A novel speculum-free imaging strategy for visualization of the internal female lower reproductive system

Abstract

Fear of the speculum and feelings of vulnerability during the gynecologic exams are two of the biggest barriers to cervical cancer screening for women. To address these barriers, we have developed a novel, low-cost tool called the Callascope to reimagine the gynecological exam, enabling clinician and self-imaging of the cervix without the need for a speculum. The Callascope contains a 2 megapixel camera and contrast agent spray mechanism housed within a form factor designed to eliminate the need for a speculum during contrast agent administration and image capture. Preliminary bench testing for comparison of the Callascope camera to a $20,000 high-end colposcope demonstrated that the Callascope camera meets visual requirements for cervical imaging. Bench testing of the spray mechanism demonstrates that the contrast agent delivery enables satisfactory administration and cervix coverage. Clinical studies performed at Duke University Medical Center, Durham, USA and in Greater Accra Regional Hospital, Accra, Ghana assessed (1) the Callascope’s ability to visualize the cervix compared to the standard-of-care speculum exam, (2) the feasibility and willingness of women to use the Callascope for self-exams, and (3) the feasibility and willingness of clinicians and their patients to use the Callascope for clinician-based examinations. Cervix visualization was comparable between the Callascope and speculum (83% or 44/53 women vs. 100%) when performed by a clinician. Visualization was achieved in 95% (21/22) of women who used the Callascope for self-imaging. Post-exam surveys indicated that participants preferred the Callascope to a speculum-based exam. Our results indicate the Callascope is a viable option for clinician-based and self-exam speculum-free cervical imaging. Clinical study registration ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/record/ NCT00900575, Pan African Clinical Trial Registry (PACTR) https://www.pactr.org/ PACTR201905806116817.

Cervical Imaging in the Low Resource Setting: A Review

“…The Callascope is a speculum-free device used for capturing images of the cervix [ 40 , 41 , 42 , 43 ]. The Callascope was developed at the Department of Biomedical Engineering at Duke University, Durham, NC, USA.…”

“…The Callascope is designed to create a speculum-free imaging system composed of an introducer and a slender camera. The introducer is a Calla Lily-shaped silicone hollow tube which can be inserted into the vagina ( Figure 2 ) [ 40 ]. The introducer is approximately 30 mm at the larger proximal end and 12 mm at the distal end [ 41 ].…”

“…The camera body is a slim 9 mm diameter tube with a length of approximately 120 mm. The camera is a 2 to 5 Megapixel CMOS sensor with a lens [ 40 , 41 ]. The camera is fitted with a hydrophobic window at the tip and is positioned in the center of the ring illuminator.…”

“…Clinic testing of the device has been performed in both the United States and Ghana, looking at two different environments of the Callascope: clinician usage and self-conducted imaging of the cervix [ 40 ]. Participant eligibility included healthy females 18 years or older.…”

Improving visualization of the cervix during pelvic exams: A physical model and a steppingstone to reducing disparities in gynecological cancers

“…However, the peer-reviewed, published literature characterizing the issue is limited. The available articles focus on sophisticated add-ons [28][29][30][31], novel speculum designs [5,20], or avoiding the issue entirely by circumventing the physical exam (favoring urinary [32,33] or vaginal self-sampling [34][35][36][37][38] instead) or using endoscopic visualization instead of a speculum [29,[39][40][41]. Despite, or perhaps because of their novelty, these methods are far from becoming the status quo for the standard o ce gynecologic exam.…”