A Surgical Pen-Type Probe Design for Real-Time Optical Diagnosis of Tumor Status Using 5-Aminolevulinic Acid

Design of a Miniature Observation Robot for Light Emitting Diode Irradiation and Indocyanine Green Fluorescence-emission Guided Lymph Node Monitoring in Operating Rooms

MOTIVATION

Typical surgical microscopes used for fluorescence-based lymph node detection experience limitations such as weight and restricted adjustability of the integrated light emitting diode (LED) and camera. This restricts the capture of detailed images of specific regions within the lesion.

RESEARCH GOAL

This study proposes a miniature observation robot design that offers adjustable working distance (WD) and rotational radius, along with zoom-in/zoom-out functionality.

METHODS

A five-degree-of-freedom manipulator was designed, with the end effector incorporating an LED and concave lens to widen the beam width for comprehensive lesion illumination. Additionally, a long-pass filter was integrated into the camera system to enhance image resolution.

EXPERIMENTAL RESULTS

Experiments were conducted using a fluorescence-expressing phantom to evaluate the performance of the robot. Results demonstrated a captured image resolution of 9600 × 3240 pixels and a zoom-in/zoom-out capacity of up to 3.68 times.

CONCLUSION

The proposed robot design is cost-effective and highly adjustable, enabling suitability for rapid and accurate detection of fresh lymph nodes during surgeries. The robot's capability to detect small lesions (<1 cm), as validated by phantom tests, holds promise for the detection of minute lymph nodes.

Design of a Long-Pass Filter with Effects on Fluorescence Image Observation for Surgical Fluorescence Microscope Applications

The goal of oncological surgery is to completely remove the tumor. Tumors are often difficult to observe with the naked eye because of the presence of numerous blood vessels and the fact the colors of the tumor and blood vessels are similar. Therefore, a fluorescent contrast medium using a surgical microscope is used to observe the removal status of the tumor. To observe the tumor removal status using a fluorescent contrast agent, fluorescence is expressed in the tumor by irradiating with an external light source, and the expressed tumor can be confirmed through a surgical microscope. However, not only fluorescence-expressed tumors are observed under a surgical microscope, but images from an external light source are also mixed and observed. Therefore, since the surgical microscope is connected to a filter, the quality of the diagnostic image is not uniform, and it is difficult to achieve a clear observation. As a result, an asymmetric image quality phenomenon occurs in the diagnostic images. In this paper, a filter with high clarity that provides a symmetrical observation of diagnostic images is developed and manufactured.