The Experts below are selected from a list of 39300 Experts worldwide ranked by ideXlab platform
Clarissa Zimmerman Cooley - One of the best experts on this subject based on the ideXlab platform.
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External dynamic interference estimation and removal editer for low field mri
Magnetic Resonance in Medicine, 2021Co-Authors: Sai Abitha Srinivas, Stephen F Cauley, Jason P Stockmann, Charlotte R Sappo, Christopher E Vaughn, Lawrence L Wald, William A Grissom, Clarissa Zimmerman CooleyAbstract:Purpose Point-of-care MRI requires operation outside of Faraday shielded rooms normally used to block image-degrading electromagnetic interference (EMI). To address this, we introduce the EDITER method (External Dynamic InTerference Estimation and Removal), an External Sensor-based method to retrospectively remove image artifacts from time-varying External interference sources. Theory and methods The method acquires data from multiple EMI detectors (tuned receive coils as well as untuned electrodes placed on the body) simultaneously with the primary MR coil during and between image data acquisition. We calculate impulse response functions dynamically that map the data from the detectors to the time varying artifacts then remove the transformed detected EMI from the MR data. Performance of the EDITER algorithm was assessed in phantom and in vivo imaging experiments in an 80 mT portable brain MRI in a controlled EMI environment and with an open 47.5 mT MRI scanner in an uncontrolled EMI setting. Results In the controlled setting, the effectiveness of the EDITER technique was demonstrated for specific types of introduced EMI sources with up to a 97% reduction of structured EMI and up to 76% reduction of broadband EMI in phantom experiments. In the uncontrolled EMI experiments, we demonstrate EMI reductions of up to 99% using an electrode and pick-up coil in vivo. We demonstrate up to a nine-fold improvement in image SNR with the method. Conclusion The EDITER technique is a flexible and robust method to improve image quality in portable MRI systems with minimal passive shielding and could reduce the reliance of MRI on shielded rooms and allow for truly portable MRI.
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External dynamic interference estimation and removal editer for low field mri
arXiv: Image and Video Processing, 2021Co-Authors: Sai Abitha Srinivas, Stephen F Cauley, Jason P Stockmann, Charlotte R Sappo, Christopher E Vaughn, Lawrence L Wald, William A Grissom, Clarissa Zimmerman CooleyAbstract:Purpose: Point-of-care MRI requires operation outside of a faraday shielded room normally used to block image-degrading electromagnetic Interference (EMI). To address this, we introduce the EDITER method, an External Sensor based dynamic EMI estimation and removal method to retrospectively remove time-varying External interference sources. Theory and Methods: The method acquires data from multiple EMI detectors (tuned receive coils and electrodes placed on the body) simultaneous with the primary MR coil during image data acquisition. We dynamically calculate impulse response functions that map the data from the detectors to the artifacts in the kspace data, then remove the transformed detected EMI from the MR data. Performance of the EDITER algorithm was assessed in phantom and in vivo imaging experiments in an 80mT portable brain MRI in a controlled EMI environment and with an open 47.5mT MRI scanner in an uncontrolled EMI setting. Results: In the controlled setting, the effectiveness of the EDITER technique was demonstrated for specific types of introduced EMI sources with up to a 97% reduction of structured EMI and up to 76% reduction of broadband EMI. In the uncontrolled EMI experiments, we demonstrate EMI reductions of 37% with a single pickup coil and 89% with a single electrode and up to 99% with both. Conclusion: The EDITER technique is a flexible and robust method to improve image quality in portable MRI systems with minimal passive shielding. This could reduce the reliance of MRI on shielded rooms and allow for truly portable MRI with specialized compact POC scanners
Rome Jutabha - One of the best experts on this subject based on the ideXlab platform.
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novel External Sensor array for capsule endoscopy
Endoscopy, 2006Co-Authors: Gary C Chen, M Leehenderson, S Mehdizadeh, O Goltzer, J Shen, James Sul, Rome JutabhaAbstract:Capsule endoscopy (CE) requires placement of an eight-lead Sensor array over the abdomen that receives image and localization data transmitted from the capsule. The current process of applying this array to the skin has several disadvantages: firstly, it is time-consuming; secondly, it can be cumbersome for the patient; and thirdly, it is often difficult to place the leads consistently. A new External Sensor array system designed to improve this process was tested. It was hypothesized that the new method would be able to receive the transmitted data adequately during CE. The new method and device were tested on an in-patient who had two sets of Sensor arrays, batteries, and data recorders placed on her simultaneously. One set was placed in the standard fashion, which served as the control, while the other set was placed using the novel External method. The data provided by the two recorders were compared and the patient's preferences were noted. The quality of the CE images provided by the two methods was identical, but the CE localization tracings were different, presumably due to movement of the gown and leads during the recording period. No signal interference was noted. The patient preferred the External device. A prepositioned External Sensor array is capable of transmitting CE data without any loss in image quality, but the localization tracing differs due to movement of the External array. This new method will require testing with a larger sample size in an outpatient setting to allow full assessment of the clinical value of the new approach.
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a novel External lead Sensor array placement approach for capsule endoscopy
Gastrointestinal Endoscopy, 2006Co-Authors: Gary Chen, S Mehdizadeh, O Goltzer, J Shen, James Sul, Christopher Chang, Rome JutabhaAbstract:A Novel External Lead Sensor Array Placement Approach for Capsule Endoscopy Gary Chen, Oren Goltzer, Jason Shen, Christopher Chang, Shahab Mehdizadeh, James Sul, Rome Jutabha Background: Capsule endoscopy (CE) of the small bowel (SB) & esophagus (ESO) requires placement of 8 lead Sensor array over the abdomen that receives image and localization data transmitted from the capsule. This current process of applying lead Sensor array to the skin has disadvantages: 1) it is time consuming, and 2) it can be uncomfortable to the patient. We hypothesized that a new External Sensor array system could adequately receive transmitted images during CE without significant data loss and have equivalent diagnostic yield with standard skin leads. Methods: We tested this new device on 13 patients from 8/2005-11/2005. 8 patients underwent esophageal CE for GERD and 5 had small bowel CE for OGIB. All 13 patients had 2 sets of Sensor arrays, batteries, and data recorders placed concurrently. The standard array was placed on the skin surface of the chest or abdomen in the usual manner (control) while the External array was pre-positioned on a gown that was worn over the skin leads. The total number of captured versus dropped images recorded by the skin and External lead systems were compared visually and then analyzed statistically. Results: 8/8 GERD patients had grade 1-2 reflux esophagitis on CE ESO. 4/5 OGIB patients had small bowel AVM’s while 1 patient had a small bowel carcinoid tumor on CE SB. The same final diagnoses were made on all 13 patients by both standard and novel External lead methods. For the 13 patients, a total of 313793 images were detected on CE procedures with the standard method while 311169 images were detected with the novel External method (99.2% of the control). All of the non-captured images missed by the External array leads occurred in short segments (4-5 frame segments); no prolonged stretches of missing data occurred with either method. The quality of captured CE images was identical between the 2 methods, but CE localization tracings were different, presumably related to movement of the leads during the recording period. Most of the patients preferred the novel External method because of less skin irritation and discomfort during the lead removal process, as well as shorter setup time without the need of removing clothing. Conclusion: 1) A pre-positioned External lead Sensor array can achieve CE data without clinically significant loss of image quality and diagnostic yield, 2) localization tracings for CE SB are different due to movement of the External array, 3) more patients preferred the novel External method than the standard method. These preliminary results must be confirmed with larger sample size.
Lawrence L Wald - One of the best experts on this subject based on the ideXlab platform.
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External dynamic interference estimation and removal editer for low field mri
Magnetic Resonance in Medicine, 2021Co-Authors: Sai Abitha Srinivas, Stephen F Cauley, Jason P Stockmann, Charlotte R Sappo, Christopher E Vaughn, Lawrence L Wald, William A Grissom, Clarissa Zimmerman CooleyAbstract:Purpose Point-of-care MRI requires operation outside of Faraday shielded rooms normally used to block image-degrading electromagnetic interference (EMI). To address this, we introduce the EDITER method (External Dynamic InTerference Estimation and Removal), an External Sensor-based method to retrospectively remove image artifacts from time-varying External interference sources. Theory and methods The method acquires data from multiple EMI detectors (tuned receive coils as well as untuned electrodes placed on the body) simultaneously with the primary MR coil during and between image data acquisition. We calculate impulse response functions dynamically that map the data from the detectors to the time varying artifacts then remove the transformed detected EMI from the MR data. Performance of the EDITER algorithm was assessed in phantom and in vivo imaging experiments in an 80 mT portable brain MRI in a controlled EMI environment and with an open 47.5 mT MRI scanner in an uncontrolled EMI setting. Results In the controlled setting, the effectiveness of the EDITER technique was demonstrated for specific types of introduced EMI sources with up to a 97% reduction of structured EMI and up to 76% reduction of broadband EMI in phantom experiments. In the uncontrolled EMI experiments, we demonstrate EMI reductions of up to 99% using an electrode and pick-up coil in vivo. We demonstrate up to a nine-fold improvement in image SNR with the method. Conclusion The EDITER technique is a flexible and robust method to improve image quality in portable MRI systems with minimal passive shielding and could reduce the reliance of MRI on shielded rooms and allow for truly portable MRI.
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External dynamic interference estimation and removal editer for low field mri
arXiv: Image and Video Processing, 2021Co-Authors: Sai Abitha Srinivas, Stephen F Cauley, Jason P Stockmann, Charlotte R Sappo, Christopher E Vaughn, Lawrence L Wald, William A Grissom, Clarissa Zimmerman CooleyAbstract:Purpose: Point-of-care MRI requires operation outside of a faraday shielded room normally used to block image-degrading electromagnetic Interference (EMI). To address this, we introduce the EDITER method, an External Sensor based dynamic EMI estimation and removal method to retrospectively remove time-varying External interference sources. Theory and Methods: The method acquires data from multiple EMI detectors (tuned receive coils and electrodes placed on the body) simultaneous with the primary MR coil during image data acquisition. We dynamically calculate impulse response functions that map the data from the detectors to the artifacts in the kspace data, then remove the transformed detected EMI from the MR data. Performance of the EDITER algorithm was assessed in phantom and in vivo imaging experiments in an 80mT portable brain MRI in a controlled EMI environment and with an open 47.5mT MRI scanner in an uncontrolled EMI setting. Results: In the controlled setting, the effectiveness of the EDITER technique was demonstrated for specific types of introduced EMI sources with up to a 97% reduction of structured EMI and up to 76% reduction of broadband EMI. In the uncontrolled EMI experiments, we demonstrate EMI reductions of 37% with a single pickup coil and 89% with a single electrode and up to 99% with both. Conclusion: The EDITER technique is a flexible and robust method to improve image quality in portable MRI systems with minimal passive shielding. This could reduce the reliance of MRI on shielded rooms and allow for truly portable MRI with specialized compact POC scanners
Tomas Olsson - One of the best experts on this subject based on the ideXlab platform.
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cost efficient drilling using industrial robots with high bandwidth force feedback
Robotics and Computer-integrated Manufacturing, 2010Co-Authors: Tomas Olsson, Rolf Johansson, Mathias Haage, Klas Nilsson, Henrik Kihlman, Anders Robertsson, Mats Bjorkman, Robert Isaksson, Gilbert Ossbahr, Torgny BrogardhAbstract:Here we present a method for high-precision drilling using an industrial robot with high-bandwidth force feedback, which is used for building up pressure to clamp-up an end-effector to the work-piece surface prior to drilling. The focus is to eliminate the sliding movement (skating) of the end-effector during the clamp-up of the end-effector to the work-piece surface, an undesired effect that is due to the comparatively low mechanical stiffness of typical serial industrial robots. This compliance also makes the robot deflect due to the cutting forces, resulting in poor hole position accuracy and to some extent in poor hole quality. Recently, functionality for high-bandwidth force control has found its way into industrial robot control systems. This could potentially open up the possibility for robotic drilling systems with improved performance, using only standard systems without excessive extra hardware and calibration techniques. Instead of automation with expensive fixtures and precise machinery, our approach was to make use of standard low-cost robot equipment in combination with Sensor feedback. The resulting sliding suppression control results in greatly improved hole positioning and quality. The conceptual idea behind the force control is useful also in many other robotic applications requiring External Sensor feedback control.
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on the use of force feedback for cost efficient robotic drilling
SAE 2007 AeroTech Congress & Exhibition Special Publications September 17-20 Los Angeles Convention Center Los Angeles California USA, 2007Co-Authors: Henrik Kihlman, Torgny Brogardh, Mathias Haage, Klas Nilsson, Tomas OlssonAbstract:Drilling is one of the most costly and labour-intensive operations in aircraft assembly. Rather than automating with expensive fixtures and precise machinery, our approach is to make use of standard low-cost robot equipment in combination with Sensor feedback. The focus is to eliminate the sliding movement of the end-effector during the clamp-up, called the skating effect, and to keep the end-effector orthogonal to the surface, thus avoiding holes that are not perpendicular. To that end, force feedback is used for building up pressure to clamp up an end-effector to the work-piece surface prior to drilling. The system, including the planning of force parameters for each hole to be drilled, was programmed in DELMIA. The drilling was accomplished with the aid of an extension to the ABB Rapid language called ExtRapid, which is an XML-like code that is interpreted by the force feedback controller downstream in the process. Although experimental results are from drilling, the conceptual idea is believed to be useful in many other applications requiring External Sensor feedback control of industrial robots.
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extending an industrial robot controller implementation and applications of a fast open Sensor interface
International Conference on Robotics and Automation, 2005Co-Authors: Anders Blomdell, Gunnar Bolmsjo, Torgny Brogardh, Per Cederberg, Mats Isaksson, Rolf Johansson, Mathias Haage, Klas Nilsson, Mona Landin Olsson, Tomas OlssonAbstract:This paper describes the design and implementation of a platform for fast External Sensor integration in an industrial robot control system. As an application and motivating example, the implementation of force controlled grinding and deburring within the AUTOFETT-project (EU Growth Programme) is reported.
William V Tamborlane - One of the best experts on this subject based on the ideXlab platform.
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fully automated closed loop insulin delivery versus semiautomated hybrid control in pediatric patients with type 1 diabetes using an artificial pancreas
Diabetes Care, 2008Co-Authors: Stuart A Weinzimer, Garry M Steil, Karena L Swan, James Dziura, Natalie Kurtz, William V TamborlaneAbstract:OBJECTIVE —The most promising β-cell replacement therapy for children with type 1 diabetes is a closed-loop artificial pancreas incorporating continuous glucose Sensors and insulin pumps. The Medtronic MiniMed External physiological insulin delivery (ePID) system combines an External pump and Sensor with a variable insulin infusion rate algorithm designed to emulate the physiological characteristics of the β-cell. However, delays in insulin absorption associated with the subcutaneous route of delivery inevitably lead to large postprandial glucose excursions. RESEARCH DESIGN AND METHODS —We studied the feasibility of the Medtronic ePID system in youth with type 1 diabetes and hypothesized that small manual premeal “priming” boluses would reduce postprandial excursions during closed-loop control. Seventeen adolescents (aged 15.9 ± 1.6 years; A1C 7.1 ± 0.8%) underwent 34 h of closed-loop control; 8 with full closed-loop (FCL) control and 9 with hybrid closed-loop (HCL) control (premeal priming bolus). RESULTS —Mean glucose levels were 135 ± 45 mg/dl in the HCL group versus 141 ± 55 mg/dl in the FCL group ( P = 0.09); daytime glucose levels averaged 149 ± 47 mg/dl in the HCL group versus 159 ± 59 mg/dl in the FCL group ( P = 0.03). Peak postprandial glucose levels averaged 194 ± 47 mg/dl in the HCL group versus 226 ± 51 mg/dl in the FCL group ( P = 0.04). Nighttime control was similar in both groups (111 ± 27 vs. 112 ± 28 mg/dl). CONCLUSIONS —Closed-loop glucose control using an External Sensor and insulin pump provides a means to achieve near-normal glucose concentrations in youth with type 1 diabetes during the overnight period. The addition of small manual priming bolus doses of insulin, given 15 min before meals, improves postprandial glycemic excursions.
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fully automated closed loop insulin delivery versus semiautomated hybrid control in pediatric patients with type 1 diabetes using an artificial pancreas
Diabetes Care, 2008Co-Authors: Stuart A Weinzimer, Garry M Steil, Karena L Swan, James Dziura, Natalie Kurtz, William V TamborlaneAbstract:OBJECTIVE: The most promising beta-cell replacement therapy for children with type 1 diabetes is a closed-loop artificial pancreas incorporating continuous glucose Sensors and insulin pumps. The Medtronic MiniMed External physiological insulin delivery (ePID) system combines an External pump and Sensor with a variable insulin infusion rate algorithm designed to emulate the physiological characteristics of the beta-cell. However, delays in insulin absorption associated with the subcutaneous route of delivery inevitably lead to large postprandial glucose excursions. RESEARCH DESIGN AND METHODS: We studied the feasibility of the Medtronic ePID system in youth with type 1 diabetes and hypothesized that small manual premeal "priming" boluses would reduce postprandial excursions during closed-loop control. Seventeen adolescents (aged 15.9 +/- 1.6 years; A1C 7.1 +/- 0.8%) underwent 34 h of closed-loop control; 8 with full closed-loop (FCL) control and 9 with hybrid closed-loop (HCL) control (premeal priming bolus). RESULTS: Mean glucose levels were 135 +/- 45 mg/dl in the HCL group versus 141 +/- 55 mg/dl in the FCL group (P = 0.09); daytime glucose levels averaged 149 +/- 47 mg/dl in the HCL group versus 159 +/- 59 mg/dl in the FCL group (P = 0.03). Peak postprandial glucose levels averaged 194 +/- 47 mg/dl in the HCL group versus 226 +/- 51 mg/dl in the FCL group (P = 0.04). Nighttime control was similar in both groups (111 +/- 27 vs. 112 +/- 28 mg/dl). CONCLUSIONS: Closed-loop glucose control using an External Sensor and insulin pump provides a means to achieve near-normal glucose concentrations in youth with type 1 diabetes during the overnight period. The addition of small manual priming bolus doses of insulin, given 15 min before meals, improves postprandial glycemic excursions.
