summary, the implementation of needle-free jet injection systems in market hog production will be beneficial by eliminating the potential for needles and needle fragments in meat products, but it may increase the occurrence of injection site abscesses in pork carcasses that will need to be trimmed in pork processing plants.; Swine Day, Manhattan, KS, November 19, 2009

Gas jet disruption mitigation studies on Alcator C-Mod

Damaging effects of disruptions are a major concern for Alcator C-Mod, ITER and future tokamak reactors. High-pressure noble gas jet injection is a mitigation technique which potentially satisfies the operational requirements of fast response time and reliability, while still being benign to subsequent discharges. Disruption mitigation experiments using an optimized gas jet injection system are being carried out on Alcator C-Mod to study the physics of gas jet penetration into high pressure plasmas, as well as the ability of the gas jet impurities to convert plasma energy into radiation on timescales consistent with C-Mod's fast quench times, and to reduce halo currents given C-Mod's high-current density. The dependence of impurity penetration and effectiveness on noble gas species (He, Ne, Ar, Kr) is also being studied. It is found that the high-pressure neutral gas jet does not penetrate deeply into the C-Mod plasma, and yet prompt core thermal quenches are observed on all gas jet shots. 3D MHD modelling of the disruption physics with NIMROD shows that edge cooling of the plasma triggers fast growing tearing modes which rapidly produce a stochastic region in the core of the plasma and loss of thermal energy. This may explain the apparent effectiveness of the gas jet in C-Mod despite its limited penetration. The higher-Z gases (Ne, Ar, Kr) also proved effective at reducing halo currents and decreasing thermal deposition to the divertor surfaces. In addition, noble gas jet injection proved to be benign for plasma operation with C-Mod's metal (Mo) wall, actually improving the reliability of the startup in the following discharge.

Findings of Study of Needle-Free Jet-Injection System with Lidocaine Are Contrary To Published Reports: In Response

Findings of Study of Needle-Free Jet-Injection System with Lidocaine Are Contrary To Published Reports: In Response

Lidocaine needle-free jet-injection system value for money?

Lidocaine needle-free jet-injection system value for money?