ABSTRACT
More efficient screening for breast cancer can lead to a reduction in the need for radical surgery and improved survival rates. Modern technology, particularly electronics and computerized instrumentation, makes such improvement feasible. We have developed an instrument for screening for breast cancer based on measuring the dielectric properties of tissues. An image of the electric properties of the breast is presented on a monitoring screen, using 512 'pixels', from which it is possible to distinguish pathological tissue. The image can be recalled on the monitor at will. The test can be performed by paramedical personnel. In the present study 6000 patients were tested with this instrument; 745 of these have undergone biopsy and these had been tested with all available instrumentation. A number of cases were found in which only this instrument detected a pathology which proved malignant. Instruments of such a type could become an additional part of breast cancer clinics.
Subject(s)
Breast Neoplasms/prevention & control , Diagnosis, Computer-Assisted , Electrodiagnosis/instrumentation , Mass Screening/instrumentation , Breast Neoplasms/diagnosis , Electric Conductivity , Equipment Design , Female , HumansABSTRACT
The important features of microprocessor design of medical instrumentation are discussed, and the Mammoscan dielectric breast scanner being developed in our laboratories is given as a specific example. The principles of dielectric breast scanning are explained, and the implementation of the technique in a working Mammoscan is is described. Typical results of Mammoscan examinations are given, including both normal and suspicious findings. Preliminary attempts at image classification are discussed, as well as the necessity of large-scale clinical data gathering for improving classification methods. The use of microprocessors makes devices such as the Mammoscan possible, both because of the power of microprocessor control and number handling, and because of its ability to store examination data locally and analyze it off-line at a central location.
Subject(s)
Breast Diseases/diagnosis , Computers , Electrodiagnosis/instrumentation , Microcomputers , Equipment Design , Female , Humans , MethodsABSTRACT
A new method for the measurement of small intestinal transit time is described. An externally applied magnetic transducer senses the presence of an ingested ferromagnetic material--50 gm. of magnesium ferrite dispersed in a test meal--upon its arrival at the cecal area. The mouth-to-cecum transit time is thus determined. The method is noninvasive and is not associated with any radiation. The method was compared to the commonly used x-ray method and good correlation was found in 24 of 28 studies. The mean transit time in a group of 20 normal subjects was 157.5 +/- 63.9 min.
Subject(s)
Gastrointestinal Motility , Intestine, Small/physiology , Magnetics , Adult , Aged , Cecum/diagnostic imaging , Cecum/metabolism , Humans , Methods , Middle Aged , Radiography , Time Factors , TransducersABSTRACT
A new ferromagnetic method for the measurement of gastric emptying is described. An inert tracer, magnesium ferrite, is added to a test meal. Its amount in the stomach is then measured at regular intervals by an external transducer using its ferromagnetic properties. The method is noninvasive and devoid of radiation exposure. The magnetic fields used are harmless. The feasibility, reliability, and reproducibility of the method are described. Gastric emptying was studied in 61 subjects. The shape of the gastric emptying curve conformed best to an exponential function. The mean half-time of gastric emptying was 49 +/- 17.4 min. In this limited series age and sex did not affect gastric emptying.
Subject(s)
Gastric Emptying , Iron , Magnetics , Adolescent , Adult , Aged , Clinical Trials as Topic , Female , Food , Humans , Magnesium , Male , Middle Aged , Radiography , Stomach/diagnostic imaging , Time FactorsABSTRACT
A new apexcardiographic recording system has been developed which is free of certain technical limitations. This noncontact magnetic transducer was tested alternately with a commonly used pneumatic piezoelectric transducer in a comparative study on ten normal subjects. The magnetic registration offered a more accurate timing and configuration of the ACG. Signal distortion, such as peaked waves and an early fall of the systolic wave, was eliminated. The magnetic transducer was capable of recording directional apex point tracings, as well as pulsations of a larger apical area. The new system proved to possess definite advantages and eliminated some of the inconveniences inherent in the pneumatically coupled system.
