S0824 A Capsule Endoscope With a Thermochromic Sensor Can Predict the Severity and Prognosis of Ulcerative Colitis

Abstract

INTRODUCTION: Though a capsule endoscope (CE) is a non-invasive device for exploring the gastrointestinal tract, it does not have any functions to clarify invisible parameters such as temperature, pH, digestion, enzymes, microbiota, inflammation and tumorous characters. Recently various types of chromic sensors without energy consumption have been developed and introduced into the engineering area including IoT. To evaluate the severity of inflammation beneath the mucosa of patients with ulcerative colitis, a thermochromic sensor was attached to a capsule endoscope(CECS). METHODS: Thermochromic sensor was a liquid crystal patch (4 × 4 × 0.3 mm NexTemp, USA) which had a resolution of ± 0.1 °C (37∼39°C). It was attached to the hood of a capsule endoscope (PillCam Colon2 Medtronics, USA) and the temperature was displayed near the perimeter of the endoscopic view. To check the inertia of a sensor the water bath was used by changing the temperature. To evaluate local the severity of inflammation around lesions, the temperature of normal skin and damaged tissue were taken. Three patients with ulcerative colitis and 10 normal volunteers were enrolled into a pilot clinical trial after the researchers obtained IRB approval from their hospital. RESULTS: In the inertia experiment it took 15 seconds to tracking the temperature of water bath, if the water bath temperature increase from 36 to 38. This result indicated that it was possible to measure the temperature in real time in vivo. The temperature around the lesion was 0.5 ± 0.1 °C higher than that of a normal area. The core temperatures in normal volunteers were 36.8 ± 0.1 °C stable. The temperature differences between a lesion and normal mucosa were closely related to the Matts endoscopic grades of ulcerative colitis evaluated from endoscopic images. Even though the parts appeared to be achieved the mucosal healing by therapy, some parts of them showed a temperature 0.2°C higher than the normal mucosa. I estimated that the submucosal inflammation was continued there though there were no abnormal endoscopic findings. CONCLUSION: The severity of ulcerative colitis could be evaluated locally by the CECS non-invasively. The next step will be to determine by long term follow up whether CECS is useful for estimating the prognosis and recurrence in future.Figure 1.: The appearance of thermochromic sensor.Figure 2.: The endoscopic image of the capsule endoscope with thermochromic sensors.