Application of a new tactile sensor to thoracoscopic surgery: experimental and clinical study.
BACKGROUND
We developed a new tactile sensor that could quantify the hardness of objects as changes in the resonance frequency of the sensor (delta f). We have applied it to thoracoscopic operations for the localization of small invisible nodules in the lung.


METHODS
When the sensor probe was moved over the lung surface, a delta f curve was depicted on the computer screen. When the sensor tip reached a point directly above a hard object, a sudden upward jump of the delta f curve was evoked. After experimental studies using pigs, the sensor was applied in 8 patients. More recently we produced a needle sensor to distinguish small nodules from bronchi that may evoke similar upward jumps of the delta f curve. Eight nodules and four bronchi in resected human lungs were probed directly using this sensor.


RESULTS
In all of the patients, the hardness of various thoracic structures could be quantified. A total of 10 nodules were found using the sensor and resected thoracoscopically. The needle sensor distinguished nodules from bronchi, as the mean delta f of the bronchial walls (-64 +/- 45.9 Hz) was significantly higher than that of nodules (-526 +/- 168 Hz, p < 0.001).


CONCLUSIONS
Thoracoscopic detection of small and invisible pulmonary nodules using our new tactile sensor is feasible.
Ohtsuka
T
T
Department of Cardiothoracic Surgery, Faculty of Medicine, University of Tokyo, Japan.
Furuse
A
A
Kohno
T
T
Nakajima
J
J
Yagyu
K
K
Omata
S
S
D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery; D000818:Animals; D001698:Biomedical Engineering / Q000295:instrumentation*; D001980:Bronchi / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000601:surgery; D004582:Electronics, Medical / Q000295:instrumentation; D006222:Hamartoma / Q000473:pathology / Q000601:surgery; D006244:Hardness; D006801:Humans; D008168:Lung / Q000473:pathology; D008171:Lung Diseases / Q000473:pathology / Q000601:surgery*; D008175:Lung Neoplasms / Q000473:pathology / Q000556:secondary / Q000601:surgery; D008838:Microcomputers; D009339:Needles; D012826:Silicone Elastomers; D013552:Swine; D020708:Thoracoscopes; D014110:Touch; D014159:Transducers; D014375:Tuberculoma / Q000473:pathology / Q000601:surgery; D014397:Tuberculosis, Pulmonary / Q000473:pathology / Q000601:surgery; D014732:Vibration
D012826:Silicone Elastomers