Evaluation of surgical skills in microgravity using force sensing.

INTRODUCTION: Force measurements can be used to characterize surgical maneuvers in microgravity. METHODS: : A series of surgical tasks was performed by a group of 20 participants (n=20) both in 1g on the ground and in 0 g aboard NASA's KC-135 aircraft in parabolic flight. The group included astronauts, a flight surgeon, surgeons, physicians, Ph.D.-scientists, and technical personnel. The interaction forces between the surgical instruments and the mock tissue were measured for a clip-applying, suturing, grasping, and cutting. Seven evaluations in 1g and a single evaluation in 0 g were performed by each of the participants. RESULTS: The data from a single participant are examined in detail. Statistical results for the group of 20 participants do not show significant differences in the average or peak forces during clip-applying or in the average forces applied during suturing in 0 g versus in 1g. However, the results do show statistically greater (43% higher) peak forces during suturing in microgravity. DISCUSSION: These data show the usefulness of analyzing force information to assess surgical task performance in microgravity. Although peak suturing forces were statistically higher in microgravity, their clinical relevance is unknown, but likely would not result in a change in clinical outcome. Overall, the data suggest that forces exerted during surgical tasks will not pose a significant barrier to effective surgery in microgravity.

A multiparameter wearable physiologic monitoring system for space and terrestrial applications.

A novel, unobtrusive and wearable, multiparameter ambulatory physiologic monitoring system for space and terrestrial applications, termed LifeGuard, is presented. The core element is a wearable monitor, the crew physiologic observation device (CPOD), that provides the capability to continuously record two standard electrocardiogram leads, respiration rate via impedance plethysmography, heart rate, hemoglobin oxygen saturation, ambient or body temperature, three axes of acceleration, and blood pressure. These parameters can be digitally recorded with high fidelity over a 9-h period with precise time stamps and user-defined event markers. Data can be continuously streamed to a base station using a built-in Bluetooth RF link or stored in 32 MB of on-board flash memory and downloaded to a personal computer using a serial port. The device is powered by two AAA batteries. The design, laboratory, and field testing of the wearable monitors are described.