Abstract: A method for measuring the CT numbers of an in vivo tissues includes the steps of calculating a histogram of a region including the tissue, locating a leading edge of a peak within the histogram, substracting CT numbers assumed to result from background and intermixing of tissues, fitting the background-substracted peak to a gaussian distribution, and calculating the mode of the resulting peak. Whe the CT numbers of two different tissues having know densities are measured according to the method of the invention, the CT numbers may be used to obtain a standard for analyzing tissues of unknow density. The method can be implemented by means of a CT scanner, a computer, and appropriate software.

Abstract: An electronic health care diary is provided for a patient logging data concerning predetermined health conditions, such as for monitoring angina attacks. Upon the onset of e.g. the angina attack the patient presses a start button whereupon a real time clock generates a data and time signal which is stored in a memory along with the fact that the episode started. When the episode is over the patient presses a "stop" switch which generates another date and time signal from the real time clock and stores it in memory along with the fact that the episode terminated. A multi-position switch is actuated by the patient to indicate the extent of the condition, such as the severity of the attack. Optionally, a switch can be provided for correcting a previous erroneous entry, and another switch indicating the time and dosage of any medication. Data logged in the memory can be downloaded through a communications port and programming instructions can be uploaded into the device.