Needle Angle Research Articles

Risk of intra-articular injection with longitudinal ultrasound-guided injection of collateral ligaments of the equine distal interphalangeal joint.

Desmopathy of the collateral ligaments of the distal interphalangeal joint is a common cause of equine foot lameness and carries a poor prognosis with conservative management. Intralesional injections may improve healing, although accuracy of radiographically guided injections is significantly less than when guided by MRI, which requires special needles. Longitudinal ultrasound-guided injection of the distal collateral ligament has not been evaluated objectively. In this prospective, anatomic study, seven equine cadaver limbs (14 collateral ligaments) were injected with methylene blue dye and radiographic contrast medium using ultrasound to guide the needle longitudinally into the collateral ligaments until contacting bone. The insertion site of the needle proximal to the coronary band was measured on the limb and the needles left in place for radiography and CT to evaluate the needle angulation, location of the contrast medium, and whether the contrast entered the distal interphalangeal joint. The limbs were frozen and sectioned with a band saw to identify the location of the dye. Fifty percentage of injections were in or around the collateral ligaments. However, the percentage of "successful" injections, defined as in the collateral ligament but not in the joint, was only 36%. All legs had dye and contrast in the joint after both ligaments had been injected. There were no significant differences between the needle angle and entry site for "successful" and "unsuccessful" injections. Findings from this study indicates that the success rate is low for injecting the distal portions of the distal interphalangeal joint collateral ligaments using ultrasound guidance alone.

Two-Dimensional Laser-Align Device for Ultrasound-Guided Injection.

Ultrasound-guided injection is a widely used technique, however, it takes substantial amounts of time for novices to master the skill. The most critical issue to improve the accuracy of the injection is to align the needle with the scan plane of the ultrasound beam and orient the needle angle after piercing skin to aim at the targeted tissue. In the present study, we developed a two-dimensional laser align device to assist physicians to accurately position the needle in the scan plane and advance it at an angle correctly pointing to the target. The device is inexpensive, light-weighted, and easy to fabricate and accommodate for any types of ultrasound probe. Statistical analysis revealed that the assistance with our device significantly reduced the successful targeting time and times of retargeting in comparison with the traditional freehand approach or only with in-plane assistance for inexperience subjects. Our results indicate that the device exhibits great potential in effectively reducing the learning time to master the skill and speeding up the procedure for ultrasound-guided injection.

Using simulation to teach patient-centered ultrasound-guided FNA skills.

Using simulation to teach patient-centered ultrasound-guided FNA skills.

First Evaluation of the Next-Generation Endobronchial Ultrasound System in Preclinical Models

The next-generation convex probe endobronchial ultrasound (CP-EBUS) was developed to improve the ease of operation and the acquisition of EBUS skills for new trainees. The aim of this study was to evaluate the changes in the prototype next-generation CP-EBUS compared with the current CP-EBUS. The prototype next-generation CP-EBUS, with a decreased forward oblique view, more flexible angulation range, smaller ultrasound probe, and sharper needle angle, was compared with the current CP-EBUS. The operability, which was evaluated by using a 5-level Likert-type scale, and safety were evaluated in 2 live pigs, a cadaveric lung, and 10 exvivo human lungs by 9 bronchoscopists. The time required to access the upper lobe bronchus and the time required to detect prespecified lymph node stations by 7 novice bronchoscopists with both CP-EBUS were compared with assess the operability difference for new trainees. In all evaluated models, operability (eg, maneuverability, endoscopic visibility, bronchial trees selectivity, insertability to the upper airway) was scored 5 (significantly improved). All trainee bronchoscopists were able to access the upper lobe bronchi and detect each lymph node except 4R significantly faster than with the current CP-EBUS without any airway damage. The next-generation CP-EBUS has improved operability, which resulted in better access to each lobar bronchus and more prompt detection of mediastinal or hilar lymph nodes. These improvements may allow more precise lymph node staging and diagnosis, as well as improve EBUS procedural skill acquisition, once introduced to clinical practice.

Application of curved needling technique in the treatment of trigeminal neuralgia by radiofrequency ablation through foramen rotundum with inward opening

Objective To observe the application effect of radiofrequency puncture needle with individualized and on-demand plastic curved needle technique in the treatment of second-branch trigeminal neuralgia by radiofrequency ablation through foramen rotundum with inward opening. Methods From November 2012 to May 2018, a total of 263 cases of second-branch trigeminal neuralgia were admitted to Department of Anesthesiology, the First Hospital of Jiaxing and underwent foramen rotundum puncture for radiofrequency ablation. All those cases were enrolled into this retrospective analysis. The paranasal sinus model of CT was used to scan the pterygoid fossa with a thickness of 3 mm, and the CT images, including the midpoint of the foramen rotundum tube, the internal and external hole, were selected and the puncture path was designed. The length of the line (puncture depth) and the angle between the straight line and the sagittal plane (the angle of puncture) were measured by using the ruler tool of CT software from the external hole of the foramen rotundum along the lateral wall of the maxillary sinus to the surface of the skin (puncturing point). If the external hole of foramen rotundum demonstrated an inward opening, the angle between the line and the direction of the foramen rotundum tube(the angle of the needle needed to bend) should be measured. The radiofrequency needle was inserted 5 mm into the self-made needle-bender, the corresponding bending angle was pulled out slightly to the side of the needle at the tip of the needle, and the individual radiofrequency needle for the patient was made. Then, puncturing under the guidance of CT followed by designed trajectory. The arc of the needle was turned to the top of the front when the needle reached the external hole of the foramen rotundum. Whereafter, the arc of the needle was turned to the bottom when the needle crossed the external hole. Subsequently, the needle was pushed into the foramen rotundum. Then, electrophysiological test was conducted for radiofrequency treatment. Results Of 263 patients undergoing radiofrequency ablation of the second branch of trigeminal nerve, 71 (27.0%) had an inward opening of the external hole of foramen rotundum, which needed the patient's individually designed radiofrequency puncture needle. The average bending angle was 21.3 °±3.6 °(14°-31 °). When using the individual puncture needle, the needle tip could always reach the puncture target. Using 0.1-0.5 mA current could induce obvious muscle tremor or numbness in the region innervated by the second branch of trigeminal nerve in electrophysiological test. Following radiofrequency ablation, the second-branch trigeminal neuralgia disappeared completely. Ipsilateral palate muscosal numbness and the skin numbness involving the side of the nose, upper lip and zygomatic facial region were reported. None of the patients developed numbness involving the first or third branch of trigeminal nerve. A total of 242 patients were followed up for an average of 3.2±0.6 years. The total recurrence rates at 6 months, 1 year, 2 years, 3 years and 4 years were 2.5% (6/242), 7.9% (19/242), 16.1% (39/242), 24.4% (59/242) and 33.9% (82/242), respectively. Conclusions CT-guided individually made curved needle technology allows the radiofrequency needle tip to bypass the sphenoid bone which obstructs the outer opening of foramen rotundum and enter the middle of foramen rotundum tube with inward opening, so as to improve the radiofrequency effect and reduce the recurrence rate. Key words: Trigeminal neuralgia; Radiofrequency coagulation; Foramen rotundum; Treatment effect

Unconventional Facial Entry Points Confirmed Using a 3D CT Reconstruction-Guided Stereotactic Approach to Radiofrequency Thermocoagulation for the Treatment of Trigeminal Neuralgia: A Series of Case Reports.

Patients with trigeminal neuralgia who are refractory to medical therapy may choose to undergo Gasserian ganglion percutaneous radiofrequency thermocoagulation. However, in cases where the foramen ovale is difficult to access due to various anatomical anomalies, the typical estimation of the facial entry point is suboptimal. Three-dimensional computed tomography reconstruction imaging performed before surgery revealed anatomical variations in each of the four adult patient cases that made it more difficult to successfully access the foramen ovale (FO) for percutaneous radiofrequency thermocoagulation. Using measurements collected from preoperative imaging that showed each specific anatomical variation in the FO, researchers marked alternate facial entry points that would allow successful probe placement into the FO and recorded the arc angle data in the stereotactic instrument. Patients were evaluated during follow-up visits ranging from seven to 26 months after surgery and asked to rate postoperative pain using a visual analog scale. These scores decreased from 10 to 3 in all four patients by the third day after the procedure. There were no permanent complications or morbidities from the surgery. One patient experienced mild facial numbness; however, this side effect subsided within three months after surgery. During the follow-up period, no patient reported pain recurrence. The expectation for clinicians approaching trigeminal nerve block using a peri-oral approach should be to expect a great degree of potential variability in terms of both distances from the corner of the mouth and needle angle taken to successfully navigate the anatomy and access the foramen ovale.

Using Simulation to Help Specify Design Parameters for Vacuum-Assisted Needle Biopsy Systems

Needle biopsy is a routine medical procedure for examining tissue or biofluids for the presence of disease using standard methods of pathology. The finite element analysis (FEA) methodology can provide guidance for optimizing the geometric parameters. The needle biopsy is simulated and analyzed while varying the needle angle, the aperture size and the slice-push ratio k. The results indicate that tissue reaction force in the axial direction of needle gradually decreases, and the stress and strain are more concentrated at the tip of needle with the increases of tip angle; the tissue reaction force decreases, and the torque increases while the slice-push ratio increases; and higher slice–push ratio can increase the peak stress concentration on the cutting edge and deformation of tissue; in the process of core needle cutting, increasing slice–push ratio can reduce the tissue reaction force significantly. While the aperture on distal wall of outer cannula becomes wider, the tissue reaction force increases significantly, and the cutting process will be more unstable. The results have the potential to provide important insight for improving the needle biopsy design process.

A hybrid camera- and ultrasound-based approach for needle localization and tracking using a 3D motorized curvilinear ultrasound probe

Three-dimensional (3D) motorized curvilinear ultrasound probes provide an effective, low-cost tool to guide needle interventions, but localizing and tracking the needle in 3D ultrasound volumes is often challenging. In this study, a new method is introduced to localize and track the needle using 3D motorized curvilinear ultrasound probes. In particular, a low-cost camera mounted on the probe is employed to estimate the needle axis. The camera-estimated axis is used to identify a volume of interest (VOI) in the ultrasound volume that enables high needle visibility. This VOI is analyzed using local phase analysis and the random sample consensus algorithm to refine the camera-estimated needle axis. The needle tip is determined by searching the localized needle axis using a probabilistic approach. Dynamic needle tracking in a sequence of 3D ultrasound volumes is enabled by iteratively applying a Kalman filter to estimate the VOI that includes the needle in the successive ultrasound volume and limiting the localization analysis to this VOI. A series of ex vivo animal experiments are conducted to evaluate the accuracy of needle localization and tracking. The results show that the proposed method can localize the needle in individual ultrasound volumes with maximum error rates of 0.7 mm for the needle axis, 1.7° for the needle angle, and 1.2mm for the needle tip. Moreover, the proposed method can track the needle in a sequence of ultrasound volumes with maximum error rates of 1.0 mm for the needle axis, 2.0° for the needle angle, and 1.7 mm for the needle tip. These results suggest the feasibility of applying the proposed method to localize and track the needle using 3D motorized curvilinear ultrasound probes.

Determination of the Optimal Angle for Needle Insertion During Caudal Epidural Steroid Injection in Adults Using Ultrasound Imaging

Background: Lumbar back pain is a common disease, which reduces life quality. Caudal epidural steroid injection (CESI) is frequently preferred to relieve lumbar back pain. However, various major complications can be observed due to CESI. A new technique of needle angle should be improved to prevent complications such as intraosseous, intrathecal or intravascular injection during CESI. Objectives: Caudal epidural steroid injection is one of the methods frequently used to treat chronic lumbar back pain. The current study aimed at examining the anatomy of the sacral hiatus and determining the optimal angle of the needle for CESI. Methods: The current clinical trial was performed in Diyarbakir Selahaddin Eyyubi State Hospital from January to June in 2017. The study included 150 adult patients (first group = 92 males (%61.3), second group = 58 females (%38.7) aged 18 - 78 years applied to the Algology Polyclinic with ASA-PS classes I and II (the American Society of Anesthesiologists (ASA) physical status classification system). Measurements were taken during the CESI applied under ultrasonography (USG) guidance of the intercornual distance, the sacral space, and the optimal needle entry angle. Results: The intercornual distance was significantly higher in group one (mean ± standard deviation (SD): 16.6 ± 2.04) than group two (mean ± SD: 15.8 ± 2.51) (P 0.79). The most appropriate entry angle for the needle in the application of CESI was mean 71.04° in the whole patient group, as 71.9° in group one and 69.7° in group two. There was no significant difference between the genders in terms of the mean optimal angle (P > 0.091). Also, no significant difference was observed among the patients in terms of the demographic data (P > 0.05). Conclusions: The results of the current study revealed that the optimal needle angle for CESI applied under USG guidance was 71.04°, different from traditional method and the injection procedure could be safely made directly to the epidural space without changing the angle after entry of the needle to the epidural space.

Method for Calculating the Bending Angle of Puncture Needle in Preoperative Planning for Transjugular Intrahepatic Portal Systemic Shunt (TIPS).

Transjugular Intrahepatic Portal Systemic Shunt is a comprehensive interventional therapy for portal hypertension. During this intervention, puncturing from hepatic vein into portal vein is a difficult step. Selecting puncture needle with a proper bending angle is vital to accurate puncture. Thus, this prospective study provides a method to calculate the angle of the puncture needle using preinterventional contrast-enhanced CT imaging. According to the geometrical characteristics of puncture needle, Bezier curve equation was adopted to describe its bending part. By testing whether each point in a specific region satisfied the equation set of Bezier curves, the possible position of needle tip was obtained. Then, the bending angle of puncture needle was obtained by calculating curvature. The method was evaluated in 13 patients from 2 centers showing now a success rate of 100% and a duration of the procedure of 141 and 161 minutes. The method based on Bezier curve equation for calculating a proper bending angle of puncture needle was proven to be effective. And the clinical study is preliminary and additional work for clinical evaluation is necessary.

Study on the nailing path of S3 ala-iliac screw in adult spinal pelvis fixation

Objective The screw insertion and parameters of S3 ala-iliac screw fixation were introduced by 3D printing spinal pelvis model and computer software-assisted navigation. Methods Determine the nailing space of the S3 segment by 3D printing model and computer software related data, and select the position of the iliac screw into the needle point. Twenty of the male and female adult patients who had undergone three-dimensional pelvic CT reconstruction scans were randomly selected. The screw point O was selected, the horizontal section X was the coronal or sacral horizontal cross-section. Spherical probe into the minimum angle of the needle angle range A, the maximum angle range B and the optimal range of nailing angle Z was measured, and the needle point screwed into the screw pin length and width. The accuracy and safety of this new method of nailing were confirmed in the corresponding adult 3D printing model. Results The needle angle is within the range of the minimum angle OA to the maximum angle OB. If the narrowest diameter is more than 7 mm, the fixation can be safely done with a universal Iliac screw (average length 80-90 mm). The range of needle angle was (47.1±1.9)°-(56.7±1.4)° for the male X-OA-OB plane and (52.3±1.1)° for the optimal angle. The X-OA-OB plane for women was 49.6±0.8)°-(59.9±1.1)°, the best angle X-OZ range (53.7±0.8)°. The range of nail path length was (91.4±2.3) mm for OA, (89.5±4.6) mm for OB and (94.2±2.1) mm for OZ. The OA level of female was (90.4±1.9) mm, (85.6±2.3) mm, OZ plane range (96.4±1.7) mm. The statistical results showed that in the best setting angle OZ, nail angle differences (F=4.276, P 0.05). OB, male and female, nail angle differences (F=8.153, P 0.05). Conclusion The iliac bone screw can be safely and effectively inserted into the iliac bone via the S3 block. In theory, the iliac bone screw is safe and stable through the O-Z needle entry point. The O-Z angle is also the best in Spinal pelvis fixation. Key words: Spinal pelvic fixation; Iliac screw; Spiral computer navigation; 3D printing and 3D reconstruction

Discussion on several contents of textbook Acupuncture and Moxibustion (New Century 4th Edition)

The textbook Acupuncture and Moxibustion (New Century 4th Edition) was published by China Press of Traditional Chinese Medicine in August of 2016. The author proposed several discussions in the textbook. The information, including the issue date of China national standard Standardized Manipulations of Acupuncture and Moxibustion, the number of foreign countries where China medical teams were assigned, and the number of acupuncture indications recommended by WHO, was not accurate. The content, including several methods of acupoint location, specification of filiform needles, rotating angle of needle, disinfection of needles and skin, locations and indications of scalp acupuncture, etc. should be corrected. Besides, the writing of textbooks should follow national or industry standards.

Efficacy and Safety in Intramuscular Injection Techniques Using Ultrasonographic Data

Delivered by intramuscular (IM) injections, Long Acting Injections (LAI), offering comparatively long term medicinal effects from several weeks to several months, are gaining much attention. The aim of this article was to indicate a safe and effective IM injection technique based on evidenced data derived from ultrasonographic data. Accurate anatomical knowledge is necessary in order to administer IM injections. It is possible to gain an adequate understanding of injection site anatomical structures by using ultrasound diagnostic devices. In particular, ultrasonography offers real-time diagnostic data allowing for observation of injection site, subcutaneous tissues, fat layers, muscle membrane, muscles and bones. To deliver the drug accurately into the muscle is essential, to achieve maximum drug efficacy and prevent injection site reactions. Therefore, when administering IM injections to the buttocks area, a suitable injection needle between 23G 25 mm to 21G or 22G 38 mm must be chosen depending on physique and drug characteristics. Needles determined as safe and effective through ultrasonographic evidence are needed such as in the case of a deltoid injection site, in which a 23G 25 mm injection needle is used in the absence of notable obesity. Not only the needle type is essential, but also the IM procedure itself. It is important to stretch the skin, inserting the needle at 90 degree angle to ensure depth of needle insertion to the muscle. Until new con-firmed evidence becomes available, it is necessary to increase the understanding of injection site selection methods, needle insertion depth, needle angle, and established IM injection techniques. The application of ultrasound devices in the development of next-generation techniques for IM injection is promising. Importantly, these techniques provide critical information from a risk management perspective.

Failed Nerve Blocks: Prevention and Management

Failed Nerve Blocks: Prevention and Management

Measuring Needle Angle and Depth for Lumbar Medial Branch Block Using Ultrasonography: An Evaluation of Efficiency Compared with Magnetic Resonance Imaging

Measuring Needle Angle and Depth for Lumbar Medial Branch Block Using Ultrasonography: An Evaluation of Efficiency Compared with Magnetic Resonance Imaging

Research on the Angle and Effective Depth of Deep Acupuncture at Baliao Points by Three-dimensional Reconstruction of Computed Tomography

To explore the needle insertion parameters of deep acupuncture at Baliao points for clinic and teaching. A retrospective analysis of 100 cases of prone pelvic CT from January to June 2016 in Nanjing Hospital was carried out. The 3 D images were scanned with continuous 5 mm slice thickness. The optimum needle angle is defined as the angle of the needle along the central axis of sacral anterior and posterior hole, and the angle between the needle body and the skin surface and the center line of the body was observed. The effect needle depth is defined as the thickness of the sacral back soft tissue plus 1/2 sacral depth, to observe the best needle angle of deep acupuncture parameters of Baliao points. For deep acupuncture at Baliao, the oblique thorn method should be used with the needle-point toward the inner bottom. The best insertion angle between needle body and skin surface is: Shangliao(BL 31) (61.04±12.15)°， Ciliao(BL 32) (57.57±10.01)°， Zhongliao(BL 33) (58.25±8.69)°， Xialiao(BL 34) (54.39±10.94)°. The optimum angle of insertion between the needle body and the posterior midline of the human body is: BL 31 (24.54±6.21)°， BL 32 (18.58±7.76)°， BL 33 (17.36±7.90)°， BL 34 (30.73±9.45)°. The effective insertion depth show a decreasing trend: BL 31 (58.16±12.43) mm, BL 32 (44.57±11.55) mm, BL 33 (33.96±10.74) mm, BL 34 (31.13±10.94) mm. The effective depth is positively correlated with BMI, and has no correlation with gender and weight. The study of the parameters of needle insertion should be taken into account both clinical efficacy and safety, and CT three-dimensional reconstruction can accurately, rationally and scientifically perform acupoint anatomical measurements.

Accessing Implantable Ports: An Opportunistic Computed Tomography-Based Audit

AimImplantable ports are typically inserted by interventional radiologists or surgeons; however, daily maintenance, access, and de-access are often performed by members of nursing staff in accordance with manufacturers' guidelines and local policy. An audit of port access using retrospective computed tomography (CT) scanning was proposed. MethodologyAcross a 4-year period, all CT scans performed for any reason while a port was accessed were reviewed. ResultsFifty-four CT scans of accessed ports were included. Mean depth of tissue between skin and port was 3.74 mm, and between port and pectoralis major was 5.91 mm. Port tilt in side-to-side and up-down axes measured 6.9° and 10.6°, respectively. Mean distance from needle to center of the septum was 1.96 mm. Mean distance from center of the chamber to the needle tip was 2.73 mm. In 2 cases (3.7%), the needle bevel was malpositioned, with the bevel still within the silicone-rubber septum. Mean angulation of the access needle from perpendicular was 11.5°. Angulation of the needle correlated with port tilt (r = 0.37; P = .006). Angle of the needle bevel relative to the port exit channel was 140.8°. No significant correlation between needle bevel directionality and needle angle, depth of port, or tilt of port was detected (all P values > .21). ConclusionsVariability in accessing of implantable ports is described relative to research- and manufacturer-recommended needle bevel angle, needle puncture angle, and central puncture position. The extent to which such deviation influences port function deserves focused clinical research.

Computed tomography-guided lung biopsy: Association between biopsy needle angle and pneumothorax development.

Computed tomography (CT)-guided lung biopsy is a well-established diagnostic method for pulmonary lesions. However, the use of this technique often results in pneumothorax development. The aim of the present study was to evaluate the association between biopsy needle angle and pneumothorax development associated with computed tomography-guided lung biopsy. We retrospectively analyzed the results of CT-guided lung biopsies for 325 cases to investigate physical risk factors for pneumothorax development. Biopsy needle angle and patient positioning were included in the analysis. Pneumothorax occurred in 160 of 325 procedures (49.2%). Discontinuation of the procedure as a result of pneumothorax occurred in 18 of 160 procedures (11.2%). Upper lung lobe pneumothorax occurred in 40.8% (58/142), middle lobe in 17.6% (25/142), and lower lobe pneumothorax occurred in 41.5% (59/142) of these procedures. Discontinuation of the procedure occurred in 2.5% of the upper lobe (4/160), 0.6% of the middle lobe (1/160), and 8.1% of the lower lobe (13/160) biopsies. Mild pneumothorax occurred in 59.4% (95/160), moderate in 25.0% (40/160), and severe in 7.5% (12/160) of the affected cases, and biopsy was discontinued in 11.2% (18/160) of the affected cases. When the needle angle was <90°, 40.3% (131/325) of the patients experienced no pneumothorax development, 40.0% (130/325) developed pneumothorax, and 4.3% (14/325) of the procedures were discontinued. The results showed that use of CT-guided lung biopsy can reduce the rate of pneumothorax development that occurs when other procedures are used. The access route is simple and easy to puncture, and proper use of breath holding reduces diaphragmatic movement.

Smartphone-Guided Needle Angle Selection During CT-Guided Procedures.

In CT-guided intervention, translation from a planned needle insertion angle to the actual insertion angle is estimated only with the physician's visuospatial abilities. An iPhone app was developed to reduce reliance on operator ability to estimate and reproduce angles. The iPhone app overlays the planned angle on the smartphone's camera display in real-time based on the smartphone's orientation. The needle's angle is selected by visually comparing the actual needle with the guideline in the display. If the smartphone's screen is perpendicular to the planned path, the smartphone shows the Bull's-Eye View mode, in which the angle is selected after the needle's hub overlaps the tip in the camera. In phantom studies, we evaluated the accuracies of the hardware, the Guideline mode, and the Bull's-Eye View mode and showed the app's clinical efficacy. A proof-of-concept clinical case was also performed. The hardware accuracy was 0.37° ± 0.27° (mean ± SD). The mean error and navigation time were 1.0° ± 0.9° and 8.7 ± 2.3 seconds for a senior radiologist with 25 years' experience and 1.5° ± 1.3° and 8.0 ± 1.6 seconds for a junior radiologist with 4 years' experience. The accuracy of the Bull's-Eye View mode was 2.9° ± 1.1°. Combined CT and smart-phone guidance was significantly more accurate than CT-only guidance for the first needle pass (p = 0.046), which led to a smaller final targeting error (mean distance from needle tip to target, 2.5 vs 7.9 mm). Mobile devices can be useful for guiding needle-based interventions. The hardware is low cost and widely available. The method is accurate, effective, and easy to implement.

超音波ガイド下末梢神経ブロック支援システムに関する研究-穿刺針の刺入位置・角度・深さの計測-

超音波ガイド下末梢神経ブロック支援システムに関する研究-穿刺針の刺入位置・角度・深さの計測-