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

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:

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.

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.

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.

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.

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.

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.

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 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.

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.

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.

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).