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Purpose Patient-reported outcomes (PROs) are an important feature in clinical evaluation of swallowing. The Eating Assessment Tool (EAT-10) and the Sydney Swallow Questionnaire (SSQ) are two validated dysphagia PROs commonly used in healthy older adult populations as screening tools for swallowing problems. The purpose of this study is to compare the consistency of the EAT-10 and SSQ scores for self-reported swallowing difficulties in a group of community-dwelling older adults (CDOA) completing both questionnaires. Method A total of 316 individuals over the age of 60 years completed the EAT-10, SSQ, and provided demographic data, including a self-report of any medical diagnoses. Participants were excluded if they had any diagnoses known to cause dysphagia. Questionnaire responses were analyzed for frequencies of responses across all participants. Results Seventy-five participants were identified as having dysphagia by the EAT-10 (23.7%), while 30 participants were identified by the SSQ (9.49%). When comparing the results of the two assessments, the scales agreed on 289 out of 316 participants (91%). There was a disagreement on the results in 27 of the 316 participants, with 26 of these self-reporting dysphagia symptoms on the EAT-10 but not on the SSQ. Conclusions Two commonly used dysphagia PROs resulted in different prevalence rates of self-reported dysphagia in a group of CDOA. CDOAs may need questionnaires specifically validated for them with special consideration for specific age-related risk factors, to ensure accurate early identification.

Purpose Both the enjoyment of foods and safe swallowing revolve around incorporating multiple streams of sensory feedback to form a positive sensory experience; these include information about the taste, smell, texture, temperature, and even the sight of food. Traditional swallowing assessment and treatment paradigms have primarily focused on the motor aspects of swallowing. However, sensory information is vital for not only enjoying foods while eating but also coordinating safe and efficient swallow behaviors. The purpose of this clinical focus article is to discuss the clinical importance of sensation in swallowing evaluation and intervention. Conclusions During their clinical assessments of swallowing, speech-language pathologists are already documenting the functional results of oropharyngeal sensorimotor impairments (e.g., residue). A combination of sensory and motor aspects is already integrated within current behavioral treatment strategies for dysphagia. Focused attention to the salient sensory features of swallowing has the potential to improve swallowing evaluation and intervention efforts. A discussion of potential future research in improved measurement and documentation of altered sensation is provided.

Purpose Self-selection and self-avoidance of certain foods is one possible indicator of preclinical (prior to any clinical intervention) dysphagia in healthy older adults. Self-selection of food choices is influenced by changes in a combination of factors, including neuromuscular, sensory, and individual patient characteristics. Changes to these factors occur both centrally or peripherally and can be part of typical, healthy aging. Alterations in motor, sensory, or cognitive skills may lead to self-imposed modifications to food choices and, therefore, highlight potential risk for dysphagia. Conclusions For effective screening and assessments procedures in healthy aging adults, the diagnosis of preclinical dysphagia will likely require a multifaceted assessment. A combination of assessment methods using objective and subjective measurements of neuromuscular, sensory, and individual patient factors, as well as knowledge of food avoidance, may provide insight for identifying community-dwelling older adults at risk for dysphagia and allow for earlier monitoring and intervention.

Frontiers in neurology 12, 1-6 (2021). doi:10.3389/fneur.2021.704329, Published by Frontiers Research Foundation, Lausanne

Attention-Deficit Hyperactivity Disorder (ADHD) is a predominant neurobehavioral disorder of childhood with motor and sensory symptoms often persisting into adulthood. Motor control theories highlight the importance of the bidirectional relationship between sensation and movement for maintaining skilled behaviors like speech. The impact of ADHD on speech in adults has not been well established. The purpose of this study is to assess group differences in quantitative speech and oral somatosensory measures in adults with and without ADHD and to describe the relationship between ADHD symptomology and speech production. A total of 50 adults (18-26 years) were recruited and divided in two groups based on diagnosis: those with (n = 28) and those without (n = 22) ADHD. All participants provided a speech sample to measure articulatory accuracy and speech rate and completed quantitative point-pressure testing using tactile detection and discrimination on bilateral sites on the lower lip and lateral edge of the tongue tip. Independent t-tests corrected for multiple comparisons identified significant group differences using FDR corrected q values in speech production for correct syllables per second and overall speech rate (q

Detection and discrimination threshold estimates for oral point pressure are assessed using Von Frey Hair monofilaments. Consistent with previously published protocols, threshold estimates are determined using a two-interval forced choice (2-IFC) paradigm with a three down/one up approach. Detection threshold estimates determine the mean force in which a participant can identify the presence of pressure. During the detection threshold procedure, the participant is instructed to choose which of two sequentially presented observation intervals contained the tactile test stimulus. If the participant performs three correct detections in a row (i.e., 3 'hits'), the researcher decreases the stimulus to the next lower target force level. With one incorrect detection (a 'miss'), the researcher increases the force delivered to the next higher level. This threshold estimation approach is known as a 3-down/1-up adaptive staircase. Reponses are recorded on a paper ballot, and a participant's estimated threshold is defined as the geometric mean of five reversals. During the discrimination threshold procedure, the participant is asked to make a choice between two serially presented stimuli as to which is the "harder" or "stronger" pressure. The same scoring of 'hits', 'misses', and stopping points are used. Detection and discrimination testing for oral point pressure at tongue midline takes approximately 20 min to complete. Using these commercially-available clinical tools, individual touch sensation profiles for the midline tongue can be achieved in a relatively time and cost effective means.

PURPOSE Current theoretical models suggest the importance of a bidirectional relationship between sensation and production in the vocal tract to maintain lifelong speech skills. The purpose of this study was to assess age-related changes in orofacial skilled force production and to begin defining the orofacial perception-action relationship in healthy adults. METHOD Low-level orofacial force control measures (reaction time, rise time, peak force, mean hold force (N) and force hold SD) were collected from 60 adults (19-84 years). Non-parametric Kruskal Wallis tests were performed to identify statistical differences between force and group demographics. Non-parametric Spearman's rank correlations were completed to compare force measures against previously published sensory data from the same cohort of participants. RESULT Significant group differences in force control were found for age, sex, speech usage and smoking status. Significant correlational relationships were identified between labial vibrotactile thresholds and several low-level force control measures collected during step and ramp-and-hold conditions. CONCLUSION These findings demonstrate age-related alterations in orofacial force production. Furthermore, correlational analysis suggests as vibrotactile detection thresholds increase, the ability to maintain low-level force control accuracy decreases. Possible clinical applications and treatment consequences of these findings for speech disorders in the ageing population are provided.

Background Our previous work demonstrates that adults with ADHD produce more force at the fingertips compared to adults without ADHD. One possibility is that somatosensation is impaired in ADHD. However, ADHD is often comorbid with anxiety, and anxiety influences sensory responsivity. Aims The goal of the current work was to evaluate differences in the self-report of sensory experiences in adults with and without ADHD, while controlling for internalizing behaviors. Methods and Procedures Forty-five adults (23 with ADHD) completed a semi-structured interview for the diagnosis of ADHD, the Adolescent/Adult Sensory Profile (AASP), and the Achenbach Adult Self Report (ASR). Outcomes and Results Adults with ADHD reported more hyper- and hypo- sensitivity compared to adults without ADHD, even when controlling for internalizing behaviors. Specifically, between group differences were found for low registration, sensation seeking, and sensory sensitivity scores, but not for sensation avoiding, and for movement, visual, touch, activity, audition, or taste/smell. Conclusions and Implications These findings demonstrate that sensory hyper- and hypo- sensitivity may be features of ADHD in adults. Further, they demonstrate that internalizing behaviors influence the perception of sensory experiences and thus should be accounted for in studies of sensory processing, integration, and modulation in adults with ADHD.

Purpose Individuals with neurogenic speech disorders require ongoing therapeutic support to achieve functional communication goals. Alternative methods for service delivery, such as tablet-based speech therapy applications, may help bridge the gap and bring therapeutic interventions to the patient in an engaging way. The purpose of this study was to evaluate an iPad-based speech therapy app that uses automatic speech recognition (ASR) software to provide feedback on speech accuracy to determine the ASR's accuracy against human judgment and whether participants' speech improved with this ASR-based feedback. Method Five participants with apraxia of speech plus aphasia secondary to stroke completed an intensive 4-week at-home therapy program using a novel word training app with built-in ASR. Multiple baselines across participants and behaviors designs were employed, with weekly probes and follow-up at 1 month posttreatment. Four sessions a week of 100 practice trials each were prescribed, with 1 being clinician-run and the remainder done independently. Dependent variables of interest were ASR–human agreement on accuracy during practice trials and human-judged word production accuracy over time in probes. Also, user experience surveys were completed immediately posttreatment. Results ASR–human agreement on accuracy averaged ~80%, which is a common threshold applied for interrater agreement. All participants demonstrated improved word production accuracy over time with the ASR-based feedback and maintenance of gains after 1 month. All participants reported enjoying using the app with support of a speech pathologist. Conclusion For these participants with apraxia of speech plus aphasia due to stroke, satisfactory gains were made in word production accuracy with an app-based therapy program providing ASR-based feedback on accuracy. Findings support further testing of this ASR-based approach as a supplement to clinician-run sessions to assist clients with similar profiles in achieving higher amount and intensity of practice as well as empowering them to manage their own therapy program. Supplemental Material https://doi.org/10.23641/asha.8206628

Changes in voice in aging adults impact their ability to use their voice to communicate in all situations and can lead to decreased quality of life (QOL). The primary objective of this study was to determine the validity and reliability of the Aging Voice Index (AVI)-a tool specifically designed for aging adults with voice disorders. A total of 92 older adults were asked to complete the Voice-Related Quality of Life Scale (VRQOL) and the AVI as well as provide their self-perceived voice severity rating of their voice problem and demographic information. Intraclass correlation for test-retest reliability was 0.952. The AVI was highly correlated to the VRQOL (P 0.0001). Additionally, the AVI score was found to distinguish between self-rated voice quality (P 0.0001) and diagnostic voice categories (P 0.0001). No significant differences were identified for sex or race. The AVI is a valid and reliable quality of life assessment for older adults with voice disorders. The AVI will capture the quality of life impact a voice disorder has on older adults. Future studies will further explore differences in clinical diagnoses and identify clinically significant changes in pre-to post-AVI scores.

Orofacial anatomy is unique from other body systems in that oral musculature inserts directly into the underlying cutaneous skin, allowing for tight temporal synchronicity between somatosensory and auditory performance feedback to maintain correct orofacial behaviours across the lifespan. Unfortunately, little is currently known regarding the changes in orofacial sensory capacities associated with ageing and how these somatosensory and auditory changes may impact feedback during functional behaviours such as speech or swallowing. The purpose of this descriptive study was to begin assessing the relationship between the auditory and labial somatosensory system in healthy ageing adults.Pure-tone hearing thresholds were determined for 500, 1000, 2000 and 4000 Hz. Using a 2-alternative forced choice paradigm, 60 adults (19-84 years) completed vibrotactile detection thresholds (VDT) at the 5 and 10 Hz test frequencies.A significant difference for age by group was identified at the 5 Hz test frequency. Spearman Correlations identified a significant correlation between age and pure tone hearing thresholds and the 5 Hz test frequency threshold.A relationship between pure tone hearing thresholds and labial somatosensory was identified. Future studies will begin the processing of modelling the complex multivariate sensorimotor relationship in healthy individuals before moving to a disordered population.

Purpose High-quality orofacial somatosensory inputs are essential for achieving rapid and accurate motor outputs. Little somatosensory testing is currently being completed in clinical settings. The purpose of this study is to assess the feasibility and test–retest reliability of clinical assessment tools for orofacial somatosensory testing in healthy young adults. Method A total of 45 healthy young adults (ages 20–41 years) was recruited. Participants reported basic health information, completed pure-tone hearing thresholds, and were assessed using two-point discrimination discs and Von Frey hair detection and discrimination thresholds for bilateral lip and tongue. A subsample of participants ( n = 18; 40%) returned to complete reliability testing. Results Descriptive results are presented for the normative group as well as the reliability group. Difference scores between Tests 1 and 2 for each testing measure and location show high agreement. Conclusion Two-point discrimination and Von Frey hair monofilament assessment for both detection- and discrimination-threshold estimates have high test–retest reliability in a healthy young population. These testing measures could be a way to easily complete objective somatosensory testing of the orofacial region in a clinical context.

Traditionally, speech-language pathologists (SLP) have been trained to develop interventions based on a select number of perceptual characteristics of speech without or through minimal use of objective instrumental and physiologic assessment measures of the underlying articulatory subsystems. While indirect physiological assumptions can be made from perceptual assessment measures, the validity and reliability of those assumptions are tenuous at best. Considering that neurological damage will result in various degrees of aberrant speech physiology, the need for physiologic assessments appears highly warranted. In this context, do existing physiological measures found in the research literature have sufficient diagnostic resolution to provide distinct and differential data within and between etiological classifications of speech disorders and versus healthy controls? The goals of this paper are (a) to describe various physiological and movement-related techniques available to objectively study various dysarthrias and speech production disorders and (b) to develop an appreciation for the need for increased systematic research to better define physiologic features of dysarthria and speech production disorders and their relation to know perceptual characteristics.

The extraluminal extent of resection in cases of advanced gastric cancer is controversial. If, however, following meticulous staging--including the detection of free abdominal tumor cells--complete resection seems possible, then multivisceral resection is justified. If complete resection is achieved, the prognosis of these patients can be improved. Left pancreatic resection should be performed only if the tumor invades the pancreas directly. Splenectomy is indicated if the tumor invades the organ directly or if there are locally advanced tumors of the proximal third of the stomach and tumors of the esophageal-gastric junction. However, it has to be kept in mind that splenectomy is an independent negative prognostic factor. The extent of lymphadenectomy (LA) in gastric cancer is still under discussion. According to the 10-year results of the Dutch Gastric Cancer Study, there might be subgroups which have a survival benefit after extended (D2) LA. These include, as the German Gastric Cancer Study corroborated, patients with very early stage II and stage IIIa lymph node metastases. As neither of these stages can at present be diagnosed before or during surgery, D2 lymphadenectomy should be the standard procedure for all patients with gastric cancer. Recent studies have shown that it might be possible with the help of the Sentinel Node Technique to individualize lymphadenectomy in locally gastric cancer as well. The beneficial effects of adjuvant chemoradiation in gastric cancer do not mean, however, that the extent of resection may be reduced. Adjuvant chemoradiation following complete resection and D2 lymphadenectomy should still not be regarded as standard therapy.

The purpose of this pilot study was to begin characterizing changes in labial vibrotactile somatosensation in healthy older adults as a foundational step in determining how changes in orofacial sensation can affect functional behaviors, such as speech and feeding. Labial vibrotactile perception capacity of healthy older adults ( n = 15) was compared to a cohort of healthy young adults ( n = 5). Vibrotactile inputs were delivered to the glabrous surface of the left lower lip at 5, 10, 50, and 150 Hz. A modified von Bekesy (staircase) method was used to identify participants' thresholds and response standard deviations for each test frequency. Consistent with findings in other body regions, a decrease in labial vibrotactile detection sensitivity was expected in healthy older adults. The threshold values for the 5 and 10 Hz test frequencies were higher in the older group and the differences in response standard deviations at these frequencies were statistically significant. This pilot study identified changes in labial perception among healthy older adults.

Grundlagen: Die anatomische Lage des Magens zwischen Pankreas, Milz, Colon transversum, Zwerchfell, Leber, Bauchwand, Nebennieren, Dunndarm und Retroperitoneum erklart, das diese Strukturen beim fortgeschrittenen Magenkarzinom infiltriert sein konnen.

Summary Objectives The purpose of this qualitative phenomenological study was to gather rich thick descriptive data regarding the lived experiences of older adults seeking treatment for a voice disorder. Design Using qualitative methodologies, participants completed semi-structured interviews with trained investigators to detail their thoughts, beliefs, feelings, and experiences of living with a voice disorder. Using a process of horizontalization, themes were identified that described the experiences of older adults with voice disorders. Setting Research was conducted at four clinical voice centers in Kentucky, Wisconsin, and Ohio. Data were analyzed in the Laryngeal and Speech Dynamics Lab at the University of Kentucky. Participants A total of 28 adults (aged 65–90 years) with voice disorders were recruited for this study. Results and Conclusions Aging adults demonstrated a strong urge to communicate; however, they tended to describe their voice quality in negative terms and were emotionally impacted by these associations. They admitted to withdrawing from some activity or social event because their voice did not meet their expectations or voice needs; thought their voice quality was part of normal aging; and had resigned to accept their current voice.

Iris recognition systems have recently become an attractive identification method because of their extremely high accuracy. Most modern iris recognition syst ems are currently deployed on traditiona l sequential digital systems, such as a computer. However, modern advancements in configurable hardware, most notably Field-Programmable Gate Arrays (FPGAs) have provided an exciting opportunity to discover the parallel nature of modern image processing algorithms. In this study, iris matching, a repeatedly executed portion of a modern iris recognition algorithm is parallelized on an FPGA system. We demonstrate a 19 times speedup of the pa rallelized algorithm on the FPGA system when compared to a state-of-the-art CPU-based version. Keywords: Iris recognition algorithms, reconfigurable computin g, parallel computing, hamming distance, biometrics 1. INTRODUCTION Iris recognition stands out as one of the most accurate biom etric methods in use today. On e of the first iris recognition algorithms was introduced by pioneer Dr. John Daugmann [1]. An alternate iris recognition algorithm, referred to as the Ridge Energy Direction (RED) algorithm [2] will be the basis for this work. The iris is the colored part of the eye, protected by the cornea that extends from the pupil to the white of the eye. Its patterns remain stable over a lifetime. An example iris image is depicted in Figure 1. Once a digital image of the iris is captured, the system begins processing the image to transform it from a two dimensional array of pixels to a two dimensional encoded string of bits for comparison (see “Segment Iris into Polar Coordinates” in Figure 1). In this, the first step is to identify the iris among other facial elements such as the eyelids, sclera (white part of the eye), pupil (dark circle in the center of the eye) and ey elashes. The algorithm accomplishes this via the segmentation method described in prior art [3]. This establishes the central point of the iris within the image’s x and y coor dinates, allowing the computer to extract only the meaningful portions of the iris. Once the iris is segmented, the algorithm takes the iris and divides it into m concentric annuli and n radial lines, which results in an m x n representation of the iris. This step is effectively a rectangular to po lar coordinate conversion. The energy of each pixel is merely the square of the value of the infrared intensity with in the pixel and is used to distinguish features within the iris. The next step is to encode the iris image from two dimensional brightness data down to a two dimensional binary signature, referred to as the template (“Template Generation” in Figure 1) To accomplish this, the energy data are passed into two directional filters to determine the existence of ridges and their orientation. The RED algorithm uses directional filtering to generate the iris template , a set of bits that meaningfully represents a person’s iris. To help perform this filtering, the energy data passed from the iris segmentation process is made periodic in the horizontal dimensions to account for edge effects when perf orming the rectangular to polar conversion. The filter passes over this periodic array taking in 81 (9x9) values at a time ( note, in [2], 11x11 is used). More specifically, the result is computed by first multiplying each filter value by the corresp onding energy data value. Then a summation is performed, and the result is stored in a memory location that corresponds to the centroid of the filter. This process repeats for each pixel in the energy data, stepping right, column-by-column, and down, row-by-row, until the filtering is complete as shown in Figure 2. Finally, the template is generated by comparing the results of two different directional filters (horizontal and vertical, see Figure 1) and writing a single bit that represents the filter with the highest output at the equivalent location. The output of each filter is compared and for each pixel, a ‘1’ is assigne d for strong vertical content or a ‘0’ for strong horizontal content. These bits are concatenated to form a bit vector unique to the “iris signal” that conveys the identifiable information. In this study, we assume a template consists of 2048 bits, representing the uniqueness of the iris.

Iris recognition has been shown to be very accurate for human identification. We investigate the performance of the use of a partial iris for recognition. A partial iris identification system based on a one-dimensional approach to iris identification is developed. Experiment results show that a more distinguishable and individually unique signal is found in the inner rings of the iris. The results also show that it is possible to use only a portion of the iris for human identification.

Iris recognition is one of the more commonly used biometrics for recognition due to its accuracy. One of the first steps in iris recognition is to segment the iris from the rest of the image for further processing. This paper investigates the use of local statistics to find the pupillary (inner) and limbic (outer) boundaries of the iris. In particular, the local standard deviation and local kurtosis have shown to be useful in this respect. The methodology and results using the University of Bath and the United States Naval Academy iris databases are presented.

Iris recognition has been shown to be very accurate for human identification. In this paper, we develop a technique for iris pattern extraction utilizing the least significant bit-plane: the least significant bit of every pixel in the image. Through binary morphology applied to the bit-plane, the pupillary boundary of the iris is determined. The limbic boundary is identified by evaluating the standard deviation of the image intensity along the vertical and horizontal axes. Because our extraction approach restricts localization techniques to evaluating only bit-planes and standard deviations, iris pattern extraction is not dependent on circular edge detection. This allows for an expanded functionality of iris identification technology by no longer requiring a frontal view, which leads to the potential for off-angle iris recognition technology. Initial results show that it is possible to fit a close elliptical approximation to an iris pattern by using only bit-planes and standard deviations for iris localization.

In this paper, we investigate the accuracy of using a partial iris image for identification and determine which portion of the iris has the most distinguishable patterns. Moreover, we compare these results with the results of Du et. al. using the CASIA database. The experimental results show that it is challenging but feasible to use only a partial iris image for human identification.

An iris identification algorithm is proposed based on adaptive thresholding. The iris images are processed fully in the spatial domain using the distinct features (patterns) of the iris. A simple adaptive thresholding method is used to segment these patterns from the rest of an iris image. This method could possibly be utilized for partial iris recognition since it relaxes the requirement of using a majority of the iris to produce an iris template to compare with the database. In addition, the simple thresholding scheme can improve the computational efficiency of the algorithm. Preliminary results have shown that the method is very effective. However, further testing and improvements are envisioned.

Aims In 2008, some synthetic cannabinoids named “Spice” were detected in herbal smoking mixtures and became popular owing to their strong cannabimimetic effects after smoking. Many other products have appeared since and are constantly changing in attempts by manufacturers to evade legislation. Hair samples, which generally contain the parent compounds, could be of interest to screen for these synthetic cannabinoids using a poor selective extraction method and a highly specific and sensitive analytical detection technique. A simple method was developed and validated for the quantitative detection of 18 synthetic cannabinoids, AM-694; AM- 2201;CP 47,497; HU-210; JWH-007; JWH-015; JWH-018 and its N-Pentanoic acid metabolite; JWH-019; JWH-020; JWH-073; JWH-081; JWH-122; JWH-200; JWH-203; JWH-210; JWH-250 and WIN 55, 212-2 in hair by HPLC-MS/MS and its application to authentic specimen. This work belong to a pilot study evaluating the prevalence of synthetic cannabinoids use in France and conducted with two other labs 2 , 3 . Methods After decontamination with methylene chloride, hair sections were cut into small pieces, weighed and incubated in methanol, overnight at 40 °C, in the presence of deuterated internal standards (JWH-018-d 9 , THC-d 3 , 11-OH-THC-d 3 , THC-COOH-d 3 ). Finally, the organic phase was evaporated to dryness and reconstituted in mobile phase. The HPLC-MS/MS system consisted of an UFLC (Shimadzu Prominence) coupled with a triple-quadrupole ABSciex 5500 QTRAP instrument. Chromatographic separation was achieved on a Kinetex™ XB-C18 (2.1×100mm, 2.6μm) column. Tandem mass spectrometry was employed using an electrospray interface in positive and negative ionisation mode and acquisition was performed in scheduled MRM mode. Results The method was linear from LQ to 500pg/mg with quantification limits ranging from 0.5 to 5 pg/mg for all the targeted synthetic cannabinoids. Intra and inter-day precisions were below 20% at 0.5; 10; 50; 75 and 250 pg/mg. Intra and inter-day accuracies were established to be between 80% and 120% for the same concentration levels. There was no carry over and the absence of significative ion suppression phenomena was controlled. Sixty-five authentic hair specimens obtained from our routine activity (French forensic cases) were screened for synthetic cannabinoids. None of the specimen was found positive for the 18 targeted compounds. These preliminary results are in favour with a current very low prevalence of synthetic cannabinoids use in France, and are in accordance with those obtained by the two other labs which investigated urine specimens for the same 18 compounds. Conclusion Regarding the rising scientific interest about the synthetic cannabinoids, it appears necessary to develop an accurate, sensitive, but also evolutive method for the detection and quantification of synthetic cannabinoids in hair. Liquid chromatographymass spectrometry was deemed the most suitable analytical technique for its accuracy and sensitivity, particularly after a simple and unique direct extraction step from hair using methanol. This first method version was developed and fully validated for the large screening of 18 synthetic cannabinoids in hair.

A one-dimensional approach to iris recognition is presented. It is translation-, rotation-, illumination-, and scale-invariant. Traditional iris recognition systems typically use a two-dimensional iris signature that requires circular rotation for pattern matching. The new approach uses the Du measure as a matching mechanism, and generates a set of the most probable matches (ranks) instead of only the best match. Since the method generates one-dimensional signatures that are rotation-invariant, the system could work with eyes that are tilted. Moreover, the system will work with less of the iris than commercial systems, and thus could enable partial-iris recognition. In addition, this system is more tolerant of noise. Finally, this method is simple to implement, and its computational complexity is relatively low.