Ultrathin Endoscope Research Articles

Tu1139 - Endosheath Ultrathin Transnasal Endoscopy as Cost-effective Method for Screening Patients with Gerd Symptoms

Tu1139 - Endosheath Ultrathin Transnasal Endoscopy as Cost-effective Method for Screening Patients with Gerd Symptoms

Biliary Cannulation Using the Ultra-thin Endoscope for Removal of a Proximally Migrated Fully Covered Self-expanding Metal Stent

Biliary Cannulation Using the Ultra-thin Endoscope for Removal of a Proximally Migrated Fully Covered Self-expanding Metal Stent

Evaluation and image quality comparison of ultra-thin fibre endoscopes for vascular endoscopy

Abstract Medical applications like vascular endoscopy can provide additional diagnostic value for future procedures [1]. For these applications an optimal compromise between image quality and fibre flexibility has to be identified. Image quality of endoscopes is normally estimated using flat test objects or charts. For the application of vascular endoscopy a tubular test set up seems to be more beneficial. We compare three fibre endoscopes with different diameters and number of integrated fibre according to image quality and flexibility. Based on the results a recommendation for possible applications in vascular endoscopy is given.

Feasibility of transnasal endoscopy in screening for esophageal and gastric varices in patients with chronic liver disease.

Background and study aims Screening for esophageal and gastric varices is indicated for patients with portal hypertension or cirrhosis. Typically, conventional endoscopy is used; however, the need for sedation increases the costs and risks, especially in cirrhotic patients. Use of transnasal endoscopy with an ultrathin endoscope enables study of the upper gastrointestinal tract without the need for sedation. The objective of this study is to evaluate the feasibility of transnasal endoscopy in screening for esophageal and gastric varices in patients with chronic liver disease. Patients and methods This was a prospective study in which transnasal endoscopy was carried out in patients with cirrhosis or portal hypertension who had indications for screening of esophageal and gastric varices. The following variables were evaluated: demographical data, duration of procedure, patient tolerance and acceptance, adverse events (AEs), endoscopic findings and interobserver agreement related to portal hypertension alterations ( kappa index). Results A total of 50 patients entered the study. The most common cause of liver disease was chronic viral hepatitis (66 %). Among the cirrhotic patients, most of the patients were Child-Pugh A (74 %). In 5 patients (10 %), nasal intubation was not possible. Two patients (4 %) experienced minor epistaxis. Tolerance was excellent or good in 92 % according with a visual analogic scale. In 16 patients (32 %), esophageal varices were detected and in 2 patients (4 %) gastric varices were detected. The mean duration of the procedure was 7 minutes. Conclusions Transnasal endoscopy is feasible, effective and well tolerated for screening of esophageal and gastric varices in patients with chronic liver disease. It can be performed in outpatient clinics safely and without the use of sedation.

Pull method percutaneous endoscopic gastrostomy using transnasal ultrathin endoscopy in head and neck cancer.

Pull method percutaneous endoscopic gastrostomy using transnasal ultrathin endoscopy in head and neck cancer.

New flexible endoscopic controlled stapler technique for the treatment of Zenker's diverticulum: A case series.

AIMTo report about the combination and advantages of a stapler-assisted diverticulotomy performed by flexible endoscopy.METHODSFrom November 2014 till December 2015 17 patients (8 female, 9 male, average age 69.8 years) with a symptomatic Zenker diverticulum (mean size 3.5 cm) were treated by inserting a new 5 mm fully rotatable surgical stapler (MicroCutter30 Xchange, Cardica Inc.) next to an ultrathin flexible endoscope through an overtube. The Patients were under conscious sedation with the head reclined in left position, the stapler placed centrally and pushed forward to the bottom of the diverticulum. The septum was divided by the staple rows under flexible endoscopic control.RESULTSIn eleven patients (64.7%) the stapler successfully divided the septum completely. Mean procedure time was 21 min, medium size of the septum was 2.8 cm (range 1.5 cm to 4 cm). In four patients the septum was shorter than 3 cm, in seven longer than 3 cm. To divide the septum, averagely 1.3 stapler cartridges were used. Two minor bleedings occurred. Major adverse events like perforation or secondary haemorrhage did not occur. After an average time of two days patients were discharged from the hospital. In 6 patients (35.3%) the stapler failed due to a thick septum or insufficient reclination of the head. Follow up endoscopy was performed after an average of two months in 9 patients; 4 patients (44.4%) were free of symptoms, 5 patients (55.6%) stated an improvement. A relapse of symptoms did not occur.CONCLUSIONFlexible endoscopic Zenker diverticulotomy by using a surgical stapler is a new, safe and efficient treatment modality. A simultaneously tissue opening and occlusion prevents major complications.

Ultrathin endoscopes based on multicore fibers and adaptive optics: a status review and perspectives.

We take stock of the progress that has been made into developing ultrathin endoscopes assisted by wave front shaping. We focus our review on multicore fiber-based lensless endoscopes intended for multiphoton imaging applications. We put the work into perspective by comparing with alternative approaches and by outlining the challenges that lie ahead.

Novel insights into esophageal diagnostic procedures.

The 21st century offers new advances in diagnostic procedures and protocols in the management of esophageal diseases. This review highlights the most recent advances in esophageal diagnostic technologies, including clinical applications of novel endoscopic devices, such as ultrathin endoscopy and confocal laser endomicroscopy for diagnosis and management of Barrett's esophagus; novel parameters and protocols in high-resolution esophageal manometry for the identification and better classification of motility abnormalities; innovative connections between esophageal motility disorder diagnosis and detection of gastroesophageal reflux disease (GERD); impedance-pH testing for detecting the various GERD phenotypes; performance of distensibility testing for better pathophysiological knowledge of the esophagus and other gastrointestinal abnormalities; and a modern view of positron emission tomography scanning in metastatic disease detection in the era of accountability as a model for examining other new technologies. We now have better tools than ever for the detection of esophageal diseases and disorders, and emerging data are helping to define how well these tools change management and provide value to clinicians. This review features novel insights from multidisciplinary perspectives, including both surgical and medical perspectives, into these new tools, and it offers guidance on the use of novel technologies in clinical practice and future directions for research.

109 Multimodal Endovascular Endoscopy in Carotid Atherosclerotic Disease

Disruption of vulnerable atherosclerotic plaque is the precipitating factor that culminates in thrombosis and ischemia. Current technologies do not have sufficient power to identify subtle thrombogenic lesions (ie, ulcers) in the arterial endoluminal surfaces nor reliably predict markers for future symptomatology. We developed an ultra-thin scanning fiber endoscope (SFE) to directly visualize the endoluminal surface of carotid arteries and identify structural, chemical, and biological markers of vulnerable and complicated atherosclerotic plaques. 1.2 mm and 2.1 mm endoscopes containing single optical fiber scanned by a piezoelectric drive mechanism were developed to illuminate tissue surfaces with red, blue, and green laser beams (RBG). Laser-induced backscattering (reflectance) and tissue fluorescence collected by a ring of optical fibers were then digitalized to reconstruct color videos with large fields of view. Then, SFE was studied ex vivo in human carotid arteries and in vivo in a rabbit model of atherosclerosis. After imaging, specimens were processed for histology; lesions were independently reviewed by 2 pathologists and matched to endoscopic images with analysis of variance. High-definition structural and chemical images of 20 carotid arteries harvested during hospital autopsies revealed 42 lesions. Based on anatomical features and tissue fluorescence, we developed a classifier that enabled identification of: healthy endovascular regions (smooth surfaces with strong homogeneous fluorescence); early plaques (dot or streak-like elevated lesions with low fluorescence); advance plaques (irregular elevated lesions with minimal to absent fluorescence); and complicated plaques (ulcers: punch-out dark-gray lesions with raised irregular bead-like borders and speckled fluorescence pattern; hematoma: absent reflection, black regions, and fluorescence). The image quality and validity of the classifier were reproduced in vivo in an atherogenic rabbit model. Multimodal SFE generates high-definition structural and label-free chemical images, and detects with high sensitivity and specificity small intravascular thrombi and subtle surface thrombogenic lesions in nonstenosing complicated plaques, even in cases not detected by conventional diagnostic modalities. Therefore, it holds the potential for becoming a new imaging platform in cerebrovascular and cardiovascular disease.

Current status of transnasal endoscopy worldwide using ultrathin videoscope for upper gastrointestinal tract.

Transnasal endoscopy with an ultrathin endoscope has been reported to be highly acceptable even without any sedative measures. Poor image quality and complex manipulation have been reported as shortcomings of this type of endoscopy compared with standard transoral endoscopy. However, image quality has improved markedly with the latest ultrathin endoscopes. To investigate the status of clinical use of endoscopes, we recently conducted a questionnaire survey involving 149 facilities (98 in Japan and 51 overseas). In Japan, transnasal endoscopes were being used primarily in clinics (34% in clinics and 9% in hospitals). Overseas, however, transnasal endoscopes were seldom used (1% in hospitals and 0% in clinics). This may be attributable to the complex pretreatment and more challenging manipulation required for transnasal endoscopes. However, it is evident that transnasal endoscopes are highly acceptable for patients. If the pretreatment required is simplified and healthcare physicians improve their skills and understanding, this type of endoscopy will have high potential for common use.

Safety of unsedated PEG placement using transoral ultrathin endoscopy in patients with amyotrophic lateral sclerosis

Background and aims: In patients with amyotrophic lateral sclerosis (ALS), percutaneous endoscopic gastrostomy (PEG) placement under sedation often causes apnea or hypoventilation. The aim of the present study was to assess whether unsedated PEG placement in ALS patients using ultrathin endoscopy (UTE) via the transoral route can improve safety.Methods: Between 2003 and 2013, PEG placement was identified and reviewed in 45 patients with ALS. PEG was performed in 14 patients using transoral UTE without sedation (UTE group), 17 patients using conventional normal-diameter esophagogastroduodenoscopy (C-EGD) without sedation (unsedated C-EGD group) and 14 patients using C-EGD with sedation (sedated C-EGD group). We compared the clinical features, cardiopulmonary data before and during PEG placement, and complications related to PEG placement among the three groups.Results: There were no significant differences in age, male/female ratio, forced vital capacity, blood pressure, oxygen saturation before and during PEG, or major complications among the three groups. No minor complications were observed in the UTE group, whereas apnea and/or hypoventilation were observed in the sedated C-EGD group and aspiration pneumonia was observed in the unsedated C-EGD group.Conclusions: Unsedated PEG placement using transoral UTE in ALS patients is a safe method.

Unusual Esophageal Mass as a Cause of Dysphagia

Question: A 73-year-old man with underlying alcoholic liver cirrhosis presented with a 1-month history of dysphagia. Upper endoscopy performed by his primary physician showed a polypoid lesion with a stricture in the middle esophagus; thus, he was referred for management. The patient has a 25 pack-year smoking history. Physical examination and laboratory testing revealed no remarkable abnormalities. Repeat endoscopy showed a small polypoid lesion but the endoscope could not be inserted due to severe stricture. Ultrathin endoscopy (GIF-XP260N; Olympus Optical Co., Ltd, Tokyo, Japan) revealed a 1.0-cm polypoid lesion with normal appearing mucosa in the esophagus, 27 cm from the incisors (Figure A). A biopsy from the lesion revealed proliferated and dysregulated epithelia throughout the mucosal layer, which was consistent with squamous intraepithelial neoplasm. Computed tomography scan showed only short segmental thickening of the middle esophageal wall. Because the patient declined surgery, we performed endoscopic resection (Figure B); however, remnant tumor under the small polypoid lesion could not be approached endoscopically (Figure C). Pathologically, the lobulating mass had proliferation of the capillaries with inflammatory cell infiltration and edematous stroma below the normal stratified squamous epithelium (Figure D). There was also disorganized squamous epithelium in the area surrounding spindle-shaped lymphovascular endothelia (Figure E). What is the diagnosis? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Pyogenic granuloma (PG), a polypoid capillary hemangioma, is a benign lesion arising from blood vessels of the skin or the oral and nasal mucosa.1Kusakabe A. Kato H. Hayashi K. et al.Pyogenic granuloma of the stomach successfully treated by endoscopic resection after transarterial embolization of the feeding artery.J Gastroenterol. 2005; 40: 530-535Crossref PubMed Scopus (25) Google Scholar In contrast with classic capillary hemangiomas, PG is composed of numerous newly formed capillaries of variable sizes arranged in a distinctive lobular pattern with or without ulceration on the surface. PGs are usually diagnosed in children and young adults and are rarely found in the alimentary tract. To date, only 42 cases of PGs in the alimentary tract have been reported, with 23 cases located in the esophagus.2Seoung H.G. Kim G.H. Song G.A. et al.Esophageal pyogenic granuloma: endosonographic findings and endoscopic treatments.Clin Endosc. 2013; 46: 81-84Crossref PubMed Scopus (6) Google Scholar No case of malignant transformation has been reported. To our knowledge, this is the first described case of PG associated with esophageal squamous cell carcinoma. Although the precise etiology is unknown, suggested etiologic factors include mechanical trauma, infection, chemical irritation, pregnancy, and hormonal mechanisms that induce reactive inflammatory and abnormal vascular responses.2Seoung H.G. Kim G.H. Song G.A. et al.Esophageal pyogenic granuloma: endosonographic findings and endoscopic treatments.Clin Endosc. 2013; 46: 81-84Crossref PubMed Scopus (6) Google Scholar Previously, a case of PG was reported originating in Barrett’s epithelium.3Craig R.M. Carlson S. Nordbrock H.A. et al.Pyogenic granuloma in Barrett's esophagus mimicking esophageal carcinoma.Gastroenterology. 1995; 108: 1894-1896Abstract Full Text PDF PubMed Scopus (26) Google Scholar In this case, the patient was treated with repeated dilations because of stricture formation caused by severe esophagitis, suggesting that it had been caused by trauma. However, the pathogenesis of co-occurring PG and squamous cell carcinoma is unclear in our case. Endoscopically, PG is seen as a protruding tumor or, sometimes, a pedunculated mass, with its color ranging from dark red to friable sanguine, reflecting the blood-rich nature of the lesion.1Kusakabe A. Kato H. Hayashi K. et al.Pyogenic granuloma of the stomach successfully treated by endoscopic resection after transarterial embolization of the feeding artery.J Gastroenterol. 2005; 40: 530-535Crossref PubMed Scopus (25) Google Scholar Although small polypoid lesions can be removed endoscopically, surgical excision is required in patients with large or deep lesions, or lesions that mimic malignant transformation.1Kusakabe A. Kato H. Hayashi K. et al.Pyogenic granuloma of the stomach successfully treated by endoscopic resection after transarterial embolization of the feeding artery.J Gastroenterol. 2005; 40: 530-535Crossref PubMed Scopus (25) Google Scholar Symptoms of esophageal PG include dysphagia, retrosternal pain, weight loss, and bleeding. PG should be differentially diagnosed from inflammatory polyps, benign and malignant vascular malformations, and angiomatous variants of Kaposi sarcoma.1Kusakabe A. Kato H. Hayashi K. et al.Pyogenic granuloma of the stomach successfully treated by endoscopic resection after transarterial embolization of the feeding artery.J Gastroenterol. 2005; 40: 530-535Crossref PubMed Scopus (25) Google Scholar Surgical resection would have been the best treatment choice in our case; however, the patient declined operative intervention. Instead, he received regional radiation of 55.8 Gy; an alternative treatment would have been photodynamic therapy. After radiation treatment, complete remission was achieved and the stricture improved (Figure F). Follow-up esophagogastroduodenoscopy at 3 and 6 months showed no evidence of recurrence.

Ultra-thin rigid endoscope: two-photon imaging through a graded-index multi-mode fiber.

Rigid endoscopes like graded-index (GRIN) lenses are known tools in biological imaging, but it is conceptually difficult to miniaturize them. In this letter, we demonstrate an ultra-thin rigid endoscope with a diameter of only 125 μm. In addition, we identify a domain where two-photon endoscopic imaging with fs-pulse excitation is possible. We validate the ultra-thin rigid endoscope consisting of a few cm of graded-index multi-mode fiber by using it to acquire optically sectioned two-photon fluorescence endoscopic images of three-dimensional samples.

Advances in direct peroral cholangioscopy using an ultrathin endoscope

Advances in direct peroral cholangioscopy using an ultrathin endoscope

An Ultrathin Endoscope with a 2.4-mm Working Channel Shortens the Esophagogastroduodenoscopy Time by Shortening the Suction Time.

Background/Aims:Poor suction ability through a narrow working channel prolongs esophagogastroduodenoscopy (EGD). The aim of this study was to evaluate suction with a new ultrathin endoscope (EG-580NW2; Fujifilm Corp.) having a 2.4-mm working channel in clinical practice.Methods:To evaluate in vitro suction, 200 mL water was suctioned and the suction time was measured. The clinical data of 117 patients who underwent EGD were retrospectively reviewed on the basis of recorded video, and the suction time was measured by using a stopwatch.Results:In vitro, the suction time with the EG-580NW2 endoscope was significantly shorter than that with the use of an ultrathin endoscope with a 2.0-mm working channel (EG-580NW; mean ± standard deviation, 22.7±1.1 seconds vs. 34.7±2.2 seconds; p<0.001). We analyzed the total time and the suction time for routine EGD in 117 patients (50 in the EG-580NW2 group and 67 in the EG-580NW group). In the EG-580NW2 group, the total time for EGD was significantly shorter than that in the EG-580NW group (275.3±42.0 seconds vs. 300.6±46.5 seconds, p=0.003). In the EG-580NW2 group, the suction time was significantly shorter than that in the EG-580NW group (19.2±7.6 seconds vs. 38.0±15.9 seconds, p<0.001).Conclusions:An ultrathin endoscope with a 2.4-mm working channel considerably shortens the routine EGD time by shortening the suction time, in comparison with an endoscope with a 2.0-mm working channel.

Transumbilical thoracic sympathectomy: a single-centre experience of 148 cases with up to 4 years of follow-up†.

Thoracic sympathectomy is considered as the most effective method to treat palmar hyperhidrosis (PH). Here, we report our experience of transumbilical thoracic sympathectomy with an ultrathin flexible endoscope for PH in a series of 148 patients with up to 4 years of follow-up. A prospective database was used in this retrospective analysis of 148 patients (61 males, 87 females, with a mean age of 21.3 years) with PH who were operated on by the same surgeon in a single institution from April 2010 to March 2014. All procedures were performed under general anaesthesia involving intubation with a double-lumen endotracheal tube. Demographic, postoperative and long-term data of patients were recorded and statistical analyses were performed. All patients were followed up at least 6 months post procedure through clinic visits or telephone/e-mail interviews. The procedure was performed successfully in 148 of the 150 patients. Two patients had to be converted to conventional thoracoscopic procedure because of severe pleural adhesions. The mean operating time was 43 min (ranging from 39 to 107 min) and the mean postoperative length of stay was 1 day (range 1-4 days). All patients were interviewed 6-48 months after surgery and no diaphragmatic hernia or syndrome was observed. The rate of resolution of PH and axillary hyperhidrosis was 98 and 74.6%, respectively. Compensatory sweating was reported in 22.3% of patients. Almost all of the patients were satisfied with the surgical results and the cosmetic outcome of the incision. This preliminary human experience suggested that transumbilical thoracic sympathectomy was a safe and efficacious alternative to the conventional approach. This technique avoided the chronic pain and chest wall paraesthesia that are associated with the chest incision. In addition, this novel procedure afforded maximum cosmetic benefits.

Understanding the Pathophysiology of Dysphagia Using an Ultrathin Endoscope via Transnasal Access

Introduction: Patients suffering from dysphagia who are introduced to the gastroenterologist often face a problem: Whereas classical esophageal entities (e.g., tumors, achalasia, Zenker's diverticulum) are easily identified, other diseases leading to dysphagia may be difficult to be anticipated in sedated patients by the endoscopist. Methods: In a multidisciplinary setting, 40 consecutive patients with suspected neurogenic dysphagia were evaluated by transnasal access applying an ultrathin video endoscope with an outer diameter of 3.8 mm. For functional endoscopy, patients were examined in sitting position while ingesting water and food of different consistencies. Diagnostic was completed by videofluoroscopy and high-resolution manometry. The study was approved by the local Ethics Committee. Results: Functional endoscopy was successfully performed in all patients suffering from Parkinson's disease, cerebellar multiple system atrophy, and oculopharyngeal muscular dystrophy. We were able to show that functional endoscopy is a feasible and save method; no adverse events were recorded. Endoscopic findings correlated well with the clinical signs of the patients and the other diagnostic modalities. A variety of disorders was documented by functional endoscopy and recorded as video files: Incomplete and delayed closure of the upper esophageal sphincter (in retroflex view), clearance disturbance of tubular esophagus, esophageal hyperperistalsis and hypomotility. The most common findings in the oral and pharyngeal phase were bolus leakage, delayed swallowing reflex, vallecular residues, and, aspiration during food intake. Conclusion: By interdisciplinary cooperation with additional assessment of the esophageal phase of deglutition using the innovative method of functional endoscopy, the diagnostic of neurogenic disorders including dysphagia may be tremendously improved leading to a better clinical understanding of complex dysfunctional patterns. To our best knowledge, this is the first study to show that a retroflex view of the ultrathin video endoscope within the esophagus may be safely performed. This comprehensive approach should be helpful to apply focused prophylactic and therapeutic actions.

Impact of Intraoperative Pancreatoscopy with Intraductal Biopsies on Surgical Management of Intraductal Papillary Mucinous Neoplasm of the Pancreas

Because of its known malignant potential, precise histologic diagnosis of intraductal papillary mucinous neoplasm of the pancreas (IPMN) during intraoperative pancreatoscopy (IOP) is essential for complete surgical resection. The impact of IOP on perioperative IPMN patient management was reviewed over 20 years of practice at Cliniques universitaires Saint-Luc, Brussels, Belgium. Among 86 IPMN patients treated by pancreatectomy between 1991 and 2013, 21 patients had a dilated main pancreatic duct enabling IOP and were retrospectively reviewed. The IOP was performed using an ultrathin flexible endoscope and biopsy forceps, and specimens of all suspicious lesions underwent frozen section examination. Complete IOP with intraductal biopsies was easily and safely performed in 21 patients, revealing 8 occult IPMN lesions. In 5 cases (23.8%), initially planned surgical resection was modified secondary to IOP: 3 for carcinoma in situ and 2 for invasive carcinoma. The postoperative morbidity rate at 3 months was 25.0% (5 of 20); 1 patient died from septic shock postoperatively and was excluded. Median follow-up was 93 months (range 13 to 248 months). Nineteen of 21 patients were still alive and free of disease at last follow-up (90.5%); there was 1 patient with invasive carcinoma at initial pathology (pT3 N1) who died of pulmonary recurrence 21 months after surgery. Intraoperative pancreatoscopy of the main pancreatic duct combined with intraductal biopsies plays a significant role in the surgical management of IPMN patients and should be used in all patients presenting a sufficiently dilated main pancreatic duct.

Ultra-thin caliber endoscopes in daily practice: uses for therapeutic application and beyond on the basis of review of 1028 procedures.

Background and study aims: Ultra-thin caliber endoscopes (UTCEs) are versatile and applicable in various conditions. However, only limited data exist on the actual daily clinical use of UTCEs. The aim of our study was to determine indications for UTCEs in a large patient cohort. In turn, our 2 main objectives were (1) to evaluate patient comfort and safety and (2) to determine benefits and potential advantages associated with the use of UTCEs in this same cohort. Patients and methods: We performed a retrospective analysis of our prospective database of 1028 procedures with UTCEs in 457 patients. All procedures were carried out in the Department of Gastroenterology and Hepatology, VU University Medical Center, in Amsterdam, the Netherlands, between May 2008 and May 2014. In these procedures, either the Fujinon (Tokyo, Japan) EG-530N UTCE or the Olympus (Tokyo, Japan) GIF N-180 UTCE was used. Results: Mean (standard deviation [SD]) age of patients was 64 (20) years, and most (60 %) of the patients were men. Most (61 %) of the underlying diseases, requiring endoscopic procedures, were found in the esophagus. Of the procedures performed, 91 % were successful, and 82 % were therapeutic. In comparison with regular endoscopes, the most important advantage of the UTCE was the ability to pass a stenosis (37 %), followed by nasogastric feeding tube placement (13 %). Newer and more innovative uses of the UTCE were percutaneous endoscopic gastrostomy (PEG)-jejunal extension placement with endoscope introduction through existing PEG tract, retrograde esophageal introduction through existing PEG tract, inspection of colonic neovagina stenosis, and direct inspection of the common bile duct. Conclusions: In everyday clinical practice, the UTCE has specific advantages over conventional endoscopes because of its small caliber. The 3 main advantages are (1) introduction of high-grade strictures; (2) introduction of fistulas, including PEG fistula; and (3) increased patient comfort. The endoscopist should appreciate these advantages and consider use of the UTCE accordingly.

Microelectromagnetic actuator based on a 3D printing process for fiber scanner application

A novel electromagnetic-actuated fiber scanner has been proposed for ultra-thin scanning fiber endoscope application. A free-fixed optical fiber cantilever with a cylindrical magnet can be driven and vibrated by a tilted coil on a tube surface under electromagnetic force. The tiny coil with a large tilt angle as the actuator is fabricated by a new three-dimensional (3D) printing technology and handmade hybrid process. It is an efficient and low-cost method for fabricating tiny 3D tilted coils compared with the complicated micromachining process. A 2.0 mm outer diameter tilted coil has been successfully developed. The line pitch, tilt angle, resistance and turns of this fabricated coil are 75 µm, 60°, 20 Ω and 100 turns, respectively. The scanning motion of the assembled scanner utilizing the fabricated 3D coil, fiber and a small magnet has been measured by a high-speed camera. The scanner consists of a 9 mm-length optical fiber, a 2 mm outer diameter cylindrical magnet, a jig and a fabricated tilted coil.The displacement of the fiber tip in the scanner is observed and measured when the alternative current-driven voltage was applied to the tilted coil, and 126.8 µm maximum displacement has been obtained. The present fiber scanner with 3D tilted coil has promise for use as an important inspecting device for biomedical endoscope application.