Optimization of online particle counting with a 3D-printed bubble trap

AbstractParticulate evaluation is needed for the approval of cardiovascular devices. Air bubbles lead to higher particle counts when light obscuration method (LOM) is used. The aim of the study was to test a custom made bubble trap that removes air bubbles (2 - 100 μm) from a flow circuit prior to online particle counting. Artificially generated air bubbles were counted with an online particle counter with and without the bubble trap. Air bubbles were reduced by about 71 % to 91 % by using the bubble trap.

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Dynamic image analysis of transparent particles released during the simulated use test of cardiovascular devices

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2019-0052 ◽

2019 ◽

Vol 5 (1) ◽

pp. 203-206

Author(s):

Anja Kurzhals ◽

Christoph Brandt-Wunderlich ◽

Niels Grabow ◽

Wolfram Schmidt ◽

Klaus-Peter Schmitz

Keyword(s):

Image Analysis ◽

Detection Threshold ◽

Dynamic Imaging ◽

Cardiovascular Devices ◽

Imaging Device ◽

Dynamic Image ◽

Light Obscuration ◽

Particle Counting ◽

Particle Counts ◽

Dynamic Image Analysis

AbstractFor product approval of coated cardiovascular devices, the assessment of particle release is essential. Particularly challenging are delivery systems equipped with hydrophilic coatings releasing highly transparent particles. The aim of this study was to compare two different methods of particle counting, namely the light obscuration method and the dynamic image analysis (DIA), with respect to optical transparent particles. The particles were collected during the simulated use of cardiovascular catheters and analysed in suspension with a dynamic imaging device (FlowCam, Fluid Imaging Technologies). Particles were detected by a greyscale threshold and imaged to analyse their shape and transparency. The statistical influence of the threshold on particle counts and size distribution was determined and compared to light obscuration particle counting (Model 9703 with sensor HRLD 400CE, HIAC ROYCO). The light obscuration method provided lower particle counts in suspensions containing a high amount of transparent particles. The lower the detection threshold, the higher the particle counts were. In conclusion, it is important to adapt the threshold value for samples that are expected to contain a high amount of transparent particles. DIA may be suggested as a valuable additional method for particulate analysis.

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Improvement of monitoring of tertiary filtration with particle counting

Water Science & Technology Water Supply ◽

10.2166/ws.2006.001 ◽

2006 ◽

Vol 6 (1) ◽

pp. 1-9

Author(s):

V. Miska ◽

J.H.J.M. van der Graaf ◽

J. de Koning

Keyword(s):

Particle Surface ◽

Minor Effect ◽

Particle Size Distributions ◽

Particle Volume ◽

Mass Distributions ◽

Particle Counting ◽

Total Particle ◽

Particle Counts ◽

A Minor ◽

Sample Dilution

Nowadays filtration processes are still monitored with conventional analyses like turbidity measurements and, in case of flocculation–filtration, with phosphorus analyses. Turbidity measurements have the disadvantage that breakthrough of small flocs cannot be displayed, because of the blindness regarding changes in the mass distributions. Additional particle volume distributions calculated from particle size distributions (PSDs) would provide a better assessment of filtration performance. Lab-scale experiments have been executed on a flocculation–filtration column fed with effluent from WWTP Beverwijk in The Netherlands. Besides particle counting at various sampling points, the effect of sample dilution on the accuracy of PSD measurements has been reflected. It was found that the dilution has a minor effect on PSD of low turbidity samples such as process filtrate. The correlation between total particle counts, total particle volume (TPV) and total particle surface is not high but is at least better for diluted measurements of particles in the range 2–10 μm. Furthermore, possible relations between floc-bound phosphorus and TPV removal had been investigated. A good correlation coefficient is found for TPV removal versus floc-bound phosphorus removal for the experiments with polyaluminiumchloride and the experiments with single denitrifying and blank filtration.

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3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

Applied Sciences ◽

10.3390/app11062563 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2563

Author(s):

Ivan Grgić ◽

Vjekoslav Wertheimer ◽

Mirko Karakašić ◽

Željko Ivandić

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Tensile Tests ◽

Biomechanical Properties ◽

Testing Procedure ◽

Laboratory Equipment ◽

Fused Deposition ◽

Custom Made ◽

3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

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Recurrent contracted sockets treated with personalized, three-dimensionally printed conformers and buccal grafts

European Journal of Ophthalmology ◽

10.1177/11206721211000013 ◽

2021 ◽

pp. 112067212110000

Author(s):

Annabel LW Groot ◽

Jelmer S Remmers ◽

Roel JHM Kloos ◽

Peerooz Saeed ◽

Dyonne T Hartong

Keyword(s):

Three Dimensional ◽

Case Series ◽

Secondary Outcome ◽

Retrospective Case ◽

Upper Eyelid ◽

Ocular Prosthesis ◽

Buccal Mucosal Graft ◽

Custom Made ◽

3D Printed

Purpose: Recurrent contracted sockets are complex situations where previous surgeries have failed, disabling the wear of an ocular prosthesis. A combined method of surgery and long-term fixation using custom-made, three-dimensional (3D) printed conformers is evaluated. Methods: Retrospective case series of nine patients with recurrent excessive socket contraction and inability to wear a prosthesis, caused by chemical burns ( n = 3), fireworks ( n = 3), trauma ( n = 2) and enucleation and radiotherapy at childhood due to optic nerve glioma ( n = 1) with three average previous socket surgeries (range 2–6). Treatment consisted of a buccal mucosal graft and personalized 3D-printed conformer designed to be fixated to the periosteum and tarsal plates for minimal 2 months. Primary outcome was the retention of an ocular prosthesis. Secondary outcome was the need for additional surgeries. Results: Outcomes were measured at final follow-up between 7 and 36 months postoperatively (mean 20 months). Eight cases were able to wear an ocular prosthesis after 2 months. Three cases initially treated for only the upper or only the lower fornix needed subsequent surgery for the opposite fornix for functional reasons. Two cases had later surgery for cosmetic improvement of upper eyelid position. Despite pre-existing lid abnormalities (scar, entropion, lash deficiency), cosmetic outcome was judged highly acceptable in six cases because of symmetric contour and volume, and reasonably acceptable in the remaining two. Conclusions: Buccal mucosal transplant fixated with a personalized 3D-designed conformer enables retention of a well-fitted ocular prosthesis in previously failed socket surgeries. Initial treatment of both upper and lower fornices is recommended to avoid subsequent surgeries for functional reasons.

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3D-Printed Connector for Revision Limb Salvage Surgery in Long Bones Previously Using Customized Implants

Metals ◽

10.3390/met11050707 ◽

2021 ◽

Vol 11 (5) ◽

pp. 707

Author(s):

Jong-Woong Park ◽

Hyun-Guy Kang ◽

June-Hyuk Kim ◽

Han-Soo Kim

Keyword(s):

Limb Salvage ◽

Salvage Surgery ◽

Revisional Surgery ◽

Limb Salvage Surgery ◽

Musculoskeletal Tumor ◽

Musculoskeletal Tumor Society ◽

Proximal Ulna ◽

Custom Made ◽

Orthopedic Oncology ◽

3D Printed

In orthopedic oncology, revisional surgery due to mechanical failure or local recurrence is not uncommon following limb salvage surgery using an endoprosthesis. However, due to the lack of clinical experience in limb salvage surgery using 3D-printed custom-made implants, there have been no reports of revision limb salvage surgery using a 3D-printed implant. Herein, we present two cases of representative revision limb salvage surgeries that utilized another 3D-printed custom-made implant while retaining the previous 3D-printed custom-made implant. A 3D-printed connector implant was used to connect the previous 3D-printed implant to the proximal ulna of a 40-year-old man and to the femur of a 69-year-old woman. The connector bodies for the two junctions of the previous implant and the remaining host bone were designed for the most functional position or angle by twisting or tilting. Using the previous 3D-printed implant as a taper, the 3D-printed connector was used to encase the outside of the previous implant. The gap between the previous implant and the new one was subsequently filled with bone cement. For both the upper and lower extremities, the 3D-printed connector showed stable reconstruction and excellent functional outcomes (Musculoskeletal Tumor Society scores of 87% and 100%, respectively) in the short-term follow-up. To retain the previous 3D-printed implant during revision limb salvage surgery, an additional 3D-printed implant may be a feasible surgical option.

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Custom-Made 3D-Printed Implants as Novel Approach to Reconstructive Surgery after Oncologic Resection in Pediatric Patients

Journal of Clinical Medicine ◽

10.3390/jcm10051056 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1056

Author(s):

Giovanni Beltrami ◽

Gabriele Ristori ◽

Anna Maria Nucci ◽

Alberto Galeotti ◽

Angela Tamburini ◽

...

Keyword(s):

Pediatric Patients ◽

Soft Tissues ◽

Lower Limbs ◽

Host Bone ◽

Limb Salvage Surgery ◽

Musculoskeletal Tumor ◽

Musculoskeletal Tumor Society ◽

Custom Made ◽

3D Printed

Recently, custom-made 3D-printed prostheses have been introduced for limb salvage surgery in adult patients, but their use has not been described in pediatric patients. A series of 11 pediatric patients (mean age 10.8 years; range 2–13) with skeletal tumors treated with custom-made implants for the reconstruction of bony defects is described. Patients were followed up every 3 months. Functional results were evaluated by the Musculoskeletal Tumor Society Score (MSTS) for upper and lower limbs. The mean follow-up was 25.7 months (range 14–44). Three patients died after a mean of 19.3 months postoperatively—two because of disease progression and the other from a previous malignancy. Three patients experienced complications related to soft tissues. One patient required device removal, debridement, and antibiotic pearls for postoperative infection. Partial osseointegration between grafts and host bone was observed within a mean of 4 months. At the final follow-up, mean MSTS score was 75%. 3D prostheses may yield biological advantages due to possible integration with the host bone and also through the use of vascularized flaps. Further research is warranted.

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Total ulna replacement with a 3D-printed custom-made prosthesis after en bloc tumor resection: A case report

Pediatric Blood & Cancer ◽

10.1002/pbc.27522 ◽

2018 ◽

Vol 66 (2) ◽

pp. e27522 ◽

Cited By ~ 1

Author(s):

Xiang Fang ◽

Wenli Zhang ◽

Zeping Yu ◽

Hongyuan Liu ◽

Yan Xiong ◽

...

Keyword(s):

Case Report ◽

Tumor Resection ◽

En Bloc ◽

Custom Made ◽

3D Printed

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Is three-dimensional–printed custom-made ultra-short stem with a porous structure an acceptable reconstructive alternative in peri-knee metaphysis for the tumorous bone defect?

World Journal of Surgical Oncology ◽

10.1186/s12957-021-02355-7 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Jie Wang ◽

Jingjing An ◽

Minxun Lu ◽

Yuqi Zhang ◽

Jingqi Lin ◽

...

Keyword(s):

Porous Structure ◽

Aseptic Loosening ◽

Bone Defect ◽

Short Stem ◽

Leg Length ◽

Musculoskeletal Tumor Society ◽

Custom Made ◽

Orthopedic Oncology ◽

3D Printed

Abstract Background Long-lasting reconstruction after extensive resection involving peri-knee metaphysis is a challenging problem in orthopedic oncology. Various reconstruction methods have been proposed, but they are characterized by a high complication rate. The purposes of this study were to (1) assess osseointegration at the bone implant interface and correlated incidence of aseptic loosening; (2) identify complications including infection, endoprosthesis fracture, periprosthetic fracture, leg length discrepancy, and wound healing problem in this case series; and (3) evaluate the short-term function of the patient who received this personalized reconstruction system. Methods Between September 2016 and June 2018, our center treated 15 patients with malignancies arising in the femur or tibia shaft using endoprosthesis with a 3D-printed custom-made stem. Osseointegration and aseptic loosening were assessed with digital tomosynthesis. Complications were recorded by reviewing the patients’ records. The function was evaluated with the 1993 version of the Musculoskeletal Tumor Society (MSTS-93) score at a median of 42 (range, 34 to 54) months after reconstruction. Results One patient who experienced early aseptic loosening was managed with immobilization and bisphosphonates infusion. All implants were well osseointegrated at the final follow-up examination. There are two periprosthetic fractures intraoperatively. The wire was applied to assist fixation, and the fracture healed at the latest follow-up. Two patients experienced significant leg length discrepancies. The median MSTS-93 score was 26 (range, 23 to 30). Conclusions A 3D-printed custom-made ultra-short stem with a porous structure provides acceptable early outcomes in patients who received peri-knee metaphyseal reconstruction. With detailed preoperative design and precise intraoperative techniques, the reasonable initial stability benefits osseointegration to osteoconductive porous titanium, and therefore ensures short- and possibly long-term durability. Personalized adaptive endoprosthesis, careful intraoperative operation, and strict follow-up management enable effective prevention and treatment of complications. The functional results in our series were acceptable thanks to reliable fixation in the bone-endoprosthesis interface and an individualized rehabilitation program. These positive results indicate this device series can be a feasible alternative for critical bone defect reconstruction. Nevertheless, longer follow-up is required to determine whether this technique is superior to other forms of fixation.

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