Abstract: A non-invasive system and method of determining the presence or absence of neural, muscular, soft tissue, bone or joint damage to a person's hand and/or wrist. The system includes a plurality of contact points, one of which is engageable by the person's thumb and two of which are engageable by other digits of the hand, at least one of the other digits being innervated by the ulnar nerve. Force detectors are operatively connected to at least two of the contact points for measuring the quantity of force applied through respective contact points as the thumb and other digits are brought toward each other in a natural gripping motion. The measured forces are displayed for analysis of the hand and/or wrist.

Abstract: A non-invasive system and method are provided for determining the presence or absence of neural, muscular, soft tissue, bone or joint damage or other disease affecting a person's hand. A preferred system includes a plurality of digit contact members, one of which is engageable by the person's thumb and others which are engageable by other digits of the hand, at least one of the other digits being innervated by the ulnar nerve. Force detectors are operatively connected to at least two of the digit contact members for measuring the quantity of force applied to the respective digit contact members by at least one digit innervated by the median nerve and a digit innervated by the ulnar nerve, as they engage in a natural gripping motion. The measured forces may be used to calculate quality indices useful in the diagnosis of disease and the monitoring of progression of disease.

Abstract: A non-invasive system and method of determining the presence or absence of neural, muscular, soft tissue, bone or joint damage to a person's hand and/or wrist. The system includes a plurality of force members, one of which is engageable by the person's thumb and two of which are engageable by other digits of the hand, at least one of the other digits being innervated by the ulnar nerve. Force detectors are operatively connected to at least two of the force members for measuring the quantity of force applied through respective force members as the thumb and other digits are brought toward each other in a natural gripping motion. The measured forces are displayed for analysis of the hand and/or wrist.

Abstract: A sacrificial anode sub and method are disclosed which provide a lower voltage at the proximately located bit than at the sacrificial anode disposed on sub to thereby deter bit balling. An electromotive force (emf) dynamo is built into the sacrificial anode sub to provide a direct current voltage source for this purpose. Annular insulator electrically insulates sacrificial anode from tubular body. An electrical connection to drill bit is made through threaded lower connector with bit. Impeller rotates in response to drilling fluid flow to rotate the rotor assembly of dynamo.

Abstract: Various steel, downhole tools and components of a drill string, including, as examples, a PDC drill bit, a rotary rock bit, a cross-over sub, a stabilizer, a reamer, a hole enlarger and a coring bit, are selectively treated to cause certain of their parts to be electro-negative with respect to steel, and certain other parts to either have the same electro-negativity as steel, or to be treated to be electro-positive with respect to steel.

Abstract: Downhole measuring apparatus includes a gamma radiation source and at least two pairs of radiation detectors carried by a housing so that radiation may be emitted from the source and scattered by the environment of the housing and detected by the detectors. Each pair of detectors is arranged so that its detectors are positioned symmetrically on opposite sides of the longitudinal axis of the housing, and each pair of detectors, in combination with the radiation source, forms a different geometrical configuration so that, in general, the radiation counts obtained by the different pairs of detectors will not be redundant. The output signals from the detectors may be processed to provide data signals indicative of the radiation counts experienced by the detectors, and which may then be used to simultaneously obtain values for two or more downhole parameters. The addition of each new, independent pair of detectors permits the simultaneous solution of an additional downhole parameter.

Abstract: A method of calibrating a radiation detector, positioned in apparatus including a source of gamma radiation such that the detector may sense radiation from the environment of the apparatus due to radiation emitted by the source and scattered by the environment, includes utilizing test environments including formations of known bulk densities. The apparatus may be positioned within the test environments at different distances from the surfaces of the formations. Count rates of the detector are compared to the formation bulk densities for the distances of the apparatus from the formation surfaces to calibrate the detector relative to the radiation source.

Abstract: A gamma radiation logging system utilizes a single fixed gamma ray source spaced from a plurality of detector means arranged in banks so that the readings of the detectors can be utilized individually and in combination to derive the formation density, mud density and borehole diameter. The subject invention is capable of making the above determinations in a while-drilling condition without requiring physical contact with the formation nor making assumptions regarding composition of the formation or requiring further information from secondary sources. Each detector generates an output signal proportional to the photons reaching the detector with the signals being used to determine formation density, mud density and borehole diameter individually and collectively.

Abstract: Two downhole measurement-while-drilling tools, at least one of which is borehole sensitive, are used to make standard measurements of borehole conditions while drilling. From these measurements, and with some prior knowledge of the lithology, the caliber of the borehole is determined by iteration. The preferred tools are a neutron porosity and a density tool with lithology having been determined by prior seismic survey techniques.

Abstract: A system for logging subterranean formations for the determination of formation density by using gamma radiation. Gamma ray source and detection means are disposed within a housing adapted for positioning within a borehole for the emission and detection of gamma rays propagating through earth formations and borehole drilling fluid. The gamma ray detection means comprises first and second gamma radiation sensors geometrically disposed within the housing the same longitudinal distance from the gamma ray source and diametrically opposed in a common plane. A formation matrix density output signal is produced in proportion to the output signal from each of the gamma ray sensors and in conjunction with certain constants established by the geometrical configuration of the sensors relative to the gamma ray source and the borehole diameter. Formation density is determined without regard to the radial position of the logging probe within the borehole in a measuring while drilling mode.