Examination of human intracellular processes is an exponentially exploding frontier in medical science that is currently studied in static cell populations at specific time points. Acquiring detailed information about dynamic changes in RNA transcription and protein expression in living cells has the potential to impact patient and animal care profoundly. We fabricated an ultrasonic device for collecting cells from the mucosal tissue of living organisms. Detailed cell activity could be ascertained by collecting and analyzing cells intermittently throughout the day using this device.

A Langevin-type oscillator generated ultrasonic sound waves that are propagated to the mucosal tissue via a metal rod. The bonds between the cells are weakened or broken by cavitation, and the cells are collected by circulating physiological saline. During the initial testing of this device, we collected over 1000 cells repeatedly from the same site of excised porcine esophageal mucosa with a sampling time of 1 minute and an ultrasonic intensity slightly exceeding the cavitation threshold. This confirms that this device can be used to collect cells multiple times per day.

It is expected that live cells can be collected for analysis during daily life. Cells can also be collected using this minimally invasive device from the mucosa of the digestive tract by attaching this device to the tip of an endoscopic tool. Cells can be collected from various organs during surgery for the analysis of pathological conditions and for analysis that could help delineate more precise surgical procedures.

Dental implant treatment is an excellent treatment method that places little burden on healthy teeth and offers many advantages in terms of masticatory function and esthetics. However, it requires advanced surgical skills, and medical accidents continue to occur. In particular, when the hardness of the cortical bone just below the maxillary sinus is high, there is a risk of damage to the maxillary sinus membrane after penetration of the cortical bone, even when variously devised drills and instruments are used. Methods to detect penetration and stop drilling based on bone density estimated by a robot have been proposed. However, they require elaborate modeling of the bone. Another method has been proposed to capture changes in bone quality by focusing on fluctuations in cutting torque. However, it is greatly affected by the direction of cutting and other factors. Therefore, this paper proposes a method to realize more robust penetration detection and stop control by superimposing vibrations in a specific frequency band in the direction of drill move and focusing on torque changes in the same frequency band. The proposed method also has the advantage of being less susceptible to vibration and noise caused by cutting vibration and magnetic flux distribution of the motor by appropriately selecting the frequency band in which vibration is superimposed. The effectiveness of the proposed method was verified through experiments, and penetration detection was achieved even when the penetration surface and cutting direction were inclined from vertical.