Agenda - NASA

Agenda - NASA

Agenda 10:05am IMM Overview D. Butler 10:15am Clinical Methods E. Kerstman 10:25am Resources L. Saile 10:30am Case Scenarios C. Minard

10:50am Discussion All 1 The Integrated Medical Model A Decision Support Tool for In-flight Crew Health Care Presenter: Doug Butler [email protected] (281) 212 -1380 Presentation to the Human Systems Integration Knowledge Broadcast Series NASA Johnson Space Center/SD4 Wyle Integrated Science and Engineering Group Houston, TX 26 May 2009 IMM Project Goals To develop an integrated, quantified,

evidence-based decision support tool useful to crew health and mission planners. To help align science, technology, and operational activities intended to optimize crew health, safety, and mission success. 3 Scope and Approach IMM addresses in-flight risk only, and uses ISS data as stepping stone Scope Forecast medical outcomes for in-flight operations only Forecast medical impacts to mission Does not assess long-term or chronic post-mission medical consequences Approach

Use ISS data as stepping stone to Exploration Program Employ best-evidence clinical research methods Employ Probability Risk Assessment (PRA) techniques Collaborate with other NASA Centers and Organizations 4 What is IMM? A software-based decision support tool Forecasts the impact of medical events on space flight missions Optimizes the medical system within the constraints of the space flight environment during simulations. 5 Software Technology Software is used across a wide range of industries to represent stochastic, probabilistic processes and uncertainty Crystal Ball Software (Oracle Corp.) Commercially available software application

Microsoft Excel user interface Stochastic forecasting and optimization SAS (Statistical Analysis Software) IMM 1.0 currently transitioning to SAS due to large number of variables in the model 6 HSI and Program Benefits How does a decision support tool like IMM aid a Program thats just forming? Knowledge Management Objectivity Prioritization Rationalization Optimization Communication 7 When does IMM prove useful? IMM supports decisions at all program phases PDR

CDR SSR 8 Who can benefit from IMM capabilities? Flight Surgeons What in-flight medical threats are greatest for reference mission A? Risk Managers What is the risk of evacuation - due to a medical event - for a 6-person, 180 day mission assuming the current in-flight medical capability? Vehicle Designers Whats the optimum medical mass allocation for given level of risk? Health Care System Designers What medical items do we fly for a given mass/volume allocation? Trainers

How do I prioritize limited crew training hours? Requirement Managers Whats the rationale for this crew health requirement? 9 Risk Vocabulary Common Risk Management Terms IMM Hazard Threat Initiating event Medical condition experienced Likelihood Probability of a medical event

Consequence Outcome End State Evacuation Loss of Crew Life Crew Health Index (CHI) Control Mitigation In-flight capability to diagnose by the crew in flight and treat the medical event 10 Risk and Risk Components Risk is whats left over after youve accounted for likelihood, outcome, and the mitigation associated with the threat.

5x5 Matrix for Threat Z Risk Mitigation A Likelihood 5 4 3 2 1 Risk Mitigation B 2 3 4 Outcome Risk

5 5x5 Matrix IMM Likelihood (Score 1-5) Medical Condition Incidence Mitigation? In-flight Medical Capabilities Outcome (Score 1-5) Crew Functional Impairment

Risk Score (2x1) for a single risk Impact to mission due to all medical conditions for the crew compliment 11 Comparison 5x5 Risk Matrix vs. IMM 5 Risk n 4 M iti ga tio Likelihood

5x5 Matrix 3 2 1 Risk 2 3 4 5 Outcome

Qualitative Categorical Subjective Single Risk No Uncertainty No Confidence Interval Limited context IMM Quantitative Probabilistic, Stochastic Evidence-based Integrated Risks Uncertainty Confidence Interval

In context Medical Conditions & Incidence Data Medical Condition Occurrences Crew Profile Crew Impairment & End States Mission Profile & Constraints Crew Functional Impairments In-flight Medical Resources Integrated Medical Model Clinical Resource Utilization

Optimization of Vehicle Constraints and Medical System Capabilities 12 IMM Conceptual Model INPUTS OUTPUTS Medical Conditions & Incidence Data Medical Condition Occurrences Crew Profile Mission Profile & Constraints Potential Crew Impairments Potential Mission End states

In-flight Medical Resources Crew Impairments Integrated Medical Model Clinical End States Mission End States Resource Utilization Optimized Medical System 13 IMM Logic INPUTS OUTPUT of Distributions Medical Conditions & Incidence Data

Medical Condition Occurrences Crew Profile Crew Impairment Mission Profile & Constraints Clinical End States Potential Crew Functional Impairments

Mission End States Resource Utilization Optimized Medical System IMM Potential Mission End States In-flight Medical Resources A simulation set may include 5-25,000 trial missions Best-Case Scenario

Medical Conditions Occur? Yes Essential Resource sAvailabl e? Yes Worst-case Scenario Available Resources Decremented No Untreated Scenario- Best Case Untreated Scenario- Worst-Case 14 Key Development Steps

Each step is in the critical path Develop a Conceptual Model Create initial list of relevant medical conditions Characterize incidence data Quantify crew impairment and clinical end states Quantify resources needed to diagnose and treat Develop a quantified Crew Health Index Understand implications of assumptions Verify & Validate Refine & Maintain Data 15 Development Status

Current Status of Model First version of IMM 1.0 completed (Sept 2008) IMM 1.0 supports assessments of 1-6 crew members 83 medical conditions represented 47 of 83 medical conditions have been recorded to occur in flight Medical Resources (type, quantity, mass, volume) per condition Capabilities Forecasts medical condition occurrences Identifies medical conditions that most influence crew impairment and mission impact Identifies key contributors to crew impairment and clinical outcomes (e.g. depleted or lack of in-flight medical resources) Compares crew health risk between different missions 16 IMM Usage History

IMM Inputs Rationale for ISS Medical Kit Redesign List of Prioritized Medical Conditions by Reference Mission Requirements rationale for vomitus and diarrhea IMM Outputs ISS Risk Model Medical Updates - Pending 17 Closing IMM addresses the observations documented by the RTF Task Group experience and instinct are poor substitutes for careful analysis of uncertainty This requires that analytical models be used appropriately to inform decisions (Source: NASA Return to Flight Task Group Final Report: Annex A.2 Individual Member Observations by Dr. Dan L. Crippen, Dr. Charles C. Daniel, Dr. Amy K. Donahue, Col. Susan J. Helms, Ms. Susan Morrisey

Livingstone, Dr. Rosemary O'Leary, and Mr. William Wegner.) 18 IMM Clinical Methods and Inputs Presenter: Eric Kerstman M.D., M.P.H. [email protected] (281) 212 - 1305 IMM Clinical Inputs Outline Development of the Medical Condition List (MCL) Overview of Incidence Determinations Functional Impairments Clinical Findings Form (CliFF) 20 Medical Condition List

Purpose To provide a list of medical conditions relevant to in-flight operations Relevant Medical Condition Has occurred in flight or has the potential to occur in flight Requires mitigation and/or results in functional impairment Current Status Consists of 83 medical conditions (47 have occurred in flight) 21 Development of the Medical Condition List MCL Phase I ISS Medical Checklist (70 conditions) MCL Phase II STS Medical Checklist (+1) MCL Phase III Longitudinal Study of Astronaut Health (LSAH) In-flight Medical Condition Occurrences (+6) MCL Phase IV

Flight Surgeon Delphi Study (+6) 22 MCL Phase III LSAH In flight Medical Condition Occurrences Includes Apollo, Skylab, Mir, Shuttle, and ISS STS-1 through STS-114 in 2005 Expedition 1 through Expedition 13 in 2006 47 relevant medical conditions 23 The Use of Incidence Incidence is a measure of the likelihood of developing a medical condition IMM uses incidence to quantify the likelihood

of occurrence of medical conditions in flight Likelihood 5 4 3 2 1 2 3 4 5 Outcome 24 Incidence Definitions The number of new medical events that occur within a specified time period Incidence Proportion (Cumulative Incidence)

The proportion of a population who develop a medical condition within a specified period of time (events/person) Incidence Rate (Incidence Density) The number of new medical events that occur within a population divided by the total time the population was at risk (events/person-year) Accounts for the different times that each individual was at risk 25 IMM Classification of Medical Conditions Space Adaptation Syndrome (SAS) Non-Space Adaptation Syndrome 26 SAS Medical Conditions 1)

2) 3) 4) 5) 6) 7) 8) 9) Back Pain Constipation Headache Insomnia Nasal Congestion Nosebleed Space Motion Sickness Urinary Incontinence Urinary Retention 27 Space Adaptation Syndrome Medical Conditions

Likelihood of occurrence is not related to mission duration Condition does not recur Incidence proportions (events/person) are determined from LSAH in flight occurrence data Example: Nasal Congestion 405 events among 660 persons = 0.614 events/person 28 Non-SAS Medical Conditions The likelihood of occurrence is related to mission duration Condition may recur Incidence rates (events/person-year) are determined from LSAH in flight occurrence data or other sources

Example: Skin Rash 90 events within 27.34 person-years = 3.29 events/person-year 29 Non-Space Adaptation Syndrome Medical Conditions Incidence Rate Determinations Conditions that have occurred in flight LSAH in flight occurrence data Conditions that have not occurred in flight External models (fractures) Environmental engineering data (altitude sickness) Terrestrial general/analog population data (appendicitis) Bayesian statistics for rare events (kidney stones) 30 The Use of Functional Impairments Impairment A loss or loss of use of a body part,

organ system, or organ function Considers both anatomic and functional loss Can develop from an illness or injury Likelihood IMM uses the concept of functional impairments to quantify the severity of medical condition outcomes 1 2 3 4 5 Outcome 31

American Medical Association Guides to the Evaluation of Permanent Impairment Impairments Percentages that reflect the severity of the medical condition No impairment = 0 percent Fully dependant/approaching death = 100 percent Examples Skin Infection = 10 to 24 percent impairment Shoulder Dislocation = 36 to 74 percent impairment 32 Clinical Findings Form (CliFF) Standardized Format for IMM Clinical Inputs The likelihood of occurrence of the medical condition Incidence proportion or incidence rate The clinical outcomes of the medical condition Considers ISS-based best case, worst case, and untreated case scenarios

Specifies functional impairments and duration times Specifies potential end states (evacuation, loss of crew life) Specifies levels of evidence for input data References sources of data 33 Summary Relevant list of medical conditions established Incidence data established for each medical conditions Crew functional impairments and end states (evacuation and loss of crew life) used to characterize impact due to medical events Standardized tool (CliFF) established for clinical inputs of likelihood and outcomes for each medical condition 34 In-flight Diagnosis & Treatment Resources

Presenter: Lynn Saile [email protected] (281) 212 -1488 Resource Tables The resource tables (RT) define the in-flight medical resources Specifies the necessary resources for diagnosis Considers the treatment of best and worst case scenarios Provides input into IMM Likelihood 5 4 3 Risk

In-flight Mitigation Risk 2 1 2 3 4 5 Outcome 36 Best and Worst Cases Best Case Scenario Consumable Consumable Disorder: Musculoskeletal

Sprain/Strain Extremities 1 Description Ace Bandage SAM splint Acetaminophen Ibuprofen 1 1 Quantity Quantity Kg Disorder Sprain/Strain Extremities 1

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Volume Volume cc3 mm3 cc3 mm3 Power

(W) Cost COTS COTS Estimates 1 0.03875 38.75 442.5 442500 $ 3.08 1 2 1-9

0.1134 0.00036 0.00066 113.4 0.36 0.66 1336.3575 0.02632 0.04202 1336357.5 26.32 42.02 $ $ $ 12.00 0.10 0.14

Worst Case Scenario Consumable Mass Mass Kg Gm GM Volume cc3 mm 3 Mass Quantity Ace Bandage SAM splint 1 1 0.03875

0.1134 38.75 113.4 442.5000 1336.3575 442500 1336357.5 $ $ 3.08 12.00 acetaminophen (2 tabs*46hr) 8 0.00036 0.36

0.0263 26.32 $ 0.10 ibuprofen (1-2 tabs*8hr) Vicodin (1-2 tabs *4-6 hr) Gauze Pads Nonsterile Gloves pr Sharps container 20 G catheter 10cc syringe Y-type catheter Tegaderm Dressing Saline, 500mL Iodine Pads Alcohol Pads Tourniquet Tape Morphine

carpuject 10 2 4 1 1 2 1 1 1 1 1 12 1 0.1 1-10ml 1 0.00066 0.00064 0.00504 0.014

0.66 0.64 5.04 14 0.0420 0.0483 7.6000 3.1000 42.02 48.30 7600.00 3100 $ $ $ $ 0.14 0.50 0.16 0.10

0.59553 0.00622 0.01123 595.53 18.51 11.23 2909.1250 7.5000 4.1700 2909125.00 7500 4170 0.00868 0.00252 8.68 2.52 0.1000

108.2000 100.00 108200 $ $ $ 0.15 0.15 0.50 0.48929 0.00108 0.00108 0.00603 489.29 1.08 1.08 6.03 750.8390

0.1500 0.1500 5.0000 750839.00 150.00 150.00 5000 $ $ $ 0.38 10.81 0.04 0.00906 0.00795 0.01524 9.06 7.95 15.24

6.4220 6.8855 5.6267 6422.00 6885.53 5626.67 $ $ $ $ $ 0.02 0.24 0.11 21.50 5.01 Kg Gm

Power Cost Estimates Description $ COTS Flight Certify Flight Sustaining Certify Eng Sustaining Eng 817.06

37 Resource Table Assumptions The resource tables reflect the current ISS medical equipment, supplies, drugs, etc. Conditions go untreated when an essential item is not available (due to depletion or omission from the health care system) Cost information only includes Commercialoff-the-shelf (COTS) Spacecraft resources (e.g. oxygen, water, power, bandwidth) are not constrained 38 In-flight Mitigation Medical resources can be optimized for

specific missions and crew profiles Best-case Resource tables identify the necessary supplies to mitigate risk by improving medical outcomes Risk 1 Worst-case Untreated-case Risk Risk Risk 2 3

4 5 Outcome 39 Integrated Medical Model Outputs and Simulated Mission Scenarios Presenter: Charles G. Minard, PhD [email protected] 281-461-2774 Integrated Medical Model Essentially, all models are wrong, but some are useful. George Box (1987) Professor Emeritus of Statistics at the University of Wisconsin 41

Statistical Methods IMM uses Monte Carlo simulation Crystal Ball software Microsoft Excel Distribution of outcomes Probability distributions Beta, Beta-PERT, Poisson, Bernoulli, Binomial, Lognormal, Uniform, Discrete uniform Crew Health Index (CHI) Quality-adjusted mission time 42 Quality-Adjusted Mission Time Modification of quality-adjusted life years (QALY) Standard epidemiologic measure Single, weighted measure of the net change in quality time 43

Example of QALY Consider the following individual: 35 years old 75 year life expectancy Medical event results in 30% functional impairment Below knee amputation What is the QALY? QALY 40 40 0.3 40 12 28 yrs 28 PQALY 100% 70% 40 Crew Health Index (CHI) With respect to IMM, Life is mission time 44 Crew Health Index (CHI)

Measure of crew performance Ranges from 0 to 100% 0% - completely impaired due to medical conditions for duration of mission 100% - no impairment due to medical conditions 45 Key Model Assumptions 83 medical conditions ISS Health Maintenance System (HMS) Conservative estimate of Crew Health Index (CHI) Medical events assumed to occur on the first day of the mission 46 6 Month Mission Is the current HMS adequate for a 6 member crew?

Consider two alternative 6 month missions 3 crew members (2M,1F) 6 crew members (5M,1F) 2 EVAs per crew member Identical medical resources (ISS) 47 Total Medical Events (3 Crew) 48 Total Medical Events (6 Crew) 49 Total Medical Events Expect about twice as many medical events Expect greater variation in the

number of events Statistic Mean Median SD 95% Inf. 3 Crew 45.6 46.0 6.6 34-59 6 Crew 91.2 91.0 9.3 73-110 50 Sensitivity Analysis

What are the most influential factors? Which variables describe the greatest variation in the distribution of the outcome? Which variables are most highly correlated with the outcome of interest? 51 Sensitivity Analysis Total Events 3 Crew Members 6 Crew Members 52 Sensitivity Analysis Total Events 3 Crew Members 1) 2) 3) 4) Late insomnia

Skin rash Skin abrasion/laceration Corneal abrasion 6 Crew Members 1) 2) 3) 4) Late insomnia Skin rash Skin abrasion/laceration Corneal abrasion 53 Crew Health Index (3 Crew) 54 Crew Health Index (6 Crew) 55

Crew Health Index Statistic Mean Median SD 95% Inference 3 Crew 84.8 89.5 13.0 51-98 6 Crew 65.3 67.0 17.6 28-93 Expect decreased CHI with 6 crew members Expect greater variation

56 CHI Sensitivity Analysis 3 Crew Members 1) Skin rash 2) Cough 6 Crew Members 1) Skin rash 2) Paresthesia Why was the CHI decreased for 6 crew members? Consider medical resources for skin rash 57 Skin Rash Resources (3 Crew) 58 Skin Rash Resources (6 Crew) 59

Lotramin AF 3 Crew Members Insufficient for 13.3% of the trials 6 Crew Members Insufficient for 76.0% of the trials 60 Summary Is the current ISS HMS adequate for a 6 member crew? Substantial decrease in CHI with three additional crew members What conditions had the greatest impact? Skin rash Paresthesia Corneal abrasions Why did skin rash impact the CHI?

Insufficient medical resources 61 Alternative Analyses Examine specific medical resources Ibuprofen Alternative resource allocation Increase supply for 6 crew, 6 month mission Shorter missions 24 versus 33 day missions Vary number of crew members 3 crew versus 4 crew 62 Alternative Outcomes Probability of evacuation

Probability of loss of crew life Summary measures that combines CHI, EVAC, and LOCL? 63 Probability of EVAC Information has not been validated. 64 Summary IMM is a tool to assist in the decision making process It does not make decisions IMM provides an objective analysis of likely medical events and outcomes during space flight IMM provides comparative analyses 65

Closing Development Milestones Support the Programs Presenter: Doug Butler [email protected] (281) 212 -1380 Next Steps Work in Progress Transition IMM to SAS software platform Optimization Algorithm Implementation Database Development & Integration Internal Verification & Validation Next 12 Months Key Milestones

Develop database user interfaces Develop IMM 2.0 Initiate external Verification & Validation Communication to stakeholders Prepare for transition to operations 67 IMM Development vs. Constellation Program Schedule PMR 08 Rev 1 As of 03/31/09 FY06 FY07 FY08 FY09 FY10 FY11 FY12

FY13 FY14 Orion 1 Flight Plan FY15 Orion 3 Orion 5 FY16 Orion 7 Orion 6 Ares I / Orion Launches Orion 2 Orion 4

Orion 8 Full Operational Capability Program Integration SDR PDR 1 PPAR SRR SDR PDR 2 PAR (NET) PDR

CDR DCR Production DDT&E SRR Project ATP Altair Proof of Concept/Prototype IMM 2.0 DDT&E IMM 1.0 IMM SAR

CDR Beta Today PDR CDR IMM 3.0 Orion SRR Alpha Production IMM Transition to Operations 68

Questions? 69 Skin Abrasion/Laceration Resources (3 Crew: Best Case only) 70 Skin Abrasion/Laceration Resources (6 Crew: Best Case only) 71 Gauze Pads 3 Crew Members Insufficient for 0.6% of the trials 6 Crew Members Insufficient for 41.9% of the trials 72

Povidone Iodine Swabs 3 Crew Members Insufficient for 4.8% of the trials 6 Crew Members Insufficient for 59.5% of the trials 73 Ibuprofen Compare Ibuprofen use 3 crew, 6 months 6 crew, 6 months What medical conditions explain the Ibuprofen usage? 74 Ibuprofen (6 Month Mission)

3 Crew Members Insufficient for 2.0% of the trials 6 Crew Members Insufficient for 45.0% of the trials 75 Ibuprofen Sensitivity Analysis 3 Crew Members 1) 2) 3) 4) 5) Back injury Sprain/Strain - Shoulder Paresthesia Back pain (SAS)

Sprain/Strain Elbow 6 Crew Members 1) 2) 3) 4) 5) Back injury Sprain/Strain - Shoulder Paresthesia Back pain (SAS) Sprain/Strain Elbow 76 Increase Medical Resource Supply Will increasing the medical supplies increase the Crew Health Index? Double these resources for 6 crew member mission

Gauze pads Povidone iodine swabs Benadryl capsules Ibuprofen Increases HMS requirement 0.42 kg 833.1 cm3 $47.60 77 Crew Health Index Current ISS Resources Mean = 48.8% Median = 49.2% 95% Inference: (15 81%) Additional Resources Mean = 59.4%

Median = 60.6% 95% Inference: (26 86%) 78 24 Day vs. 33 Day Missions Does a 33 day lunar mission require a different level of care than a 24 day lunar mission? Variable Mission 1 Mission 2 Mission length 24 Days 33 Days # Crew 4 (3M, 1F) 4 (3M, 1F) # EVAs/Person 4 5 Resources ISS ISS 79

Total Medical Events 24 Days Mean Median St. Dev. Minimum Maximum 95% Inference 33 Days 18.3 18.0 3.6 4.0 33.0

21.0 21.0 4.0 5.0 38.0 12 - 26 13 - 29 80 Sensitivity Analysis 24 Day Mission Headache (SAS) Nasal congestion (SAS) Space motion sickness (SAS)

Insomnia (SAS) Back pain (SAS) 33 Day Mission Headache (SAS) Nasal congestion (SAS) Space motion sickness (SAS) Skin rash Late insomnia 81 Crew Health Index 24 Day Mission 33 Day Mission 82

Crew Health Index Mean Median St. Dev. Minimum Maximum 95% Inference 24 Days 33 Days 89.6% 92.0% 7.9%

50.0% 99.6% 89.0% 91.6% 8.4% 26.8% 99.7% 69.0-98.2% 66.9-98.1% 83 IMM Logic For each comparative assessment, the identical questions are asked 5,000+ times to develop outcome distributions 1. 2. 3. 4. 5.

Did the medical condition happen? How many times? 4 Best or worst-case scenario? 3 2 Were resources available? 1 What was the outcome? 5 84 What if? Questions IMM is designed to help answer specific in-flight questions Questions Is the current ISS medical kit adequate for a crew of 6 on a 6-month mission? Does a 33-day lunar sortie mission require a different Level of Care than a 24-day lunar sortie mission?

Are we carrying enough Ibuprofen for a crew of six on a 12month mission? How does risk change if the ventilator fails at the start of a 3year mission? Questions What is the probability of a bone fracture occurring 10-years after a 6-month mission? What is the probability of renal stone formation after a 12month mission? 85

Recently Viewed Presentations

  • MMGW19_AGNmergers


    - gas dynamical friction - accretion torque . BH capture to an AGN disk. v. BH. In gas dynamical friction, a BH receives a drag force by gravitationally interacting with a density wake behind the BH. In accretion torque, a...
  • CSCI 200 Data MINING Lecture 1 Recommended Textbooks

    CSCI 200 Data MINING Lecture 1 Recommended Textbooks

    Nielsen MyBestSegments is in the clustering business which provides a demographic profile of each oi the geographic areas in the country, as defined by zip code. Clustering Mechanisms - PRIZM segmentation system, which describes every American zip code area in...
  • CS193J: Programming in Java Summer Quarter 2003 Lecture

    CS193J: Programming in Java Summer Quarter 2003 Lecture

    CS193J: Programming in Java Summer Quarter 2003 Lecture 2 OOP/Java Manu Kumar [email protected]
  • (Téma) -

    (Téma) -

    Obsah Rozdelenie kostry človeka Kostra hlavy - lebka (neurocranium) Kostra hlavy - lebka (splanchnocranium) Kostra trupu - chrbtica Kostra trupu - rebrá Kostra trupu - hrudná kosť Kostra končatín - horná končatina Kostra končatín - dolná končatina Choroby kostí Použité...
  • Reproduction in Angiosperms

    Reproduction in Angiosperms

    Reproduction in flowering plants Flowering plants contain their reproductive organs in the flower Flowers are often hermaphrodite structures both male and female parts Draw and Label … A diagram showing the structure of a dicotyledonous animal pollinated flower Sepal, petal,...
  • Shear Stresses in Concrete Beams - University of Kentucky ...

    Shear Stresses in Concrete Beams - University of Kentucky ...

    Shear Stresses in Concrete Beams Stresses Near Support Shear Failure Path Vertical reinforcing steel, shear stirrups, are added to resist the portion of the shear force not resisted by the concrete. Shear Strength of Concrete The shear strength of a...
  • Chapter 3

    Chapter 3

    A microculture defined by sexual identity numbering up to 10% of U.S. population. LGBT (Lesbian, Gay, Bisexual, Transgender) has a long history of societal oppression. Transgender is the state of one's self-identification as woman, man, neither or both, does not...
  • CSE 240 (291) week3

    CSE 240 (291) week3

    T-junctions indicate occlusion: top is occluding edge while bar is the occluded edge Bench occludes lamp post leg occludes bench lamp post occludes fence railing occludes trees trees occlude steeple Perspective scaling: railing looks smaller at the left; bench looks...