An ultrasonic reflex imaging device and a method are described. A device according to the invention may include a platen, a generator, and a receiver positioned between the platen and the generator. A backer may be positioned so that the insonification device is between the receiver array and the backer. The backer may be configured to absorb or delay energy that originated from the generator. The generator produces an energy pulse, which travels through the receiver and the platen to reach a biological object. Part of the energy pulse is reflected from the biological object. The reflected energy pulse travels through the platen to the detector. The detector converts the reflect energy pulse to electric signals, which are then interpreted to create an image of the biological object.

In one form, an acoustic signal is generated for an acoustic transducer, where the acoustic transducer is susceptible to reverberation that defines a close proximity indication zone. The start of a close proximity indication zone window is defined after the generation of the acoustic signal at a first time. During the close proximity indication zone window, a signal is received from the acoustic transducer. When the signal is received, an obstacle is detected in the close proximity indication zone if the magnitude of a first pulse received from the transducer at a second time is less than a first threshold but greater than a second threshold for a debounce time. Additionally, a magnitude of a second pulse received from the transducer outside the close proximity indication zone window at a third time should be less than the second threshold but greater than a third threshold for the debounce time. In this form, the third time is equal to the first time plus two times the difference between the second time and the first time.