Difference between revisions of "Point Of Care Testing"
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Point of Care Testing (POCT) aptly refers to clinical laboratory testing performed “at the point of patient care or treatment,” which bypasses the routine steps of collection of specimens, transportation to a clinical laboratory for testing, and appropriate storage of specimen post testing. The major benefit of POCT is rapid turn-around-time (1). | Point of Care Testing (POCT) aptly refers to clinical laboratory testing performed “at the point of patient care or treatment,” which bypasses the routine steps of collection of specimens, transportation to a clinical laboratory for testing, and appropriate storage of specimen post testing. The major benefit of POCT is rapid turn-around-time (1). | ||
| − | Contents | + | Contents [Hide] |
| − | 1.Introduction | + | |
| − | 2.Specimen Requirements and Procedures | + | 1. Introduction |
| − | 2.1.Interfering Factors | + | 2. Specimen Requirements and Procedures |
| − | 3.Methodology | + | 2.1. Interfering Factors |
| − | 3.1.Test strips and Lateral-flow | + | 3. Methodology |
| − | 3.2.Immunoassays | + | 3.1. Test strips and Lateral-flow Testing |
| − | 3.3 | + | 3.2. Immunoassays |
| − | + | 3.3. Molecular POCT | |
| − | 4.Clinical Significance | + | 4. Clinical Significance |
| − | 5.Connectivity and Integration with Electronic Health Record | + | 5. Connectivity and Integration with Electronic Health Record |
| − | 5.1.Manual Entry of Results | + | 5.1. Manual Entry of Results |
| − | 5.2.POCT Connectivity and Data Management System | + | 5.2. POCT Connectivity and Data Management System |
| − | 6.Quality Assurance Management | + | 6. Quality Assurance Management |
| − | 7.Lab-on-Chip | + | 7. Lab-on-Chip |
| − | 8.Artificial intelligence assisted POCT | + | 8. Artificial intelligence assisted POCT |
| − | 9.References | + | 9. References |
'''Introduction''' | '''Introduction''' | ||
| + | ---- | ||
Traditionally, when a laboratory testing order is placed in the electronic health system (EHR), specimen is collected, transported to a centralized clinical laboratory performing the test where the test is performed, and finally resulted. Depending on the patient location, the turnaround time (TAT) of this multistep process can vary from less than an hour (inpatient) to nearly 24 hours (ambulatory). Performing the test at bedside allows for rapid availability of results, significantly reducing time required for decision-making related to patient care and health care cost. | Traditionally, when a laboratory testing order is placed in the electronic health system (EHR), specimen is collected, transported to a centralized clinical laboratory performing the test where the test is performed, and finally resulted. Depending on the patient location, the turnaround time (TAT) of this multistep process can vary from less than an hour (inpatient) to nearly 24 hours (ambulatory). Performing the test at bedside allows for rapid availability of results, significantly reducing time required for decision-making related to patient care and health care cost. | ||
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'''Specimen Requirements and Procedures''' | '''Specimen Requirements and Procedures''' | ||
| + | |||
| + | ---- | ||
There are three phases of a laboratory test: pre-analytic, analytical, and post-analytical. The pre-analytical phase, which typically consists of collection, transport, preparation, and loading of specimen, is brief with fewer steps in POCT testing. Therefore, it is imperative that personnel performing POCT strictly adhere to the manufacturer's instructions for use (IFU), or the package insert to maintain the integrity, accuracy, and safety of the testing process. | There are three phases of a laboratory test: pre-analytic, analytical, and post-analytical. The pre-analytical phase, which typically consists of collection, transport, preparation, and loading of specimen, is brief with fewer steps in POCT testing. Therefore, it is imperative that personnel performing POCT strictly adhere to the manufacturer's instructions for use (IFU), or the package insert to maintain the integrity, accuracy, and safety of the testing process. | ||
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Briefly, the procedure for POCT involves collection of samples appropriately using manufacturer’s IFU, application of the sample to the POCT device after processing such as centrifugation, if needed, performing the test, and finally reading the results. | Briefly, the procedure for POCT involves collection of samples appropriately using manufacturer’s IFU, application of the sample to the POCT device after processing such as centrifugation, if needed, performing the test, and finally reading the results. | ||
| − | ''' | + | '''''Interfering Factors''''' |
| + | |||
Pre-analytic phase is the most error prone phase in any laboratory testing. Factors such as humidity, temperature, time to testing, and oxygen content can fluctuate more in POCT environment compared to conventional laboratory. Of the errors related to specimen collection, hemolysis is the most challenging to identify especially when performing POCT test using whole blood including finger stick. Other sample related factors such as lipemia and icterus similarly may cause results to be inaccurate. Certain over the counter supplements such as biotin, when consumed in larger doses can interfere with certain immunoassays (1). | Pre-analytic phase is the most error prone phase in any laboratory testing. Factors such as humidity, temperature, time to testing, and oxygen content can fluctuate more in POCT environment compared to conventional laboratory. Of the errors related to specimen collection, hemolysis is the most challenging to identify especially when performing POCT test using whole blood including finger stick. Other sample related factors such as lipemia and icterus similarly may cause results to be inaccurate. Certain over the counter supplements such as biotin, when consumed in larger doses can interfere with certain immunoassays (1). | ||
| − | ''' | + | '''Methodology''' |
| − | '' | + | |
| + | ---- | ||
| + | '''''Test Strips and Lateral Flow Testing''''' | ||
Test strips, for example urine test strips, are the most basic POCT testing available. Interpretation of test strips is mostly based on color change that occurs because of reaction between the analyte, when present in the specimen with the substance impregnated or coated in the test strip. | Test strips, for example urine test strips, are the most basic POCT testing available. Interpretation of test strips is mostly based on color change that occurs because of reaction between the analyte, when present in the specimen with the substance impregnated or coated in the test strip. | ||
| − | ''' | + | '''''Immunoassays''''' |
| + | |||
POCT testing using antibodies directed against wide range of targets such as drugs, pathogens, and proteins are categorized under immunoassays. These assays include both individual tests and platforms with multiple built-in tests. Most common tests in this category are group A Streptococcus, mononucleosis, and influenza A and B. | POCT testing using antibodies directed against wide range of targets such as drugs, pathogens, and proteins are categorized under immunoassays. These assays include both individual tests and platforms with multiple built-in tests. Most common tests in this category are group A Streptococcus, mononucleosis, and influenza A and B. | ||
| − | ''' | + | '''''Molecular POCT''''' |
| + | |||
In general, molecular tests have high sensitivity and specificity and a rapid TAT. The method primarily amplifies and detects nucleic acid including deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) sequences for identification of the condition. Most common examples are COVID-19, RSV, and influenza A and B testing. | In general, molecular tests have high sensitivity and specificity and a rapid TAT. The method primarily amplifies and detects nucleic acid including deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) sequences for identification of the condition. Most common examples are COVID-19, RSV, and influenza A and B testing. | ||
'''Clinical Significance''' | '''Clinical Significance''' | ||
| + | |||
| + | ---- | ||
POCT offers several advantages impacting clinical outcomes such as appropriate use of antibiotics, prevention of unnecessary treatment escalation, drug dose adjustment, and health management in chronic conditions. The ease of performing a test has allowed a non-laboratory staff to operate POCT promoting its availability in a variety of healthcare settings. The types of institutions that are currently licensed to perform POCT include physicians’ office, pharmacies, skilled nurse facilities, home health agencies, hospitals, and others (2). | POCT offers several advantages impacting clinical outcomes such as appropriate use of antibiotics, prevention of unnecessary treatment escalation, drug dose adjustment, and health management in chronic conditions. The ease of performing a test has allowed a non-laboratory staff to operate POCT promoting its availability in a variety of healthcare settings. The types of institutions that are currently licensed to perform POCT include physicians’ office, pharmacies, skilled nurse facilities, home health agencies, hospitals, and others (2). | ||
'''Connectivity and Integration with Electronic Health Record''' | '''Connectivity and Integration with Electronic Health Record''' | ||
| + | |||
| + | ---- | ||
Because POCT testing is used to make clinical decisions, accreditation and regulatory standards require integration of results into the patient’s EHR. The results should be documented with associated reference ranges, units of measurements, critical values if applicable, and date and time of testing. In addition, the test should be traceable to device serial number, operator identification number, reagent lot number, and quality control results (3). | Because POCT testing is used to make clinical decisions, accreditation and regulatory standards require integration of results into the patient’s EHR. The results should be documented with associated reference ranges, units of measurements, critical values if applicable, and date and time of testing. In addition, the test should be traceable to device serial number, operator identification number, reagent lot number, and quality control results (3). | ||
| − | '' | + | '''''Manual Entry Of Results''''' |
| + | |||
Traditionally, POCT results have been manually transcribed in the patient’s chart. However, manual transcription is time-consuming and error prone. On average a 3-5% transcription rate has been reported in an inpatient medicine unit setting. Another audit study reported omission of as high as 12% of POC glucose results that were never recorded into patient’s charts. The error in manual reporting is directly related to complexity of POCT. For example, POC blood gas analysis and POC urinanalysis have multiple components with multiple result options for each component. Errors may occur due to selection of an incorrect result or mismatching test components and results. | Traditionally, POCT results have been manually transcribed in the patient’s chart. However, manual transcription is time-consuming and error prone. On average a 3-5% transcription rate has been reported in an inpatient medicine unit setting. Another audit study reported omission of as high as 12% of POC glucose results that were never recorded into patient’s charts. The error in manual reporting is directly related to complexity of POCT. For example, POC blood gas analysis and POC urinanalysis have multiple components with multiple result options for each component. Errors may occur due to selection of an incorrect result or mismatching test components and results. | ||
| − | '''POCT Connectivity and Data Management System''' | + | '''''POCT Connectivity and Data Management System''''' |
| + | |||
The use of connectivity provides a safe and reliable method for transfer of data from POCT devices to EHR. Connectivity of POCT devices to EHR requires a data management system (DMS) or also known as middleware. Depending on the system, multiple POCT devices can be interfaced to a single DMS permitting automation, real-time, bi-directional, electronic wired or wireless transfer of data. Some of the features of DMS include remote access capability allowing for remote monitoring and review, and ability to interface with Admission, Discharge, and Transfer (ADT) systems. | The use of connectivity provides a safe and reliable method for transfer of data from POCT devices to EHR. Connectivity of POCT devices to EHR requires a data management system (DMS) or also known as middleware. Depending on the system, multiple POCT devices can be interfaced to a single DMS permitting automation, real-time, bi-directional, electronic wired or wireless transfer of data. Some of the features of DMS include remote access capability allowing for remote monitoring and review, and ability to interface with Admission, Discharge, and Transfer (ADT) systems. | ||
'''Quality Assurance Management''' | '''Quality Assurance Management''' | ||
| + | |||
| + | ---- | ||
Under CLIA 1988, laboratory testing using human specimens is subject to regulations. Although, most of the POCT are waived, some are non-waived and subcategorized as moderately complex, requiring specific quality standards including proficiency testing, quality control, and personnel competency requirements. To avoid improper performance of POCT testing or erroneous result entry, accreditation bodies including CLIA require monitoring of quality control and quality assurance programs at all sites where POCT is performed. Additionally, a robust training program for all testing personnel (laboratory and non-laboratory staff) must be maintained to ensure competency (1–3). | Under CLIA 1988, laboratory testing using human specimens is subject to regulations. Although, most of the POCT are waived, some are non-waived and subcategorized as moderately complex, requiring specific quality standards including proficiency testing, quality control, and personnel competency requirements. To avoid improper performance of POCT testing or erroneous result entry, accreditation bodies including CLIA require monitoring of quality control and quality assurance programs at all sites where POCT is performed. Additionally, a robust training program for all testing personnel (laboratory and non-laboratory staff) must be maintained to ensure competency (1–3). | ||
'''Lab-On-Chip''' | '''Lab-On-Chip''' | ||
| + | |||
| + | ---- | ||
A lab-on-chip is a miniaturized device that enables performance of biological and biochemical analyses of a sample in a single platform. These plastic devices are engineered with tiny channels, valves, and pumps capable of transporting, mixing, and analyzing proteins, DNA, and other chemicals in the body fluids. The chips often require insertion into a portable reader or a scanner. The main advantages of lab-on-chip are ease of use, less error prone, rapid turn-around-time, low sample volume, portability, high sensitivity, low cost, and high accessibility. Major limitations of this technology include lack of readiness for industrialization, increased signal/noise ratio, and ethics. | A lab-on-chip is a miniaturized device that enables performance of biological and biochemical analyses of a sample in a single platform. These plastic devices are engineered with tiny channels, valves, and pumps capable of transporting, mixing, and analyzing proteins, DNA, and other chemicals in the body fluids. The chips often require insertion into a portable reader or a scanner. The main advantages of lab-on-chip are ease of use, less error prone, rapid turn-around-time, low sample volume, portability, high sensitivity, low cost, and high accessibility. Major limitations of this technology include lack of readiness for industrialization, increased signal/noise ratio, and ethics. | ||
Some of the applications of lab-on-chip include molecular biology, proteomics, and chemistry. One noteworthy example is the newborn screening test for presence of lysosomal storage disorders, which currently uses FDA-authorized lab-on-chip device. Many lab-on-chip devices such as one that can detect presence of sickle cell disease, assist in identifying targeted therapy for asthma and COPD, or assist in identifying anti-viral drugs that can be used in patients infected with COVID-19 are in various stages of development (4,5). | Some of the applications of lab-on-chip include molecular biology, proteomics, and chemistry. One noteworthy example is the newborn screening test for presence of lysosomal storage disorders, which currently uses FDA-authorized lab-on-chip device. Many lab-on-chip devices such as one that can detect presence of sickle cell disease, assist in identifying targeted therapy for asthma and COPD, or assist in identifying anti-viral drugs that can be used in patients infected with COVID-19 are in various stages of development (4,5). | ||
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'''Artificial Intelligence Assisted POCT''' | '''Artificial Intelligence Assisted POCT''' | ||
| + | |||
| + | ---- | ||
Artificial intelligence (AI) is finding application in various aspects of healthcare including POCT. AI is being used to make POCT economical, faster, and easier to check for quality control. Some key areas where AI is being used include lateral flow immunoassays (LFIA), bright-field microscopy diagnostic testing especially for parasitic infections such as malaria, hematology including complete blood cell count (CBC), and hemoglobin variant detection (7,8). | Artificial intelligence (AI) is finding application in various aspects of healthcare including POCT. AI is being used to make POCT economical, faster, and easier to check for quality control. Some key areas where AI is being used include lateral flow immunoassays (LFIA), bright-field microscopy diagnostic testing especially for parasitic infections such as malaria, hematology including complete blood cell count (CBC), and hemoglobin variant detection (7,8). | ||
'''References''' | '''References''' | ||
| + | |||
| + | ---- | ||
1. Point-of-Care Testing - StatPearls - NCBI Bookshelf. | 1. Point-of-Care Testing - StatPearls - NCBI Bookshelf. | ||
2. Point of Care Testing - ASCLS. Point Care Test. | 2. Point of Care Testing - ASCLS. Point Care Test. | ||
Revision as of 03:14, 2 May 2024
Point of Care Testing (POCT) aptly refers to clinical laboratory testing performed “at the point of patient care or treatment,” which bypasses the routine steps of collection of specimens, transportation to a clinical laboratory for testing, and appropriate storage of specimen post testing. The major benefit of POCT is rapid turn-around-time (1).
Contents [Hide]
1. Introduction 2. Specimen Requirements and Procedures 2.1. Interfering Factors 3. Methodology 3.1. Test strips and Lateral-flow Testing 3.2. Immunoassays 3.3. Molecular POCT 4. Clinical Significance 5. Connectivity and Integration with Electronic Health Record 5.1. Manual Entry of Results 5.2. POCT Connectivity and Data Management System 6. Quality Assurance Management 7. Lab-on-Chip 8. Artificial intelligence assisted POCT 9. References
Introduction
Traditionally, when a laboratory testing order is placed in the electronic health system (EHR), specimen is collected, transported to a centralized clinical laboratory performing the test where the test is performed, and finally resulted. Depending on the patient location, the turnaround time (TAT) of this multistep process can vary from less than an hour (inpatient) to nearly 24 hours (ambulatory). Performing the test at bedside allows for rapid availability of results, significantly reducing time required for decision-making related to patient care and health care cost.
The concept of bedside or near-patient testing can be traced back to the 1950s. In the 1980s, the term “point-of-care testing” was introduced by Dr. Kost, while performing biosensor-based monitoring of ionized calcium levels in whole blood at bedside of patients undergoing hepatic transplantation.
As laboratory testing developed, Clinical Laboratory Improvement Amendments (CLIA) program was introduced to ensure quality laboratory testing. Under the CLIA’88, laboratory tests were categorized as waived, moderately complex, and highly complex based on technical difficulty and potential harm to patient. POCT are considered waived tests because of the ease of use and no reasonable risk of harm to a patient. With advancement in technology, the original list of nine analytes approved as “waived” has exploded to more than 100 (link to latest list of waived tests: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfClia/analyteswaived.cfm) Of note, with the growth, many tests available as POCT have also been categorized as moderately complex and are no longer CLIA waived (1,2).
Specimen Requirements and Procedures
There are three phases of a laboratory test: pre-analytic, analytical, and post-analytical. The pre-analytical phase, which typically consists of collection, transport, preparation, and loading of specimen, is brief with fewer steps in POCT testing. Therefore, it is imperative that personnel performing POCT strictly adhere to the manufacturer's instructions for use (IFU), or the package insert to maintain the integrity, accuracy, and safety of the testing process.
Compared to the conventional laboratory testing, POCT is more susceptible to interfering substances and has a narrow margin of error due to smaller sample size. Proper technique, for example, flushing the line with heparin and discarding at least twice the volume of the line (2 to 5 ml), if using central line, or maintaining anaerobic conditions when collecting sample for blood gas analysis, is essential to reduce error. Briefly, the procedure for POCT involves collection of samples appropriately using manufacturer’s IFU, application of the sample to the POCT device after processing such as centrifugation, if needed, performing the test, and finally reading the results.
Interfering Factors
Pre-analytic phase is the most error prone phase in any laboratory testing. Factors such as humidity, temperature, time to testing, and oxygen content can fluctuate more in POCT environment compared to conventional laboratory. Of the errors related to specimen collection, hemolysis is the most challenging to identify especially when performing POCT test using whole blood including finger stick. Other sample related factors such as lipemia and icterus similarly may cause results to be inaccurate. Certain over the counter supplements such as biotin, when consumed in larger doses can interfere with certain immunoassays (1).
Methodology
Test Strips and Lateral Flow Testing Test strips, for example urine test strips, are the most basic POCT testing available. Interpretation of test strips is mostly based on color change that occurs because of reaction between the analyte, when present in the specimen with the substance impregnated or coated in the test strip.
Immunoassays
POCT testing using antibodies directed against wide range of targets such as drugs, pathogens, and proteins are categorized under immunoassays. These assays include both individual tests and platforms with multiple built-in tests. Most common tests in this category are group A Streptococcus, mononucleosis, and influenza A and B.
Molecular POCT
In general, molecular tests have high sensitivity and specificity and a rapid TAT. The method primarily amplifies and detects nucleic acid including deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) sequences for identification of the condition. Most common examples are COVID-19, RSV, and influenza A and B testing.
Clinical Significance
POCT offers several advantages impacting clinical outcomes such as appropriate use of antibiotics, prevention of unnecessary treatment escalation, drug dose adjustment, and health management in chronic conditions. The ease of performing a test has allowed a non-laboratory staff to operate POCT promoting its availability in a variety of healthcare settings. The types of institutions that are currently licensed to perform POCT include physicians’ office, pharmacies, skilled nurse facilities, home health agencies, hospitals, and others (2).
Connectivity and Integration with Electronic Health Record
Because POCT testing is used to make clinical decisions, accreditation and regulatory standards require integration of results into the patient’s EHR. The results should be documented with associated reference ranges, units of measurements, critical values if applicable, and date and time of testing. In addition, the test should be traceable to device serial number, operator identification number, reagent lot number, and quality control results (3).
Manual Entry Of Results
Traditionally, POCT results have been manually transcribed in the patient’s chart. However, manual transcription is time-consuming and error prone. On average a 3-5% transcription rate has been reported in an inpatient medicine unit setting. Another audit study reported omission of as high as 12% of POC glucose results that were never recorded into patient’s charts. The error in manual reporting is directly related to complexity of POCT. For example, POC blood gas analysis and POC urinanalysis have multiple components with multiple result options for each component. Errors may occur due to selection of an incorrect result or mismatching test components and results.
POCT Connectivity and Data Management System
The use of connectivity provides a safe and reliable method for transfer of data from POCT devices to EHR. Connectivity of POCT devices to EHR requires a data management system (DMS) or also known as middleware. Depending on the system, multiple POCT devices can be interfaced to a single DMS permitting automation, real-time, bi-directional, electronic wired or wireless transfer of data. Some of the features of DMS include remote access capability allowing for remote monitoring and review, and ability to interface with Admission, Discharge, and Transfer (ADT) systems.
Quality Assurance Management
Under CLIA 1988, laboratory testing using human specimens is subject to regulations. Although, most of the POCT are waived, some are non-waived and subcategorized as moderately complex, requiring specific quality standards including proficiency testing, quality control, and personnel competency requirements. To avoid improper performance of POCT testing or erroneous result entry, accreditation bodies including CLIA require monitoring of quality control and quality assurance programs at all sites where POCT is performed. Additionally, a robust training program for all testing personnel (laboratory and non-laboratory staff) must be maintained to ensure competency (1–3).
Lab-On-Chip
A lab-on-chip is a miniaturized device that enables performance of biological and biochemical analyses of a sample in a single platform. These plastic devices are engineered with tiny channels, valves, and pumps capable of transporting, mixing, and analyzing proteins, DNA, and other chemicals in the body fluids. The chips often require insertion into a portable reader or a scanner. The main advantages of lab-on-chip are ease of use, less error prone, rapid turn-around-time, low sample volume, portability, high sensitivity, low cost, and high accessibility. Major limitations of this technology include lack of readiness for industrialization, increased signal/noise ratio, and ethics. Some of the applications of lab-on-chip include molecular biology, proteomics, and chemistry. One noteworthy example is the newborn screening test for presence of lysosomal storage disorders, which currently uses FDA-authorized lab-on-chip device. Many lab-on-chip devices such as one that can detect presence of sickle cell disease, assist in identifying targeted therapy for asthma and COPD, or assist in identifying anti-viral drugs that can be used in patients infected with COVID-19 are in various stages of development (4,5). This concept of lab-on-chip was over zealously sold by Elizabeth Holmes, founder of Theranos. The promise to deliver devices that could perform multiple tests using just a finger prick of blood was never realized. Ultimately, Elizabeth Holmes was charged with defrauding investors and misleading patients. In the post-Theranos period however, technological advances made such as volumetric adsorptive microsampling (VAM), integrated point-of-care (POC) devices, wearables and telemedicine are reaching a turning point that could realize Elizabeth Holmes’s idea (6).
Artificial Intelligence Assisted POCT
Artificial intelligence (AI) is finding application in various aspects of healthcare including POCT. AI is being used to make POCT economical, faster, and easier to check for quality control. Some key areas where AI is being used include lateral flow immunoassays (LFIA), bright-field microscopy diagnostic testing especially for parasitic infections such as malaria, hematology including complete blood cell count (CBC), and hemoglobin variant detection (7,8).
References
1. Point-of-Care Testing - StatPearls - NCBI Bookshelf. 2. Point of Care Testing - ASCLS. Point Care Test. 3. Fung AWS. Utilizing connectivity and data management system for effective quality management and regulatory compliance in point of care testing. Pract Lab Med. 2020 Nov;22:e00187. 4. Cooper JM. Challenges in lab-on-a-chip technology. Front Lab Chip Technol. 2022 Sep 20;1:979398. 5. Future of medicine: Lab-on-a-chip devices starting to make an impact | NHLBI, NIH. 6. The post-Theranos world. Nat Biotechnol. 2022 Feb;40(2):139–139. 7. Khan AI, Khan M, Khan R. Artificial Intelligence in Point-of-Care Testing. Ann Lab Med. 2023 Sep 1;43(5):401–7. 8. Lee S, Park JS, Woo H, Yoo YK, Lee D, Chung S, et al. Rapid deep learning-assisted predictive diagnostics for point-of-care testing. Nat Commun. 2024 Feb 24;15(1):1695.
Submitted by (Suparna Nanua)
