Health | NIST

<!DOCTYPE html> <html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# "> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("https://www.nist.gov/health","20230314214441","https://web.archive.org/","web","/_static/", "1678830281"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <meta charset="utf-8"/><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["gov-bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;(()=>{var e,t,r={9071:(e,t,r)=>{"use strict";r.d(t,{I:()=>n});var n=0,i=navigator.userAgent.match(/Firefox[\/\s](\d+\.\d+)/);i&&(n=+i[1])},6562:(e,t,r)=>{"use strict";r.d(t,{P_:()=>v,Mt:()=>h,C5:()=>d,DL:()=>y,OP:()=>R,lF:()=>L,Yu:()=>A,Dg:()=>p,CX:()=>f,GE:()=>w,sU:()=>M});var n={};r.r(n),r.d(n,{agent:()=>x,match:()=>O,version:()=>T});var i=r(6797),o=r(909),a=r(8610);class s{constructor(e,t){try{if(!e||"object"!=typeof e)return(0,a.Z)("New setting a Configurable requires an object as input");if(!t||"object"!=typeof t)return(0,a.Z)("Setting a Configurable requires a model to set its initial properties");Object.assign(this,t),Object.entries(e).forEach((e=>{let[t,r]=e;const n=(0,o.q)(t);n.length&&r&&"object"==typeof r&&n.forEach((e=>{e in r&&((0,a.Z)('"'.concat(e,'" is a protected attribute and can not be changed in feature ').concat(t,". It will have no effect.")),delete r[e])})),this[t]=r}))}catch(e){(0,a.Z)("An error occured while setting a Configurable",e)}}}const c={beacon:i.ce.beacon,errorBeacon:i.ce.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},u={};function d(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!u[e])throw new Error("Info for ".concat(e," was never set"));return u[e]}function f(e,t){if(!e)throw new Error("All info objects require an agent identifier!");u[e]=new s(t,c),(0,i.Qy)(e,u[e],"info")}const l={allow_bfcache:!0,privacy:{cookies_enabled:!0},ajax:{deny_list:void 0,enabled:!0,harvestTimeSeconds:10},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},ssl:void 0,obfuscate:void 0,jserrors:{enabled:!0,harvestTimeSeconds:10},metrics:{enabled:!0},page_action:{enabled:!0,harvestTimeSeconds:30},page_view_event:{enabled:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,long_task:!1},session_trace:{enabled:!0,harvestTimeSeconds:10},spa:{enabled:!0,harvestTimeSeconds:10}},g={};function v(e){if(!e)throw new Error("All configuration objects require an agent identifier!");if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function p(e,t){if(!e)throw new Error("All configuration objects require an agent identifier!");g[e]=new s(t,l),(0,i.Qy)(e,g[e],"config")}function h(e,t){if(!e)throw new Error("All configuration objects require an agent identifier!");var r=v(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}const m={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},b={};function y(e){if(!e)throw new Error("All loader-config objects require an agent identifier!");if(!b[e])throw new Error("LoaderConfig for ".concat(e," was never set"));return b[e]}function w(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");b[e]=new s(t,m),(0,i.Qy)(e,b[e],"loader_config")}const A=(0,i.mF)().o;var E=r(2053),x=null,T=null;if(navigator.userAgent){var _=navigator.userAgent,D=_.match(/Version\/(\S+)\s+Safari/);D&&-1===_.indexOf("Chrome")&&-1===_.indexOf("Chromium")&&(x="Safari",T=D[1])}function O(e,t){if(!x)return!1;if(e!==x)return!1;if(!t)return!0;if(!T)return!1;for(var r=T.split("."),n=t.split("."),i=0;i<n.length;i++)if(n[i]!==r[i])return!1;return!0}var j=r(5526),k=r(2374);const P="NRBA_SESSION_ID";function S(){if(!k.il)return null;try{let e;return null===(e=window.sessionStorage.getItem(P))&&(e=(0,j.ky)(16),window.sessionStorage.setItem(P,e)),e}catch(e){return null}}var I=r(8226);const C=e=>({customTransaction:void 0,disabled:!1,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,offset:(0,E.yf)(),onerror:void 0,origin:""+k._A.location,ptid:void 0,releaseIds:{},sessionId:1==h(e,"privacy.cookies_enabled")?S():null,xhrWrappable:"function"==typeof k._A.XMLHttpRequest?.prototype?.addEventListener,userAgent:n,version:I.q}),N={};function R(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!N[e])throw new Error("Runtime for ".concat(e," was never set"));return N[e]}function M(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");N[e]=new s(t,C(e)),(0,i.Qy)(e,N[e],"runtime")}function L(e){return function(e){try{const t=d(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}(e)}},8226:(e,t,r)=>{"use strict";r.d(t,{q:()=>n});const n="1227.PROD"},9557:(e,t,r)=>{"use strict";r.d(t,{w:()=>o});var n=r(8610);const i={agentIdentifier:""};class o{constructor(e){try{if("object"!=typeof e)return(0,n.Z)("shared context requires an object as input");this.sharedContext={},Object.assign(this.sharedContext,i),Object.entries(e).forEach((e=>{let[t,r]=e;Object.keys(i).includes(t)&&(this.sharedContext[t]=r)}))}catch(e){(0,n.Z)("An error occured while setting SharedContext",e)}}}},4329:(e,t,r)=>{"use strict";r.d(t,{L:()=>d,R:()=>c});var n=r(3752),i=r(7022),o=r(4045),a=r(2325);const s={};function c(e,t){const r={staged:!1,priority:a.p[t]||0};u(e),s[e].get(t)||s[e].set(t,r)}function u(e){e&&(s[e]||(s[e]=new Map))}function d(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:"",t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:"feature";if(u(e),!e||!s[e].get(t))return a(t);s[e].get(t).staged=!0;const r=Array.from(s[e]);function a(t){const r=e?n.ee.get(e):n.ee,a=o.X.handlers;if(r.backlog&&a){var s=r.backlog[t],c=a[t];if(c){for(var u=0;s&&u<s.length;++u)f(s[u],c);(0,i.D)(c,(function(e,t){(0,i.D)(t,(function(t,r){r[0].on(e,r[1])}))}))}delete a[t],r.backlog[t]=null,r.emit("drain-"+t,[])}}r.every((e=>{let[t,r]=e;return r.staged}))&&(r.sort(((e,t)=>e[1].priority-t[1].priority)),r.forEach((e=>{let[t]=e;a(t)})))}function f(e,t){var r=e[1];(0,i.D)(t[r],(function(t,r){var n=e[0];if(r[0]===n){var i=r[1],o=e[3],a=e[2];i.apply(o,a)}}))}},3752:(e,t,r)=>{"use strict";r.d(t,{ee:()=>u});var n=r(6797),i=r(3916),o=r(7022),a=r(6562),s="nr@context";let c=(0,n.fP)();var u;function d(){}function f(){return new d}function l(){u.aborted=!0,u.backlog={}}c.ee?u=c.ee:(u=function e(t,r){var n={},c={},g={},v=!1;try{v=16===r.length&&(0,a.OP)(r).isolatedBacklog}catch(e){}var p={on:b,addEventListener:b,removeEventListener:y,emit:m,get:A,listeners:w,context:h,buffer:E,abort:l,aborted:!1,isBuffering:x,debugId:r,backlog:v?{}:t&&"object"==typeof t.backlog?t.backlog:{}};return p;function h(e){return e&&e instanceof d?e:e?(0,i.X)(e,s,f):f()}function m(e,r,n,i,o){if(!1!==o&&(o=!0),!u.aborted||i){t&&o&&t.emit(e,r,n);for(var a=h(n),s=w(e),d=s.length,f=0;f<d;f++)s[f].apply(a,r);var l=T()[c[e]];return l&&l.push([p,e,r,a]),a}}function b(e,t){n[e]=w(e).concat(t)}function y(e,t){var r=n[e];if(r)for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)}function w(e){return n[e]||[]}function A(t){return g[t]=g[t]||e(p,t)}function E(e,t){var r=T();p.aborted||(0,o.D)(e,(function(e,n){t=t||"feature",c[n]=t,t in r||(r[t]=[])}))}function x(e){return!!T()[c[e]]}function T(){return p.backlog}}(void 0,"globalEE"),c.ee=u)},9252:(e,t,r)=>{"use strict";r.d(t,{E:()=>n,p:()=>i});var n=r(3752).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},4045:(e,t,r)=>{"use strict";r.d(t,{X:()=>o});var n=r(9252);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.E,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.E);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},8544:(e,t,r)=>{"use strict";r.d(t,{bP:()=>s,iz:()=>c,m$:()=>a});var n=r(2374);let i=!1,o=!1;try{const e={get passive(){return i=!0,!1},get signal(){return o=!0,!1}};n._A.addEventListener("test",null,e),n._A.removeEventListener("test",null,e)}catch(e){}function a(e,t){return i||o?{capture:!!e,passive:i,signal:t}:!!e}function s(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2];window.addEventListener(e,t,a(r))}function c(e,t){let r=arguments.length>2&&void 0!==arguments[2]&&arguments[2];document.addEventListener(e,t,a(r))}},5526:(e,t,r)=>{"use strict";r.d(t,{Rl:()=>i,ky:()=>o});var n=r(2374);function i(){var e=null,t=0,r=n._A?.crypto||n._A?.msCrypto;function i(){return e?15&e[t++]:16*Math.random()|0}r&&r.getRandomValues&&(e=r.getRandomValues(new Uint8Array(31)));for(var o,a="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx",s="",c=0;c<a.length;c++)s+="x"===(o=a[c])?i().toString(16):"y"===o?(o=3&i()|8).toString(16):o;return s}function o(e){var t=null,r=0,n=self.crypto||self.msCrypto;n&&n.getRandomValues&&Uint8Array&&(t=n.getRandomValues(new Uint8Array(31)));for(var i=[],o=0;o<e;o++)i.push(a().toString(16));return i.join("");function a(){return t?15&t[r++]:16*Math.random()|0}}},2053:(e,t,r)=>{"use strict";r.d(t,{nb:()=>s,os:()=>c,yf:()=>a,zO:()=>o});var n=(new Date).getTime(),i=n;function o(){return performance?.now?Math.round(performance.now()):(n=Math.max((new Date).getTime(),n))-i}function a(){return n}function s(e){i=e}function c(){return i}},6625:(e,t,r)=>{"use strict";r.d(t,{s:()=>a,v:()=>s});var n=r(8283),i=r(2053),o=r(2374);let a=!0;function s(e){var t=function(){a=!1;const e=o._A?.performance?.timeOrigin||o._A?.performance?.timing?.navigationStart;if(!e)return;return Math.round(e)}();t&&((0,n.B)(e,"starttime",t),(0,i.nb)(t))}},8283:(e,t,r)=>{"use strict";r.d(t,{B:()=>o,L:()=>a});var n=r(2053),i={};function o(e,t,r){void 0===r&&(r=(0,n.zO)()+(0,n.os)()),i[e]=i[e]||{},i[e][t]=r}function a(e,t,r,n){const o=e.sharedContext.agentIdentifier;var a=i[o]?.[r],s=i[o]?.[n];void 0!==a&&void 0!==s&&e.store("measures",t,{value:s-a})}},2545:(e,t,r)=>{"use strict";r.d(t,{L:()=>c});var n=r(9071),i=r(8544),o=r(8305),a=r(2374),s=r(6998);if(a.v6){a._A.cleanupTasks=[];const e=a._A.close;a._A.close=()=>{for(let e of a._A.cleanupTasks)e();e()}}function c(e,t){if(a.il)if(t)(0,s.N)(e,!0),(0,i.bP)("pagehide",e);else{var r=(0,o.Z)(e);!n.I||navigator.sendBeacon?(0,i.bP)("pagehide",r):(0,i.bP)("beforeunload",r),(0,i.bP)("unload",r)}else a.v6&&a._A.cleanupTasks.push(e)}},8610:(e,t,r)=>{"use strict";function n(e,t){console&&console.warn&&"function"==typeof console.warn&&(console.warn("New Relic: ".concat(e)),t&&console.warn(t))}r.d(t,{Z:()=>n})},3916:(e,t,r)=>{"use strict";r.d(t,{X:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},2374:(e,t,r)=>{"use strict";r.d(t,{_A:()=>o,il:()=>n,lW:()=>a,v6:()=>i});const n=Boolean("undefined"!=typeof window&&window.document),i=Boolean("undefined"!=typeof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator);let o=(()=>{if(n)return window;if(i){if("undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope)return globalThis;if(self instanceof WorkerGlobalScope)return self}throw new Error('New Relic browser agent shutting down due to error: Unable to locate global scope. This is possibly due to code redefining browser global variables like "self" and "window".')})();function a(){return o}},7022:(e,t,r)=>{"use strict";r.d(t,{D:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t){var r=[],i="",o=0;for(i in e)n.call(e,i)&&(r[o]=t(i,e[i]),o+=1);return r}},8305:(e,t,r)=>{"use strict";r.d(t,{Z:()=>o});var n=r(8683),i=r.n(n);function o(e){var t,r=!1;return function(){return r?t:(r=!0,t=e.apply(this,i()(arguments)))}}},2650:(e,t,r)=>{"use strict";r.d(t,{K:()=>a,b:()=>o});var n=r(8544);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.bP)("load",e,t)}function a(e){if(i())return e();(0,n.iz)("DOMContentLoaded",e)}},6797:(e,t,r)=>{"use strict";r.d(t,{EZ:()=>u,Qy:()=>c,ce:()=>o,fP:()=>a,gG:()=>d,mF:()=>s});var n=r(2053),i=r(2374);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return i._A.NREUM||(i._A.NREUM={}),void 0===i._A.newrelic&&(i._A.newrelic=i._A.NREUM),i._A.NREUM}function s(){let e=a();return e.o||(e.o={ST:i._A.setTimeout,SI:i._A.setImmediate,CT:i._A.clearTimeout,XHR:i._A.XMLHttpRequest,REQ:i._A.Request,EV:i._A.Event,PR:i._A.Promise,MO:i._A.MutationObserver,FETCH:i._A.fetch}),e}function c(e,t,r){let i=a();const o=i.initializedAgents||{},s=o[e]||{};return Object.keys(s).length||(s.initializedAt={ms:(0,n.zO)(),date:new Date}),i.initializedAgents={...o,[e]:{...s,[r]:t}},i}function u(e,t){a()[e]=t}function d(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},6998:(e,t,r)=>{"use strict";r.d(t,{N:()=>i,e:()=>o});var n=r(8544);function i(e){let t=arguments.length>1&&void 0!==arguments[1]&&arguments[1];return void(0,n.iz)("visibilitychange",(function(){if(t){if("hidden"!=document.visibilityState)return;e()}e(document.visibilityState)}))}function o(){return"hidden"===document.visibilityState?-1:1/0}},6034:(e,t,r)=>{"use strict";r.d(t,{gF:()=>o,mY:()=>i,t9:()=>n,vz:()=>s,xS:()=>a});const n=r(2325).D.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},2484:(e,t,r)=>{"use strict";r.d(t,{t:()=>n});const n=r(2325).D.pageViewEvent},6382:(e,t,r)=>{"use strict";r.d(t,{t:()=>n});const n=r(2325).D.pageViewTiming},1509:(e,t,r)=>{"use strict";r.d(t,{W:()=>s});var n=r(6562),i=r(3752),o=r(2384),a=r(6797);class s{constructor(e,t,r){this.agentIdentifier=e,this.aggregator=t,this.ee=i.ee.get(e,(0,n.OP)(this.agentIdentifier).isolatedBacklog),this.featureName=r,this.blocked=!1,this.checkConfiguration()}checkConfiguration(){if(!(0,n.lF)(this.agentIdentifier)){let e={...(0,a.gG)().info?.jsAttributes};try{e={...e,...(0,n.C5)(this.agentIdentifier)?.jsAttributes}}catch(e){}(0,o.j)(this.agentIdentifier,{...(0,a.gG)(),info:{...(0,a.gG)().info,jsAttributes:e}})}}}},2384:(e,t,r)=>{"use strict";r.d(t,{j:()=>w});var n=r(8683),i=r.n(n),o=r(2325),a=r(6562),s=r(9252),c=r(7022),u=r(3752),d=r(2053),f=r(4329),l=r(2650),g=r(2374),v=r(8610),p=r(6034);function h(e){["setErrorHandler","finished","addToTrace","inlineHit","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError"].forEach((t=>{e[t]=function(){for(var r=arguments.length,n=new Array(r),i=0;i<r;i++)n[i]=arguments[i];return function(t){for(var r=arguments.length,n=new Array(r>1?r-1:0),i=1;i<r;i++)n[i-1]=arguments[i];Object.values(e.initializedAgents).forEach((e=>{e.exposed&&e.api[t]&&e.api[t](...n)}))}(t,...n)}}))}var m=r(6797);const b={stn:[o.D.sessionTrace],err:[o.D.jserrors,o.D.metrics],ins:[o.D.pageAction],spa:[o.D.spa]};const y={};function w(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:{},n=arguments.length>2?arguments[2]:void 0,w=arguments.length>3?arguments[3]:void 0,{init:A,info:E,loader_config:x,runtime:T={loaderType:n},exposed:_=!0}=t;const D=(0,m.gG)();let O={};return E||(A=D.init,E=D.info,x=D.loader_config,O=D),g.v6&&(E.jsAttributes={...E.jsAttributes,isWorker:!0}),(0,a.CX)(e,E),(0,a.Dg)(e,A||{}),(0,a.GE)(e,x||{}),(0,a.sU)(e,T),function(e,t,n){n||(0,f.R)(e,"api"),h(t);var m=u.ee.get(e),b=m.get("tracer"),y="api-",w=y+"ixn-";function A(){}(0,c.D)(["setErrorHandler","finished","addToTrace","inlineHit","addRelease"],(function(e,r){t[r]=x(y,r,!0,"api")})),t.addPageAction=x(y,"addPageAction",!0,o.D.pageAction),t.setCurrentRouteName=x(y,"routeName",!0,o.D.spa),t.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,a.OP)(e).customTransaction=(r||"https://web.archive.org/web/20230314214441/http://custom.transaction")+t,x(y,"setPageViewName",!0,"api")()},t.setCustomAttribute=function(t,r){const n=(0,a.C5)(e);return(0,a.CX)(e,{...n,jsAttributes:{...n.jsAttributes,[t]:r}}),x(y,"setCustomAttribute",!0,"api")()},t.interaction=function(){return(new A).get()};var E=A.prototype={createTracer:function(e,t){var r={},n=this,i="function"==typeof t;return(0,s.p)(w+"tracer",[(0,d.zO)(),e,r],n,o.D.spa,m),function(){if(b.emit((i?"":"no-")+"fn-start",[(0,d.zO)(),n,i],r),i)try{return t.apply(this,arguments)}catch(e){throw b.emit("fn-err",[arguments,this,"string"==typeof e?new Error(e):e],r),e}finally{b.emit("fn-end",[(0,d.zO)()],r)}}}};function x(e,t,r,n){return function(){return(0,s.p)(p.xS,["API/"+t+"/called"],void 0,o.D.metrics,m),(0,s.p)(e+t,[(0,d.zO)()].concat(i()(arguments)),r?null:this,n,m),r?void 0:this}}function T(){r.e(439).then(r.bind(r,5692)).then((t=>{let{setAPI:r}=t;r(e),(0,f.L)(e,"api")})).catch((()=>(0,v.Z)("Downloading runtime APIs failed...")))}(0,c.D)("actionText,setName,setAttribute,save,ignore,onEnd,getContext,end,get".split(","),(function(e,t){E[t]=x(w,t,void 0,o.D.spa)})),t.noticeError=function(e,t){"string"==typeof e&&(e=new Error(e)),(0,s.p)(p.xS,["API/noticeError/called"],void 0,o.D.metrics,m),(0,s.p)("err",[e,(0,d.zO)(),!1,t],void 0,o.D.jserrors,m)},g.v6?T():(0,l.b)((()=>T()),!0)}(e,O,w),(0,m.Qy)(e,D,"api"),(0,m.Qy)(e,_,"exposed"),(0,m.EZ)("activatedFeatures",y),(0,m.EZ)("setToken",(t=>function(e,t){var r=u.ee.get(t);e&&"object"==typeof e&&((0,c.D)(e,(function(e,t){if(!t)return(b[e]||[]).forEach((t=>{(0,s.p)("block-"+e,[],void 0,t,r)}));y[e]||((0,s.p)("feat-"+e,[],void 0,b[e],r),y[e]=!0)})),(0,f.L)(t,o.D.pageViewEvent))}(t,e))),O}},909:(e,t,r)=>{"use strict";r.d(t,{Z:()=>i,q:()=>o});var n=r(2325);function i(e){switch(e){case n.D.ajax:return[n.D.jserrors];case n.D.sessionTrace:return[n.D.ajax,n.D.pageViewEvent];case n.D.pageViewTiming:return[n.D.pageViewEvent];default:return[]}}function o(e){return e===n.D.jserrors?[]:["auto"]}},2325:(e,t,r)=>{"use strict";r.d(t,{D:()=>n,p:()=>i});const n={ajax:"ajax",jserrors:"jserrors",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionTrace:"session_trace",spa:"spa"},i={[n.pageViewEvent]:1,[n.pageViewTiming]:2,[n.metrics]:3,[n.jserrors]:4,[n.ajax]:5,[n.sessionTrace]:6,[n.pageAction]:7,[n.spa]:8}},8683:e=>{e.exports=function(e,t,r){t||(t=0),void 0===r&&(r=e?e.length:0);for(var n=-1,i=r-t||0,o=Array(i<0?0:i);++n<i;)o[n]=e[t+n];return o}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.n=e=>{var t=e&&e.__esModule?()=>e.default:()=>e;return i.d(t,{a:t}),t},i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>(({78:"page_action-aggregate",147:"metrics-aggregate",193:"session_trace-aggregate",317:"jserrors-aggregate",348:"page_view_timing-aggregate",439:"async-api",729:"lazy-loader",786:"page_view_event-aggregate",873:"spa-aggregate",898:"ajax-aggregate"}[e]||e)+"."+{78:"2f41aaf7",147:"28086cfb",178:"52056f28",193:"545db67a",317:"941c6e17",348:"a7d9d7be",439:"737e0ca6",729:"540ab0d1",786:"2ae3c96c",873:"494130b7",898:"52cc993d"}[e]+"-1227.min.js"),i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),d=0;d<u.length;d++){var f=u[d];if(f.getAttribute("src")==r||f.getAttribute("data-webpack")==t+o){s=f;break}}s||(c=!0,(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r),e[r]=[n];var l=(t,n)=>{s.onerror=s.onload=null,clearTimeout(g);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},g=setTimeout(l.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=l.bind(null,s.onerror),s.onload=l.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://web.archive.org/web/20230314214441/https://js-agent.newrelic.com/",(()=>{var e={703:0,946:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=window.webpackChunkNRBA=window.webpackChunkNRBA||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})();var o={};(()=>{"use strict";i.r(o);var e=i(2325),t=i(6562);const r=Object.values(e.D);function n(e){const n={};return r.forEach((r=>{n[r]=function(e,r){return!1!==(0,t.Mt)(r,"".concat(e,".enabled"))}(r,e)})),n}var a=i(2384),s=i(909),c=i(9252),u=i(2053),d=i(8283),f=i(6625),l=i(4329),g=i(1509),v=i(2650),p=i(2374),h=i(8610);class m extends g.W{constructor(e,t,r){let n=!(arguments.length>3&&void 0!==arguments[3])||arguments[3];super(e,t,r),this.hasAggregator=!1,this.auto=n,this.abortHandler,n&&(0,l.R)(e,r)}importAggregator(){if(this.hasAggregator||!this.auto)return;this.hasAggregator=!0;const e=async()=>{try{const{lazyLoader:e}=await i.e(729).then(i.bind(i,8110)),{Aggregate:t}=await e(this.featureName,"aggregate");new t(this.agentIdentifier,this.aggregator)}catch(e){(0,h.Z)("Downloading ".concat(this.featureName," failed...")),this.abortHandler?.()}};p.v6?e():(0,v.b)((()=>e()),!0)}}var b,y,w,A=i(2484);class E extends m{constructor(e,t){let r=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,A.t,r),(0,f.v)(e),(0,d.B)(e,"firstbyte",(0,u.yf)()),(0,v.K)((()=>this.measureDomContentLoaded())),(0,v.b)((()=>this.measureWindowLoaded()),!0),this.importAggregator()}measureWindowLoaded(){var t=(0,u.zO)();(0,d.B)(this.agentIdentifier,"onload",t+(0,u.os)()),(0,c.p)("timing",["load",t],void 0,e.D.pageViewTiming,this.ee)}measureDomContentLoaded(){(0,d.B)(this.agentIdentifier,"domContent",(0,u.zO)()+(0,u.os)())}}b=E,y="featureName",w=A.t,(y=function(e){var t=function(e,t){if("object"!=typeof e||null===e)return e;var r=e[Symbol.toPrimitive];if(void 0!==r){var n=r.call(e,t||"default");if("object"!=typeof n)return n;throw new TypeError("@@toPrimitive must return a primitive value.")}return("string"===t?String:Number)(e)}(e,"string");return"symbol"==typeof t?t:String(t)}(y))in b?Object.defineProperty(b,y,{value:w,enumerable:!0,configurable:!0,writable:!0}):b[y]=w;var x=i(9557),T=i(7022);class _ extends x.w{constructor(e){super(e),this.aggregatedData={}}store(e,t,r,n,i){var o=this.getBucket(e,t,r,i);return o.metrics=function(e,t){t||(t={count:0});return t.count+=1,(0,T.D)(e,(function(e,r){t[e]=D(r,t[e])})),t}(n,o.metrics),o}merge(e,t,r,n,i){var o=this.getBucket(e,t,n,i);if(o.metrics){var a=o.metrics;a.count+=r.count,(0,T.D)(r,(function(e,t){if("count"!==e){var n=a[e],i=r[e];i&&!i.c?a[e]=D(i.t,n):a[e]=function(e,t){if(!t)return e;t.c||(t=O(t.t));return t.min=Math.min(e.min,t.min),t.max=Math.max(e.max,t.max),t.t+=e.t,t.sos+=e.sos,t.c+=e.c,t}(i,a[e])}}))}else o.metrics=r}storeMetric(e,t,r,n){var i=this.getBucket(e,t,r);return i.stats=D(n,i.stats),i}getBucket(e,t,r,n){this.aggregatedData[e]||(this.aggregatedData[e]={});var i=this.aggregatedData[e][t];return i||(i=this.aggregatedData[e][t]={params:r||{}},n&&(i.custom=n)),i}get(e,t){return t?this.aggregatedData[e]&&this.aggregatedData[e][t]:this.aggregatedData[e]}take(e){for(var t={},r="",n=!1,i=0;i<e.length;i++)t[r=e[i]]=j(this.aggregatedData[r]),t[r].length&&(n=!0),delete this.aggregatedData[r];return n?t:null}}function D(e,t){return null==e?function(e){e?e.c++:e={c:1};return e}(t):t?(t.c||(t=O(t.t)),t.c+=1,t.t+=e,t.sos+=e*e,e>t.max&&(t.max=e),e<t.min&&(t.min=e),t):{t:e}}function O(e){return{t:e,min:e,max:e,sos:e*e,c:1}}function j(e){return"object"!=typeof e?[]:(0,T.D)(e,k)}function k(e,t){return t}var P=i(6797),S=i(5526);var I,C=i(6998),N=i(8544),R=i(6382),M=-1,L=function(e){addEventListener("pageshow",(function(t){t.persisted&&(M=t.timeStamp,e(t))}),!0)},B=function(){return window.performance&&performance.getEntriesByType&&performance.getEntriesByType("navigation")[0]},z=function(){var e=B();return e&&e.activationStart||0},V=function(e,t){var r=B(),n="navigate";return M>=0?n="back-forward-cache":r&&(n=document.prerendering||z()>0?"prerender":document.wasDiscarded?"restore":r.type.replace(/_/g,"-")),{name:e,value:void 0===t?-1:t,rating:"good",delta:0,entries:[],id:"v3-".concat(Date.now(),"-").concat(Math.floor(8999999999999*Math.random())+1e12),navigationType:n}},W=function(e,t,r){try{if(PerformanceObserver.supportedEntryTypes.includes(e)){var n=new PerformanceObserver((function(e){Promise.resolve().then((function(){t(e.getEntries())}))}));return n.observe(Object.assign({type:e,buffered:!0},r||{})),n}}catch(e){}},q=function(e,t){var r=function r(n){"pagehide"!==n.type&&"hidden"!==document.visibilityState||(e(n),t&&(removeEventListener("visibilitychange",r,!0),removeEventListener("pagehide",r,!0)))};addEventListener("visibilitychange",r,!0),addEventListener("pagehide",r,!0)},Z=function(e,t,r,n){var i,o;return function(a){t.value>=0&&(a||n)&&((o=t.value-(i||0))||void 0===i)&&(i=t.value,t.delta=o,t.rating=function(e,t){return e>t[1]?"poor":e>t[0]?"needs-improvement":"good"}(t.value,r),e(t))}},H=function(e){document.prerendering?addEventListener("prerenderingchange",(function(){return e()}),!0):e()},F=(new Date,0),U=1/0,G=0,X=function(e){e.forEach((function(e){e.interactionId&&(U=Math.min(U,e.interactionId),G=Math.max(G,e.interactionId),F=G?(G-U)/7+1:0)}))},Q=function(){return I?F:performance.interactionCount||0},K=function(){"interactionCount"in performance||I||(I=W("event",X,{type:"event",buffered:!0,durationThreshold:0}))},Y=0,J=function(){return Q()-Y},$=[],ee={},te=function(e){var t=$[$.length-1],r=ee[e.interactionId];if(r||$.length<10||e.duration>t.latency){if(r)r.entries.push(e),r.latency=Math.max(r.latency,e.duration);else{var n={id:e.interactionId,latency:e.duration,entries:[e]};ee[n.id]=n,$.push(n)}$.sort((function(e,t){return t.latency-e.latency})),$.splice(10).forEach((function(e){delete ee[e.id]}))}},re=i(2545);class ne extends m{constructor(r,n){var i;let o=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];if(super(r,n,R.t,o),i=this,p.il){if(this.pageHiddenTime=(0,C.e)(),this.performanceObserver,this.lcpPerformanceObserver,this.clsPerformanceObserver,this.fiRecorded=!1,"PerformanceObserver"in window&&"function"==typeof window.PerformanceObserver){this.performanceObserver=new PerformanceObserver((function(){return i.perfObserver(...arguments)}));try{this.performanceObserver.observe({entryTypes:["paint"]})}catch(e){}this.lcpPerformanceObserver=new PerformanceObserver((function(){return i.lcpObserver(...arguments)}));try{this.lcpPerformanceObserver.observe({entryTypes:["largest-contentful-paint"]})}catch(e){}this.clsPerformanceObserver=new PerformanceObserver((function(){return i.clsObserver(...arguments)}));try{this.clsPerformanceObserver.observe({type:"layout-shift",buffered:!0})}catch(e){}}this.fiRecorded=!1;["click","keydown","mousedown","pointerdown","touchstart"].forEach((e=>{(0,N.iz)(e,(function(){return i.captureInteraction(...arguments)}))})),function(e,t){t=t||{},H((function(){var r=[200,500];K();var n,i=V("INP"),o=function(e){e.forEach((function(e){e.interactionId&&te(e),"first-input"===e.entryType&&!$.some((function(t){return t.entries.some((function(t){return e.duration===t.duration&&e.startTime===t.startTime}))}))&&te(e)}));var t,r=(t=Math.min($.length-1,Math.floor(J()/50)),$[t]);r&&r.latency!==i.value&&(i.value=r.latency,i.entries=r.entries,n())},a=W("event",o,{durationThreshold:t.durationThreshold||40});n=Z(e,i,r,t.reportAllChanges),a&&(a.observe({type:"first-input",buffered:!0}),q((function(){o(a.takeRecords()),i.value<0&&J()>0&&(i.value=0,i.entries=[]),n(!0)})),L((function(){$=[],Y=Q(),i=V("INP"),n=Z(e,i,r,t.reportAllChanges)})))}))}((t=>{let{name:r,value:n,id:i}=t;(0,c.p)("timing",[r.toLowerCase(),n,{metricId:i}],void 0,e.D.pageViewTiming,this.ee)})),!0===(0,t.Mt)(this.agentIdentifier,"page_view_timing.long_task")&&(e=>{const t=t=>{t.forEach((t=>{const r={name:"LT",value:t.duration,info:{ltFrame:t.name,ltStart:t.startTime,ltCtr:t.attribution[0].containerType}};"window"!==r.info.ltCtr&&Object.assign(r.info,{ltCtrSrc:t.attribution[0].containerSrc,ltCtrId:t.attribution[0].containerId,ltCtrName:t.attribution[0].containerName}),e(r)}))};let r;try{PerformanceObserver.supportedEntryTypes.includes("longtask")&&(r=new PerformanceObserver((e=>{Promise.resolve().then((()=>{t(e.getEntries())}))})),r.observe({type:"longtask",buffered:!0}))}catch(e){}r&&(0,re.L)((()=>{t(r.takeRecords())}),!0)})((t=>{let{name:r,value:n,info:i}=t;(0,c.p)("timing",[r.toLowerCase(),n,i],void 0,e.D.pageViewTiming,this.ee)})),(0,C.N)((()=>{this.pageHiddenTime=(0,u.zO)(),(0,c.p)("docHidden",[this.pageHiddenTime],void 0,e.D.pageViewTiming,this.ee)}),!0),(0,N.bP)("pagehide",(()=>(0,c.p)("winPagehide",[(0,u.zO)()],void 0,e.D.pageViewTiming,this.ee))),this.importAggregator()}}perfObserver(t,r){t.getEntries().forEach((t=>{"first-paint"===t.name?(0,c.p)("timing",["fp",Math.floor(t.startTime)],void 0,e.D.pageViewTiming,this.ee):"first-contentful-paint"===t.name&&(0,c.p)("timing",["fcp",Math.floor(t.startTime)],void 0,e.D.pageViewTiming,this.ee)}))}lcpObserver(t,r){var n=t.getEntries();if(n.length>0){var i=n[n.length-1];if(this.pageHiddenTime<i.startTime)return;var o=[i],a=this.addConnectionAttributes({});a&&o.push(a),(0,c.p)("lcp",o,void 0,e.D.pageViewTiming,this.ee)}}clsObserver(t){t.getEntries().forEach((t=>{t.hadRecentInput||(0,c.p)("cls",[t],void 0,e.D.pageViewTiming,this.ee)}))}addConnectionAttributes(e){var t=navigator.connection||navigator.mozConnection||navigator.webkitConnection;if(t)return t.type&&(e["net-type"]=t.type),t.effectiveType&&(e["net-etype"]=t.effectiveType),t.rtt&&(e["net-rtt"]=t.rtt),t.downlink&&(e["net-dlink"]=t.downlink),e}captureInteraction(r){if(r instanceof t.Yu.EV&&!this.fiRecorded){var n=Math.round(r.timeStamp),i={type:r.type};this.addConnectionAttributes(i),n<=(0,u.zO)()?i.fid=(0,u.zO)()-n:n>(0,u.os)()&&n<=Date.now()?(n-=(0,u.os)(),i.fid=(0,u.zO)()-n):n=(0,u.zO)(),this.fiRecorded=!0,(0,c.p)("timing",["fi",n,i],void 0,e.D.pageViewTiming,this.ee)}}}!function(e,t,r){(t=function(e){var t=function(e,t){if("object"!=typeof e||null===e)return e;var r=e[Symbol.toPrimitive];if(void 0!==r){var n=r.call(e,t||"default");if("object"!=typeof n)return n;throw new TypeError("@@toPrimitive must return a primitive value.")}return("string"===t?String:Number)(e)}(e,"string");return"symbol"==typeof t?t:String(t)}(t))in e?Object.defineProperty(e,t,{value:r,enumerable:!0,configurable:!0,writable:!0}):e[t]=r}(ne,"featureName",R.t);const ie={dedicated:Boolean(p._A?.Worker),shared:Boolean(p._A?.SharedWorker),service:Boolean(p._A?.navigator?.serviceWorker)};let oe,ae,se;var ce=i(6034);class ue extends m{constructor(t,r){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(t,r,ce.t9,n),function(e){if(!oe){if(ie.dedicated){oe=Worker;try{p._A.Worker=r(oe,"Dedicated")}catch(e){o(e,"Dedicated")}if(ie.shared){ae=SharedWorker;try{p._A.SharedWorker=r(ae,"Shared")}catch(e){o(e,"Shared")}}else n("Shared");if(ie.service){se=navigator.serviceWorker.register;try{p._A.navigator.serviceWorker.register=(t=se,function(){for(var e=arguments.length,r=new Array(e),n=0;n<e;n++)r[n]=arguments[n];return i("Service",r[1]?.type),t.apply(navigator.serviceWorker,r)})}catch(e){o(e,"Service")}}else n("Service");var t;return}n("All")}function r(e,t){return"undefined"==typeof Proxy?e:new Proxy(e,{construct:(e,r)=>(i(t,r[1]?.type),new e(...r))})}function n(t){p.v6||e("Workers/".concat(t,"/Unavailable"))}function i(t,r){e("Workers/".concat(t,"module"===r?"/Module":"/Classic"))}function o(t,r){e("Workers/".concat(r,"/SM/Unsupported")),(0,h.Z)("NR Agent: Unable to capture ".concat(r," workers."),t)}}((t=>(0,c.p)(ce.xS,[t],void 0,e.D.metrics,this.ee))),this.importAggregator()}}!function(e,t,r){(t=function(e){var t=function(e,t){if("object"!=typeof e||null===e)return e;var r=e[Symbol.toPrimitive];if(void 0!==r){var n=r.call(e,t||"default");if("object"!=typeof n)return n;throw new TypeError("@@toPrimitive must return a primitive value.")}return("string"===t?String:Number)(e)}(e,"string");return"symbol"==typeof t?t:String(t)}(t))in e?Object.defineProperty(e,t,{value:r,enumerable:!0,configurable:!0,writable:!0}):e[t]=r}(ue,"featureName",ce.t9),new class{constructor(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:(0,S.ky)(16);this.agentIdentifier=t,this.sharedAggregator=new _({agentIdentifier:this.agentIdentifier}),this.features={},this.desiredFeatures=new Set(e.features||[]),this.desiredFeatures.add(E),Object.assign(this,(0,a.j)(this.agentIdentifier,e,e.loaderType||"agent")),this.start()}get config(){return{info:(0,t.C5)(this.agentIdentifier),init:(0,t.P_)(this.agentIdentifier),loader_config:(0,t.DL)(this.agentIdentifier),runtime:(0,t.OP)(this.agentIdentifier)}}start(){const t="features";try{const r=n(this.agentIdentifier),i=Array.from(this.desiredFeatures);i.sort(((t,r)=>e.p[t.featureName]-e.p[r.featureName])),i.forEach((t=>{if(r[t.featureName]||t.featureName===e.D.pageViewEvent){const e=(0,s.Z)(t.featureName),n=e.every((e=>r[e]));n||(0,h.Z)("".concat(t.featureName," is enabled but one or more dependent features has been disabled (").concat(JSON.stringify(e),"). This may cause unintended consequences or missing data...")),this.features[t.featureName]=new t(this.agentIdentifier,this.sharedAggregator)}})),(0,P.Qy)(this.agentIdentifier,this.features,t)}catch(e){(0,h.Z)("Failed to initialize all enabled instrument classes (agent aborted) -",e);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,P.fP)();return delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.[t],delete this.sharedAggregator,r.ee?.abort(),delete r.ee?.get(this.agentIdentifier),!1}}}({features:[E,ne,ue],loaderType:"lite"})})(),window.NRBA=o})();</script> <noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style> </noscript><script async src="https://web.archive.org/web/20230314214441js_/https://www.googletagmanager.com/gtag/js?id=UA-66610693-3"></script> <script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {cookie_flags: 'SameSite=None;Secure'});gtag("config", "UA-66610693-3", {"groups":"default","anonymize_ip":true,"page_placeholder":"PLACEHOLDER_page_path","link_attribution":true,"allow_ad_personalization_signals":false,"custom_map":{"dimension2":"node_title","dimension3":"node_id","dimension7":"content_type"}});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("config", "UA-33523145-1", {"groups":"default","anonymize_ip":true,"page_placeholder":"PLACEHOLDER_page_path","link_attribution":true,"allow_ad_personalization_signals":false,"custom_map":{"dimension2":"node_title","dimension3":"node_id","dimension7":"content_type"}});gtag("event", "custom", {"node_title":"Health","node_id":"1079336","content_type":"Topic Landing Page"});</script> <link rel="canonical" href="https://web.archive.org/web/20230314214441/https://www.nist.gov/health"/> <link rel="shortlink" href="https://web.archive.org/web/20230314214441/https://www.nist.gov/node/1079336"/> <meta name="description" content="NIST provides measurement assurance for biomedical stakeholders through the development of measurement tools for medical devices, clinical diagnostics, imaging tools and the characterization of biotherapeutics."/> <meta name="dcterms.title" content="Health"/> <meta name="dcterms.description" content="NIST provides measurement assurance for biomedical stakeholders through the development of measurement tools for medical devices, clinical diagnostics, imaging tools and the characterization of biotherapeutics."/> <meta name="dcterms.date" content="2016-06-30T13:50-04:00"/> <meta name="dcterms.type" content="text"/> <meta name="dcterms.format" content="text/html"/> <meta name="dcterms.identifier" content="https://www.nist.gov/health"/> <meta name="dcterms.source" content="NIST"/> <meta name="dcterms.created" content="2016-06-30T13:50-04:00"/> <meta name="dcterms.modified" content="2021-05-11T14:57-04:00"/> <meta name="citation_title" content="Health | NIST"/> <meta property="og:site_name" content="NIST"/> <meta property="og:type" content="Article"/> <meta property="og:url" content="https://web.archive.org/web/20230314214441/https://www.nist.gov/health"/> <meta property="og:title" content="Health"/> <meta property="og:description" content="NIST provides measurement assurance for biomedical stakeholders through the development of measurement tools for medical devices, clinical diagnostics, imaging tools and the characterization of biotherapeutics."/> <meta property="og:image" content="https://web.archive.org/web/20230314214441im_/https://www.nist.gov/sites/default/files/images/2018/10/18/healthy_human_t_cell_blog_image.jpg"/> <meta property="og:image:width" content="220"/> <meta property="og:image:height" content="220"/> <meta property="article:published_time" content="2016-06-30T13:50-04:00"/> <meta property="article:modified_time" content="2021-05-11T14:57-04:00"/> <meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA"/> <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:site" content="NIST"/> <meta name="twitter:description" content="NIST provides measurement assurance for biomedical stakeholders through the development of measurement tools for medical devices, clinical diagnostics, imaging tools and the characterization of biotherapeutics."/> <meta name="twitter:title" content="Health"/> <meta name="twitter:url" content="https://web.archive.org/web/20230314214441im_/https://www.nist.gov/health"/> <meta name="twitter:image:height" content="220"/> <meta name="twitter:image:width" content="220"/> <meta name="twitter:image" content="https://web.archive.org/web/20230314214441im_/https://www.nist.gov/sites/default/files/images/2018/10/18/healthy_human_t_cell_blog_image.jpg"/> <meta name="Generator" content="Drupal 9 (https://www.drupal.org)"/> <meta name="MobileOptimized" content="width"/> <meta name="HandheldFriendly" content="true"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <meta name="nist_search_modified" class="elastic" content="2021-05-11T14:57:00-04:00"/> <script type="application/ld+json">{ "@context": "https://web.archive.org/web/20230314214441/https://schema.org", "@graph": [ { "@type": "Article", "headline": "Health | NIST", "description": "NIST provides measurement assurance for biomedical stakeholders through the development of measurement tools for medical devices, clinical diagnostics, imaging tools and the characterization of biotherapeutics.", "image": { "@type": "ImageObject", "representativeOfPage": "True", "url": "https://web.archive.org/web/20230314214441/https://www.nist.gov/sites/default/files/images/2018/10/18/healthy_human_t_cell_blog_image.jpg", "width": "220", "height": "220" }, "datePublished": "2016-06-30T13:50-04:00", "dateModified": "2021-05-11T14:57-04:00" } ] }</script> <meta name="nist_search_bundle" class="elastic" content="topic_landing_page"/> <link rel="icon" href="/web/20230314214441im_/https://www.nist.gov/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon"/> <title>Health | NIST</title> <link rel="stylesheet" media="all" href="/web/20230314214441cs_/https://www.nist.gov/sites/default/files/css/css_F2gAVVlSdR3arDUpXp31o79SNgjcEodwd2bnXsnktzU.css"/> <link rel="stylesheet" media="screen" href="/web/20230314214441cs_/https://www.nist.gov/sites/default/files/css/css_gD8QmGaNfUQuThtjB-S0EwEOZZNJP1QfUU1bDdLHbMU.css"/> <link rel="stylesheet" media="print" href="/web/20230314214441cs_/https://www.nist.gov/sites/default/files/css/css_zbjDhj-AmeVwgu9y0DlPwEfp7l-a5BpoK3MpoGmRB6o.css"/> <link rel="stylesheet" media="all" href="/web/20230314214441cs_/https://www.nist.gov/sites/default/files/css/css_PV0KmreUx3hVeYI6yGypf71UDz9BSQl1Z5DjiESDh-Y.css"/> <link rel="stylesheet" media="screen" href="/web/20230314214441cs_/https://www.nist.gov/sites/default/files/css/css_dXhP8gFSR5hd16LUS1TrwJ15l9WTOxqff1l1a5ojF4o.css"/> <script src="/web/20230314214441js_/https://www.nist.gov/sites/default/files/js/js_VDwaIMNiRtzQn-NZvj1F9loIzJ-i4yEDiruzS8Z6Ejo.js"></script> </head> <body class="node-1079336"> <a href="#main-content" class="visually-hidden focusable" data-elastic-exclude> Skip to main content </a> <div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>  <section data-elastic-exclude class="usa-banner" aria-label="Official government website"> <div class="usa-accordion"> <header class="usa-banner__header"> <div class="usa-banner__inner"> <div class="grid-col-auto"> <img class="usa-banner__header-flag" src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag"> </div> <div class="grid-col-fill tablet:grid-col-auto"> <p class="usa-banner__header-text">An official website of the United States government</p> <p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p> </div> <button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default"> <span class="usa-banner__button-text">Here’s how you know</span> </button> </div> </header> <div class="usa-banner__content usa-accordion__content" id="gov-banner-default"> <div class="grid-row grid-gap-lg"> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Official websites use .gov</strong> <br/> A <strong>.gov</strong> website belongs to an official government organization in the United States. </p> </div> </div> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Secure .gov websites use HTTPS</strong> <br/> A <strong>lock</strong> ( <span class="icon-lock"> <svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false"> <title id="banner-lock-title">Lock</title> <desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg> </span> ) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. </p> </div> </div> </div> </div> </div> </section>  <div data-elastic-exclude>  <div class="nist-print-header" style="display:none;"> <p class="nist-print-header__url">https://www.nist.gov/health</p> <img class="nist-print-header__logo" width="289" height="38" src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology"/> </div> <div class="usa-overlay"></div> <header class="usa-header nist-header--www nist-header--minimal" role="banner"> <div class="usa-navbar"> <div class="usa-logo flex-fill"> <a href="/web/20230314214441/https://www.nist.gov/" title="National Institute of Standards and Technology" aria-label="Home"> <img src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px"/> </a> </div> <div class="usa-header__right grid-row flex-auto"> <div class="grid-col-fill nist-header__search-group"> <form class="usa-search usa-search--small" accept-charset="UTF-8" action="/web/20230314214441/https://www.nist.gov/search" id="search_form" method="get"> <div role="search"> <label class="usa-sr-only" for="search-form">Search NIST</label> <input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128"> <button class="usa-button" type="submit"><img src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button> </div> </form> </div> <div class="grid-col-auto padding-left-1"> <button class="usa-menu-btn">Menu</button> </div> </div> </div> <nav aria-label="Primary navigation" class="usa-nav"> <div class="usa-nav__inner"> <button class="usa-nav__close">Close</button> <ul class="usa-nav__primary usa-accordion"> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link usa-current" aria-expanded="false" aria-controls="primary_menu-1"><span>Topics</span></button> <div id="primary_menu-1" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/topics" class="usa-nav__link">All Topics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/advanced-communications" class="usa-nav__link">Advanced communications</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/bioscience" class="usa-nav__link">Bioscience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/buildings-construction" class="usa-nav__link">Buildings and construction</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/chemistry" class="usa-nav__link">Chemistry</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/climate" class="usa-nav__link">Climate</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/cybersecurity" class="usa-nav__link">Cybersecurity</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/electronics" class="usa-nav__link">Electronics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/energy" class="usa-nav__link">Energy</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/environment" class="usa-nav__link">Environment</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/fire" class="usa-nav__link">Fire</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/forensic-science" class="usa-nav__link">Forensic science</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/health" class="usa-nav__link usa-current">Health</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/information-technology" class="usa-nav__link">Information technology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/infrastructure" class="usa-nav__link">Infrastructure</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/manufacturing" class="usa-nav__link">Manufacturing</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/materials" class="usa-nav__link">Materials</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/metrology" class="usa-nav__link">Metrology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/nanotechnology" class="usa-nav__link">Nanotechnology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/neutron-research" class="usa-nav__link">Neutron research</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/performance-excellence" class="usa-nav__link">Performance excellence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/physics" class="usa-nav__link">Physics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/public-safety" class="usa-nav__link">Public safety</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/resilience" class="usa-nav__link">Resilience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/standards" class="usa-nav__link">Standards</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/transportation" class="usa-nav__link">Transportation</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <a class="usa-nav__link" href="/web/20230314214441/https://www.nist.gov/publications">Publications</a> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs & Major Programs</span></button> <div id="primary_menu-3" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/labs-major-programs/laboratories" class="usa-nav__link">Laboratories</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20230314214441/https://www.nist.gov/ctl" class="usa-nav__link">Communications Technology Laboratory</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/el" class="usa-nav__link">Engineering Laboratory</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/itl" class="usa-nav__link">Information Technology Laboratory</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/mml" class="usa-nav__link">Material Measurement Laboratory</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/pml" class="usa-nav__link">Physical Measurement Laboratory</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/labs-major-programs/user-facilities" class="usa-nav__link">User Facilities</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20230314214441/https://www.nist.gov/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/cnst" class="usa-nav__link">CNST NanoFab</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/laboratories/projects-programs" class="usa-nav__link">Research Projects</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/laboratories/tools-instruments" class="usa-nav__link">Tools & Instruments</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/labs-major-programs/major-programs" class="usa-nav__link">Major Programs</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20230314214441/https://www.nist.gov/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/chips" class="usa-nav__link">CHIPS for America Initiative</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/oam" class="usa-nav__link">Office of Advanced Manufacturing</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/spo" class="usa-nav__link">Special Programs Office</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/tpo" class="usa-nav__link">Technology Partnerships Office</a> </li> </ul> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services & Resources</span></button> <div id="primary_menu-4" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/services-resources/standards-and-measurements" class="usa-nav__link">Standards and Measurements</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20230314214441/https://www.nist.gov/calibrations" class="usa-nav__link">Calibration Services</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/nist-quality-system" class="usa-nav__link">Quality System</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/standardsgov" class="usa-nav__link">Standards.gov</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/pml/owm" class="usa-nav__link">Office of Weights and Measures</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/services-resources/software" class="usa-nav__link">Software</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/data" class="usa-nav__link">Data</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20230314214441/https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a> </li> <li> <a href="https://web.archive.org/web/20230314214441/https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/srd" class="usa-nav__link">Standard Reference Data (SRD)</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/shop" class="usa-nav__link">Storefront</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/tpo" class="usa-nav__link">License & Patents</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20230314214441/https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/nist-research-library" class="usa-nav__link">NIST Research Library</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News & Events</span></button> <div id="primary_menu-5" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news" class="usa-nav__link">News</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/news-events/events" class="usa-nav__link">Events</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/blogs" class="usa-nav__link">Blogs</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/feature-stories" class="usa-nav__link">Feature Stories</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/awards" class="usa-nav__link">Awards</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/video-gallery" class="usa-nav__link">Video Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/image-gallery" class="usa-nav__link">Image Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/director/pao/media-contacts" class="usa-nav__link">Media Contacts</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button> <div id="primary_menu-6" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/about-nist" class="usa-nav__link">About Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/about-nist/contact-us" class="usa-nav__link">Contact Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/about-nist/visit" class="usa-nav__link">Visit</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/careers" class="usa-nav__link">Careers</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/director/nist-organization-structure" class="usa-nav__link">Our Organization</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20230314214441/https://www.nist.gov/director" class="usa-nav__link">Office of the Director</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/director/nist-organization-structure/budget-planning" class="usa-nav__link">Budget & Planning</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/about-nist/work-nist" class="usa-nav__link">Work with NIST</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/history" class="usa-nav__link">History</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20230314214441/http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/nist-museum" class="usa-nav__link">NIST Museum</a> </li> <li> <a href="/web/20230314214441/https://www.nist.gov/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20230314214441/https://www.nist.gov/education" class="usa-nav__link">Educational Resources</a> </li> </ul> </div> </div> </div> </li> </ul> </div> </nav> </header>  </div> <div class="grid-container"> <div data-drupal-messages-fallback class="hidden"></div> </div> <div id="block-nist-www-content" class="nist-block"> <section class="nist-page__content usa-section clearfix"> <a id="main-content" tabindex="-1"></a> <div> <div class="nist-section-header nist-section-header--topic nist-section-header--hero"> <div class="nist-section-header__hero-img"> <div class="nist-block nist-block--no-margin"> <div class="entity-reference"> <img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/images/2021/03/08/Health_1200x248.jpg" width="1200" height="248" alt="Black background. Up close bright blue orb" loading="lazy" typeof="foaf:Image"/> </div> </div> </div> <div class="nist-section-header__main grid-container"> <div class="grid-row"> <div class="nist-section-header__title"> <h1 class="nist-page__title">Health</h1> </div> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-page__region nist-page__region--topic-description padding-top-4 margin-top-1"> <div class="nist-region-heading"> <h2>Overview</h2> </div> <div class="grid-row"> <div class="tablet:grid-col-8 padding-right-5 margin-bottom-4"> <div class="text-with-summary"> <p>NIST provides measurement assurance for biomedical stakeholders through the development of measurement tools for medical devices, clinical diagnostics, imaging tools and the characterization of complex biotherapeutics.</p> </div> </div> <div class="tablet:grid-col-4"> </div> </div> </div> </div> <div class="bg-base-lightest padding-y-5 margin-y-4"> <div class="nist-page__region nist-page__region--topic-list grid-container"> <div class="views-element-container nist-block margin-bottom-0"> <div><div class="js-view-dom-id-445fa9470c359bb5e7b4d6cf416213ef0a808fc066790b045d4119ccef6b106d"> <div class="nist-block margin-bottom-0"> <div class="nist-region-heading"> <h2>Health Topics</h2> </div> <ul class="add-list-reset link-list"> <div class="grid-row"> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/pharmaceuticals" hreflang="en">Pharmaceuticals</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/clinical-diagnostics" hreflang="en">Clinical diagnostics</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/dentistry" hreflang="en">Dentistry</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/food-nutrition" hreflang="en">Food & nutrition</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/medical-imaging" hreflang="en">Medical imaging</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/precision-medicine" hreflang="en">Precision medicine</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20230314214441/https://www.nist.gov/regenerative-medicine" hreflang="en">Regenerative medicine</a></div></div></li> </div> </div> </ul> </div> </div> </div> </div> </div> </div> <div class="nist-page__region nist-page__region--main"> <div class="nist-block"> <div class="grid-container margin-y-5"> <div class="paragraph paragraph--type--topic-text paragraph--view-mode--default"> <div class="nist-region-heading"> <h2> Key Accomplishments </h2> </div> <div class="tablet-lg:grid-col-8 padding-right-5"> <div class="text-long"><ul><li><strong>Face coverings:</strong> In an effort to improve the fabric masks that people wear to slow the spread of COVID-19, <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="40e44538-1db5-48c1-9ba3-ba3817c1d6f6" href="/web/20230314214441/https://www.nist.gov/feature-stories/masks-under-microscope" title="Masks Under the Microscope">NIST scientists have measured</a> how well various fabrics filter out aerosols that might contain the virus. This research contributed to standards for fabric face masks that will give people information on how well their masks work.</li> <li><strong>Biopharmaceuticals: </strong>The <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="f208228f-a2bc-4692-8b6e-183b133ceac3" href="/web/20230314214441/https://www.nist.gov/news-events/news/2016/07/extraordinary-standard-new-nist-protein-could-spur-biopharmaceutical" title="An Extraordinary Standard: New NIST Protein Could Spur Biopharmaceutical Innovation">NIST Monoclonal Antibody reference material</a> is an intensively analyzed protein of over 20,000 atoms that researchers and manufacturers use when developing vaccines and treatments for cancer and other diseases. Also called the NISTmAb, this material promotes innovation in the biopharmaceutical industry and helps ensure the quality and safety of our drug supply.</li> <li><strong>Nutrition labeling:</strong> To help ensure the accuracy of nutrition labels, NIST manufactures over 30 <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="7663e40c-c210-4ff8-8b7f-15c506924517" href="/web/20230314214441/https://www.nist.gov/programs-projects/measurements-and-standards-support-nutrition-labeling" title="Measurements and Standards to Support Nutrition Labeling">food-based reference materials</a>, including infant formula, baking chocolate, spinach and food oils. Labs use these reference materials to calibrate their instruments for measuring the carbohydrates, proteins, calories and other values listed on nutrition labels.</li> <li><strong>MRI calibration:</strong> The <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="fa7fd4b5-1a08-4d69-9f10-ce8ea6d7874f" href="/web/20230314214441/https://www.nist.gov/physics/what-are-imaging-phantoms" title="What Are Imaging Phantoms?">NIST phantom</a> helps ensure that magnetic resonance imaging (MRI) machines produce accurate results. Also called the “phannie,” this plastic sphere is about the size of a person’s head and contains contrast-enhancing agents and other materials that aid in calibrating MRI instruments.</li> </ul></div> </div> </div> </div> <div class="grid-container margin-y-5"> <div class="paragraph paragraph--type--topic-research paragraph--view-mode--default"> <div class="nist-region-heading"> <h2>The Research</h2> </div> <div class="grid-row"> <div class="tablet:grid-col-8 padding-right-5 margin-y-2"> <h2 class="nist-block__title">Projects & Programs</h2> <article role="article" about="/programs-projects/genome-bottle" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20230314214441/https://www.nist.gov/programs-projects/genome-bottle" hreflang="en"><img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2019/05/15/giab_logo_color.png?itok=KdsryiNW" width="72" height="100" alt="GIAB Logo" loading="lazy" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20230314214441/https://www.nist.gov/programs-projects/genome-bottle"><span>Genome in a Bottle</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> Consortium hosted by NIST dedicated to authoritative characterization of benchmark human genomes. Sign up for General GIAB and Analysis Team email lists. Public </div> </div> </div> </article> <article role="article" about="/programs-projects/and-polyfluoroalkyl-substances-pfas" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20230314214441/https://www.nist.gov/programs-projects/and-polyfluoroalkyl-substances-pfas" hreflang="en"><img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2022/09/12/water_glass.png?itok=-yqisx6J" width="100" height="71" alt="Water" loading="lazy" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20230314214441/https://www.nist.gov/programs-projects/and-polyfluoroalkyl-substances-pfas"><span>Per- and Polyfluoroalkyl Substances (PFAS)</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> NIST works to improve confidence in measurements and conducts research on PFAS for better human health and the environment. </div> </div> </div> </article> <article role="article" about="/programs-projects/cell-based-assay-mechanistically-based-prediction-cytoxicity" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20230314214441/https://www.nist.gov/programs-projects/cell-based-assay-mechanistically-based-prediction-cytoxicity" hreflang="en"><img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2018/07/10/ricin_assay3_1.jpg?itok=wt9BiPje" width="88" height="100" loading="lazy" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20230314214441/https://www.nist.gov/programs-projects/cell-based-assay-mechanistically-based-prediction-cytoxicity"><span>Cell-based Assay for Mechanistically-based Prediction of Cytoxicity</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> The most commonly used cell-based assays for measuring cytotoxicity often show poor reproducibility, require 24 h to complete, and rely on a nonspecific </div> </div> </div> </article> <article role="article" about="/programs-projects/consistency-analysis-and-uncertainty-omic-data" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20230314214441/https://www.nist.gov/programs-projects/consistency-analysis-and-uncertainty-omic-data" hreflang="en"><img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2020/08/14/Component%20One.png?itok=8HpbY2BE" width="100" height="29" alt="component 1" loading="lazy" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20230314214441/https://www.nist.gov/programs-projects/consistency-analysis-and-uncertainty-omic-data"><span>Consistency Analysis and Uncertainty in ‘omic Data</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> As ‘omics moves into industrial and commercial applications, there is a need for quality and process control to ensure safety and efficacy of products and </div> </div> </div> </article> <div class="link-list"><a href="/web/20230314214441/https://www.nist.gov/laboratories/projects-programs/topic/248651">View All Projects/Programs</a></div> </div> <div class="tablet:grid-col-4 margin-y-2"> <h2 class="nist-block__title">Additional Resources Links</h2> <div class="nist-field nist-field--label-hidden nist-field--link-list link nist-field--link-list font-sans-sm"> <div class="nist-field__items"> <div class="nist-field__item"><a href="/web/20230314214441/https://www.nist.gov/publications/search?k=&d%5Bmin%5D=&d%5Bmax%5D=&t=&a=&s=All&ta%5B0%5D=248651&ta%5B1%5D=248651&n=">Publications</a></div> </div> </div> </div> </div> </div> </div> <div class="grid-container margin-y-4"> <div class="nist-region-heading"> <h2>News</h2> </div> <div class="margin-bottom-5"> <div class="entity-reference"> <div class="nist-card nist-card--horizontal nist-card--horizontal-full"> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20230314214441/https://www.nist.gov/blogs/taking-measure/developing-exposure-notification-system-blunt-spread-covid-19-and-future"> <div class="entity-reference"> <img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2020/11/09/covid-tech.png?itok=omWbYpTI" width="600" height="360" alt="a man and a woman walking toward one another with exposure notification system bracelets on. "Waves" coming off the bracelets show that they are coming too close to one another. " loading="lazy" typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title"> <h3><span>Developing an Exposure Notification System to Blunt the Spread of COVID-19 and Future Pandemics</span> </h3> </div> <div class="nist-card__content"> <div class="text-with-summary">I am part of a grassroots effort at the National Institute of Standards and Technology (NIST) that is developing an exposure notification system for pandemics in general, though we hope it could be used in at least a limited fashion during the current COVID-19 pandemic. We are fortunate at NIST to have all the expertise required to tackle this multidisciplinary problem, solutions to which have the</div> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20230314214441/https://www.nist.gov/blogs/taking-measure/developing-exposure-notification-system-blunt-spread-covid-19-and-future" class="usa-button ">Read more</a> </div> </div> </div> </div> </div> </div> <div class="paragraph paragraph--type--dynamic-news-list-topic paragraph--view-mode--default"> <div class="views-element-container"><div class="js-view-dom-id-ebbb216c45261b64c7d0368201a856fa59492e33e2a043e23033d29f4a26d283"> <div class="grid-row grid-gap-2"> <div class="nist-card tablet:grid-col-4 nist-card--topic "> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news/2023/01/back-popular-demand-new-showcase-nist-innovative-technologies-coming-soon"> <div class="entity-reference"> <img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2023/01/23/NIST%20Showcase%20Banner_2023%20copy.png?itok=6TB-D-wS" width="800" height="400" alt="NIST INNOVATIVE TECHOLOGIES SHOWCASE 2" loading="lazy" typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title padding-y-5"> <h3><span property="schema:name">BACK BY POPULAR DEMAND, A NEW SHOWCASE OF NIST INNOVATIVE TECHNOLOGIES IS COMING SOON</span> </h3> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news/2023/01/back-popular-demand-new-showcase-nist-innovative-technologies-coming-soon" class="usa-button ">Read more</a> </div> </div> </div> </div> <div class="nist-card tablet:grid-col-4 nist-card--topic "> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news/2023/01/new-dna-biosensor-could-unlock-powerful-low-cost-clinical-diagnostics"> <div class="entity-reference"> <img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2023/01/24/DNA-biosensor-draft.png?itok=ZpO2QDAF" width="800" height="400" alt="A graphical representation of a DNA biosensor device for clinical diagnostics that is the size and shape of a smartphone." loading="lazy" typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title padding-y-5"> <h3><span property="schema:name">New DNA Biosensor Could Unlock Powerful, Low-Cost Clinical Diagnostics</span> </h3> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news/2023/01/new-dna-biosensor-could-unlock-powerful-low-cost-clinical-diagnostics" class="usa-button ">Read more</a> </div> </div> </div> </div> <div class="nist-card tablet:grid-col-4 nist-card--topic "> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news/2023/01/nist-partners-develop-living-reference-material-producing-monoclonal"> <div class="entity-reference"> <img src="/web/20230314214441im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2022/08/09/NISTCHO_RCB.jpeg?itok=yU-l9e9R" width="800" height="400" alt="A gloved hand holds a glass flask partly full of pinkish liquid, with a label in marker saying in part "NISTCHO RCB."" loading="lazy" typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title padding-y-5"> <h3><span property="schema:name">NIST, Partners Develop Living Reference Material for Producing Monoclonal Antibodies</span> </h3> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20230314214441/https://www.nist.gov/news-events/news/2023/01/nist-partners-develop-living-reference-material-producing-monoclonal" class="usa-button ">Read more</a> </div> </div> </div> </div> </div> <footer> <div class="link-list"><a href="/web/20230314214441/https://www.nist.gov/news-events/news-updates/topic/248651">View All News and Updates</a></div> </footer> </div> </div> </div> </div> <div class="padding-5 bg-primary-dark"> <h2 class="text-white text-center">Stay in Touch</h2> <p class="text-white text-center">Sign up for our newsletter to stay up to date with the latest research, trends, and news for Health.</p> <form action="https://web.archive.org/web/20230314214441/https://public.govdelivery.com/accounts/USNIST/subscribers/qualify" accept-charset="UTF-8" method="post"> <input name="utf8" type="hidden" value="✓"/> <input type="hidden" name="topic_id" id="topic_id" value="USNIST_5"/> <div class="grid-row grid-gap-1 flex flex-justify-center"> <div class="tablet:grid-col-3"> <label class="usa-sr-only" for="email">Enter Email Address</label> <input class="usa-input" type="email" name="email" id="email" placeholder="Enter your email"> </div> <div class="grid-row flex-wrap margin-top-1"> <input type="submit" name="commit" value="Sign Up" class="usa-button usa-button--outline usa-button--inverse"> </div> </div> </form> </div> <div class="grid-container margin-y-4"> </div> </div> </div> </section> </div> <div data-elastic-exclude>  <footer class="nist-footer padding-bottom-4"> <div class="grid-container nist-footer__info"> <div class="grid-row"> <div class="tablet:grid-col-6"> <div class="nist-footer__logo"> <a href="/web/20230314214441/https://www.nist.gov/" title="National Institute of Standards and Technology" rel="home"> <img class="nist-footer__logo-img" src="/web/20230314214441im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px"/> </a> </div> <div class="nist-footer__contact"> <h3 class="nist-footer__contact-heading">HEADQUARTERS</h3> <address> 100 Bureau Drive<br> Gaithersburg, MD 20899<br> <a href="https://web.archive.org/web/20230314214441/tel:301-975-2000">301-975-2000</a> </address> <p> <a href="https://web.archive.org/web/20230314214441/mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/visit">Our Other Offices</a> </p> </div> </div> <div class="tablet:grid-col-6"> <div class="nist-footer__social-links"> <a class="nist-social nist-social--twitter-white" href="https://web.archive.org/web/20230314214441/https://twitter.com/NIST"> <span>Twitter</span> </a> <a class="nist-social nist-social--facebook-white" href="https://web.archive.org/web/20230314214441/https://www.facebook.com/NIST"> <span>Facebook</span> </a> <a class="nist-social nist-social--linkedin-white" href="https://web.archive.org/web/20230314214441/https://www.linkedin.com/company/nist"> <span>LinkedIn</span> </a> <a class="nist-social nist-social--instagram-white" href="https://web.archive.org/web/20230314214441/https://www.instagram.com/nist/"> <span>Instagram</span> </a> <a class="nist-social nist-social--youtube-white" href="https://web.archive.org/web/20230314214441/https://www.youtube.com/NIST"> <span>YouTube</span> </a> <a class="nist-social nist-social--giphy-white" href="https://web.archive.org/web/20230314214441/https://giphy.com/nist"> <span>Giphy</span> </a> <a class="nist-social nist-social--rss-white" href="https://web.archive.org/web/20230314214441/https://www.nist.gov/news-events/nist-rss-feeds"> <span>RSS Feed</span> </a> <a class="nist-social nist-social--envelope-white" href="https://web.archive.org/web/20230314214441/https://public.govdelivery.com/accounts/USNIST/subscriber/new"> <span>Mailing List</span> </a> </div> <div class="nist-footer__feedback"> How are we doing? <a class="usa-button" rel="nofollow" href="/web/20230314214441/https://www.nist.gov/form/nist-gov-feedback?destination=/health" title="Provide feedback">Feedback</a> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-footer__nav" role="navigation"> <ul> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/privacy-policy">Site Privacy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/oism/accessibility">Accessibility</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/privacy">Privacy Program</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/oism/copyrights">Copyrights</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/office-director/freedom-information-act">FOIA</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/environmental-policy-statement">Environmental Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://www.commerce.gov/">Commerce.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/http://www.science.gov/">Science.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/http://www.usa.gov/">USA.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20230314214441/https://vote.gov/">Vote.gov</a> </li> </ul> </div> </div> </footer>  </div> </div> <script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","scriptPath":null,"pathPrefix":"","currentPath":"node\/1079336","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"UA-66610693-3","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip","trackDomainMode":1},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":"","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"append","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"user":{"uid":0,"permissionsHash":"582eea317b4636ab5a0dffc8c6a006df3d6901ea5610498a0bbefc925ea1da0f"}}</script> <script src="/web/20230314214441js_/https://www.nist.gov/sites/default/files/js/js_DNL6VrEuHPrL959oUExCzGY3A7BXQIMYib7aZLaICi4.js"></script> <script src="https://web.archive.org/web/20230314214441js_/https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script> <script src="/web/20230314214441js_/https://www.nist.gov/sites/default/files/js/js_c0hecns0CAftnzmCOwBYLxRa48pqi1xWMZwQH4JQ1gU.js"></script> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"gov-bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFkVVVABoWlcAUQQ=","queueTime":0,"applicationTime":98,"atts":"TBtXQQMaH0k=","errorBeacon":"gov-bam.nr-data.net","agent":""}</script></body> </html>

CINXE.COM

Health | NIST