Simulating lower extremity nerve blocks with virtual reality

Regional anesthesia offers many potential benefits to patients, and provides a gratifying aspect of practice to anesthesiologists. Unfortunately, these techniques are often avoided because practitioners lack familiarity with the procedures. Current methods of teaching regional anesthesia require the clinician to learn while performing actual procedures on patients. This approach poses a barrier to learning because it can create anxiety among student, teacher, and patient. We have developed a method of simulating regional anesthesia with the goal of allowing physicians to gain technical familiarity with these procedures before actual patient contact. Our approach involves the visual presentation of a patient using virtual reality that is created from CT-scan data and presented in stereo through a head-mounted display. The sense of touch and needle resistance is simulated with a PHANToM servo-controlled force transduction device. The system provides satisfactory realism to allow the user to suspend disbelief, and accept the environment as representing a patient upon whom a regional anesthetic procedure can be performed. Because the simulation is derived from patient CT data and biomechanical testing of tissue properties, actual patient characteristics may be modeled. Procedures can be rehearsed and alternative approaches attempted before actual patient contact. By using virtual reality, this approach reduces the space, expense, and inflexibility of a mannequin-based simulator. Early experience with the system suggests that physicians find this tool useful in learning the anatomy and technical approach to regional anesthesia.