Abstract: A system and method for growing and maintaining biological material including producing a protein associated with the tissue, selecting cells associated with the tissue, expanding the cells, creating at least one tissue bio-ink including the expanded cells, printing the at least one tissue bio-ink in at least one tissue growth medium mixture, growing the tissue from the printed at least one tissue bio-ink, and maintaining viability of the tissue.

Abstract: A collision detector for a vehicle, comprises a waveguide which is locatable on and acoustically isolated from the vehicle. The waveguide allows stress waves to propagate therethrough, and the waveguide is arranged to produce stress wave activity when the waveguide is deformed due to collision. A pair of transducers are acoustically coupled to the waveguide and the transducers convert any stress waves into electrical signals. A processor analyses the electrical signals and gives an output signal to indicate the occurrence of a collision. The transducers detect different frequency bands and the processor compares the electrical signals and indicates the occurrence of a crash if the ratio or difference is greater than a predetermined value. The waveguide is a metallic member which has a glass coating and a protective coating. Alternatively the waveguide may be a fibre reinforced plastic, tin, or a metallic member which has an interface with a semi-rigid plastic member.

Abstract: An apparatus for processing electrical signals corresponding to acoustic emissions produced in a machine or process comprises a transducer acoustically coupled to the machine or process, which detects the acoustic emissions and converts them into an output signal. The output signal is amplified by an amplifier, rectified and enveloped by an enveloper having a short time constant to produce an electrical signal. An enveloper having a long time constant, measures the mean level of the electrical signal. A DC component remover removes the DC component from the electrical signal and an enveloper, having a long time constant, measures the mean level of the rectified AC component of the electrical signal. A processor having a low sampling rate, measures a power of the ratio between the mean level of the rectified AC component of the electrical signal and the mean level of the electrical signal.

Abstract: The invention relates to a method and apparatus for testing the response of a stress wave sensor to confirm that the transducer and amplifier are functioning satisfactorily.A pulser is connected to the stress wave sensor at a point between the transducer and the amplifier. The pulser supplies a first and a second electrical pulse in series to the stress wave sensor. The first electrical pulse has a large amplitude such that it causes an operative transducer to oscillate and produce an additional electrical pulse. The first electrical pulse and the additional electrical pulse are supplied to the amplifier. An operative amplifier amplifies the first electrical pulse and any additional pulse to give an output signal, the output signal indicates if either the transducer or amplifier are not operating satisfactorily, the lack of an output signal indicates the amplifier is inoperative.