Jon J. Erickson

Noninvasive detection of small bowel electrical activity from SQUID magnetometer measurements using SOBI

We report a robust method for noninvasive biomagnetic detection of small bowel electrical activity. Simultaneous Superconducting QUantum Interference Device (SQUID) magnetometer (MENG) and serosal electrode recordings were made on pig small bowel. The SOBI blind-source separation algorithm was used to separate the underlying source signals of the MENG. Comparison of identified SOBI components to the serosal recordings validated the underlying MENG sources as being enteric in origin. Non-invasive detection of small bowel electrical activity could have significant implications in a clinical setting.

DIGITAL RADIOGRAPHY IN THE ANALYSIS OF PAINTINGS: A NEW AND PROMISING TECHNIQUE

AbstractRecent advances in computer processing of images and the development of electronic x-ray detectors have made possible the development of digital radiographic techniques, which offer great potential for the analysis of paintings. The ability to distinguish very small differences in x-ray attenuation characteristics provides the possibility of quantitative analysis of pigment structures. The very sophisticated image processing techniques that have been developed for the space industry and medicine also may be applied to the analysis of paintings through the use of the digital radiographic images. In this communication, digital fluoroscopy, scanned projection radiography, and scanned point-source methods will be described. The virtues and limitations of each are noted. An initial experience with two of these methods will be the major subject of this communication.

QUALITY ASSURANCE IN MEDICAL IMAGING

The philosophy and general test methods that can be used on a routine basis to assure the quality of medical imaging systems are summarized in this article. Quality assurance must be observed throughout the entire imaging process from the initial order for a particular procedure to the generation, interpretation, and reporting of results. Key areas of concern include the optimization of the decision process (selection of the proper imaging procedure or sequence of procedures); the utilization of contrast agents, pharmaceuticals (including radiopharmaceuticals), and pharmacologically enhanced imaging procedures; the biodistribution and dosimetry; and the possible side effects of external agents.

A Stand Alone Data Collection Station Based on an Autonomous CAMAC Crate

The increasing cost of software and hardware for complex acquisition and control systems has made it desirable to implement small stand alone systems with less complex software and more versatile hardware. This paper discusses two applications of an autonomous CAMAC crate based on an LSI-11 controller. The first application is an EKG gated single probe system for cardiac ejection fraction measurement. The second is the control system for a rectilinear scanner in a low level counting facility.

CAMAC Applications in Nuclear Medicine at Vanderbilt: Present Status and Future Plans

CAMAC has been used for data acquisition and control of nuclear measurement systems in the Vanderbilt University Nuclear Medicine Laboratory for approximately two years. The implementation of the CAMAC crate controller used with a PDP/9 computer is described. Data are acquired from three types of devices. These include a stationary multi-probe system, a computer driven scanner and a dual probe scanner not under computer control. Future extensions of our system are discussed, including the collection of data from higher data rate instruments (Anger-type scintillation camera) as well as computer networking. The CAMAC system required a higher initial dollar investment when compared to a single dedicated scanner interface. However, it provided a much more versatile and more easily expanded system. When a second device is added, we found that the use of CAMAC can be defended successfully on a cost basis alone. The CAMAC standard allows the replication of systems by laboratories without the large investments in time and money usually needed to interface specialized measurement systems to computers. The modularity permits orderly growth of systems and protects against obsolescence. Almost any standard would be better than no standard, and we plan to use CAMAC for all applications where data-transmission-rate requirements permit. We hope that users in the nonnuclear field will come to utilize CAMAC in their measurement and data reduction systems where similar benefits should be obtained.

Two inexpensive automatic sample changers for use with an MCA

Abstract Two inexpensive automatic sample changers for use with automatic-cycling multichannel analyzers are described. Both small dry samples and small liquid samples can be used.