Sai Naga Sri Harsha Chittajallu
@dreamvu.com
Director Opto Mechanical Design and Manufacturing
DreamVu India Private Limited
EDUCATION
B.Tech in Mechanical Engineering
M.Tech in CAD/CAM
Ph.D. in Biomechanics from IIT Hyderabad and Swinburne University in Technology
RESEARCH, TEACHING, or OTHER INTERESTS
Biomaterials, Mechanics of Materials, Multidisciplinary, Mechanical Engineering
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Himanshu Gururani, Sai Naga Sri Harsha Chittajallu, Minal Doulatramani, Ramji Manoharan, Sayan Basu, and Viswanath Chinthapenta
Elsevier BV
Sai Naga Sri Harsha Chittajallu, Himanshu Gururani, Kwong Ming Tse, Subha Narayan Rath, Sayan Basu, and Viswanath Chinthapenta
Springer Science and Business Media LLC
AbstractFracture toughness of the human cornea is one of the critical parameters in suture-involved corneal surgeries and the development of bioengineered mimetics of the human cornea. The present article systematically studied the fracture characteristics of the human cornea to evaluate its resistance to tear in the opening (Mode-I) and trouser tear mode (Mode-III). Tear experiments reveal the dependency of the fracture behavior on the notch size and its location created in the corneal specimens. The findings indicate lamellar tear and collagen fiber pull-out as a failure mechanism in trouser tear and opening mode tests, respectively. Experimental results have shown a localized variation of tear behavior in trouser tear mode and indicated an increasing resistance to tear from the corneal center to the periphery. This article demonstrated the complications of evaluating fracture toughness in opening mode and showed that the limbus was weaker than the cornea and sclera against tearing. The overall outcomes of the present study help in designing experiments to understand the toughness of the diseased tissues, understanding the effect of the suturing location and donor placement, and creating numerical models to study parameters affecting corneal replacement surgery.
Himanshu Gururani, Sai Naga Sri Harsha Chittajallu, Ramji Manoharan, Sayan Basu, and Viswanath Chinthapenta
Elsevier BV
H. Gururani, S. N. S. H. Chittajallu, M. Ramji, S. Basu, and V. Chinthapenta
Springer Science and Business Media LLC
Rohit Dhakal, Jagadesh Rao Rudrapankte, Harsha S. N. S. Chittajallu, John G. Lawrenson, Byki Huntjens, Rakhee Shah, and Pavan K. Verkicharla
Wiley
AbstractPurposeWe developed a clip‐on light tracker (MyLyt) for estimating light exposure in real time. This study aimed at validating and investigating the feasibility of using MyLyt in children and adults.MethodThe study was conducted in two phases. Phase 1 involved validation against a factory‐calibrated digital lux meter in three separate conditions: controlled environmental set‐up, outdoors and indoors where intra‐test (two measurements by the same tracker), inter‐test (measurements among trackers) and inter‐device (MyLyt tracker and lux meter) validations were conducted. Phase 2 involved a feasibility study where MyLyt was used in a real‐world setting by 21 adults and 8 children. Participants were asked to log their real‐time movements in an ‘activity diary’, which were correlated with the lux levels measured by the tracker.ResultsA strong positive correlation and non‐significant difference in the recorded mean illuminance levels were observed during intra‐test (inter‐class correlation: 1.00, p = 0.99), inter‐test (0.91–1.00, p > 0.15) and inter‐device (0.91–1.00, p > 0.56) validation in all three testing conditions (p > 0.49), except the indoor location. While the lux level measured by MyLyt was significantly higher than that of the lux meter (p < 0.01) in the indoor locations, differences were minimal and clinically insignificant. A Bland–Altman plot showed a minimal mean difference (95% limits of agreement) between the MyLyt tracker and lux meter in all three conditions (controlled environmental set‐up: 641 [−949, 2230], outdoor: 74 [−2772, 2920] and indoor: −35 [−151, 80] lux). Phase 2 validation showed an expected illuminance level against the corresponding location with high sensitivity (97.8%) and specificity (99%) to accurately differentiate between outdoor and indoor locations.ConclusionThe MyLyt tracker showed good repeatability, strong correlation and comparable values with the lux meter in the three tested conditions, making it suitable for tracking light exposure patterns for both research and clinical purposes.
Murshid Imam, Sai Naga Sri Harsha Chittajallu, Himanshu Gururani, Hajime Yamamoto, Kazuhiro Ito, Pradeep Kumar Parchuri, Rajnish Mishra, Abhay Sharma, Ashutosh Richhariya, and Viswanath Chinthapenta
Elsevier BV
Sai Naga Sri Harsha Chittajallu, Ashutosh Richhariya, Kwong Ming Tse, and Viswanath Chinthapenta
MDPI AG
Computational modelling of damage and rupture of non-connective and connective soft tissues due to pathological and supra-physiological mechanisms is vital in the fundamental understanding of failures. Recent advancements in soft tissue damage models play an essential role in developing artificial tissues, medical devices/implants, and surgical intervention practices. The current article reviews the recently developed damage models and rupture models that considered the microstructure of the tissues. Earlier review works presented damage and rupture separately, wherein this work reviews both damage and rupture in soft tissues. Wherein the present article provides a detailed review of various models on the damage evolution and tear in soft tissues focusing on key conceptual ideas, advantages, limitations, and challenges. Some key challenges of damage and rupture models are outlined in the article, which helps extend the present damage and rupture models to various soft tissues.
Sirisha Senthil, Gaddam Manoj Kumar, Sai Naga Sri Harsha Chittajallu, Nikhil S. Choudhari, Chandrasekar Garudadri, and Ashutosh Richhariya
Ovid Technologies (Wolters Kluwer Health)
Precis: With a newly designed blade, slicing of the Ahmed glaucoma valve (AGV) leaflets helped to convert the flow-restrictive AGV into a non–flow-restrictive device. Flow characteristics by our in-vitro study confirmed the loss of resistance of AGV valve leaflets. Purpose: To describe a new blade to destroy the valve leaflets of AGV and to report the in-vitro flow characteristics of AGV after valve destruction. Methods: All the newly opened AGV implants and the Aurolab aqueous drainage implants (AADI, used as controls) were tested by connecting to a 27-G cannula, open manometer, digital manometer, and automated infusion pump. Data logging was done using a digital manometer at 4 Hz using computerized software. When the AGV’s flow characterization reached the steady phase, their valve functionality was destroyed by disrupting the valve leaflets, using a specially designed blade. The flow characteristics after valve slicing were compared with that of AADI. Results: A total of 5 FP7 AGVs and 2 AADIs were tested. After initial resistance to flow (5, 8 mm Hg) observed in the case of AADI for 1 to 3 hours, it dropped to 1 mm Hg in both the implants. The flow-restrictive AGV showed 3 distinct phases in the flow characterization. The first phase included the transient phase followed by the steady phase wherein the pressure was 11.2±2.6 (min 7, max 14) mm Hg. The pressure resistance of the AGV dropped significantly (P<0.001) to a mean of 0.4±0.54 mm Hg (1 mm Hg in 2 devices and 0 mm Hg in 3 devices) after the valve functionality was destroyed. The average time taken for this drop in pressure resistance after valve slicing was 10.2±3.0 minutes (min 7, max 15). Conclusions: It was possible to convert the flow-restrictive AGV into a non–flow-restrictive device by destroying the functionality of the valve leaflets. The pressure of the AGVs was similar to AADI after destroying its valve functionality.
Mukesh Taneja, Kiranmayi Chappidi, Sai Naga Sri Harsha Ch, Ashutosh Richhariya, Ashik Mohamed, and Varsha M. Rathi
Elsevier BV
Nikhil S. Choudhari, Swathi Vallabh Badakere, Ashutosh Richhariya, Sai Naga Sri Harsha Chittajallu, Sirisha Senthil, and Chandra Sekhar Garudadri
Association for Research in Vision and Ophthalmology (ARVO)
Purpose To investigate the mechanism of action and consistency in flow characteristics of the Ahmed glaucoma valve (AGV) under simulated physiological conditions in-vitro and to evaluate whether resistance during priming has any effect on performance of the device. Methods Each newly opened AGV device was connected to a digital manometer and was primed with normal saline. The device was then placed in a saline bath and connected to an open manometer, a digital manometer, and an infusion pump. Saline was infused at a rate of 3 μL/min for 24 hours. Digital manometer readings were recorded at 4 Hz. Results Data obtained from 9 devices are presented as medians (ranges). The priming pressure was 1130 (835, 1625) mm Hg. Pressure versus time curves showed two distinct phases; transient and steady phases. The transient phase peak pressure was 24 (13, 45) mm Hg. In the steady phase, opening and closing pressures were 13 (10, 17) and 7 (4, 9) mm Hg, respectively; the valve leaflets briefly opened every 73.9 (51, 76.6) minutes and the fluctuation of pressure (difference between opening and closing pressures) was 6 (3, 9) mm Hg. The Spearman correlation coefficient between priming and opening and priming and closing pressure was ρ = −0.13 (P = 0.72) and ρ = −0.36 (P = 0.33), respectively. Conclusions The device showed functionality like a valve. The resistance during priming did not affect opening and closing pressures of the AGV. This study showed variable in vitro performance of the AGV. Translational Relevance These laboratory findings might, at least partly, explain the variability in the clinical outcome of the device.
S.N.S.H. Chittajallu, T.R. Ramamohan, and Karupparaj R. Thundil
Trans Tech Publications, Ltd.
There are formalisms available in the literature for determining the force and torque on a particle moving in a fluid at zero and low Reynolds numbers. The formalism for determining the force and torque on a particle in a fluid at arbitrary Reynolds numbers has only recently been developed, Magnaudet [. This paper focuses on developing a formalism for the special case of a sphere moving in a quiescent fluid at arbitrary Reynolds numbers using the formalism of Magnaudet.
SHUENN-YIH CHANG*, Suad Bahar and Jingying Zhao
CRC Press