Abstract: An ultrasonic sounding apparatus is described for measuring backfat and determining pregnancy in animals, having a plurality of self-test features to ensure integrity of the measurements. In the preferred embodiment, a hand-held ultrasonic device is described for detecting increased amounts of amniotic fluid in an animal's uterus for an indication of pregnancy. Every two and one half seconds the hand-held ultrasonic device emits a small tone indicating that the transducer is in correct contact with the body of the animal. The generation of this skin contact tone is performed using the same ultrasonic circuitry that is used to detect the amniotic fluid, thereby providing the dual function of circuit self-test and skin contact test. In addition, the device includes a power-up confidence test to test the components of the circuit and indicate by an audible tone that everything is working properly. This power-up confidence test also uses the same ultrasonic circuitry that performs the detection of amniotic fluid.

Abstract: A housing is disclosed for an apparatus for determining pregnancy in animals which includes a pressure activated switch. The housing includes a housing portion formed from integrally molded synthetic plastic which is selected to have a rigidity which varies with the thickness of the material. The handle includes walls which define a chamber for receiving components of the apparatus including a pressure activated switch. The walls are selected to have material thickness sufficient for the walls to be rigid in response to a pressure applied by an operator's hand. A digit engaging portion of one of the walls is provided with a reduced thickness sufficient for the digit engaging portion to flex into the chamber in response to a pressure applied by an operator's hand and returned to a rest position when pressure is withdrawn. The pressure activated switch is included within the chamber and has a pressure activated element opposing the digit engaging portion.

Abstract: An automatic digital backfat meter. An apparatus and method primarily for measuring the thickness of backfat in an animal which automatically adjusts sensitivity and notifies the user when a proper reading is obtained. The transducer (62) produces pulses which pass amplifier (64), threshold detector (68), and are counted in counter (74). If two counts are received, indicator (76) is activated. If two counts are not received, the cycle is repeated and the amplifier (64) has its gain increased by sensitivity control (66) in a stepwise increment until the first fat layer is detected. Time delay (78) prevents the first echo from being counted at counter (74).

Abstract: An automatic digital backfat meter. An apparatus and method primarily for measuring the thickness of backfat in an animal which automatically adjusts sensitivity and notifies the user when a proper reading is obtained. The transducer (62) produces pulses which pass amplifier (64), threshold detector (68), and are counted in counter (74). If two counts are received, indicator (76) is activated. If two counts are not received, the cycle is repeated and the amplifier (64) has its gain increased by sensitivity control (66) in a stepwise increment until indicator light (76) is activated. Time delay (78) prevents the first echo from being counted at counter (74).

Abstract: A pulsed ultrasonic detection system particularly adapted for detection of biological tissue includes a probe for placement against the body, apparatus for transmitting ultrasonic energy into the body and for receiving return pulses, signal processing circuits and a cathode ray tube display for displaying the return pulses as a function of time. A gating signal is generated after a predetermined time delay from each transmitted pulse, and the time delay and the duration of the gating signal are selected to correspond to the timing of a particular expected return pulse. Return pulses are gated into an audible signal device by a switching device, but only during the time interval thus defined by the gating signal. If a return pulse of sufficient amplitude occurs during the gated interval, the audible signal device is energized.