Medplum

// SPDX-FileCopyrightText: Copyright Orangebot, Inc. and Medplum contributors // SPDX-License-Identifier: Apache-2.0 import { LOINC, UCUM, createReference } from '@medplum/core'; import type { CodeableConcept, Encounter, Observation, ObservationComponent, Patient, Quantity, } from '@medplum/fhirtypes'; /** * Tries to get the observation quantity value. * @param obs - The observation to check. * @param component - Optional sub-component code to check. * @returns The observation quantity value, if available. Otherwise, undefined. */ export function getObservationValue(obs: Observation, component?: string): Quantity | undefined { if (component) { return obs.component?.find((c) => c.code?.coding?.[0].code === component)?.valueQuantity; } return obs.valueQuantity; } export function createObservation( patient: Patient, encounter: Encounter | undefined, code: string, title: string, valueQuantity: Quantity ): Observation | undefined { if (!isValidNumber(valueQuantity.value)) { return undefined; } return { ...createBaseObservation(patient, encounter, code, title), valueQuantity, }; } export function createCompoundObservation( patient: Patient, encounter: Encounter | undefined, code: string, title: string, components: ObservationComponent[] ): Observation | undefined { const component = components.filter((c) => isValidNumber(c.valueQuantity?.value)); if (component.length === 0) { return undefined; } return { ...createBaseObservation(patient, encounter, code, title), component, }; } export function createBaseObservation( patient: Patient, encounter: Encounter | undefined, code: string, title: string ): Observation { return { resourceType: 'Observation', status: 'preliminary', subject: createReference(patient), encounter: encounter ? createReference(encounter) : undefined, effectiveDateTime: new Date().toISOString(), category: [ { coding: [ { system: 'http://terminology.hl7.org/CodeSystem/observation-category', code: 'vital-signs', display: 'Vital Signs', }, ], }, ], code: createLoincCode(code, title), }; } export function createLoincCode(code: string, display: string): CodeableConcept { return { coding: [ { code, display, system: LOINC, }, ], text: display, }; } export function createQuantity(value: number, unit: string): Quantity { return { value, system: UCUM, unit, code: unit, }; } function isValidNumber(value: number | undefined): boolean { return value !== undefined && !Number.isNaN(value) && Number.isFinite(value); }