Optimizing resource utilization during proficiency-based training of suturing skills in medical students: a randomized controlled trial of faculty-led, peer tutor-led, and holography-augmented methods of teaching.

BACKGROUND: Suturing is a fundamental skill in undergraduate medical education. It can be taught by faculty-led, peer tutor-led, and holography-augmented methods; however, the most educationally effective and cost-efficient method for proficiency-based teaching of suturing is yet to be determined. METHODS: We conducted a randomized controlled trial comparing faculty-led, peer tutor-led, and holography-augmented proficiency-based suturing training in pre-clerkship medical students. Holography-augmented training provided holographic, voice-controlled instructional material. Technical skill was assessed using hand motion analysis every ten sutures and used to construct learning curves. Proficiency was defined by one standard deviation within average faculty surgeon performance. Intervention arms were compared using one-way ANOVA of the number of sutures placed, full-length sutures used, time to proficiency, and incremental costs incurred. Surveys were used to evaluate participant preferences. RESULTS: Forty-four students were randomized to the faculty-led (n = 16), peer tutor-led (n = 14), and holography-augmented (n = 14) intervention arms. At proficiency, there were no differences between groups in the number of sutures placed, full-length sutures used, and time to achieve proficiency. The incremental costs of the holography-augmented method were greater than faculty-led and peer tutor-led instruction ($247.00 ± $12.05, p < 0.001) due to the high cost of the equipment. Faculty-led teaching was the most preferred method (78.0%), while holography-augmented was the least preferred (0%). 90.6% of students reported high confidence in performing simple interrupted sutures, which did not differ between intervention arms (faculty-led 100.0%, peer tutor-led 90.0%, holography-augmented 83.3%, p = 0.409). 93.8% of students felt the program should be offered in the future. CONCLUSION: Faculty-led and peer tutor-led instructional methods of proficiency-based suturing teaching were superior to holography-augmented method with respect to costs and participants' preferences despite being educationally equivalent.

Cone-shaped optical fiber tip for cost-effective digital lensless holographic microscopy.

In this work, the development and application of a cost-effective and robust digital lensless holographic microscopy (DLHM) system is presented. In the simple architecture of DLHM based on a point source and a digital camera, the production of the former is introduced by means of an engineered step-index optical fiber with a cone-shaped end tip. The conventional and regularly expensive point source in DLHM is produced by means of a high-numerical-aperture microscope objective and a metallic wavelength-sized pinhole. The proposed replacement renders to DLHM additional simplicity of building, in addition to mechanical stability and robustness, and further reduces the cost of the microscope. The simplified cost-effective DLHM architecture is utilized for imaging resolution test targets and samples of human blood and pond water, revealing competitive mechanical stability and trustable phase images of the imaged specimens.

Wide-field computational imaging of pathology slides using lens-free on-chip microscopy.

Optical examination of microscale features in pathology slides is one of the gold standards to diagnose disease. However, the use of conventional light microscopes is partially limited owing to their relatively high cost, bulkiness of lens-based optics, small field of view (FOV), and requirements for lateral scanning and three-dimensional (3D) focus adjustment. We illustrate the performance of a computational lens-free, holographic on-chip microscope that uses the transport-of-intensity equation, multi-height iterative phase retrieval, and rotational field transformations to perform wide-FOV imaging of pathology samples with comparable image quality to a traditional transmission lens-based microscope. The holographically reconstructed image can be digitally focused at any depth within the object FOV (after image capture) without the need for mechanical focus adjustment and is also digitally corrected for artifacts arising from uncontrolled tilting and height variations between the sample and sensor planes. Using this lens-free on-chip microscope, we successfully imaged invasive carcinoma cells within human breast sections, Papanicolaou smears revealing a high-grade squamous intraepithelial lesion, and sickle cell anemia blood smears over a FOV of 20.5 mm(2). The resulting wide-field lens-free images had sufficient image resolution and contrast for clinical evaluation, as demonstrated by a pathologist's blinded diagnosis of breast cancer tissue samples, achieving an overall accuracy of ~99%. By providing high-resolution images of large-area pathology samples with 3D digital focus adjustment, lens-free on-chip microscopy can be useful in resource-limited and point-of-care settings.