Abstract: A neurosurgery system for probing brain tissue of a patient for tumorous tissue. The system including a suction tool, an excitation source, an optical instrument, and a controller. The suction tool including a suction cannula defining a lumen, an optical fiber configured to transmit fluorescence emitted by the brain tissue; and an indicator configured to selectively emit visible light. An excitation source is configured to emit an excitation light having a wavelength to induce the fluorescence in the tumorous tissue. The optical instrument is coupled to the optical fiber. The optical instrument configured to convert the fluorescence emitted by the brain tissue and transmitted by the optical and configured to determine that the brain tissue is tumorous based on the electrical signal and activate the indicator based on the determination.

Abstract: A method for assessing the particle size of a bulk particulate material (1), such as powdered or granular material includes transmitting sound energy (as herein defined) through the particulate material (1) from a source (2) to a detector (3), and assessing the particle size from the time taken to pass through the material from the source (2) to detector (3) or signal velocity, through the material (1). Typically the signal is a frequency or frequencies in the range about 20 Hz to 20 kHz (but higher frequencies are envisaged), and the particulate material may be in a moving production stream of the particulate material (1). Apparatus is also claimed.