Abstract: Apparatus for assaying an analyte in blood in a patient's blood vessel comprising: a light provider comprising at least one light source that illuminates a tissue region in which a blood vessel is located with light that stimulates photoacoustic waves in the region; at least one acoustic transducer that generates signals responsive to the photoacoustic waves; a controller that receives the signals and processes them to determine which are responsive to photoacoustic waves that originate in the blood vessel and uses the determined signals to assay the analyte; wherein, the light provider and at least one transducer define a field of view that overlaps the blood vessel, said field of view having a central region and a lateral extent greater than about 4 mm.

Abstract: Apparatus for assaying an analyte of blood in a patient's blood vessel comprising: a mounting module adapted so that it can be adhered to the skin of the patient overlying a tissue region comprising the blood vessel; a sensor unit mounted to the module that generates signals responsive to characteristics of the tissue region; and a controller that receives the signals and uses received signals to assay the analyte and to determine a degree to which the sensor unit is aligned with the blood vessel.

Abstract: A system for monitoring a position of an instrument in a subject includes a light transmission medium configured to transmit light pulses to a desired region to produce an acoustic signal, at least one ultrasound sensor configured to receive the acoustic signal and to produce a transduced signal from the acoustic signal, and a processing unit connected to the at least one ultrasound sensor and configured to locate a source of the acoustic signal using the transduced signal.

Abstract: A system for monitoring a position of an instrument in a subject includes a light transmission medium configured to transmit light pulses to a desired region to produce an acoustic signal, at least one ultrasound sensor configured to receive the acoustic signal and to produce a transduced signal from the acoustic signal, and a processing unit connected to the at least one ultrasound sensor and configured to locate a source of the acoustic signal using the transduced signal.