Gynecologic surgery accounts for 75% of all intraoperative injuries to the ureters, which often occur due to the close proximity of the ureter to the uterine artery. We propose dual-wavelength photoacoustic imaging in order to distinguish the ureter from the uterine artery, identify the position of the surgical tool in proximity to these critical structures, […]
Photoacoustic (PA) imaging is a hybrid imaging technology which combines the best of optical (contrast) and ultrasound (resolution) imaging. PA imaging uses intrinsic contrast agents in the body like blood (hemoglobin), melanin, etc. But the contrast from the intrinsic contrast agents might not be sufficient for different applications. So, external contrast agents are needed for […]
Prenatal ethanol exposure (PEE) can lead to structural and functional abnormalities in fetal brain. Although neural developmental deficits due to PEE have been recognized, the immediate effects of PEE on fetal brain vasculature and hemodynamics remain poorly understood. One of the major obstacles that preclude the rapid advancement of studies on fetal vascular dynamics is […]
Many cardiac interventional procedures (e.g., radiofrequency ablation) require fluoroscopy to navigate catheters in veins toward the heart. However, this image guidance method lacks depth information and increases the risks of radiation exposure for both patients and operators. To overcome these challenges, we developed a robotic visual servoing system that maintains visualization of segmented photoacoustic signals […]
Photoacoustic imaging (PAI) maps functional and molecular optical contrasts of tissue at ultrasonic spatial resolution and imaging depth. To generate detectable PA signals from deeper regions, expensive, bulky and high-energy class IV lasers are conventionally employed. Light emitting diodes (LED) have recently emerged as an alternative excitation source for PA imaging offering many advantages including […]
Real-time intraoperative guidance during minimally invasive neurosurgical procedures (e.g., endonasal transsphenoidal surgery) is often limited to endoscopy and CT-guided image navigation, which can be suboptimal at locating underlying blood vessels and nerves. Accidental damage to these critical structures can have severe surgical complications, including patient blindness and death. Photoacoustic image guidance was previously proposed as […]
Clinical 2D photoacoustic (PA) imaging can be easily implemented in a traditional ultrasound (US) system. However, 3D PA imaging is still preferable because 2D B-mode PA/US imaging suffers from low reproducibility and high-operator dependency. Here, we demonstrate a compact clinical handheld 3D PA/US scanner using an 1D linear array US transducer combined with a mechanical […]
Photoacoustic temperature measurement is a new type of thermometric technology with noninvasive, real-time, high precision and space resolution. For improving the measurement accuracy and reliability, the method of using a multiwavelength photoacoustic signal to monitor the temperature named as multiwavelength photoacoustic temperature measurement was proposed in this paper. Based on the basic photoacoustic effect theory, […]
A low-cost adjustable illumination scheme for hand-held photoacoustic imaging probe is presented, manufactured and tested in this paper. Compared with traditional photoacoustic probe design, it has the following advantages: (1) Different excitation modes can be selected as needed. By tuning control parameters, it can achieve bright-field, dark-field, and hybrid field light illumination schemes. (2) The […]
Photoacoustic imaging is a promising technique to provide guidance during multiple surgeries and procedures. One challenge with this technique is that major blood vessels in the liver are difficult to differentiate from surrounding tissue within current safety limits, which only exist for human skin and eyes. In this paper, we investigate the safety of raising […]