<?xml version="1.0" encoding="utf-8"?>
<!--XBRL document created with Toppan Merrill Bridge  10.9.0.3 -->
<!--Based on XBRL 2.1-->
<!--Created on: 3/21/2025 11:11:22 PM-->
<!--Modified on: 3/21/2025 11:11:22 PM-->
<xsd:schema targetNamespace="http://www.heliusmedical.com/20241231" attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:deprecated="http://www.xbrl.org/2009/role/deprecated" xmlns:us-roles="http://fasb.org/us-roles/2024" xmlns:currency="http://xbrl.sec.gov/currency/2024" xmlns:ref="http://www.xbrl.org/2006/ref" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xl="http://www.xbrl.org/2003/XLink" xmlns:us-types="http://fasb.org/us-types/2024" xmlns:srt-roles="http://fasb.org/srt-roles/2024" xmlns:utr="http://www.xbrl.org/2009/utr" xmlns:us-gaap="http://fasb.org/us-gaap/2024" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:sic="http://xbrl.sec.gov/sic/2024" xmlns:stpr="http://xbrl.sec.gov/stpr/2024" xmlns:srt-types="http://fasb.org/srt-types/2024" xmlns:enum2="http://xbrl.org/2020/extensible-enumerations-2.0" xmlns:country="http://xbrl.sec.gov/country/2024" xmlns:net="http://www.xbrl.org/2009/role/net" xmlns:naics="http://xbrl.sec.gov/naics/2024" xmlns:dei="http://xbrl.sec.gov/dei/2024" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31" xmlns:negated="http://www.xbrl.org/2009/role/negated" xmlns:exch="http://xbrl.sec.gov/exch/2024" xmlns:attributeFormDefault="unqualified" xmlns:srt="http://fasb.org/srt/2024" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:hsdt="http://www.heliusmedical.com/20241231" xmlns:dtr="http://www.xbrl.org/2009/dtr" xmlns:xbrldi="http://xbrl.org/2006/xbrldi" xmlns:us-gaap-ebp="http://fasb.org/us-gaap-ebp/2024" xmlns:cyd-af-sub="http://xbrl.sec.gov/cyd-af-sub/2024" xmlns:ecd="http://xbrl.sec.gov/ecd/2024" xmlns:ecd-sub="http://xbrl.sec.gov/ecd-sub/2024" xmlns:cyd="http://xbrl.sec.gov/cyd/2024">
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/StatementConsolidatedBalanceSheets" id="StatementConsolidatedBalanceSheets">
        <link:definition>995200100 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss" id="StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss">
        <link:definition>995200200 - Statement - Consolidated Statements of Operations and Comprehensive Loss</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" id="StatementConsolidatedStatementsOfCashFlows">
        <link:definition>995200400 - Statement - Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresInventoryNetDetails" id="DisclosureSupplementalBalanceSheetDisclosuresInventoryNetDetails">
        <link:definition>99940402 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES - Inventory, net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresPrepaidExpensesAndOtherCurrentAssetsDetails" id="DisclosureSupplementalBalanceSheetDisclosuresPrepaidExpensesAndOtherCurrentAssetsDetails">
        <link:definition>99940403 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES - Prepaid expenses and other current assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresPropertyAndEquipmentNetDetails" id="DisclosureSupplementalBalanceSheetDisclosuresPropertyAndEquipmentNetDetails">
        <link:definition>99940404 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES - Property and equipment, net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresAccruedAndOtherCurrentLiabilitiesDetails" id="DisclosureSupplementalBalanceSheetDisclosuresAccruedAndOtherCurrentLiabilitiesDetails">
        <link:definition>99940405 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES - Accrued and other current liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureLeasesDetails" id="DisclosureLeasesDetails">
        <link:definition>99940501 - Disclosure - LEASES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureLeasesDetailsCal2" id="DisclosureLeasesDetailsCal2">
        <link:definition>40501 - Disclosure - LEASES (Details) - Cal 2</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIntangibleAssetsSummaryDetails" id="DisclosureIntangibleAssetsSummaryDetails">
        <link:definition>99940601 - Disclosure - INTANGIBLE ASSETS - Summary (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxesLossBeforeProvisionForIncomeTaxesDetails" id="DisclosureIncomeTaxesLossBeforeProvisionForIncomeTaxesDetails">
        <link:definition>99941101 - Disclosure - INCOME TAXES - Loss Before Provision for Income Taxes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxesReconciliationOfIncomeTaxProvisionComputedAtStatutoryRatesDetails" id="DisclosureIncomeTaxesReconciliationOfIncomeTaxProvisionComputedAtStatutoryRatesDetails">
        <link:definition>99941102 - Disclosure - INCOME TAXES - Reconciliation of Income Tax Provision Computed at Statutory Rates (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxesComponentsOfDeferredIncomeTaxAssetsAndLiabilitiesDetails" id="DisclosureIncomeTaxesComponentsOfDeferredIncomeTaxAssetsAndLiabilitiesDetails">
        <link:definition>99941103 - Disclosure - INCOME TAXES - Components of Deferred Income Tax Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/StatementConsolidatedStatementsOfStockholdersEquity" id="StatementConsolidatedStatementsOfStockholdersEquity">
        <link:definition>995200300 - Statement - Consolidated Statements of Stockholders' Equity</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureCommonStockAndWarrantsTables" id="DisclosureCommonStockAndWarrantsTables">
        <link:definition>99930803 - Disclosure - COMMON STOCK AND WARRANTS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureStockBasedCompensationTables" id="DisclosureStockBasedCompensationTables">
        <link:definition>99930903 - Disclosure - STOCK-BASED COMPENSATION (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureDescriptionOfBusinessDetails" id="DisclosureDescriptionOfBusinessDetails">
        <link:definition>99940101 - Disclosure - DESCRIPTION OF BUSINESS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureSignificantAccountingPoliciesAdditionalInformationDetails" id="DisclosureSignificantAccountingPoliciesAdditionalInformationDetails">
        <link:definition>99940201 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresAccountsReceivableNetDetails" id="DisclosureSupplementalBalanceSheetDisclosuresAccountsReceivableNetDetails">
        <link:definition>99940401 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES - Accounts receivable, net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresDeferredRevenueDetails" id="DisclosureSupplementalBalanceSheetDisclosuresDeferredRevenueDetails">
        <link:definition>99940406 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES - Deferred revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureCommonStockAndWarrantsEquityTransactionsDetails" id="DisclosureCommonStockAndWarrantsEquityTransactionsDetails">
        <link:definition>99940802 - Disclosure - COMMON STOCK AND WARRANTS - Equity transactions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureCommonStockAndWarrantsWarrantFairValueInputsDetails" id="DisclosureCommonStockAndWarrantsWarrantFairValueInputsDetails">
        <link:definition>99940803 - Disclosure - COMMON STOCK AND WARRANTS - Warrant fair value inputs (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureCommonStockAndWarrantsWarrantsDetails" id="DisclosureCommonStockAndWarrantsWarrantsDetails">
        <link:definition>99940804 - Disclosure - COMMON STOCK AND WARRANTS - Warrants (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureStockBasedCompensationPlanInformationDetails" id="DisclosureStockBasedCompensationPlanInformationDetails">
        <link:definition>99940901 - Disclosure - STOCK-BASED COMPENSATION - Plan information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureStockBasedCompensationFairValueAssumptionsAndOtherDetails" id="DisclosureStockBasedCompensationFairValueAssumptionsAndOtherDetails">
        <link:definition>99940902 - Disclosure - STOCK-BASED COMPENSATION - Fair value assumptions and other (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureStockBasedCompensationNonvestedRestrictedStockUnitActivityDetails" id="DisclosureStockBasedCompensationNonvestedRestrictedStockUnitActivityDetails">
        <link:definition>99940904 - Disclosure - STOCK-BASED COMPENSATION - Nonvested Restricted Stock Unit Activity (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails" id="DisclosureStockBasedCompensationStockBasedCompensationExpenseDetails">
        <link:definition>99940905 - Disclosure - STOCK-BASED COMPENSATION - Stock-based compensation expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureBasicAndDilutedLossPerSharePublicOfferingDetails" id="DisclosureBasicAndDilutedLossPerSharePublicOfferingDetails">
        <link:definition>99941002 - Disclosure - BASIC AND DILUTED LOSS PER SHARE - Public Offering (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureBasicAndDilutedLossPerShareAntidilutiveSecuritiesDetails" id="DisclosureBasicAndDilutedLossPerShareAntidilutiveSecuritiesDetails">
        <link:definition>99941003 - Disclosure - BASIC AND DILUTED LOSS PER SHARE - Antidilutive securities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxesNetOperatingLossesDetails" id="DisclosureIncomeTaxesNetOperatingLossesDetails">
        <link:definition>99941104 - Disclosure - INCOME TAXES - Net operating losses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxesTaxCreditCarryforwardDetails" id="DisclosureIncomeTaxesTaxCreditCarryforwardDetails">
        <link:definition>99941105 - Disclosure - INCOME TAXES - Tax credit carryforward (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureCommitmentsAndContingenciesLicenseAgreementDetails" id="DisclosureCommitmentsAndContingenciesLicenseAgreementDetails">
        <link:definition>99941301 - Disclosure - COMMITMENTS AND CONTINGENCIES - License agreement (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSegmentAndGeographicInformationDetails" id="DisclosureSegmentAndGeographicInformationDetails">
        <link:definition>99941401 - Disclosure - SEGMENT AND GEOGRAPHIC INFORMATION (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSubsequentEventsDetails" id="DisclosureSubsequentEventsDetails">
        <link:definition>99941501 - Disclosure - SUBSEQUENT EVENTS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DocumentDocumentAndEntityInformation" id="DocumentDocumentAndEntityInformation">
        <link:definition>995200090 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" id="StatementConsolidatedBalanceSheetsParenthetical">
        <link:definition>995200105 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureDescriptionOfBusiness" id="DisclosureDescriptionOfBusiness">
        <link:definition>995210101 - Disclosure - DESCRIPTION OF BUSINESS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureSignificantAccountingPolicies" id="DisclosureSignificantAccountingPolicies">
        <link:definition>995210201 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureFixedAssetImpairment" id="DisclosureFixedAssetImpairment">
        <link:definition>995210301 - Disclosure - FIXED ASSET IMPAIRMENT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosures" id="DisclosureSupplementalBalanceSheetDisclosures">
        <link:definition>995210401 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureLeases" id="DisclosureLeases">
        <link:definition>995210501 - Disclosure - LEASES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIntangibleAssets" id="DisclosureIntangibleAssets">
        <link:definition>995210601 - Disclosure - INTANGIBLE ASSETS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureFairValueMeasurements" id="DisclosureFairValueMeasurements">
        <link:definition>995210701 - Disclosure - FAIR VALUE MEASUREMENTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureCommonStockAndWarrants" id="DisclosureCommonStockAndWarrants">
        <link:definition>995210801 - Disclosure - COMMON STOCK AND WARRANTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureStockBasedCompensation" id="DisclosureStockBasedCompensation">
        <link:definition>995210901 - Disclosure - STOCK-BASED COMPENSATION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureBasicAndDilutedLossPerShare" id="DisclosureBasicAndDilutedLossPerShare">
        <link:definition>995211001 - Disclosure - BASIC AND DILUTED LOSS PER SHARE</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxes" id="DisclosureIncomeTaxes">
        <link:definition>995211101 - Disclosure - INCOME TAXES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureDefinedContributionPlan" id="DisclosureDefinedContributionPlan">
        <link:definition>995211201 - Disclosure - DEFINED CONTRIBUTION PLAN</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureCommitmentsAndContingencies" id="DisclosureCommitmentsAndContingencies">
        <link:definition>995211301 - Disclosure - COMMITMENTS AND CONTINGENCIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSegmentAndGeographicInformation" id="DisclosureSegmentAndGeographicInformation">
        <link:definition>995211401 - Disclosure - SEGMENT AND GEOGRAPHIC INFORMATION</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSubsequentEvents" id="DisclosureSubsequentEvents">
        <link:definition>995211501 - Disclosure - SUBSEQUENT EVENTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureSignificantAccountingPoliciesPolicies" id="DisclosureSignificantAccountingPoliciesPolicies">
        <link:definition>99920202 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSupplementalBalanceSheetDisclosuresTables" id="DisclosureSupplementalBalanceSheetDisclosuresTables">
        <link:definition>99930403 - Disclosure - SUPPLEMENTAL BALANCE SHEET DISCLOSURES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureLeasesTables" id="DisclosureLeasesTables">
        <link:definition>99930503 - Disclosure - LEASES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIntangibleAssetsTables" id="DisclosureIntangibleAssetsTables">
        <link:definition>99930603 - Disclosure - INTANGIBLE ASSETS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureBasicAndDilutedLossPerShareTables" id="DisclosureBasicAndDilutedLossPerShareTables">
        <link:definition>99931003 - Disclosure - BASIC AND DILUTED LOSS PER SHARE (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureIncomeTaxesTables" id="DisclosureIncomeTaxesTables">
        <link:definition>99931103 - Disclosure - INCOME TAXES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureSegmentAndGeographicInformationTables" id="DisclosureSegmentAndGeographicInformationTables">
        <link:definition>99931403 - Disclosure - SEGMENT AND GEOGRAPHIC INFORMATION (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureFixedAssetImpairmentDetails" id="DisclosureFixedAssetImpairmentDetails">
        <link:definition>99940301 - Disclosure - FIXED ASSET IMPAIRMENT (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureCommonStockAndWarrantsOtherDetails" id="DisclosureCommonStockAndWarrantsOtherDetails">
        <link:definition>99940801 - Disclosure - COMMON STOCK AND WARRANTS - Other (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/20220331/taxonomy/role/DisclosureStockBasedCompensationStockOptionActivityDetails" id="DisclosureStockBasedCompensationStockOptionActivityDetails">
        <link:definition>99940903 - Disclosure - STOCK-BASED COMPENSATION - Stock Option Activity (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureBasicAndDilutedLossPerShareComputationDetails" id="DisclosureBasicAndDilutedLossPerShareComputationDetails">
        <link:definition>99941001 - Disclosure - BASIC AND DILUTED LOSS PER SHARE - Computation (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureDefinedContributionPlanDetails" id="DisclosureDefinedContributionPlanDetails">
        <link:definition>99941201 - Disclosure - DEFINED CONTRIBUTION PLAN (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:type="simple" xlink:href="hsdt-20241231_pre.xml" xlink:title="Presentation Links, all" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="hsdt-20241231_cal.xml" xlink:title="Calculation Links, all" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="hsdt-20241231_def.xml" xlink:title="Definition Links, all" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="hsdt-20241231_lab.xml" xlink:title="Label Links, all" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:roleType roleURI="http://www.heliusmedical.com/role/DisclosureStandardAndCustomAxisDomainDefaults" id="DisclosureStandardAndCustomAxisDomainDefaults">
        <link:definition>99900 - Disclosure - Standard And Custom Axis Domain Defaults</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:import namespace="https://xbrl.org/2023/calculation-1.1" schemaLocation="https://www.xbrl.org/2023/calculation-1.1.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/ecd/2024" schemaLocation="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/currency/2024" schemaLocation="https://xbrl.sec.gov/currency/2024/currency-2024.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/country/2024" schemaLocation="https://xbrl.sec.gov/country/2024/country-2024.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <xsd:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/dei/2024" schemaLocation="https://xbrl.sec.gov/dei/2024/dei-2024.xsd" />
  <xsd:import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
  <xsd:import namespace="http://fasb.org/srt/2024" schemaLocation="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd" />
  <xsd:import namespace="http://fasb.org/us-gaap/2024" schemaLocation="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd" />
  <xsd:import namespace="http://fasb.org/us-roles/2024" schemaLocation="https://xbrl.fasb.org/us-gaap/2024/elts/us-roles-2024.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/ecd-sub/2024" schemaLocation="https://xbrl.sec.gov/ecd/2024/ecd-sub-2024.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/cyd/2024" schemaLocation="https://xbrl.sec.gov/cyd/2024/cyd-2024.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/cyd-af-sub/2024" schemaLocation="https://xbrl.sec.gov/cyd/2024/cyd-af-sub-2024.xsd" />
  <xsd:element name="StockIssuedDuringPeriodSharesWarrantExercised" id="hsdt_StockIssuedDuringPeriodSharesWarrantExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodValueWarrantExercised" id="hsdt_StockIssuedDuringPeriodValueWarrantExercised" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfSignificantAccountingPoliciesLineItems" id="hsdt_ScheduleOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfSignificantAccountingPoliciesTable" id="hsdt_ScheduleOfSignificantAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ComputerSoftwareAndHardwareMember" id="hsdt_ComputerSoftwareAndHardwareMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="HealthTechConnexIncorporationMember" id="hsdt_HealthTechConnexIncorporationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AcquiredProprietarySoftwareMember" id="hsdt_AcquiredProprietarySoftwareMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ReacquiredRightsMember" id="hsdt_ReacquiredRightsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfStockholdersEquityLineItems" id="hsdt_ScheduleOfStockholdersEquityLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfStockholdersEquityTable" id="hsdt_ScheduleOfStockholdersEquityTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightExercised" id="hsdt_ClassOfWarrantOrRightExercised" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantsOrRightExpirationPeriod" id="hsdt_ClassOfWarrantsOrRightExpirationPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ProceedsFromIssuanceOfCommonStockNet" id="hsdt_ProceedsFromIssuanceOfCommonStockNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="TwoThousandTwentyOneInducementPlanMember" id="hsdt_TwoThousandTwentyOneInducementPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AccruedFranchiseFeeCurrent" id="hsdt_AccruedFranchiseFeeCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="PercentageOfRoyaltyOnNetRevenue" id="hsdt_PercentageOfRoyaltyOnNetRevenue" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CommitmentsAndContingenciesLineItems" id="hsdt_CommitmentsAndContingenciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CommitmentsAndContingenciesTable" id="hsdt_CommitmentsAndContingenciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AdvancedNeuroRehabilitationLimitedLiabilityCompanyMember" id="hsdt_AdvancedNeuroRehabilitationLimitedLiabilityCompanyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="LicenseAgreementForExclusiveRightsOnPatentPendingTechnologyMember" id="hsdt_LicenseAgreementForExclusiveRightsOnPatentPendingTechnologyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="SupplementalBalanceSheetDisclosuresAbstract" id="hsdt_SupplementalBalanceSheetDisclosuresAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NumberOfOperatingLeases" id="hsdt_NumberOfOperatingLeases" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="InventoryReservesChargedAgainstWorkInProcessInventory" id="hsdt_InventoryReservesChargedAgainstWorkInProcessInventory" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="EquityIncentive2022PlanMember" id="hsdt_EquityIncentive2022PlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="PreFundedWarrantsMember" id="hsdt_PreFundedWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="PublicWarrantsMember" id="hsdt_PublicWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="SaleOfStockCombinedOfferingPricePerShare" id="hsdt_SaleOfStockCombinedOfferingPricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="SaleOfStockPreFundedWarrantsAndAccompanyingPublicWarrantsPricePerShare" id="hsdt_SaleOfStockPreFundedWarrantsAndAccompanyingPublicWarrantsPricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="PublicOfferingMember" id="hsdt_PublicOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CommonStockWarrantsMember" id="hsdt_CommonStockWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="IncomeTaxReconciliationChangeInDerivativeLiability" id="hsdt_IncomeTaxReconciliationChangeInDerivativeLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxesTable" id="hsdt_IncomeTaxesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxesLineItems" id="hsdt_IncomeTaxesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="MaximumAggregateOfferingAmount" id="hsdt_MaximumAggregateOfferingAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationAnnualIncreaseInAuthorizedSharesAsPercentageOfFullyDilutedSharesOfCommonStockOutstanding" id="hsdt_ShareBasedCompensationAnnualIncreaseInAuthorizedSharesAsPercentageOfFullyDilutedSharesOfCommonStockOutstanding" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="AugustTwoThousandTwentyTwoOfferingMember" id="hsdt_AugustTwoThousandTwentyTwoOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="AccruedAndOtherCurrentLiabilities." id="hsdt_AccruedAndOtherCurrentLiabilities." type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="InventoryRelatedAssetsCurrent" id="hsdt_InventoryRelatedAssetsCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ScheduleOfAccruedAndOtherCurrentLiabilitiesTableTextBlock" id="hsdt_ScheduleOfAccruedAndOtherCurrentLiabilitiesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ExclusivityRightsNumberOfAdditionalTerms" id="hsdt_ExclusivityRightsNumberOfAdditionalTerms" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ExclusivityRightsAdditionalTerm" id="hsdt_ExclusivityRightsAdditionalTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ExclusivityRightsPeriodOfWrittenNoticeForRenewal" id="hsdt_ExclusivityRightsPeriodOfWrittenNoticeForRenewal" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="DefinedContributionPlanFirstEmployerMatchingContributionPercentOfEmployeesGrossPay" id="hsdt_DefinedContributionPlanFirstEmployerMatchingContributionPercentOfEmployeesGrossPay" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="DefinedContributionPlanNextEmployerMatchingContributionPercentOfEmployeesGrossPay" id="hsdt_DefinedContributionPlanNextEmployerMatchingContributionPercentOfEmployeesGrossPay" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="CustomerOneMember" id="hsdt_CustomerOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExpirationPeriodAxis" id="hsdt_ExpirationPeriodAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExpirationPeriodDomain" id="hsdt_ExpirationPeriodDomain" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="IndefiniteOneMember" id="hsdt_IndefiniteOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="OperatingLossCarryforwardExpirationPeriod1Member" id="hsdt_OperatingLossCarryforwardExpirationPeriod1Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="OperatingLossCarryforwardExpirationPeriod2Member" id="hsdt_OperatingLossCarryforwardExpirationPeriod2Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="TaxCreditCarryforwardExpirationPeriod1Member" id="hsdt_TaxCreditCarryforwardExpirationPeriod1Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="TaxCreditCarryforwardExpirationPeriod2Member" id="hsdt_TaxCreditCarryforwardExpirationPeriod2Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExclusiveDistributionAgreementMember" id="hsdt_ExclusiveDistributionAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ExclusivityRightGrantedValue" id="hsdt_ExclusivityRightGrantedValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="DividendDeclaredSharesOfPreferredStockForEachShareOfCommonStockOutstanding" id="hsdt_DividendDeclaredSharesOfPreferredStockForEachShareOfCommonStockOutstanding" type="xbrli:decimalItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="PreferredStockVotingRightsPerShare" id="hsdt_PreferredStockVotingRightsPerShare" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="AttheMarketOfferingMember" id="hsdt_AttheMarketOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="MaximumCommissionRateAsPercentageOfGrossProceeds" id="hsdt_MaximumCommissionRateAsPercentageOfGrossProceeds" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="TwoCustomersMember" id="hsdt_TwoCustomersMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfCustomers" id="hsdt_NumberOfCustomers" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="PreferredStockRedemptionRatePerShare" id="hsdt_PreferredStockRedemptionRatePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="ClassOfWarrantOrRightCancelled" id="hsdt_ClassOfWarrantOrRightCancelled" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="DerivativeWarrantLiabilityReclassifiedToEquityOnExerciseOfWarrants" id="hsdt_DerivativeWarrantLiabilityReclassifiedToEquityOnExerciseOfWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="EmployeeRetentionCreditPolicyTextBlock" id="hsdt_EmployeeRetentionCreditPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="EmployeeRetentionCreditReceivable" id="hsdt_EmployeeRetentionCreditReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="EmployeeRetentionCredit" id="hsdt_EmployeeRetentionCredit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="GrossProceedsFromExerciseOfWarrants" id="hsdt_GrossProceedsFromExerciseOfWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="DeferredOfferingCostsReclassifiedToEquityUponPublicOffering" id="hsdt_DeferredOfferingCostsReclassifiedToEquityUponPublicOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="SeriesWarrantsMember" id="hsdt_SeriesWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="SeriesBWarrantsMember" id="hsdt_SeriesBWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="Warrants2022Member" id="hsdt_Warrants2022Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ForeignCurrencyTransactionIncludingOtherGainLossBeforeTax" id="hsdt_ForeignCurrencyTransactionIncludingOtherGainLossBeforeTax" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ClassOfWarrantOrRightSettlement" id="hsdt_ClassOfWarrantOrRightSettlement" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="FixedAssetImpairmentDisclosureAbstract" id="hsdt_FixedAssetImpairmentDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DerivativeGainLossOnDerivativeNetCashFlowImpact" id="hsdt_DerivativeGainLossOnDerivativeNetCashFlowImpact" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LesseeOperatingLeaseRentExpensePerMonth" id="hsdt_LesseeOperatingLeaseRentExpensePerMonth" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ExistingWarrantsMember" id="hsdt_ExistingWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="InducementWarrantsMember" id="hsdt_InducementWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="OperatingLossCarryforwardExpirationPeriod3Member" id="hsdt_OperatingLossCarryforwardExpirationPeriod3Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ProceedsFromWarrantExercisesNetOfExpenses" id="hsdt_ProceedsFromWarrantExercisesNetOfExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="CumulativeStockIssuedShares" id="hsdt_CumulativeStockIssuedShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="CumulativeProceedsFromIssuanceOfCommonStockNet" id="hsdt_CumulativeProceedsFromIssuanceOfCommonStockNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="CommonStockWarrantsExcludingPreFundedWarrantsMember" id="hsdt_CommonStockWarrantsExcludingPreFundedWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
</xsd:schema>
