Purpose: Several institutions have developed MRI guidelines for patients with MR‐unsafe or MR‐conditional pacemakers. Here we highlight the role of a medical physicist in implementing these guidelines for non‐pacemaker dependent patients. Guidelines: Implementing these guidelines requires involvement from several medical specialties and a strong collaboration with the site MRI supervisor to develop a structured workflow. A medical physicist is required to be present during the scan to supervise the MR scanning and to maintain a safety checklist that ensures: 1) uninterrupted patient communication with the technologist, 2) continuous patient physiologic monitoring (e.g. blood pressure and electrocardiography) by a trained nurse, 3) redundant patient vitals monitoring (e.g. pulse oximetry) due to the possibility of in vivo electrocardiography reading fluctuations during image acquisition. A radiologist is strongly recommended to be available to review the images before patients are discharged from the scanner. Pacemaker MRI should be restricted to 1.5T field strength. The MRI sequences should be optimized by the physicist with regards to: a) SAR: limited to <1.5 W/Kg for MR‐unsafe pacemakers in normal operating mode, b) RF exposure time: <30 min, c) Coils: use T/R coils but not restricted to such, d) Artifacts: further optimization of sequences whenever image quality is compromised due to the pacemaker. In particular, cardiac, breast and left‐shoulder MRIs are most susceptible to these artifacts. Possible strategies to lower the SAR include: a) BW reduction, 2) echo‐train‐length reduction, 3) increase TR, 4) decrease number of averages, 5) decrease flip angle, 6) reduce slices and/or a combination of all the options. Conclusion: A medical physicist in collaboration with the MR supervisor plays an important role in the supervision/implementation of safe MR scanning of pacemaker patients. Developing and establishing a workflow has enabled our institution to scan over 30 patients with pacemakers without complications, including 3 cardiac MR exams.
In this paper, we present a Matlab and Simulink based software platform that enables the use of inexpensive microcontrollers for data acquisition and control tasks. The proposed framework is well suited for data acquisition and control tasks that require graphical user interface (GUI) and/or advanced computational capabilities but do not require stringent hardware performance. We illustrate the efficacy of our data acquisition and control technique by performing position control of a DC motor using a Basic Stamp 2 (BS2) microcontroller and our Matlab data acquisition and control toolbox
We think that it is medically necessary to perform MRI of a patient with a pacemaker: is that possible? Short AnswerIf the patient has a pacemaker that is labeled "MR Conditional" by the manufacturer as part of the U.S. Food and Drug Administration (FDA) approval process, it is possible to safely scan the patient using MRI as long as all scanning conditions specified by the manufacturer are met.If the patient has a pacemaker that is considered "MR Unsafe"-almost all pacemakers implanted before 2011 fall in this category, it may still be possible to scan the patient using MRI; however, whether MRI is possible depends on many factors.Some sites scan patients with MR Unsafe pacemakers.There are studies in the literature that support the safe scanning of certain patients with MR Unsafe pacemakers following strict guidelines [1, 2].
Abstract NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Development of a Matlab Data Acquisition and Control Toolbox for PIC Microcontrollers Abstract—This paper presents a personal computer (PC)-based data acquisition and control tool that uses a Peripheral Interface Controller (PIC) microcontroller, Matlab, and Simulink. Specifically, a library of PIC microcontroller functions for Simulink is created. Moreover, the PIC microcontroller and Matlab are merged, by exploiting their serial communication capability, to produce an inexpensive data acquisition and control platform. Finally, the efficacy of this data acquisition and control platform is illustrated by performing angular position control of a DC motor. 1. Introduction Data acquisition and control boards are essential for interfacing sensors/actuators with decision making devices such as a PC. Thus, data acquisition and control boards are used in monitoring/instrumentation applications involving machinery, process, environment, etc., and in automatic control applications. Even though a variety of data acquisition and control boards have become widely available in the last 15 years, the systems that target the educational sector and provide support for icon-based programming environments, such as LabVIEW1 and Simulink,2 tend to be quite expensive (over $500 to several thousand dollars). Moreover, instructional labs generally may not require the intrinsic high-performance features of many of the commercially available data acquisition and control boards (e.g., high sampling rates, high resolution analog to digital converters, etc.) for the typical electro-mechanical laboratory experiments. This paper proposes a microcontroller-based data acquisition and control system that is particularly suitable for educators interested in developing lab experiments that do not require high-cost, high- performance data acquisition hardware and yet can benefit from the icon-based programming environment of Simulink. Several recent papers have focused on interfacing low-cost microcontrollers (such as Basic Stamp 2 (BS2) and PIC) with icon-based programming environments such as LabVIEW and Simulink. Specifically, Refs. 3—5 concentrated primarily on endowing microcontrollers with graphical user interface (GUI) capability by exploiting the GUI tools of LabVIEW and Simulink. However, the methodology of Refs. 3—5 requires manually programming the microcontroller for all sensing, control computation, and actuation tasks and for serial communication with the GUI running on the PC. To program a PIC microcontroller or a BS2 microcontroller using PIC assembly programming language or PBasic programming language, respectively, requires knowledge and experience with the syntax of these languages and is often tedious. This paper proposes a PIC microcontroller based low-cost data acquisition and control system that exploits Matlab and Simulink as the key software components for implementing data acquisition and control algorithms using a block-diagram format. Specifically, the paper exploits a newly developed library of PIC functions for Simulink and the serial communication capability
This paper presents a personal computer (PC)-based data acquisition and control tool that uses a Peripheral Interface Controller (PIC) microcontroller, Matlab, and Simulink. Specifically, a library of PIC microcontroller functions for Simulink is created. Moreover, the PIC microcontroller and Matlab are merged, by exploiting their serial communication capability, to produce an inexpensive data acquisition and control platform. Finally, the efficacy of this data acquisition and control platform is illustrated by performing angular position control of a DC motor.
