IWangLang: Observation Visual Acuity

🚀 Quick Start

Install:

# npm
npm i @iwanglang/observation-visual-acuity

# yarn
yarn add @iwanglang/observation-visual-acuity

Import:

// ESM / Typescript
import { ObservationVisualAcuity } from "@iwanglang/observation-visual-acuity";

// CommonJS
const {
  ObservationVisualAcuity,
} = require("@iwanglang/observation-visual-acuity");

🥸 Get Snellen Scale for create Chart

import { ObservationVisualAcuity } from "@iwanglang/observation-visual-acuity";

const visualAcuity = new ObservationVisualAcuity();
const snellenChartScaleFoot = visualAcuity.getSnellenChartScales("foot");
const snellenChartScaleMetre = visualAcuity.getSnellenChartScales("metre");

console.log(snellenChartScaleFoot[0]);
// { "display": "20/200", "numerator": 20, "denominator": 200, "LogMAR": 1.00 }

console.log(snellenChartScaleMetre[0]);
// { "display": "6/60", "numerator": 6, "denominator": 60, "LogMAR": 1.00 }

use getSnellenChartScales function to get list of snellen scales for prepare data of Visual Acuity that will save into server

Example for Snellen Chart

| Foot | Metre | LogMAR | | :-----: | :---: | :----: | | 20/200 | 6/60 | 1.00 | | 20/160 | 6/48 | 0.90 | | 20/125 | 6/38 | 0.80 | | 20/100 | 6/30 | 0.70 | | 20/80 | 6/24 | 0.60 | | 20/63 | 6/18 | 0.50 | | 20/50 | 6/15 | 0.40 | | 20/40 | 6/12 | 0.30 | | 20/32 | 6/9.5 | 0.20 | | 20/25 | 6/7.5 | 0.10 | | 20/20 | 6/6 | 0.00 | | 20/16 | 6/4.8 | −0.10 | | 20/12.5 | 6/3.8 | −0.20 | | 20/10 | 6/3 | −0.30 |

🥸 Convert Snellen to LogMAR

import { ObservationVisualAcuity } from "@iwanglang/observation-visual-acuity";

const visualAcuity = new ObservationVisualAcuity();
const snellenChartScaleMetre = visualAcuity.getSnellenChartScales("metre");

console.log(snellenChartScaleMetre[0]);
// { "display": "6/60", "numerator": 6, "denominator": 60, "LogMAR": 1.00 }

// LogMAR VA = 0.1 + LogMAR value of the best line read – 0.02 X (number of optotypes read)
// default optotypesRead is -2
console.log(`LogMAR is ${visualAcuity.convertSnellenToLogMAR(snellenChartScaleMetre[0].numerator, snellenChartScaleMetre[0].denominator)}`);
// LogMAR is 1

🥸 Create Visual Acuity to Fhir Server

import { ObservationVisualAcuity, SnomedCodeBodySite } from "@iwanglang/observation-visual-acuity";

const visualAcuity = new ObservationVisualAcuity('https://hapi.fhir.org/baseR4');

// Set Authorization for Fhir Server that require authentication
visualAcuity.setToken('Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c');

// Create VisualAcuity value 0.60 LogMAR with bodySite left eye structure to Fhir Server
visualAcuity.createLogMARVisualAcuity('Patient/1', SnomedCodeBodySite.LeftEyeStructure, 0.60);