Medical Devices, Smart Drug Delivery, Wearables and Technology for the treatment of Diabetes Mellitus.

The field of magnetic robotics aims to obviate physical connections between the actuators and end‐effectors. Such tetherless control may enable new ultraminimally invasive surgical manipulations in clinical settings. While wireless actuation offers advantages in medical applications, the challenge of providing sufficient force to magnetic needles for tissue penetration remains a barrier to practical application. Applying sufficient force for tissue penetration is required for tasks such as biopsy, suturing, cutting, drug delivery, and accessing deep‐seated regions of complex structures in organs such as the eye. To expand the force landscape for such magnetic surgical tools, an impact force‐based suture needle capable of penetrating in vitro and ex vivo samples with 3‐degrees‐of‐freedom (DOF) planar motion is proposed. Using custom‐built 14 and 25 G needles, generation of 410 mN penetration force is demonstrated, a 22.7‐fold force increase with more than 20 times smaller volume compared with similar magnetically guided needles. With the Magnetic Pulse Actuated Collisions for Tissue‐penetrating (MPACT)‐Needle, gauze mesh suturing onto an agar gel is demonstrated. In addition, the tip size is reduced to 25 G, a typical needle size for eye interventions, to demonstrate ex vivo penetration in a rabbit eye towards corneal injections and transscleral drug delivery.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/aisy.202200072

Overcoming the Force Limitations of Magnetic Robotic Surgery: Magnetic Pulse Actuated Collisions for Tissue‐Penetrating‐Needle for Tetherless Interventions

Belt grinding (BG), widely used in Inconel 718 machining, can result in desired surface strengthening. However, the grinding-induced strengthening effect diminishes in subsequent belt polishing (BP), thus deserving special attention. This paper proposes isotropic etching polishing (IEP) as an alternative finishing process to effectively retain the robotic BG strengthened layer and concurrently improve the surface quality of BG Inconel 718. The strengthening effect and quality of surface layers processed by BG, BG + BP and BG + IEP are systematically compared and evaluated. The results indicate that BG can introduce an ~150-μm-thickness gradient strengthened layer, featured by high microhardness, significant domain refinement, large microstrain increment, high residual compressive stress, and a strong 〈100〉 texture. The optimized IEP retains approximately 86.1% (maximum) of the strengthening effect and 75.1% of the BG strengthened layer. The microhardness of the BG + IEP surface reaches 523 HV, which is about 6 times higher than that of the BG + BP surface. The BG + IEP surface of superior quality is very smooth (platykurtic) and clean, in contrast to the rough and defective BG + BP surface. The IEP is proposed to be an effective way to simultaneously realize the BG strengthened layer retention and the surface quality improvement. 

Isotropic etching polishing of belt ground Inconel 718 to improve surface strengthening and quality

Fracture behaviour of human skin in deep needle insertion can be captured using validated cohesive zone finite-element method.

ABSTRACT Bone plates are essential for providing mechanical support during the healing of bone fractures by adapting to the biochemical environment. The surface quality of bone plates plays a vital role in their sustainability under adverse conditions. Magnetorheological Finishing (MRF) is an advanced surface finishing process that provides high surface finishing without disturbing the polished surface topography. However, while mapping to the workspace has a hole or pocket feature, the Magnetorheological (MR) fluid is not stable and gets trapped inside. Hence, a Feature-based hybrid MRF planning system is developed to overcome the challenge during MRF. The final average surface roughness (Ra) value of 21.56 nm from its initial roughness value of 324.12 nm is achieved on the polished surface bone plate made of Ti–6Al–4V. The enhancement in the surface characteristics of the MRF polished surface leads to the biomaterial's enhanced wear and corrosion resistance.

Surface properties and biocompatibility studies on bone plate by magnetorheological finishing

Fear of injection-related pain is a drawback to injectable therapy. Hypodermic injections are a cause for great anxiety and reduced adherence to the subcutaneous application of insulin for glycemic control in diabetics or in the treatment of multiple sclerosis, increasing the risk of complications and mortality. Injured or sick people have to undergo several daily injections, forcing them to rotate the veins and regions used to recover from the trauma caused by the perforation of the skin, tissue, muscles, veins, and arteries. People who suffer from type 1 diabetes mellitus (DM1) need to have their glycemic control 3 to 5 times a day and to take insulin up to 3 times a day. In both cases, the patient needs to perforate the skin. To quantify the pain perceived by the patients depends on the evaluation of each patient and therefore is subjective. This study aims to understand the application and self-application of hypodermic injections and decrease pain during its application and the phobia of the patient, following the reasoning that the lower the effort to penetrate the needle, the less trauma in the tissue and therefore the pain provoked. For that, it was analyzed how some of the characteristics of the needle can influence the sensation of pain in the injection. The needle penetration effort was measured in an artificial tissue (substitute skin model) for different cannula diameters, roughness, depth of penetration, lubrication, and angles of the perforating tip bevel. This study aimed to find alternatives to facilitate the application and self-application of hypodermic injections, increase safety and comfort, and reduce the pain intensity perceived by the patient. To do this, the bevel of needles used repeatedly was analyzed in the profile projector and SEM to verify the loss of the profile or the formation of burrs that could hamper the penetration or traumatize the tissue during the reuse of needles. It has also been mechanically analyzed, which can be done to prevent that the needles used in the subcutaneous application do not inadvertently reach the muscle. The greater penetration effort observed in the needles with greater angle of the bevel is responsible for the patient’s perception of pain.

/pdf/variation-of-the-penetration-effort-in-an-artificial-tissue-20ahmrlzax.pdf

Variation of the Penetration Effort in an Artificial Tissue by Hypodermic Needles.

Roller burnishing process is a post-machining surface finishing technique that has an advantage over other finishing processes, such as shot blasting or abrasive-tooling processes, because of its s...

Samuel José Casarin

Papers

Variation of the Penetration Effort in an Artificial Tissue by Hypodermic Needles.

Effect of burnishing on Inconel 718 workpiece surface heated by infrared radiation

Analysis of the Inconel 718 properties after roller burnishing.