3-dimensional Imaging System Research Articles

3D Whole-body skin imaging for automated melanoma detection.

Existing artificial intelligence for melanoma detection has relied on analysing images of lesions of clinical interest, which may lead to missed melanomas. Tools analysing the entire skin surface are lacking. To determine if melanoma can be distinguished from other skin lesions using data from automated analysis of 3D-images. Single-centre, retrospective, observational convenience sample of patients diagnosed with melanoma at a tertiary care cancer hospital. Eligible participants were those with a whole-body 3D-image captured within 90 days prior to the diagnostic skin biopsy. 3D-images were obtained as standard of care using VECTRA WB360 Whole Body 3-dimensional Imaging System (Canfield Scientific). Automated data from image processing (i.e. lesion size, colour, border) for all eligible participants were exported from VECTRA DermaGraphix research software for analysis. The main outcome was the area under the receiver operating characteristic curve (AUC). A total of 35 patients contributed 23,538 automatically identified skin lesions >2 mm in largest diameter (102-3021 lesions per participant). All were White patients and 23 (66%) were males. The median (range) age was 64 years (26-89). There were 49 lesions of melanoma and 22,489 lesions that were not melanoma. The AUC for the prediction model was 0.94 (95% CI: 0.92-0.96). Considering all lesions in a patient-level analysis, 14 (28%) melanoma lesions had the highest predicted score or were in the 99th percentile among all lesions for an individual patient. In this proof-of-concept pilot study, we demonstrated that automated analysis of whole-body 3D-images using simple image processing techniques can discriminate melanoma from other skin lesions with high accuracy. Further studies with larger, higher quality, and more representative 3D-imaging datasets would be needed to improve and validate these results.

Lip Lifting Efficacy of Hyaluronic Acid Filler Injections: A Quantitative Assessment Using 3-Dimensional Photography.

The study aimed to compare the volume enhancement and the lifting capacity of two different hyaluronic acid gels for lip injection. Thirty-six Korean female patients were randomized into two groups according to the cross-linking degree of the hyaluronic acid filler injected. Using a fixed injection protocol, patients were injected with 1 mL of hyaluronic acid filler in the lips and followed up at four and 12 weeks after injection. Lip volume, lip projection, and columella–labial angle were measured using a 3-dimensional imaging system at each time point. Follow-up values were compared with baseline. Compared with pre-treatment values, there was a statistically significant increase in mean lip volume and lip projection at four and 12 weeks after injection, with no significant differences between the two groups. Lips injected with hyaluronic acid filler of intermediate cross-link density resulted in more acute angles than lips injected with lightly cross-linked hyaluronic acid. The difference was statistically significant at each follow-up time point. No serious complications were observed throughout the study period. Our results imply that in patients who want a prominent upper lip lift, lip injections using hyaluronic acid fillers with intermediate cross-linking density can be a good option due to their lift capacity. The degree of cross-linking may not be a significant determinant of simple lip volume augmentation when other variables are constant.

A Quasi-Experimental Study Compared the Learning Experiences of Inexperienced Trainees Using Laparoscopic Surgery with 2-Dimensional and 3-Dimensional Imaging Systems

A Quasi-Experimental Study Compared the Learning Experiences of Inexperienced Trainees Using Laparoscopic Surgery with 2-Dimensional and 3-Dimensional Imaging Systems

Comparison of surgical outcomes between 3-dimensional and 2-dimensional laparoscopy of ovarian cyst (LOOC): a randomised controlled trial

The purpose of this study was to compare the surgical outcomes and efficacy of 3-dimensional (3D) versus 2-dimensional (2D) imaging systems for the treatment of ovarian cyst. A total of 46 patients undergoing a laparoscopic ovarian cystectomy were randomly assigned to either the 3D or 2D laparoscopy group. The primary outcome measure was the operative blood loss. The secondary outcome measure was visually induced motion sickness (VIMS), task efficacy during laparoscopy, and postoperative complication. There were no differences in baseline demographics between the two groups. The operative blood loss was significantly smaller in the 3D groups (28.7 ± 11.6 mL) than in the 2D groups (46.5 ± 24.4 mL) (p = .012). VIMS score was significantly higher in the 3D groups than the 2D groups (p < .001). 3D laparoscopy was superior to 2D in terms of the task efficacy of ovarian cyst enucleation (p < .001), adhesiolysis or dissection (p < .001), and ovarian suturing (p = .008). None of the patients in both groups developed operative complications. In conclusion, a 3D imaging system showed a more favourable surgical outcome and improved task efficacy than 2D in laparoscopic ovarian cystectomy. However, 3D laparoscopy tends to cause more frequent VIMS in surgeons. Impact statement What is already known on this subject? Several studies examining the possible benefits and drawbacks of a 3D imaging system versus 2D in laparoscopic surgery have brought about conflicting results. However, there have been few studies comparing the surgical outcomes of 3D and 2D laparoscopic ovarian cystectomy. What do the results of this study add? 3D laparoscopy showed favourable surgical outcomes and improved task efficacy than 2D laparoscopy in ovarian cystectomy. What are the implications of these findings for clinical practice and/or further research? More complex procedures, such as suturing and adhesiolysis, might be easier to perform with 3D laparoscopy than with 2D laparoscopy. Therefore, further large studies of 3D gynaecologic laparoscopy with different complexities and for surgeons with different surgical skills are needed.

A Single-Blinded Prospective Study on Using Botulinum Toxin Type A for Reducing Alar Mobility.

With widespread utilization of instant social media, people desire a minimally invasive treatment to improve alar dynamic aesthetic, but few practical procedures on reducing alar mobility have been conducted. This study aimed to verify the effects of botulinum toxin on reducing nasal alar mobility and provide a supplemental treatment of rhinoplasty. This single-blind prospective study included a cohort of 20 participants with the desire to improve their alar dynamic aesthetic. The experimental group was injected with 3U botulinum toxin type A at dilator naris anterior, dilator naris vestibularis, levator labii superioris alaeque nasi, and dilator naris, and the control group received the equivalent of saline. Standardized facial movement (from rest to maximum smile without revealing teeth) was recorded with a 3-dimensional imaging system. The changes between rest and maximum smile statuses represented alar mobility and were generated by MOBILITY=WIDTHsmile-WIDTHrestWIDTHrest×100%. Alar mobility and root mean square analysis were employed for postoperative evaluations. In the experimental group, alar flaring mobility decreased from 10.05% ± 6.40% to 4.91% ± 3.48%(P < 0.05), and alar base mobility decreased from 16.83% ± 5.69% to 12.50% ± 4.89% (P < 0.05), whereas no significant changes in alar mobility were found in the control group. In root mean square analysis, changes in the experimental group were significantly higher than in the control group (P < 0.05). Botulinum toxin type A can effectively restrain alar mobility without any significant adverse events and improve alar dynamic esthetic, which can serve as a minimally invasive method or supplemental treatment for rhinoplasty.

A comparison of volume and anthropometric breast measurements using the Crisalix and VECTRA XT 3-dimensional surface imaging systems in women who have undergone breast-conserving surgery

Introduction Three-dimensional surface imaging (3D-SI) of the breasts enables the measurement of anthropometric distances and breast volume. These measurements may be used in surgical planning and to facilitate clear communication with patients. The aim of this study was to compare measurements using a portable 3D-SI system, Crisalix, with a more established non-mobile camera, the VECTRA XT. Methods Participants were imaged three times using the Crisalix and the VECTRA XT system. Breast volume, sternal notch to nipple distance, nipple to nipple distance and breast width were measured. Intra-observer agreement was measured using the co-efficient of variation (CV). Agreement between the two methods was represented with Bland Altman agreement plots. Results Intra-method variation was low for both methods (maximum CV 3.3% for Crisalix and 3.2% for VECTRA XT), with only nipple-to-nipple distance being statistically significant, marginally in favour of VECTRA. The mean inter-method differences were small but the limits of agreement (LoA) were wide for all parameters: best for sternal notch to nipple distance, mean difference (MD) -0.03cm and LoA 1.8 to -1.8cm; the widest LoA were for breast volume: MD 31.1cm3 and LoA 286.7 to -244.6cm3. Conclusion This is the first comparison of anthropometric distances and breast volume measured using the two most widely used 3D-SI systems, Crisalix and VECTRA XT. Intra-method variation is low but currently it would not be appropriate to use the two systems interchangeably due to the wide limits of agreement for all four parameters assessed.

Prospective Evaluation of the Time Required for Insertion of 380 Lumbar and Sacral Pedicle Screws Using Navigation with an Intraoperative 3-Dimensional Imaging System

The aim of this study was to evaluate the time required for various parts of the procedure to insert lumbar and sacral pedicle screws using navigation with an intraoperative, 3-dimensional imaging system. Comparison of these timings was carried out for different surgical indications. This was a single-surgeon prospective cohort study of 69 consecutive patients (between August 2013 and June 2018) who underwent insertion of 380 pedicle screws into the lumbar and sacral vertebrae. Surgical indications, average time required for surgical exposure and attachment of the reference frame, average time required until completion of the first pedicle screw insertion, and average time required for insertion of a single pedicle screw were evaluated. The average time required from skin incision to reference frame attachment was 28.3 ± 20.4 (mean ± SD) minutes, and the average time required from reference frame attachment to completion of first pedicle screw insertion was 22.3 ± 9.6 minutes. The average time required for insertion of a single pedicle screw was 7.8 ± 2.7 minutes. When surgical indications were compared, the average time required for insertion of a single pedicle screw was 7.7 ± 2.6 minutes in surgery for spondylosis-related stenosis, 8.1 ± 2.8 minutes for degenerative scoliosis, and 8.2 ± 3.6 minutes for metastatic tumor (P = .89). There were no significant changes in these timings over consecutive 6-month periods. There is no significant learning curve and no significant difference in navigation setup and pedicle screw insertion timings with intraoperative 3-dimensional navigation systems for surgeries of different pathologies and levels of surgery. 2.

An Innovative Assessment of the Dynamics of Facial Movements in Surgically Managed Unilateral Cleft Lip and Palate Using 4D Imaging.

Objective:Assess facial asymmetry during maximum smile in patients with surgically managed unilateral cleft lip and palate (UCLP), using a dynamic 3-dimensional (3D) imaging (4-dimensional) system.Design:Prospective 2 cohort comparative study.Methods:Twenty-five surgically managed UCLP cases and 75 controls at 8 to 10 years of age were recruited. Facial movements during maximum smile were recorded using video stereophotogrammetry at a rate of 60 3D facial images per second. Maximum smile took approximately 3 seconds and generated 180 3D facial images for the analysis. A generic facial mesh which consists of more than 7000 quasi landmarks was used for the assessment of facial asymmetry at 5 key 3D frames representing the pattern of maximum smile.Results:Statistically significant differences were seen regarding the magnitude of facial asymmetry between the UCLP group and the noncleft controls. Higher average asymmetry in the UCLP group was seen in the 3D frame midway between maximum smile and rest (frame 4) followed by the frame at peak expression of maximum smile (frame 3). The average magnitude of nasolabial asymmetry of the control group was within 0.5 mm in comparison with the UCLP cases which was about 1.8 mm.Conclusion:This study provided for the first time, an objective tool for analysis of the dynamics of muscle movements which provided an unprecedented insight into the anatomical basis of the residual dysmorphology. The research demonstrates the limitations of the primary lip repair in achieving symmetrical results and underpins the required refinements to improve the quality of surgical repair of cleft lip.

Assessing the Accuracy of a 3-Dimensional Surface Imaging System in Breast Volume Estimation.

Preoperative prediction of breast volume can guide patient expectations and aid surgical planning in breast reconstruction. Here, we evaluate the accuracy of a portable surface imager (Crisalix S.A., Lausanne, Switzerland) in predicting breast volume compared with anthropomorphic estimates and intraoperative specimen weights. Twenty-five patients (41 breasts) undergoing mastectomy were scanned preoperatively with the Crisalix surface imager, and 1 of 3 attending plastic surgeons provided an anthropomorphic volume estimate. Intraoperative mastectomy weights were used as the gold standard. Volume conversions were performed assuming a density of 0.958 g/cm. The Pearson correlation coefficient between imager estimates and intraoperative volumes was 0.812. The corresponding value for anthropomorphic estimates and intraoperative volumes was 0.848. The mean difference between imager and intraoperative volumes was -233.5 cm, whereas the mean difference between anthropomorphic estimates and intraoperative volumes was -102.7 cm. Stratifying by breast volume, both surface imager and anthropomorphic estimates closely matched intraoperative volumes for breast volumes 600 cm and less, but the 2 techniques tended to underestimate true volumes for breasts larger than 600 cm. Stratification by plastic surgeon providing the estimate and breast surgeon performing the mastectomy did not eliminate this underestimation at larger breast volumes. For breast volumes 600 cm and less, the accuracy of the Crisalix surface imager closely matches anthropomorphic estimates given by experienced plastic surgeons and true volumes as measured from intraoperative specimen weights. Surface imaging may potentially be useful as an adjunct in surgical planning and guiding patient expectations for patients with smaller breast sizes.

Utility of radiation-free imaging for initial evaluation of pectus excavatum.

The OrtenBodyOne scanner is a radiation-free, 3-dimensional imaging system recently developed for evaluation of the severity of pectus excavatum (PE). The goal of this study was to evaluate the utility of this new imaging system compared with that of computed tomography (CT) for the evaluation of the severity of PE. Patients treated for PE from April 2015 to January 2017 with available CT and OrtenBodyOne data were included. Correlations between indexes calculated from CT and from OrtenBodyOne were determined by applying the non-parametric Spearman correlation procedure with a Bonferroni correction to adjust for multiple comparisons. Forty men (90.9%) and 4 women (9.1%), 20 with symmetrical (45.5%) and 24 with asymmetrical PE (54.5%), were included. The median age was 16.1 years (range 4.3-63.5 years). The following measures and indexes acquired using OrtenBodyOne and CT were significantly correlated: pectus depth (r = 0.84; P = 0.002), anthropometric index (r = 0.81; P = 0.002) and asymmetry index (r = 0.67; P = 0.002). The correlation between the CT Haller index and the external Haller index was only significant for symmetrical PE (r = 0.57; P = 0.008). The OrtenBodyOne imaging system can be used to evaluate the severity of symmetrical PE using the external Haller index. Asymmetry and anthropometric indexes are more reliable for the evaluation of asymmetrical PE. Measures can be repeated throughout treatment while avoiding unnecessary irradiation.

Clinical Evaluations of a Novel Thread Lifting Regimen Using Barbed Polyglyconate Suture for Facial Rejuvenation: Analysis Using a 3-Dimensional Imaging System.

Thread lifting with absorbable sutures has recently gained prominence for rejuvenating ptotic and sagging soft tissues in aging face. A barbed, delayed absorbable polyglyconate monofilament shows significantly high tensile loads with superior flexibility and elasticity. To evaluate the safety and efficacy of novel thread lifting regimen with barbed polyglyconate suture for counteracting the descent and laxity of the aging face. A retrospective chart review was conducted for 25 Korean patients with mild to moderate facial skin laxity receiving thread lifting procedures using barbed polyglyconate suture. Dermatologists' objective assessments using a 5-point Global Aesthetic Improvement Scale (GAIS), 3D imaging system, and subjective satisfaction were recorded at baseline and 4 months after treatments. In most patients (84%), GAIS scores were more than score 3 ("improved"), with 40% of score 4 ("much improved") and 24% of score 5 ("excellent") at the follow-up point. Subjective assessments paralleled these patterns. Three-dimensional analysis quantitatively showed volume migration of low face upward, clinically interpreted as facial lifting. No serious adverse effect was observed. This novel thread lifting procedure using barbed polyglyconate suture is a safe and effective method for tightening and lifting for aging face with mild to moderate face sagging.

Perspective: Are We Ready to Measure Child Nutritional Status with Lasers?

ABSTRACTThe continued use of basic, manual anthropometric tools (e.g., boards and tapes) leaves anthropometry susceptible to human error. A potential solution, 3-dimensional (3D) imaging systems for anthropometry, has been around since the 1950s. In the 1980s, 3D imaging technology advanced from photographs to the use of lasers for body digitization; and by the 2000s, the falling price of 3D scanners made commercial application feasible. The garment sector quickly adopted imaging technology for surveys because of the need for numerous measurements and large sample sizes. In the health sector, 3D imaging for anthropometry was not widely adopted; its use was limited to research and specialized purposes. The different cost and logistical requirements for measurement in the garment and health sectors help to explain why the technology was adopted in one sector and not the other. Despite reductions, the price of 3D imaging systems remained a barrier to the use of 3D imaging for regular nutritional assessment in the health sector. Additional barriers in the health sector were that imaging systems required dedicated space and were not designed for capturing measurements in young children. In recent years, the development of light-coding technology may have removed these barriers, and a handheld imaging system was developed specifically for young children. There are not yet recommendations to replace manual equipment with 3D imaging for nutritional assessment, and there is a need for more research on low-cost, handheld imaging systems—particularly research that evaluates the ability of 3D imaging to improve the quality of anthropometric data and indicators.

Novel Stereoscopic Optical System for Objectively Measuring Above-Surface Scar Volume-First-Time Quantification of Responses to Various Treatment Modalities.

Current approaches use subjective semiquantitative or cumbersome objective methodologies to assess physical characteristics of hypertrophic and keloid scars. This pilot study aimed to evaluate the accuracy and feasibility of a new stereoscopic optical and high-resolution 3-dimensional imaging system, for objectively measuring changes in above-surface scar volume after various interventions. Feasibility and accuracy were assessed by monitoring the above-surface scar volume of 5 scars in 2 patients for 5 successive months. Above-surface scar volume and Vancouver Scar Scale scores and the investigator and patient volume improvement assessment scores were assessed before and 12 weeks after last intervention. Scar volume measured by the imaging system correlated significantly with the gold standard (actual weight). The greatest volume reduction followed a combination of cryotherapy and intralesional triamcinolone acetonide and 5-fluorouracil injections in Patient 1 and a combination of pulse dye laser and intralesional triamcinolone acetonide injections in Patient 2. The new stereoscopic optical system is a valid, accurate, and practical objective method for assessing scar volume and for monitoring treatment response. It is more sensitive and accurate than semiquantitative objective scales. Further studies with a higher number of patients and scars are required to increase the measurement validity of the system.

Resetting the Bar to Reduce Radiation Exposure During Ablation of Cardiac Arrhythmias

See Article by Pani et al Electrophysiology procedures are dependent on imaging technologies to position pacemaker or implantable cardioverter defibrillator leads, perform extractions, or position catheters for diagnostic studies or ablation procedures. In most cases, these procedures depend on radiological imaging, which exposes patients and medical personnel to the potential risks of radiation exposure. This has been the subject of 2 consensus documents developed by the American College of Radiology to improve safe practice during interventional procedures for coronary artery disease, valve disease, or electrophysiological studies.1,2 The emphasis of these documents has been on best practice to achieve the lowest reasonably achievable dose. These goals depend on up-to-date imaging systems, collimation of the beam, minimizing steep angulation, optimizing distance between patient and the x-ray tube and the image intensifier, and avoiding any exposure that is not necessary. There are guidelines for hospitals to ensure that their physicians have received basic training for radiation safety and know how to operate their equipment to achieve these goals.3 Because our procedures have become more complex, the need for detailed imaging has become more important. This has increased the potential risks of radiation exposure to patients and the lifetime exposure for medical personnel, which is greatest for the physicians who perform the procedure. In response to these concerns, industry has devoted substantial effort into development of electroanatomic 3-dimensional imaging systems that do not depend on radiation and new radiographic technologies that reduce our exposure to radiation. Reductions in frame rate and other measures compromise the image quality to some extent, but these parameters can be adjusted during the case to enhance the image …

Quantitative Analysis of Face and Neck Skin Tightening by Microfocused Ultrasound With Visualization in Asians.

Previous studies of microfocused ultrasound with visualization (MFU-V) on facial and neck laxity were largely based on masked physician assessments, histological analysis, and safety profile. More quantitative studies are needed. To evaluate the 800 treatment lines of MFU-V on skin tightening effect of face and neck in Asians using 2 quantitative analysis systems at 0, 90, and 180 days after treatment. Total 25 subjects were recruited in this prospective study. Subjects were treated with MFU-V to the face and neck using 2 different transducers: 4 MHz, 4.5-mm focal depth and 7 MHz, 3.0-mm focal depth with total 800 lines. The subjects were evaluated by skin complexion analysis and 3-dimensional imaging system at 0, 90, and 180 days. Mean brow height lift and submental lift were calculated. All 25 subjects completed treatment and received the follow-up examinations at 90 and 180 days. Two of the 25 subjects were male. Mean patient age was 53.3 years (range: 39.8-61.1 years). Wrinkles, texture, and pores were 3 variables relevant to analysis of skin laxity. Only mean wrinkles score reduction at 90 days was statistically significant (p = .0222). There was a mean 0.47 mm brow lift at 90 days (p = .0165), but there was a 0.12 mm decrease in brow height compared to baseline at 180 days (p = .6494). At 90 days, a mean 26.44 mm submental lift was noted (p = .0217). And at 180 days, a mean 13.76 mm submental lift was noted (p = .243). This study showed that the most prominent change after the 800-line MFU-V treatments in Asians was the significant submental lift at 90 days. Other noninvasive or minimally invasive treatment modalities can be considered to combine with MFU-V for the optimal treatment response. Additional MFU-V treatments can be considered 3 months after the first treatment.

Mechanistic Insights of Cells in Porous Scaffolds via Integrated Culture Technologies

This research aimed to combine 3 cell and tissue culture technologies to obtain mechanistic insights of cells in porous scaffolds. When cultivated on 2D (2-dimensional) surfaces, HDFs (human dermal fibroblasts) behaved individually and had no strict requirement on seeding density for proliferation; while HaCat cells relied heavily on initial densities for proliferation and colony formation, which was facilitated when co-cultured with HDFs. Experiments using a 3D CCIS (3-dimensional cell culture and imaging system) indicated that HDFs colonised open pores of varying sizes (125-420 μm) on modular substrates via bridge structures; while HaCat cells formed aperture structures and only colonised small pores (125 μm). When co-cultured, HDFs not only facilitated HaCat attachment on the substrates, but also coordinated with HaCat cells to colonise open pores of varying sizes via bridge and aperture structures. Based on these observations, a 2-stage strategy for the culture of HDFs and HaCat cells on porous scaffolds was proposed and applied successfully on a cellulosic scaffold. This research demonstrated that cell colonisation in scaffolds was dependent on multiple factors; while the integrated 2D&3D culture technologies and the 3D CCIS was an effective and efficient approach to obtain mechanistic insights of their influences on tissue regeneration.

Early Changes in Facial Profile Following Structured Filler Rhinoplasty: An Anthropometric Analysis Using a 3-Dimensional Imaging System.

Quantitative measurements are important for objective evaluation of postprocedural outcomes. Three-dimensional (3D) imaging is known as an objective, accurate, and reliable system for quantifying the soft tissue dimensions of the face. To compare the preprocedural and acute postprocedural nasofrontal, nasofacial, nasolabial, and nasomental angles, early changes in the height and length of the nose, and nasal volume using a 3D surface imaging with a light-emitting diode. The 3D imaging analysis of 40 Korean women who underwent structured nonsurgical rhinoplasty was conducted. The 3D assessment was performed before, immediately after, 1 day, and 2 weeks after filler rhinoplasty with a Morpheus 3D scanner (Morpheus Co., Seoul, Korea). There were significant early changes in facial profile following nonsurgical rhinoplasty with a hyaluronic acid filler. An average increase of 6.03° in the nasofrontal angle, an increase of 3.79° in the nasolabial angle, increase of 0.88° in the nasomental angle, and a reduction of 0.83° in the nasofacial angle was observed at 2 weeks of follow-up. Increment in nasal volume and nose height was also found after 2 weeks. Side effects, such as hematoma, nodules, and skin necrosis, were not observed. The 3D surface imaging quantitatively demonstrated the early changes in facial profile after structured filler rhinoplasty. The study results describe significant acute spatial changes in nose shape following treatment.

Stereoscopic 3-dimensional spectral imaging systems based on a single acousto-optical tunable filter

The novel technique for 3-dimensional (3D) spectral imaging is proposed. It is based on simultaneous spectral acousto-optic filtration of a pair of stereoscopic convergent light beams via single acoustic wave. A few promising configurations of such acousto-optic tunable filters (AOTFs) is proposed, discussed and compared. It is shown that these elements may be ultra-compact and PC controlled modules, ready to be integrated into many existing schemes of stereoscopic 3D imagers.The experiment carried out with the help of single-AOTF-based spectral stereomicroscope demonstrates the efficiency of proposed technique.

Design of an intra-operative imaging system for the cochlear implant.

Research has shown that closer proximity of a cochlear implant electrode array to the inner modiolar wall can improve hearing performance in a recipient. It is understood that developing a real-time intra-operative imaging technique would bring the surgeon visual feedback that can correlate with tactile resistances during electrode insertion, reducing various risks of insertion traumas, while guiding the electrode for optimal placement. This paper presents the design of a 3-dimensional magnetic imaging system which provides a means for real-time imaging by reconstructing uniform segments of the electrode array's contours. In addition, the theoretical error of this reconstruction method is evaluated to select an optimal number of sensors within the electrode design. The theoretical error of the reconstruction method is evaluated for 7 to 22 inductive sensors within the electrode design. For 16 or more sensors, the error is improves to less than 0.5%. A working prototype was confirmed on a 10:1 scale with orthogonal Helmholtz coils at 85-115 kHz.

Anatomical disruption and length-tension dysfunction of anal sphincter complex muscles in women with fecal incontinence.

Anal sphincter complex muscles, the internal anal sphincter, external anal sphincter, and puborectalis muscles, play an important role in the anal continence mechanism. Patients with symptoms of fecal incontinence have weak anal sphincter complex muscles; however, their length-tension properties and relationship to anatomical disruption have never been studied. This study aimed to assess the anatomy of the anal sphincter complex muscles with the use of a 3-dimensional ultrasound imaging system and to determine the relationship between the anatomical defects and the length-tension property of external anal sphincter and puborectalis muscles in women with incontinence symptoms and in control subjects. Severity of anal sphincter muscle damage was determined by static and dynamic 3-dimensional ultrasound imaging. The length-tension property was determined by anal and vaginal pressure with the use of custom-designed probes. Forty-four asymptomatic controls and 24 incontinent patients participated in this study. The anatomical defects and length-tension dysfunction of anal sphincter complex muscles in patients with fecal incontinence were evaluated. The prevalence of injury to sphincter muscles is significantly greater in the incontinent patients than in the controls. Eighty-five percent of patients but only 9% controls reveal damage to ≥2 of the 3 muscles of the anal sphincter complex. Anal and vaginal squeeze pressures increased with the increase in the probe size (length-tension curve) in the majority of controls. In patients, the increase in anal and vaginal squeeze pressures was either significantly smaller than in controls or it decreased with the increasing probe size (abnormal length-tension). We studied patients with severe symptoms. Whether our findings are applicable to patients with mild to moderate symptoms remains to be determined. The length-tension property of the external anal sphincter and puborectalis muscles is significantly impaired in incontinent patients. Our findings have therapeutic implications for the treatment of anal incontinence.