Background

The medical needle or syringe is quite interesting when you take time to understand the many layers of development it has undergone. Clearly a design of necessities, an Irish doctor invented the first medical needle prototype in 1844 for the first subcutaneous injection of its kind to inject a sedative to treat neuralgia. Improvements to the medical needle followed suit in 1853 in the form of a fine needle syringe developed by Charles Ravaz and Alexander Wood.

Early designs through the 1950s featured glass syringes that required rigorous cleaning and sterilizing, but patents introducing disposable syringes became the standard. The introduction of the disposable plastic syringe ushered in a great deal of convenience especially as large-scale polio immunization campaigns began to take place, which translated into laborious administration procedures. The HYPAK syringe was the medical device responsible for administering one million polio vaccines. The novel glass injector model was mass produced and made by New Jersey-based Becton, Dickinson, and Company, also known today as BD.

Then in 1956, looking to facilitate his animal vaccination process, Colin Murdoch developed a disposable pre-filled syringe. In 1961, the BD Company commercially scaled Murdoch’s unique injection prototype, the Plastipak, to gain a foothold on the disposable syringe market. The medical syringe disposable attribute continues as a mainstay in the commercial market, but with many evolved improvements to the original design.

Modern drug delivery systems

Many of the evolutionary aspects concerning modern drug delivery development are centered around improving the patient experience. The industry understands the fear associated with needles and therefore has taken measures to reduce the pain associated with injections. Other design considerations focused on reusability and disposable options to help keep costs down and minimize risk factors associated with use.

Interestingly, the overall design of the original injection needle hasn't changed rapidly over the years. Medical device manufacturers suggest the slow-moving regulatory requirements have stalled the commercialization process, but we have seen many amendments directed toward the industry to help optimize safety standards such as the Needlestick Safety and Prevention Act of 2000.

Reflecting the new safety standards, the modern medical needle is more smartly designed to fulfill diverse clinical needs. For example, there are syringes specifically for intravenous, intradermal, intramuscular injections, and blood collection, whereas specialized considerations are applied toward needle length, size, fluid types and drug viscosity when creating drug delivery devices.

Innovations in the market are demonstrating next-level technology, especially in clinically relevant areas such as surgical, self-monitoring and administration, OBGYN and dental applications. Notable device disruptors include many exciting manufacturing advances in the following areas:

Insulin management

One of the best examples of improvements in patient administered injections are those associated with insulin management. The introduction of smart pens and injection port and inserter patches represented one of the largest paradigm-shifts within a condition-specific (diabetes) industry. The improvements were met with much enthusiasm in those whose lives depend on multiple sugar tests throughout the day to regulate insulin levels.

Retractable needles

Conventional syringe designs leave an exposed needle at the time of post-injection. The user is then tasked with placing it in a Sharps container, but delays that happen often in hospital settings leave an unintentional window for non-intended punctures to occur. Consequently, safety measures spurred the retractable needle into fruition.

Introduced in 1989 by Thomas Shaw, retractable syringes feature an enhanced safety profile for users in high-trafficked clinical areas such as hospitals. Retractable needles work by way of a mechanism that retracts the needle back into the body of the syringe, preventing the user and others from accidental sticks.

Needle-free syringes

Needle-free connectors are injection devices that connect directly to the infusion line without the need for a needle. Recognized for an optimized safety profile, they are used in healthcare settings to reduce the risk of accidental punctures and cross-contamination. A report performed in 2020 cited that globally, Healthcare workers (HCWs) experience in excess of 2 million occupational needle-stick injuries (NSIs) annually.

Jet injectors

Favored by the military, jet injectors use a high pressure or a spring-powered force to deliver a vaccine or therapeutic by means of a narrow stream of fluid that can penetrate the skin in lightning speed without using a power source or a needle. The FDA halted its use citing issues with infections and other various incidents that compromise patient and user safety standards. To date, the U.S. Food & Drug Administration hasn't approved jet injector devices for use, further amplified by even discouraging use during the coronavirus pandemic due to needle shortages.

Early-stage devices

Surgical smart-needles

From a design perspective, the surgical smart needle is a brand-new methodology for delivering therapeutics to targeted areas, retrieving tissue samples, debulking or sectioning pieces of a tumor out in diagnostic procedures: brachytherapy, biopsy and cancer lumpectomy. These types of medical devices for precise operating room procedures utilize a state-of-the-art robotic needle insertion system, with advanced actuators, and control programs that help to guide the smart needle inside tissue with ultrasound imaging, or electromagnetic position feedback.

Bioimpedance-based biopsy needles are also a form of smart needle and is sometimes referred to as a tissue penetrating smart needle because the tip once inserted into the targeted tissue can provide real-time classification data. Introduced into clinical studies, the biopsy needle has undergone some modifications to mitigate certain clinical challenges and now uses a size and tip geometry equal comprised of biocompatible and sterilizable materials.

Intelligent tissue-sensitive-smart needles

Like the tissue penetrating needle design capable of obtaining classification data, new developmental research led by Harvard Medical School scientists at Brigham and Women’s Hospital, feature impressive clinical data on their new device, a tissue-sensitive intelligent injector for tissue targeting (i2T2). Capable of detecting minute changes in resistance to deliver medication properly and safely, this intelligent smart needle offers a major advantage toward accuracy and safety since it is completely non-reliant on user technique.

Additionally, another type of cancer diagnostic-needle was also introduced that uses light and optics to analyze real-time heterogeneity and other biomarkers needed to validate the clinical findings. This type of real-time diagnostic technology saves life-saving diagnostic time, as traditional samples would need to be delivered to pathology.

Looking forward

Major movements within this narrow niche market are in motion and there are many more advances in medical needle technology to draw inspiration from. The landscape of innovative medical device designs provides an advanced layer of surgical precision and safety. It is easy to see how the advances could easily result in a permanent shift in healthcare practices once the innovative technologies are fully adopted. Looking forward, we can expect to see continued advancement in the applications, materials, and user viability redefine what's possible in medical needle technology.

About the author

Candace Kastanis, a previous laboratory professional, is a freelance medical and science writer. As a California native and resident, she enjoys the outdoors and spending time with her family and friends. Also a creative writer, Candace is excited about her upcoming fictional novel debut.