NCCOSC RDTE Division Code 02214B 53570 Silvergate Avenue Bldg A33 San Diego CA 92152-5113

70 -- SOFTWARE DESIGNING & DEVELOPING SOL N66001-95-Q-4334 DUE 083195 POC Purchasing Agent, Irene Solis, (619)524-2081. Contracting Officer, P.A. Brown. Bid Clerk, J.C. Norris, (619)553-4331. Interactive computer model for estimation of neck loading during flight. 1. INTRODUCTION: Naval Health Research Center has collected extensive laboratory and field data that quantifies neck and back fatigue profiles. Surface electromyograms (EMGs) have been successfully recorded in fixed and rotary wing military aircraft using new solid-state recording technology. In addition, NHRC has developed the capability of recording surface EMGs simultaneous with video images. This capability allows for the in-flight modeling of the head, neck, and back. 2. SCOPE: The focus of this work unit will be to design an interactive computer program to predict neck loading with different helmets, helmet configurations (night vision goggles, oxygen masks, etc). Background: NHRC needs to an interactive model which adequately describes human loadings during flight in military aircraft. Current models of the neck do not articulate the forces imparted by high performance aircraft loading. 3. CONTRACTOR RESPONSIBILITY: Contractor shall evaluate the scientific literature to adequately evaluate current models that describe neck loading and predict injury patterns. A new interactive computer model based on evaluation of current models, shall be generated to determine neck loading due to gravitational and rectilinear acceleration forces acting on head-mounted systems. Potential differences between genders are to be addressed. REPORTS, DATA AND DELIVERABLES: The contractor shall provide computer software consisting of ''object'' and executable files together with example program input and output. Complete manuals shall be developed that will be sufficient to enable an untrained user to successfully operate the program. The contractor shall: A. Prepare computer source code in the C++ computer language, in a form suitable for compilantion by the Borland C++ compiler system (version 3.1). The software shall perform user friendly functions in the MS DOS (versions greater than 3.1) graphical user interface (GUI) to feature windows, menus, hot keys, input validation, and mouse sensitivity. All model parameters shall be changeable and/or entered via the keyboard. Entered model parameters shall be saveable into an expandable database for easy retrieval and modification. Additionally, the user shall have the option to save model results to disk and have printed reporting available. B. Provide a computer model to determine neck loading during gravitational and rectilinear acceleration forces acting on the head system which includes the head and all rigid bodies supported by the head and neck. The source code shall provide reports of results ad accommodate expandable databases for helmets, helmet accoutrements, and gender specific data. C. Prepare source code to display three orthogonal views of the head with center of gravity vectors, muscle force vectors, and joint reaction force vectors superimposed with contrasting colors for easy identification. The interactive program shall assist the user in studying axial loading (from the point of the second vertebra of the neck on which the head and first vertebra turn on a pivot) as a function of the following changeable parameters: 1. Head mass and center of gravity; 2. Helmet mass and center of gravity; 3. Mass and center of gravity of helmet attachments such as night vision goggles, visors, oxygen mask, target acquisition sytems, etc.; 4. Tri-axial accelerometer data. The center of gravity vector shall depict a vector with the tail located at the center of gravity of the head, the length shall be proportional to the force acting on the corresponding mass, and the direction is governed by the direction of the external force acting on the center of gravity of the head. D. Prepare the source code to allow te user to enter rectilinear acceleration vectors from the keyboard or import the data from a text file for batch processing. When all parameters have been entered and verified by the program, a resultant value shall be generated to represent the +Gz loading of the spinal column. E. Prepare the source code to allow the user to attach counter weights to the helmet and when queried, all resultant values as previously described shall be generated and displayed. Additionally, when queried, the program shall generate recommended placement of counter weights to reduce the resultant force vector to the +Gz direction exclusively. F. Generate simplified graphical displays of the multiple head system configurations using the various helmets and helmet attachments with and without counterweights. 4. GOVERNMENT-FURNISHED PROPERTY/MATERIAL: A. Data tables on the mass and center of gravity for helmets and helmet attachments. B. Identify the location of the helmet attachments on the various helmets. 5. TRAVEL: One or two trips to testing sites may be required. If so, additional funds will be made available to the contractor. 6. OTHER: 6.1 SECURITY: No security clearance is required. 6.2 PLACE OF PERFORMANCE: All work will be conducted at the contractor site. 6.3 INSPECTION AND ACCEPTANCE: CDR S. J. Feith, NHRC Code 21D, (619)524-4519. The applicable Standard Industrial Code (SIC) and size standard is 7373 - 18.0 Million. Solicitation document to be issued on or about 08/30/95. Facsimile letters are acceptable at (619)553-6976. For copies of solicitations only written request will be honored. See Numbered Note(s): 22. (0227)

Loren Data Corp. http://www.ld.com (SYN# 0276 19950816\70-0001.SOL)