Entries by Katy

Parking sensor-inspired approach to photoacoustic-guided hysterectomy demonstrated with human cadavers

Similar to the parking-assist sensors on modern automobiles, which alert drivers of impending impact to an object, we are developing an auditory photoacoustic-based guidance system to assist with avoidance of impending injuries to ureters during hysterectomy procedures. The contribution described in this paper considers international standards for medical alarms. The system was demonstrated during both […]

Photoacoustic differentiation of cortical from cancellous bone in the lumbar vertebrae of an intact human cadaver to prevent bone breaches during spinal fusion surgeries

In spinal fusion surgeries, it is critical to maintain correct trajectories during the process of creating pedicle holes for screw insertion, in order to avoid accidental bone breaches and screw misplacement, which are characterized by screws placed within surrounding cortical bone rather than the cancellous core of the pedicle. One key difference between these two […]

A photoacoustic image reconstruction method for point source recovery

In this paper, a novel Delay and Glow (DAG), back projection-based photoacoustic reconstruction, for point source recovery is presented. The projections of the absorber coefficients are delayed and weighed based on the transducer directivity sensitivity and matched with the other projections from other transducer elements leading to glow the point source at the exact location. […]

Spatially distributed sensor array calibration for photoacoustic imaging

To eliminate the limited angle effect of photoacoustic imaging based on ultrasound linear array, spatially distributed ultrasound sensor array is applied. The accurate sensor array position determines the quality of the imaging results. We proposed two methods based on photoacoustic and ultrasound signals to enhance the imaging quality using a full-ring array. Photoacoustic signals are […]

Polyacrylamide hydrogel phantoms for performance evaluation of multispectral photoacoustic imaging systems

As photoacoustic imaging (PAI) begins to mature and undergo clinical translation, there is a need for well-validated, standardized performance test methods to support device development, quality control, and regulatory evaluation. Despite recent progress, current PAI phantoms may not adequately replicate tissue light and sound transport over the full range of optical wavelengths and acoustic frequencies employed by […]

Characterizing the aggressiveness of prostate cancer using an all-optical needle photoacoustic sensing probe: feasibility study

In our previous studies, we have developed a prototype interstitial needle sensing probe that can acquire broadband A-line photoacoustic (PA) signals encoding both tissue microarchitecture and histochemical information comparable to that accessible by histology. Paving the road toward clinical translation of this technology, we replaced the piezoelectric hydrophone in the needle PA probe with a […]

Photostability enhancement of silica-coated gold nanostars for photoacoustic imaging guided photothermal therapy

Gold nanostars (GNSs) are promising contrast agents for simultaneous photothermal therapy and photoacoustic imaging (PAI) owing to their excellent photothermal conversion efficiency. However, GNSs are easily reshaped under transient high-intensity laser pulses, which can cause a rapid shift in the light absorption peak, resulting in a decrease in both therapeutic and monitoring effects. In this work, we synthesized GNSs without toxic […]

Development of a relative quantification method for infrared matrix‐assisted laser desorption electrospray ionization mass spectrometry imaging of Arabidopsis …

Mass spectrometry imaging of young seedlings is an invaluable tool in understanding how mutations affect metabolite accumulation in plant development. However, due to numerous biological considerations, established methods for the relative quantification of analytes using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging are not viable options. In this study, we report a […]

Determination of Optimal Electrospray Parameters for Lipidomics in Infrared-Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry Imaging

Infrared matrix-assisted laser desorption ionization (IR-MALDESI) is an ambient mass spectrometry imaging (MSI) technique that relies on electrospray ionization (ESI) for ion generation of desorbed neutrals. Although many mechanisms in IR-MALDESI have been studied in depth, there has not yet been a comprehensive study of how the ESI parameters change the profiles of tissue specific […]