Endoscopic diamond magnetometer for cancer surgery

Intraoperative measurements using magnetic sensors are a valuable technique in cancer surgery for finding magnetic tracers. Here we present a fiber-coupled nitrogen-vacancy center magnetometer capable of detecting iron oxide suspension (MagTrace™ from Endomagnetics Ltd.) used in breast cancer surgeries. Detection of an iron mass as low as 0.56 mg has been demonstrated, 100 times less than that of a recommended dose at a maximum distance of 5.8 mm. Detection of an iron concentration as low as 2.8 mg/ml has also been demonstrated, 20 times less than a recommended dose. The maximum working distance from the sensor can be as large as 14.6 mm for higher concentrations. The sensor head has a maximum diameter of 10 mm which would allow it to be used for endoscopy, laparoscopy, and intraoperative surgery.