Adopting drone technology for blood delivery: a feasibility study to evaluate its efficiency and sustainability

Abstract

Background

Understanding what drives effective implementation is the key to making more sustainable developments. Blood and its components are critical for life-saving transfusions, however, their availability at the point of care is often limited. Moreover, the logistical challenges associated with blood product transport are substantial and maintaining the cold chain throughout the supply route is crucial to sustain their functional integrity as the temperature fluctuations can compromise its oxygen-carrying capacity. Furthermore, factors such as unpredictable demand, remote geographical locations, and extreme climatic conditions can further compound these difficulties. With India’s diverse and distinct topographical variations and geographical spread, last-mile service deliveries of healthcare supplies face multiple challenges. Unmanned Aerial Vehicles (UAVs) or drones are emerging technologies with the potential to leapfrog the last mile logistics solution for transporting medical supplies thus, strengthening the overall healthcare system.

Methods

This study investigates the impact of drone-based delivery on the quality and stability of blood components, relative to conventional transport methods along with the operational challenges associated with implementing a drone-based blood delivery system. To achieve these objectives, the EPIS (Exploration, Preparation, Implementation, Sustainment) framework was adopted, which facilitates a systematic approach to this complex implementation process. The drone-related technical and logistic challenges encountered during the study were also identified.

Results

The study documents the challenges experienced by the study team during the drone-based delivery of blood while maintaining the biochemical parameters of blood components. During the drone based transportation the temperature, integrity of blood cells, and other parameters were maintained, while slight changes in few parameters were observed via both transportation modes. In this study the drone travelled around 36 km in 8 min, while van took around 55 min to cover the same distance.

Conclusions

The present study was done to assess the impact of drone-based delivery on the blood components after the transportation and their comparison to conventional modes of transportation, also, to lay foundation for the successful and sustainable drone-based blood delivery programs. This study suggests that the blood and its components can be transported safely by drone following standard guidelines, which could be helpful particularly in determining blood in emergency situation and difficult terrains.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-025-01650-z.

Text box 1. Contributions to the literature
• Understanding the operational challenges for the transportation of blood bags via drones will provide evidence for the technical and operational feasibility of using drones for blood bag delivery.
• The experiences gained by the present study can be utilized for Improved emergency response in delivering blood in inaccessible areas as a time-efficient alternative.
• In the future, drones could be an option to deliver other important and time-sensitive medical supplies, such as emergency drugs or any other pharmaceutical products as well.

Background

Blood and blood components transfusions may be life-saving for patients in emergencies like hemorrhagic shocks, surgeries and accidents. Even in best resource settings blood components are not always available readily and cannot be transported at the needed place. Blood contains various cellular components (red blood cells, platelets, white blood cells) and plasma proteins, each with specific temperature requirements for optimal function and viability. Deviations from the recommended temperature ranges can lead to irreversible damage [1]. Transportation of blood and its components is complicated as they need to be stored at a specified temperature, else their functionality is affected such as oxygen carrying ability of blood is greatly reduced. Also, the risk of bacterial contamination and hemolysis rises if it is exposed to aseptic conditions or warm environment. Conversely, blood exposed to extreme lower temperatures may get hemolyzed and can lead to a fatal transfusion reaction [2]. Maintaining cold chain integrity is essential for compliance and accreditation. Blood banks and transfusion services adhere to stringent national and international regulations and quality standards that mandate strict temperature control throughout the blood supply chain, from collection to transfusion [3].

Overall, management and transportation of blood and its components is a complex task due to stringent storage conditions, limited shelf life, the unpredictable requirements, complex geographical and climatic conditions [4]. Climatic conditions are crucial since drone transportation and blood biochemicals can be affected by environmental factors. With India’s diverse and distinct topographical variations and geographical spread, delivery of healthcare supplies faces multiple challenges, as India’s climate mirrors its geographical diversity, with the majority of the country experiencing a tropical climate. The interior regions display a blend of wet and dry tropical weather, while the northern parts show a humid tropical climate. Wet tropical areas are located along the western coast, and a semi-arid climate extends in a strip up the country’s center and across the northwest. The delivery of these components is conventionally done via road, which may take time due to traffic, remote locations and poor road conditions, may affect the quality of blood components. During management sometimes unavailability of blood during emergency may drastically impact patient’s life needing a blood transfusion [5]. Overcoming the challenges of distance and infrastructure through innovative solutions is essential for improving healthcare equity, enhancing emergency response capabilities, and ultimately saving lives in underserved communities as accidents, injuries, and sudden illnesses occur regardless of location.

Advanced modes of transport such as air ambulances, and helicopters are being used these days for emergency deliveries. The timely delivery will eventually lead to fewer stockout of blood and its components. Similarly, also UAVs are being considered as one of the potential solutions to the logistic challenges, as they can reach inaccessible areas in shorter duration. Drones have been proven to have great potential for increasing the capacity and efficiency of the healthcare systems [6].

Few Indian studies have explored their potential in delivering medical supplies in the difficult terrain of north-eastern region and high altitude of Himalayan region of India [6]. The transfer of blood and other medical supplies from a designated medical facility to hard-to-reach villages can be costly and time-consuming [7] via conventional mode. Drone technology has offered an improved opportunity in the healthcare sector, primarily in remote environments by enabling just-intime lifesaving medical supply delivery, specially, in rural areas [8]. Also, the vital role of UAVs in supplying medical products such as medicines, vaccines, blood samples, and equipment, in challenging areas where road transport is difficult has been discussed by Sharma & Sharma et al. [9]. Another study by Aggarwal et al. observed that drones present a viable solution for enhancing healthcare accessibility in hard-to-reach regions, particularly for expeditiously delivering diagnostic samples and essential medications during emergencies [10].

The primary concerns during drone based delivery of medical supplies are temperature sensitivity (maintaining cold chain integrity), regulatory concerns (airspace regulations, safety and reliability, data privacy and security, specific medical product regulations) and packaging (protection against physical damage), payload weight and size, while the challenges and limitations associated with UAV-Based delivery systems are battery life, regulatory restrictions (VLOS/BVLOS), weather conditions, airspace regulations, security risks, operational costs [11, 12]. Addressing these critical discussions and challenges through ongoing research, technological advancements, robust regulatory frameworks, and careful operational planning is essential to realize the full potential of drone-based medical delivery and ensure its safe and effective implementation.

This study aims to determine how drone delivery impacts the quality and stability of blood components after transport, compared to traditional delivery methods. In addition to assessing blood quality, the study also seeks to document the operational challenges encountered during implementing drone delivery. To achieve these objectives, the EPIS (Exploration, Preparation, Implementation, Sustainment) framework was implemented, which provides a structured approach for implementing new programs and interventions [13]. In essence, the study is a practical investigation into the feasibility and effectiveness of using drones to deliver blood in emergencies including the impact on the blood, as well as the real-world challenges of setting up and running such a system.

Drone trials in several countries such as Italy and Rwanda have indicated drone as a viable solution for blood transportation not affecting the integrity of the blood and its components, in spite of the accelerations-decelerations sometimes. Another study which was conducted in a Southeast Asian country suggests that obstacles for ground vehicles including geographical distances, challenging topographical features such as mountains and rivers, poor or underdeveloped road systems can be overcome with drones as a mode of transportation [14]. Therefore, the drone is a potential alternative to explore in tropical countries as a first response vehicle in emergencies. But more scientific evidences are required about the practicality, operational challenges and impact on the quality of blood after transportation via drone [15]. Understanding the operational challenges for the transportation of blood bags via drones is a vital step and integrating its feasibility studies in the existing healthcare system may impart several challenges. The primary aim of the present study was to assess the impact of drone based delivery on the blood components after the transportation and their comparison to conventional modes of transportation and will also try to identify the challenges encountered in the process. In order to assess the applicability of drone-based delivery of blood and its components during emergency situations, the EPIS implementation framework was employed.

Methodology

Implementation framework

The key objective of this study was to assess the effects of drone-based delivery in emergency situations on the quality and stability of blood components post-transport, relative to standard transport method, and to document the operational challenges encountered during its implementation. Such as the 2001 Bhuj earthquake resulted in significant morbidity and mortality. During which cases with gangrene (death of tissue due to inadequate blood supply and superadded infections) required elective amputation (surgical removal or loss of a body part), depicting the urgent need of transfusable blood. The major criteria for a better healthcare system are universal and adequate access, affordability, accountability and empathy of service providers, quality care and the cost-effective use of resources, and wide coverage and attention to vulnerable groups. To fulfill this objective, an EPIS implementation framework approach was adopted to assess the applicability of drone based delivery of blood and its components during emergency situations [11] (Fig. 1; Table 1).

Fig. 1.

EPIS implementation framework depiction

Table 1.

Steps involved for the EPIS framework implementation for the drone based blood bag delivery

Exploration	Preparation	Implementation	Sustainment
1. Conducted formative research	1. Planning for assessment of practicality, acceptability, potential risks, operational challenges and impact on the physical characteristics of the medical supplies	1. Bringing the plan into action for the assessment of practicality, acceptability, operational challenges and impact on the properties of the medical supplies	1. Monitoring, evaluation and validation
2. Consultation with hematologists, public health experts, and information technology specialists	2. Training and Education of drone operators and healthcare staff	2. Assessment using prospective repeated measure double blinded study design	2. Guidance document preparation
3. Identification of key healthcare priorities for emergency situations	3. Engagement of healthcare providers, community workers, regulatory agencies	3. Sites and stakeholders’ identification; drone selection, ethical and regulatory approvals	3. Adaptation and integration in the program
4. Conventional transport modalities (helicopters, ground vehicles, and trains) are constrained by availability, cost-effectiveness, regulatory requirements, expertise requirement, and logistic difficulties	4. Compliance with airspace regulations, permits, approvals and safety standards	4. Sample collection and pretesting	4. Policy discussions to support the long-term integration of drone delivery into the healthcare system
	5. Drone selection, payload management, flight planning	5. Sample transportation via conventional mode and via UAV	5. Information dissemination and adoption by National Blood Transfusion and Council (NBTC)
	6. Emergency protocols and communication protocols	6. Return to medical colleges and post transportation testing; Statistical analysis
	7. Quality assessment by temperature monitoring, blood integrity etc	7. Monitoring and evaluation

By addressing these key factors, we laid foundation for the successful and sustainable drone-based blood delivery programs, as during recent years unmanned Aircraft System (UAS) usage in the medical sector as an alternative to traditional means of goods transport has grown significantly. Emerging evidences suggest the potential of UAVs for healthcare logistics and currently the Indian Council of Medical Research (ICMR) is investigating their application in this context. Even though the reduced response time achieved with UAVs can be lifesaving in critical situations, their usage must comply with technological constraints such as range, speed and capacity, while minimizing potential risks. By systematically addressing the challenges occurring while implementing the EPIS framework, healthcare organizations can increase the likelihood of successfully implementing and sustaining drone-based delivery services to improve healthcare access and outcomes (Fig. 2).

Fig. 2.

Steps involved in the EPIS framework

Implementing drone-based blood delivery involved bringing the prepared plans into action comprising the following:

• a. Study design

The present study utilizes a prospective repeated measure double blinded study design to evaluate changes in hematological quality parameter in blood and its components transported by drones. The hematological parameters of blood were collected and analyzed at two timepoints: Baseline at blood banks and second after drone-based transportation. The primary objective is to determine the intra-operation variability and any temporal changes in hematological parameters. Simultaneously one set of blood samples from the same blood bags were also transported by road (conventional) and compared by drones’ transported samples. The study was conducted for three months from May–July 2023 when the ambient temperature was ~ 30–40ºC with an average wind speed of 3.0 m/s.

• b. Study settings

The study was conducted in National Capital Region and Delhi in India. Three sites with appropriate infrastructure, i.e. Lady Hardinge Medical College (LHMC) New Delhi: Site 1, Government Institute of Medical Sciences (GIMS) Greater Noida: Site 2 and Jaypee Institute of Information Technology (JIIT) Noida were included in the study (Fig. 3). Both the medical colleges were having the blood bank and blood testing facility. Also, LHMC has been identified by NACO as a national Reference Lab for HIV testing, which is also providing comprehensive blood physiology diagnostics services. Additionally, the engineering institute was selected as operational hub, which was located in the green zone on the DigitalSky platform as per the drone rules, which is the airspace up to 400 feet and areas within 8–12 km from the perimeter of an operational airport up to 200 feet [14]. DigitalSky platform is the online platform hosted by the Directorate General of Civil Aviation (DGCA), India for various activities related to the management of unmanned aircraft system activities in India. Geographically JIIT was in the center and both the medical colleges were 20 km and 35 km (30–55 min for travel) away from it. For the study, blood samples and its components were taken from both the medical colleges to ensure the repeatability and reproducibility of findings. Study involved an interdisciplinary team consisting of medical professionals, paramedics, engineers, biotechnology and drone technology experts. The study followed a prospective comparative double- and was conducted for a period of three months, from April-June 2023.

• c. Study sample and collection

Fig. 3.

Map showing the geographical locations and distances of the three sites from National Capital Region (NCR)/New Delhi included in the study (Courtesy: Google Maps)

The study was conducted with 15 bags each of whole blood (350 ml each), Packed red blood cells (PRBCs, 350 ml each), fresh frozen plasma (FFP, 60 ml each) and platelets (100 ml each) (Fig. 4). All the blood bags were provided by both blood bank pac. Blood samples were drawn from healthy donors as per National Blood Transfusion and Council (NBTC), National Aids Control Organization (NACO) guidelines with their consent [15]. The blood and its components were stored under aseptic conditions as per the NBTC guidelines, and per their part of routine blood collection from donors.

• d. Study variables

Fig. 4.

Framework showing study design and steps of implementation* (*Both medical colleges followed this testing flow only)

The blood bags were selected from both the blood banks and were analyzed before drone sorties to know the baseline characteristics of blood bags. To comprehensively assess the impact of drone-based delivery on blood components, a multi-faceted approach was taken up, focusing on comparing the quality of blood transported by drones with that of traditionally transported blood ensuring the double blinding of samples. Few essential criteria have been identified for safe blood transfusion by the NBTC [15], which is essential to ensure for safe blood transfusion in India. These criteria include temperature, whole blood/PRBC: Hemoglobin, hematocrit value; fresh frozen plasma: fibrinogen, factor-VIII and platelets: platelet count. However, in the present study in addition to above listed parameters, we observed the post transportation variation in few additional parameters as well. Thus, all blood samples were tested for biochemical parameters corresponding to each blood component, like (hematocrit, hemoglobin, LDH, K⁺ and Cl⁻ for WB and PRBC; activated partial thromboplastin clotting time (APTT), factor-VIII and fibrinogen levels for FFP; platelet counts and pH for Platelets) prior to the transportation.

• e. Data collection

Standard collection methods were used to measure the hematological parameters of blood and blood components, which are given in Suppl. Table 1.

Double blinding of sample testing

To conceal the information about the samples'transportation method (drone or van) and to reduce the observers’ and measurement bias from the individuals involved in the testing and analysis, blinding of samples were done, which involved following steps:

Initial testing and division

Each blood bag underwent initial testing for its hematological and biochemical parameters to provides a baseline for comparison after transportation. These original bags were then divided into two smaller bags, each containing half the volume, which created paired samples for comparison between the two transportation methods.

Coding and randomization (The first level of blinding)

Each of these smaller bags was assigned a unique, arbitrary code, which disconnected the sample from its original identification and the transportation method it later underwent. These uniquely coded bags were then randomly assigned to either drone or van transportation, thus ensuring that any inherent differences between the samples are evenly distributed across the two transportation groups, reducing the chance of systematic bias. The investigators kept the link between the unique code and the transportation method strictly confidential ensuring that the individuals handling and analyzing the samples remain unaware of how each specific bag was transported.

Transportation and post-transportation analysis (the second level of blinding)

The coded bags were transported according to their random assignment. After the transportation sortie, the investigators decoded the unique codes to reveal the original institutional labels of the blood bags. The bags were then handed over to the respective medical college teams without disclosing the transportation mode.

• f. Selection of drones

A fixed wing hexacopter (VTOL: vertical take-off and landing; Suppl. Figure 1) with a payload capacity of ~ 5.0 kg and endurance of a distance of 40 km was chosen for operations, as approximately 4–6 bags were taken per sortie along with 3–4 refrigerated gel packs to maintain the desired temperature thus making a total weight (3.5–4.0 kg). All flight operations were conducted in Beyond Visual Line of Sight (BVLOS) range and in accordance to India's drones regulatory framework (2021) [14]. The keyhole Markup Language (KML) files were generated by drone operators prior to flights to get geographic data of the path covered during the operation.

• g. Study implementation plan

  • i.
    Transportation of the bags from blood banks to the drone operational sites for drone sorties

The drone bags were transported in a specially designed battery-operated refrigerated transport box made up of plastic to maintain temperature (Suppl. Figure 1). Outer Material of the transportation box was prepared with durable and potentially impact-resistant plastics like high-density polyethylene (HDPE) or polypropylene (PP) comprising robustness and ease of cleaning. Also, material like expanded polystyrene (EPS) was used to create a thermal barrier and maintain a stable internal temperature. These transportation bags were specially designed to carry at least 6–8 blood bags along with 2–4 gel packs (approximately 24 Liters) and had an in-built digital temperature logger to check the cold chain maintenance. Small, battery-powered digital data loggers, which can record temperature (and sometimes humidity) at pre-set intervals were used for the study. The refrigerated transport box might be pre-cooled to the target temperature range before loading the blood bags. Depending on the type of blood component and blood bags, the number of ice/gel packs were placed (Table 2) as per NBTC guidelines [15]. The drone and van both travelled on a pre-defined path of around 30 km with the blood bags. Upon completion of the sortie, the temperature was recorded, and bags were checked for any physical damage or spillage.

Table 2.

Blood components with their recommended storage conditions

Blood component	Whole Blood & PRBC	Platelet Concentrates	Fresh frozen Plasma
Recommended Storage Conditions	Temperature + 2℃ to + 6℃	+ 20℃ to + 24℃	− 30℃ or below
Transportation techniques used	In a battery-operated blood transportation box	In a battery-operated blood transportation box	In a battery-operated blood transportation box
Adaptations Made	4–5 blood bags in the soft cooler bag with 2–3 refrigerated gel packs	6–8 platelet bags	4–5 FFP bags with frozen packs to facilitate thawing

• ii. Return to the medical colleges and re-testing of samples

Post- transportation quality assessment of the received blood components was done at the medical colleges. Further, the change in each parameter was recorded, via drone and road both, to observe the effect of mode of transportation on the biochemical parameters as compared to the conventional means i.e. via road. The results of blood bag testing were entered in data sheet, decoded and analyzed.

Dry run and piloting of actual study

A dry run (without blood bags) of drone was performed to optimize the operating system of the drone. Afterwards, a pilot run was conducted with a few expired blood bags to understand any necessary operational changes to the protocol before implementing the main feasibility study. The research and UAV technical teams were present during the pilot study to allow a thorough review of the flight plan, sortie schedules and other associated parameters, so as to avoid any trouble during the actual sortie. The technical and operational challenges encountered at any step related to maintaining optimal temperature, unavailability of advanced machinery, storage of drones was documented by the research team.

• h. Statistical analysis

Descriptive statistics was used to calculate the mean, and standard deviation within the data group. Descriptive statistics provided a snapshot of the baseline characteristics and the variability of each blood parameter within each group being studied. To evaluate changes in blood parameters after transportation, Repeated measures ANOVA was used to compares the means of same variables across multiple observations of the same samples. In the study’s context of hematological parameter analysis, the technique is particularly useful for examining how blood parameters change while being delivered via different modes and also before, and after the transportation. This analysis requires fewer participants compared to a between-subjects design to achieve the same statistical power. Also, the strategy helps in determining if the act of transportation (and the mode of transportation) causes a statistically significant change in the blood parameters of the same blood units over the course of the study. The difference between observations was considered significant at p < 0.05, therefore the parameter values with p > 0.05 signify no difference via both the transportation modes.

• i. Safety measures adopted by the team

For safety and security purposes, local authorities including Department of Delhi Fire Services were duly informed about the schedules of the drone flight prior the operations. An ambulance with a doctor and a paramedical staff was also deployed at the site of the drone flight in case of any unforeseen circumstances. Before each flight, drone teams carefully plan the route, taking into account factors such as weather conditions, airspace restrictions, and potential obstacles. Drone teams formulated well-defined procedures to follow in case of emergencies such as lost communication, unexpected landing etc. Also, the weather conditions were closely monitored, as flying in adverse weather could lead to accidents and loss of essential supplies.

• j. Ethical permissions and compliance to drone rules of India

The Institutional Ethics Committee (IEC) from all three institutes granted ethical approvals for the study. Local authorities were duly informed and administrative approvals were obtained wherever required as per Ministry of Civil Aviation (MoCA) [13]. JIIT Noida was a green zone as per the Drone Rules 2021, thus, exempted from technical approvals from the Ministry of Civil Aviation (MoCA) and the Director General of Civil Aviation (DGCA).

Results

An EPIS (Exploration, Preparation, Implementation, Sustainment) implementation framework approach was adopted to assess the applicability of drone based delivery of blood and its components during emergency situations [11] (Fig. 5).

Fig. 5.

Implementation framework practiced for drone based blood bag delivery

A total 60 blood (and blood components) bags were taken for the study. Out of these 60 bags 32 were from male donors, while 28 were from female donors. Average age of the blood varied from 5 to 23 days. All blood bags were negative for Hepatitis B/C, HIV, and Malaria parasite. The present study has recorded the changes in physical and biochemical quality of blood post transportation via drone as compared to transportation by conventional means. Also, the technical and operational challenges of the research team engaged in implementation of drone-based delivery of blood bags were documented. None of the bag showed hemolysis or clumping signs. Temperature of the blood bags was also remained maintained during the sortie.

The study also investigated the time efficiency of two delivery methodologies: an unmanned aerial vehicle (UAV) and the conventional delivery method. The drone travelled on a pre-defined path of around 36 km in the mean travel time of ~ 30 min with the mean velocity of 70–75 km/h Suppl. Figure 1. In contrast, van travelled the same distance in a mean travel time of 55 min with an average velocity of 10–15 km/h depending upon the traffic situation (The raw data of time taken by both methods are given under supplementary data (Suppl. Table 2). These data demonstrate that the UAV facilitated significantly faster deliveries. Also, t-value was found to be 9.9920, which demonstrate that the difference is statistically significant, as a t-statistic of 2 or higher is considered to be statistically significant.

Comparison of Hematological parameters (Baseline and after sortie)

Blood components’ Hematological parameters are as follow:

• (A) Characterization of whole blood parameters

For the transfusion of whole blood, the essential criteria as per the NBTC guidelines are temperature, hemoglobin and hematocrit value. An increase in the average temperature (0.5ºC) of whole blood bags was observed after transportation via both i.e. van and drones, however this increase was within acceptable range. Levels of hemoglobin decreased by ~ 0.2 units via both the modes of transportation however these changes were in acceptable ranges. Additionally, few parameters such as LDH, K⁺ and Cl⁻ levels were also compared. These additional parameters were also observed to be under the standard range, e.g. hematocrit (± 1.2–2.1%), LDH (± 22–47 U/L), Potassium (± 0.3–0.5 mEq/L) and Chlorine (± 0.7–1.7 mg/dL). As the differences were not significant in all the parameters via both the modes, thus there is no significant difference in the biochemical parameters’ levels from the initial levels (Table 3).

Table 3.

Whole blood parameters baseline and after transportation

Site 1					Site 2
Parameter	Pre-flight	Drone	Van	p-value*	Pre-flight	Drone	Van	p-value*
Temp. (ºC)**	4.3 ± 0.5	6.8 ± 1.7	..	0.13	4.5 ± 0.7	5 ± 0	5 ± 0	0.06
HCT (%)**	36.7 ± 3.3	38.8 ± 3.1	38.1 ± 4.7	0.01	40.8 ± 3.9	39.6 ± 4.9	40.2 ± 3.7	0.27
Hb (g/dL)**	12.0 ± 0.9	12.0 ± 1.0	11.9 ± 1.2	0.84	13.9 ± 1.3	13.5 ± 1.7	13.7 ± 1.3	0.27
LDH (U/L)**	389.0 ± 261.0	436.6 ± 310.6	424.7 ± 242.8	0.05	411.0 ± 173.6	365.7 ± 146.0	389.0 ± 169	0.04
Plasma Hb (% hemolysis)**	0.1 ± 0.1	0.1 ± 0.1	0.1 ± 0.0	0.14	0.1 ± 0.2	0.1 ± 0.1	0.1 ± 0.2	0.89
K+ (mEq/L)**	7.9 ± 3.1	8.4 ± 3.6	8.3 ± 3.2	0.09	8.3 ± 3.8	8.0 ± 3.0	8.8 ± 3.4	0.11
Cl− (mg/dL)**	76.3 ± 4.2	75.6 ± 4.1	75.6 ± 3.6	0.55	77.6 ± 20.2	79.3 ± 5.3	82.1 ± 5.4	0.50

^* Calculated by Repeated measures ANOVA

.. Could not be recorded due to technical glitches

^** p-value > 0.05, thus there is no significant difference in these parameters between both the transportation modes

• (B) Analysis of Fresh Frozen plasma

For the transfusion of Fresh Frozen plasma, the essential criteria as per the NBTC guidelines are fibrinogen and Factor-VIII. A decrease in factor-VIII (Drone: 32.3, 5.0; Van: 32.2, 18.9 respectively for site 1 and site 2) and fibrinogen value were observed irrespective of the mode of the delivery (Table 4). Additionally, APTT were also observed for changes post transportation and an increase in the APTT value (Drone: 0.8, 2.0; Van: 1.5, 2.7 respectively for site 1 and site 2) was observed. No significant difference was observed in fibrinogen, factor-VIII and APTT levels via both the transportation modes from initial levels (p > 0.05).

Table 4.

Fresh frozen plasma parameters baseline and after transportation

Site 1					Site 2
Parameter	Pre-flight	Drone	Van	p-value*	Pre-flight	Drone	Van	p-value*
Temp**	−20.0 ± 0.0	−18.5 ± 0.5	−19.0 ± 0.5	0.09	−40.0 ± 0	−40.0 ± 0	−39.0 ± 0	0.10
APTT**	28.5 ± 2.2	30.5 ± 2.7	31.2 ± 2.3	0.00	31.8 ± 1.4	32.6 ± 2.6	33.3 ± 2.6	0.10
Fibrinogen**	256.2 ± 42.6	238.9 ± 34.5	234.8 ± 39.9	0.08	281.8 ± 59.5	272.0 ± 68.7	272.6 ± 74.1	0.66
Factor- VIII**	127.2 ± 45.5	94.9 ± 28.7	95.0 ± 29.0	0.99	169.2 ± 71.8	164.2 ± 68.7	150.3 ± 65.2	0.04

^* Calculated by Repeated measures ANOVA

^** p-value > 0.05, thus there is no significant difference in these parameters between both the transportation modes

• (C) Hematological parameter analysis of Packed red blood cells (PRBC)

For the transfusion of PRBC, the essential criteria as per the NBTC guidelines are temperature, hemoglobin and hematocrit value. An increase in the temperature (1.0–1.6ºC) of PRBC samples was observed after transportation via both the modes (Table 5). Similar patterns were evident in the hematocrit (± 0.4–0.7%) levels also. Additionally, few other parameters such as LDH, potassium ion and chlorine levels were also observed for changes post transportation. These additional parameters were also found to be under the standard range, e.g. LDH (100–200), Potassium (± 1.2–2.0 mEq/L) and Chlorine (± 1.4–3.9 mg/dL) ions. Thus, for hematocrit, haemoglobin and Cl⁻ values, there was no significant difference between both the transportation modes from initial levels (p > 0.05).

Table 5.

PRBC parameters baseline and after transportation

Site 1					Site 2
Parameter	Pre-flight	Drone	Van	p-value*	Pre-flight	Drone	Van	p-value*
Temp. (ºC)**	4.0 ± 0	5.5 ± 1.0	5.6 ± 0	0.07	4.0 ± 0	5.0 ± 0	5.0 ± 0	0.03
HCT (%)**	68.9 ± 6.0	68.5 ± 5.7	69.4 ± 5.1	0.52	63.7 ± 3.1	64.0 ± 3.8	64.4 ± 3.2	0.01
Hb (g/dL)**	20.2 ± 1.6	20.1 ± 1.6	20.6 ± 1.5	0.12	21.6 ± 1.0	21.8 ± 1.3	21.7 ± 1.1	0.55
LDH (U/L)	1941.9 ± 562.5	2043.9 ± 704.7	2147.1 ± 730.5	0.03	649.3 ± 498.7	854.8 ± 425.2	844.5 ± 396.1	0.00
Plasma Hb (% hemolysis)**	0.6 ± 0.4	0.6 ± 0.5	0.6 ± 0.5	0.01	0.1 ± 0.1	0.1 ± 0.1	0.2 ± 0.2	0.24
K+ (mEq/L)**	..	..	..	NA	19.6 ± 6.1	20.8 ± 5.1	21.6 ± 6.4	0.71
Cl− (mg/dL)**	80.4 ± 12.9	82.8 ± 13.3	84.3 ± 13.1	0.00	113.5 ± 4.9	112.1 ± 3.2	112.1 ± 3.0	0.23

^* Calculated by Repeated measures ANOVA

^** p-value > 0.05, thus there is no significant difference in these parameters between both the transportation modes

..Could not be recorded due to technical glitches

NA Not applicable

• (D) Analysis of platelets

For the transfusion of Platelets, the essential criteria as per the NBTC guidelines is platelet count. A decrease in the platelet count (0.5–0.8) was observed after transportation via both the modes. Additionally, no significant difference in pH was observed from the initial levels via both the transportation modes (Table 6).

Table 6.

Platelets parameters Baseline and after transportation

Site 1					Site 2
Parameter	Pre-flight	Drone	Van	p-value*	Pre-flight	Drone	Van	p-value*
Temp.**	22 ± 0	21.6 ± 0.4	21.4 ± 0.0	0.21	22.0 ± 0	21.5 ± 0	21.4 ± 0	0.07
Platelet Count**	8.6 ± 4.7	7.9 ± 4.9	7.8 ± 5.0	0.01	5.7 ± 0.5	5.2 ± 0.6	4.9 ± 0.6	0.18
pH**	7.2 ± 0.2	7.2 ± 0.2	7.2 ± 0.3	0.28	7.3 ± 0.1	7.3 ± 0.1	7.4 ± 0.1	0.20

^* Calculated by Repeated measures ANOVA

^** p-value > 0.05, thus there is no significant difference in these parameters between both the transportation modes

(ii) Study implementation and challenges

With the inception of the study, the team faced certain challenges along the way and adapted solutions to overcome them. On the other hand, feasibility studies for integrating novel technologies in the existing healthcare system have several challenges at the operational level experienced by the implementing unit [16] (Fig. 6). The implementation of the study, challenges observed, and solutions adapted are listed here:

1. Keeping the understanding of drone pilots in mind, as they were not much aware about the blood products, aseptic conditions, precautions etc., before conducting the drone operations hands-on training of local medical team, health care workers, drone operators for the drone-based delivery of medical supplies was organized to increase their participation in the study. It was made sure that the training module and presentations were prepared in easy/local language and visuals.

2. Weather plays an important role during the flight, therefore the weather conditions were closely monitored, as flying in adverse weather, such as heavy rain, strong winds, or fog, could lead to accidents and loss of essential supplies. Therefore, it was ensured that sorties were carried out in good weather conditions. As the study was conducted in New Delhi during the months of April and May, which typically constitute the sunny season, we experienced predominantly clear skies and a low incidence of adverse weather events. However, we encountered two instances where drone flights had to be postponed due to sandstorm conditions. All other flight attempts proceeded as scheduled under favorable weather.

3. Seeking administrative approvals is an important task to be ensured beforehand. So, the local authorities were duly informed and all the administrative approvals were obtained beforehand as per drone rules. Ethical approvals were obtained from the Institutional Ethical Committees of respective institutions.

4. All the details of flight take-off time, total sortie time, flight landing time, speed, distance and maximum altitude covered by the drone were immediately documented to execute strict time management, traffic and handling of unforeseen events.

5. There were few administration‑related challenges, such as the processing of documents involves multiple departments, also delays in the administrative process due to changes in administrative rules, site-specific administrative hindrances and leadership created bottlenecks for file processing.

6. Although the DigitalSky platform aims to be a single-window system, navigating the requirements for registration, obtaining Unique Identification Numbers (UIN), and securing flight permissions, especially for Beyond Visual Line of Sight (BVLOS) operations, can still be complex and time-consuming.

7. Few drones related technical challenges and logistic challenges were: deployment of suitable drones, payload capacity, time management for operations, storage and transportation of drones. To overcome these challenges, SOPs were developed and regular maintenance and inspection of batteries, motors, propellers etc. were done to ensure efficient working conditions and drone pilots were familiarized with the local regulations and guidelines before the operations.

Fig. 6.

Challenges encountered during healthcare delivery via drone

Key technical challenges encountered during the study are as follow:

1. Payload Capacity and Weight Management

2. Temperature Control and Maintenance

3. Flight Range and Endurance

4. Navigation and Autonomous Flight

5. Air Traffic Management and Integration

6. Maintenance and Operational Logistics

Discussion

The EPIS implementation framework [11] guided the evaluation of UAV-based delivery of blood and blood products in emergency settings. The initial exploration phase involved investigating the problem of availability of blood during emergency situation and potential solutions, such as researching the potential of drone technology for this purpose, assessing the feasibility of using drones, considering factors like regulations, technology capabilities, and cost. In one study, UAV-based simulation method designed for air pollution measurement was executed within the Unity 3D environment [17, 18]. The preparation stage focused on planning and getting ready for implementation including development of protocols for drone delivery (e.g., flight paths, safety procedures, handling of blood products, emergency situations) obtaining necessary approvals and permits, training personnel on drone operation and related procedures., setting up the necessary infrastructure (e.g., landing sites, storage facilities). During implementation phase, the actual deployment of the drone delivery system took place, including pilot tests or trials to evaluate the system in real-world scenarios, monitoring performance and making adjustments as needed, gathering data on the effectiveness and efficiency of drone delivery. The next phase i.e. sustainment will focus on ensuring the long-term viability and continuation of the drone delivery system as a regular transportation mean during emergencies. This will include establishing maintenance procedures for the drones, securing funding for ongoing operations, integrating the drone delivery system into existing emergency response protocols, evaluating the long-term impact and making further improvements.

The advent of COVID-19 pandemic and the restrictions imposed due to lockdowns also provided opportunities for flourishing alternative methods supporting contactless delivery of services in varied destinations [19]. The present study documents the challenges experienced by the study team during the drone-based delivery of blood while maintaining the biochemical parameters of blood components. In this study the drone travelled around 36 km in 8 min with a velocity 70–75 mtr/sec, while van took around 55 min to cover the same distance (with a velocity of 10–15 mtr/sec), thus travelling time was reduced by half when the samples were transported via drone as compared to van. Also, a study in the USA found that drones resulted in a median time saving of 16 min for automated external defibrillator delivery [20]. Furthermore, a study in San Francisco’s Mission district (USA) found a time reduction of 83 min for prescription drug delivery [21]. In Rwanda, a study was conducted to evaluate the effect of drones on the blood components resulted into a decrease in blood components expiration and also appropriate for emergency settings as the delivery was faster than the conventional mode. Unlike road transport of blood components, drones resulted in a shorter delivery duration and less exposure to poor roadways, potentially leading to less damage to delivered blood components in Rwanda [22]. Thus, 7.1% decrease in blood unit expirations per month was observed.

As evident from the data of the present studies, whole blood parameters don’t get affected due to transportation via drone and while few parameters changed, such as PRBC, FFP and platelets but these slight changes were evident via conventional transportation method also. For instance, no leakage was observed in any of the sample bags after transportation. Temperature of any of the samples did not vary much after the transportation as compared to the initial temperature. No incident of clumping was observed in platelets sample. Although levels of some parameters such as PRBC, FFP and platelets altered, but these values were also in standard ranges. Similar findings were observed in the studies that assessed the effect of similar drone delivery systems of medical supplies in other countries. Importantly, the available evidence also shows no major effect of drone delivery on the quality of blood components [19] and other medical products [23]. Apart from this, in another study investigators have used an unmanned, rotary- wing drone to simulate the delivery of a customizable, 4.5 kg load of medical equipment, including tourniquets, dressings, analgesics, and blood products in austere environments, which can be beneficial for austere care of military and civilian casualties [24].

It strongly reinforces the feasibility and safety of using drones for blood delivery. This addresses a primary concern regarding the potential impact of flight conditions (vibration, temperature fluctuations) on these delicate biological materials.

As the primary concern surrounding the transport of delicate biological materials like blood via unconventional methods is the potential for damage due to factors like vibration, temperature fluctuations, pressure changes, and physical stress during flight and landing, these evidences indicate no major negative impact of drone delivery on blood component quality. Thus, it will pave the way for leveraging the speed, reach, and efficiency of drones to improve access to life-saving blood products for patients in diverse settings and facilitate the development and approval of regulations governing drone-based medical deliveries. Therefore, present study clearly indicates that drones can act as a powerful tool for bridging the gap between the blood supply and demand ensuring that more patients receive the blood they need, when they need it.

The significant contributions of this study include:

1. The study provides empirical evidence that drone-based transportation can maintain the biochemical parameters, temperature, and integrity of blood components effectively, comparable to those observed through conventional methods.

2. The study also demonstrated significant time efficiency in delivering blood and its component via drone.

3. The research documents the practical operational and technical challenges encountered during the implementation of a drone-based blood delivery system, providing valuable insights for future deployments.

4. It lays groundwork for the sustainable integration of drone technology into blood delivery programs, particularly for emergency situations and difficult terrains.

5. The findings of this study suggest the broader applicability of drones for delivering other critical medical supplies, such as emergency drugs and pharmaceutical products.

Selection of drones, battery related issues and storage of these machineries was technical challenges in the field for the research team as well as drone operators. Since the quality and quantity of the medical supply delivery may vary in a case-to-case manner, the type of drone was selected accordingly for each location [25]. However, still there is a need for low weight and high-capacity batteries for transporting medical supplies to a longer distance. The safe storage and security of the drones near the deployment site was a major concern, considering their high maintenance cost, chances of misuse, damage causing delays in operations. Also, it must be carefully examined that the consignment may not exceed the maximum payload capacity of the drone.

Apart from above issues, air temperature, wind speed, precipitation, and other atmospheric phenomena were observed to adversely affect drone endurance, control, aerodynamics, airframe integrity, line-of-sight visibility, airspace monitoring, and sensors for navigation and collision avoidance. Factors such as wind speed hinder the operations as they affect quality of sensors, and battery [26]. Similar to the experiences in this study, these weather conditions have posed challenges for drones leading to deviations from the predetermined routes earlier as well [27, 28], therefore checking the weather prior to the operations is a pre-requisite [29]. Additionally, the drone operations were restricted to watch hours of the local ATC in the present study, which is a common practice across the globe to avoid the mis-happenings and accidents in night.

Scope of the present study

This feasibility study on adopting drone technology for blood delivery was conducted under controlled conditions with the prime objective to evaluate the efficiency. By controlling variables such as flight paths, and payload etc. the study is aimed to establish a baseline understanding of drone performance under critical situation. This approach allowed for a focused assessment of technical feasibility and the identification of optimal operational parameters and challenges in a predictable environment. While acknowledging that true emergency situations involve significant variability, this controlled study provides foundational data to inform future research and development in more complex and dynamic settings.

Limitations of the study

The present work is a study in controlled environment which was conducted under the supervision of experts. The real field scenario may be little different, however the challenges faced during the implementation in the study will aid in understanding of drone based delivery. The challenges faced during small-scale implementation will be important to understand and provide the evidence base for large-scale implementation, but the final recommendation can be sought by physicians based upon the blood component being transported and also upon the local conditions.

Based on these challenges faced and solutions adapted by the team, few recommendations have been listed in the box to provide future directions.

Key learning points

1. Drone sorties should be compliant to the drone rules.

2. NBTC guidelines should be followed for ensuring blood and its components quality.

3. Study should be designed as per weather conditions at the site.

4. Integrity must be ensured while packing and transporting health-care supplies.

5. Physical characteristics of blood bags, loading time, temperature, payload capacity must be noted.

6. The communication between the drone and the ground control station must be encrypted to prevent data breaches.

7. Efficient emergency protocol to handle mid-air malfunctions must be kept in hand.

8. While flying in the populated areas privacy concerns must be taken into account.

Research in context

Evidence before this study: A major focus of emergency medical services (EMS) systems and prehospital medicine has been improving the time until medical intervention in these time-sensitive emergencies, often by reducing the time required to deliver critical medical supplies to the scene of the emergency. It is a tool complementary to existing transport systems offering advantages over traditional approaches in specific circumstances. Medical indications for using unmanned aerial vehicles, or drones, are rapidly expanding, including the delivery of time-sensitive medical supplies. Drones have been used in Taiwan, Nepal, and other countries to reach remote villages and hospitals. Unmanned vehicles successfully delivered small aid packages after the Haitian earthquake in 2012 and helped in humanitarian operations for collecting data and imagery when the infrastructure was destroyed in the Philippines after a typhoon in 2013.

Added value of this study: Drones present a tremendous opportunity to address supply chain shortcomings in the healthcare sector, reducing stockouts and wastage. Further, research demonstrating functionality in real-world scenarios, as well as research that integrates drones into the existing EMS structure will be necessary before drones can reach their full potential. For drones to be effective, the effects of flight must not alter medical supplies. Several studies have confirmed that there are no changes in temperature, pressure and forces of gravity of the articles being supplied. However, the present study analyzes the effect of drone flight on blood and its components’ crucial hematological parameters. Implications of all the available evidence: Our findings have generated evidences to validate the potential use of drones in blood and blood components’ delivery. The study also provides a basis for efficient and optimal application of drones in enabling just-in-time lifesaving medical supply/device delivery.

Conclusions

The evaluation of UAV-based delivery of blood and blood products in emergency settings was conducted using the EPIS framework as a guiding methodological structure. Implementing drone-based technology for the delivery of blood components will be useful during emergency situations and in difficult terrains which currently face delayed healthcare responses due to inaccessibility. Overall, the experience gained during this study will help to develop strategies for transporting blood components via drones for faster and efficient delivery. UAV transportation of blood components may be best used during pandemic situations, especially if ground transportation is limited. The present study focuses on the implementation of drone technology for transporting blood and challenges encountered during the process. Under the study, four different types of blood components were successfully transported by UAVs using dedicated shipping boxes with thermoregulation capabilities and also the transportation was significantly faster via drones than through conventional mode i.e. via van. No incident of hemolysis was observed in the transported blood samples via both modes. The temperature of the blood components remained within their respective acceptable ranges during the flight and after the flight. As observed from the data whole blood parameters did not get affected due to transportation via drone and while few parameters of PRBC, FFP and platelets changed by both transportation modes. These experiences can be utilized by state collaborators for delivering blood through new technology along with conventional modes in inaccessible areas as a time-efficient alternative with limitation of requirement of KML file and location coordinates. In the future, drones could be an option to deliver other important and time-sensitive medical supplies, such as emergency drugs or any other pharmaceutical products as well.

Abbreviations

UAV

Unmanned Aerial Vehicles

EMS

Emergency medical services

EPIS

Exploration, Preparation, Implementation, Sustainment

UAS

Unmanned Aircraft System

ICMR

Indian Council of Medical Research

JIT

Jaypee Institute of Information Technology, Noida, India

LHMC

Lady Hardinge Medical College, New Delhi, India

GIMS

Government Institute of Medical Sciences

DGCA

Directorate General of Civil Aviation

NCR

National capital region

PRBC

Packed red blood cells

FFP

Fresh frozen plasma

NBTC

National Blood Transfusion and Council

NACO

National Aids Control Organization

IEC

Institutional Ethics Committee

MoCA

Ministry of Civil Aviation

Authors’ contributions

PG: Implementation and Supervision; AN: Implementation and Supervision; SB: Implementation, Supervision and data collection; SP: Implementation, Supervision and review; SD: Implementation and data collection; KA: Supervision; SS: Supervision; DA: Implementation and data collection; MJ: Supervision; RS: Supervision; RP: Supervision; P: Implementation and data collection; RG: Lab testing and management; SS: Implementation and data collection; PA: Manuscript drafting, editing, Statistical analysis; RMP: Statistical analysis; BA: Implementation; KN: Draft proposal writing, Implementation, data collection, manuscript drafting; SA: Conceptualization, Implementation, Supervision, editing and final review. All authors had full access to the data in the study and read and approved the final version of the manuscript.

Funding

This study was supported and funded by the Indian Council of Medical Research, New Delhi, India.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

The Institutional Ethics Committee (IEC) from all three institutes granted ethical approvals for the study. Local authorities were duly informed and administrative approvals were obtained wherever required as per Ministry of Civil Aviation (MoCA) [8]. JIIT Noida was a green zone as per the Drone Rules 2021, thus, exempted from technical approvals from the Ministry of Civil Aviation (MoCA) and the Director General of Civil Aviation (DGCA). Consent to participate: Not required.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.