scholarly journals Development of Soft sEMG Sensing Structures Using 3D-Printing Technologies

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4292
Author(s):  
Gerjan Wolterink ◽  
Pedro Dias ◽  
Remco G. P. Sanders ◽  
Frodo Muijzer ◽  
Bert-Jan van Beijnum ◽  
...  

3D printing of soft EMG sensing structures enables the creation of personalized sensing structures that can be potentially integrated in prosthetic, assistive and other devices. We developed and characterized flexible carbon-black doped TPU-based sEMG sensing structures. The structures are directly 3D-printed without the need for an additional post-processing step using a low-cost, consumer grade multi-material FDM printer. A comparison between the gold standard Ag/AgCl gel electrodes and the 3D-printed EMG electrodes with a comparable contact area shows that there is no significant difference in the EMG signals’ amplitude. The sensors are capable of distinguishing a variable level of muscle activity of the biceps brachii. Furthermore, as a proof of principle, sEMG data of a 3D-printed 8-electrode band are analyzed using a patten recognition algorithm to recognize hand gestures. This work shows that 3D-printed sEMG electrodes have great potential in practical applications.

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2518
Author(s):  
Nunzio Cennamo ◽  
Lorena Saitta ◽  
Claudio Tosto ◽  
Francesco Arcadio ◽  
Luigi Zeni ◽  
...  

In this work, a novel approach to realize a plasmonic sensor is presented. The proposed optical sensor device is designed, manufactured, and experimentally tested. Two photo-curable resins are used to 3D print a surface plasmon resonance (SPR) sensor. Both numerical and experimental analyses are presented in the paper. The numerical and experimental results confirm that the 3D printed SPR sensor presents performances, in term of figure of merit (FOM), very similar to other SPR sensors made using plastic optical fibers (POFs). For the 3D printed sensor, the measured FOM is 13.6 versus 13.4 for the SPR-POF configuration. The cost analysis shows that the 3D printed SPR sensor can be manufactured at low cost (∼15 €) that is competitive with traditional sensors. The approach presented here allows to realize an innovative SPR sensor showing low-cost, 3D-printing manufacturing free design and the feasibility to be integrated with other optical devices on the same plastic planar support, thus opening undisclosed future for the optical sensor systems.


2021 ◽  
Vol 7 ◽  
Author(s):  
Jasamine Coles-Black ◽  
Damien Bolton ◽  
Jason Chuen

Introduction: 3D printed patient-specific vascular phantoms provide superior anatomical insights for simulating complex endovascular procedures. Currently, lack of exposure to the technology poses a barrier for adoption. We offer an accessible, low-cost guide to producing vascular anatomical models using routine CT angiography, open source software packages and a variety of 3D printing technologies.Methods: Although applicable to all vascular territories, we illustrate our methodology using Abdominal Aortic Aneurysms (AAAs) due to the strong interest in this area. CT aortograms acquired as part of routine care were converted to representative patient-specific 3D models, and then printed using a variety of 3D printing technologies to assess their material suitability as aortic phantoms. Depending on the technology, phantoms cost $20–$1,000 and were produced in 12–48 h. This technique was used to generate hollow 3D printed thoracoabdominal aortas visible under fluoroscopy.Results: 3D printed AAA phantoms were a valuable addition to standard CT angiogram reconstructions in the simulation of complex cases, such as short or very angulated necks, or for positioning fenestrations in juxtarenal aneurysms. Hollow flexible models were particularly useful for device selection and in planning of fenestrated EVAR. In addition, these models have demonstrated utility other settings, such as patient education and engagement, and trainee and anatomical education. Further study is required to establish a material with optimal cost, haptic and fluoroscopic fidelity.Conclusion: We share our experiences and methodology for developing inexpensive 3D printed vascular phantoms which despite material limitations, successfully mimic the procedural challenges encountered during live endovascular surgery. As the technology continues to improve, 3D printed vascular phantoms have the potential to disrupt how endovascular procedures are planned and taught.


Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Zhonghua Sun

Aim: To determine a printing material that has both elastic property and radiology equivalence close to real aorta for simulation of endovascular stent graft repair of aortic dissection. Background: With the rapid development of three-dimensional (3D) printing technology, a patient-specific 3D printed model is able to help surgeons to make better treatment plan for Type B aortic dissection patients. However, the radiological properties of most 3D printing materials have not been well characterized. This study aims to investigate the appropriate materials for printing human aorta with mechanical and radiological properties similar to the real aortic computed tomography (CT) attenuation. Objective: Quantitative assessment of CT attenuation of different materials used in 3D printed models of aortic dissection for developing patient-specific 3D printed aorta models to simulate type B aortic dissection. Method: A 25-mm length of aorta model was segmented from a patient’s image dataset with diagnosis of type B aortic dissection. Four different elastic commercial 3D printing materials, namely Agilus A40 and A50, Visijet CE-NT A30 and A70 were selected and printed with different hardness. Totally four models were printed out and conducted CT scanned twice on a 192-slice CT scanner using the standard aortic CT angiography protocol, with and without contrast inside the lumen.Five reference points with region of interest (ROI) of 1.77 mm2 were selected at the aortic wall and intimal flap and their Hounsfield units (HU) were measured and compared with the CT attenuation of original CT images. The comparison between the patient’s aorta and models was performed through a paired-sample t-test to determine if there is any significant difference. Result: The mean CT attenuation of aortic wall of the original CT images was 80.7 HU. Analysis of images without using contrast medium showed that the material of Agilus A50 produced the mean CT attenuation of 82.6 HU, which is similar to that of original CT images. The CT attenuation measured at images acquired with other three materials was significantly lower than that of original images (p<0.05). After adding contrast medium, Visijet CE-NT A30 had an average CT attenuation of 90.6 HU, which is close to that of the original images with statistically significant difference (p>0.05). In contrast, the CT attenuation measured at images acquired with other three materials (Agilus A40, A50 and Visiject CE-NT A70) was 129 HU, 135 HU and 129.6 HU, respectively, which is significantly higher than that of original CT images (p<0.05). Conclusion: Both Visijet CE-NT and Agilus have tensile strength and elongation close to real patient’s tissue properties producing similar CT attenuation. Visijet CE-NT A30 is considered the appropriate material for printing aorta to simulate contrast-enhanced CT imaging of type B aortic dissection. Due to lack of body phantom in the experiments, further research with simulation of realistic anatomical body environment should be conducted.


Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 783 ◽  
Author(s):  
Matthias Kahr ◽  
Wilfried Hortschitz ◽  
Harald Steiner ◽  
Michael Stifter ◽  
Andreas Kainz ◽  
...  

This paper reports a novel 3D printed MEMS magnetometer with optical readout, which demonstrates the advantages of 3D printing technology in terms of rapid prototyping. Low-cost and fast product development cycles favour 3D printing as an effective tool. Sensitivity measurement with such devices indicate high accuracy and good structural performance, considering material and technological uncertainties. This paper is focusing on the novelty of the rapid, 3D-printing prototyping approach and verification of the working principle for printed MEMS magnetometers.


2020 ◽  
Vol 44 (2) ◽  
pp. 69-73
Author(s):  
Paul D. Bishop ◽  
Thomas Fultz ◽  
Lisa Smith ◽  
Ryan S. Klatte ◽  
Francis Loth ◽  
...  

Three-dimensional (3D) printing of anatomical structures has yielded valuable models for simulation, education, and surgical planning applications. Applications for 3D printing have continued to expand to include some ultrasound applications. The goal of this effort was to evaluate if a 3D printed model of a superficial femoral artery (SFA) would have realistic ultrasound characteristics. A computed tomography scan was 3D reconstructed and segmented using TeraRecon Aquarius Intuition software (TeraRecon, Foster City, California) to obtain an atherosclerotic SFA geometry. Both the lumen geometry and calcified plaque geometry of the SFA were exported as a stereolithographic (STL) file. The STL file was printed with An Object350 Connex 3D System using 2 different materials selected based on published elastic modulus data. VeroWhite was selected for the calcified plaque and TangoPlus Clear was selected for the artery wall. After printing, the SFA model was imaged in a water bath with a Phillips IU22 duplex ultrasound console and L12-9 ultrasound probe. Ultrasound imaging of the SFA model yielded grayscale views of artery geometry. Lumen geometry of the SFA model was similar to the actual artery geometry. Ultrasound was able to discern between the 3D print materials and visualize regions with stenosis. Suboptimal ultrasound parameters of echogenicity and wave velocity noted to differ from biological tissue. Total 3D print material cost was estimated at below $20. Although the 3D printed model did not have fully accurate ultrasound characteristics, it still provided realistic imaging. With further research, 3D printed models may offer a low-cost alternative for ultrasound phantoms.


2019 ◽  
Vol 11 (1) ◽  
pp. 14-23 ◽  
Author(s):  
W. H. Ho ◽  
I. J. Tshimanga ◽  
M. N. Ngoepe ◽  
M. C. Jermy ◽  
P. H. Geoghegan

Abstract Purpose Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication. Methods Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin. Results An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH4SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies. Conclusions This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.


Author(s):  
Frank Celentano ◽  
Nicholas May ◽  
Edward Simoneau ◽  
Richard DiPasquale ◽  
Zahra Shahbazi ◽  
...  

Professional musicians today often invest in obtaining antique or vintage instruments. These pieces can be used as collector items or more practically, as performance instruments to give a unique sound of a past music era. Unfortunately, these relics are rare, fragile, and particularly expensive to obtain for a modern day musician. The opportunity to reproduce the sound of an antique instrument through the use of additive manufacturing (3D printing) can make this desired product significantly more affordable. 3D printing allows for duplication of unique parts in a low cost and environmentally friendly method, due to its minimal material waste. Additionally, it allows complex geometries to be created without the limitations of other manufacturing techniques. This study focuses on the primary differences, particularly sound quality and comfort, between saxophone mouthpieces that have been 3D printed and those produced by more traditional methods. Saxophone mouthpieces are commonly derived from a milled blank of either hard rubber, ebonite or brass. Although 3D printers can produce a design with the same or similar materials, they are typically created in a layered pattern. This can potentially affect the porosity and surface of a mouthpiece, ultimately affecting player comfort and sound quality. To evaluate this, acoustic tests will be performed. This will involve both traditionally manufactured mouthpieces and 3D prints of the same geometry created from x-ray scans obtained using a ZEISS Xradia Versa 510. The scans are two dimensional images which go through processes of reconstruction and segmentation, which is the process of assigning material to voxels. The result is a point cloud model, which can be used for 3D printing. High quality audio recordings of each mouthpiece will be obtained and a sound analysis will be performed. The focus of this analysis is to determine what qualities of the sound are changed by the manufacturing method and how true the sound of a 3D printed mouthpiece is to its milled counterpart. Additive manufacturing can lead to more inconsistent products of the original design due to the accuracy, repeatability and resolution of the printer, as well as the layer thickness. In order for additive manufacturing to be a common practice of mouthpiece manufacturing, the printer quality must be tested for its precision to an original model. The quality of a 3D print can also have effects on the comfort of the player. Lower quality 3D prints have an inherent roughness which can cause discomfort and difficulty for the musician. This research will determine the effects of manufacturing method on the sound quality and overall comfort of a mouthpiece. In addition, we will evaluate the validity of additive manufacturing as a method of producing mouthpieces.


2021 ◽  
Vol 8 ◽  
Author(s):  
Qian Zhao ◽  
Zhenglei Yu ◽  
Yunhong Liang ◽  
Lei Ren ◽  
Luquan Ren

Near infrared laser- (NIR-) driven intelligent hydrogel actuator systems including printable N-isopropylacrylamide- (NIPAm-) nanosized synthetic hectorite clay-nanofibrillated cellulose (NFC) hydrogels and NIPAm-4-hydroxybutyl acrylate- (4HBA-) NFC hydrogels with a high response rate were prepared via three-dimensional (3D) printing and hydrothermal synthesis, respectively. The addition of NFC was beneficial to the improvement in rheology. The 3D printed intelligent hydrogel actuators with a structure pattern of Model I and Model II exhibited the saddle and inverted saddle deformations, respectively, to prove the validity of 3D printing. In order to improve the response rate and enrich movement patterns, the hydrothermal synthesized intelligent hydrogel actuators were prepared on the base of the 3D printed intelligent hydrogel compositions. The addition of NFC maintained the controllable NIR response. Based on a wedge-shaped design, the hydrothermal synthesized intelligent hydrogel pushed the resin ball with weight of 130 mg forward 8 mm in 39 s. By changing the torque values of a hydrogel in a different direction, the actuator realized controllable continuous rollover movement. Attributed to the longilineal shape, the intelligent hydrogel actuator reached an effective displacement of 20 mm in 10 s via a forward movement. The characteristics and structure design of a hydrogel material significantly realized multiple controllable functional four-dimensional (4D) printed deformations and movements. The combination of advantages of the 3D printed and hydrothermal synthesized intelligent hydrogels provided a new direction of development and abundant material candidates for the practical applications of 4D printing in soft robot, information sensing, and health engineering.


2021 ◽  
Vol 18 (1) ◽  
pp. 07-13
Author(s):  
Neha Thakur ◽  
Hari Murthy

Three-dimensional printing (3DP) is a digitally-controlled additive manufacturing technique used for fast prototyping. This paper reviews various 3D printing techniques like Selective Laser Sintering (SLS), Fused Deposition Modeling, (FDM), Semi-solid extrusion (SSE), Stereolithography (SLA), Thermal Inkjet (TIJ) Printing, and Binder jetting 3D Printing along with their application in the field of medicine. Normal medicines are based on the principle of “one-size-fits-all”. This is not true always, it is possible medicine used for curing one patient is giving some side effects to another. To overcome this drawback “3D Printed medicines” are developed. In this paper, 3D printed medicines forming different Active Pharmaceutical Ingredients (API) are reviewed. Printed medicines are capable of only curing the diseases, not for the diagnosis. Nanomedicines have “theranostic” ability which combines therapeutic and diagnostic. Nanoparticles are used as the drug delivery system (DDS) to damaged cells’ specific locations. By the use of nanomedicine, the fast recovery of the disease is possible. The plant-based nanoparticles are used with herbal medicines which give low-cost and less toxic medication called nanobiomedicine. 4D and 5D printing technology for the medical field are also enlightened in this paper.


BioTechniques ◽  
2021 ◽  
Author(s):  
Vedika J Shenoy ◽  
Chelsea ER Edwards ◽  
Matthew E Helgeson ◽  
Megan T Valentine

3D printing holds potential as a faster, cheaper alternative compared with traditional photolithography for the fabrication of microfluidic devices by replica molding. However, the influence of printing resolution and quality on device design and performance has yet to receive detailed study. Here, we investigate the use of 3D-printed molds to create staggered herringbone mixers (SHMs) with feature sizes ranging from ∼100 to 500 μm. We provide guidelines for printer calibration to ensure accurate printing at these length scales and quantify the impacts of print variability on SHM performance. We show that SHMs produced by 3D printing generate well-mixed output streams across devices with variable heights and defects, demonstrating that 3D printing is suitable and advantageous for low-cost, high-throughput SHM manufacturing.


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