So How Does The Nickel™ work? The Nickel™ is battery operated device which senses acoustic pulses that are transmitted from a functional element within the array of the probe. When a sufficient threshold signal is received from an element the LED indicator on the device will toggle from steady state red to a slow to steady state pulsating green indicating a functional element. The device will then transmit an acoustic signal back to that element which is processed by the ultrasound system and displayed on the system's monitor as a bright signal along the appropriate vector lines that make up the transducer display format. This indicates that the receive, processing and display electronics within the ultrasound system for all modalities are functional. The Nickel™ acoustic signal also tests Pulsed Doppler, Colour Flow and M-Mode functions
The sensor is an integral PVDF transducer designed for direct contact to the lens of the probe. The PVDF transducer assembly has a "V" or "Barn Roof" plastic lens with a peak dimension small enough to allow only acoustic energy from a single element assuming the peak of the roof is parallel to the element. The PVDF material is broadband, thus signals from any diagnostic imaging probe can be sensed. The user knows that a signal has been received when the LED on The Nickel™ goes from red to green
The received signal is amplified and then compared to a fixed reference level such that signals larger than the reference level indicate that an acoustic pulse has been received. Crossing this signal threshold level results in a digital signal that is sent to a CPLD (complex programmable logic device), which starts an oscillator (˜10 MHz) synchronous with the received pulse and contains counters used to generate three return targets back to the system
The first target signal is 10 MHz and is transmitted continuously for 2 cm of depth from 3 to 5 cm. The second target is 5 MHz and is transmitted from 5 to 7 cm and the third target frequency is 2.5 MHz and is transmitted from the 7 to 9 cm. These returning signals are then displayed in real-time on the system monitor at various depths within the image format |