This prospective study will be held in two steps.

The aim of the first step is to assess the technical validity of transmitting data remotely from different devices connected to a telerehabilitation system. These will include real-time oximetry data during exercise on a cycle ergometer (heart rate and transcutaneous oxygen saturation) as well as daily step count from a commercially available physical activity tracker.

The aim of the second step of the study is to assess the clinical feasibility of using the telerehabilitation system in real life conditions (in the home environment). Briefly, participants will benefit from a eight weeks pulmonary rehabilitation program performed at home, using the telerehabilitation system. Further details about the content of the program and the outcomes are provided below.

Before taking part in the study, participants will undergo an incremental cardiopulmonary exercise testing as their baseline assessment before referral to a pulmonary rehabilitation program.

Participants referred for pulmonary rehabilitation to the ADIR Association will be screened for eligibility. They will be contacted to initiate their program. During the first session, they will be offered to participate in the study.

This protocol will be held in two steps : the first step will aim to assess the clinical validity of the data transmitted remotely through the system (from two different devices) and the second step will aim to assess the clinical feasibility of using the system in the home environment.

Participant recruitment for each of these steps will be performed chronologically (the first twenty eligible participants will participate in the technical validity step of the study and the last twenty eligible participants will participate in the clinical feasibility step).

Step one: Clinical validity. The first step of the study aims to assess the clinical validity of data transmitted remotely from two devices connected to the telerehabilitation system (a. oximetry data during exercise and b. daily step count from a commercially available physical activity tracker).

1. Oxymetry data during exercise on a cycle ergometer.

   Participants who agree to participate will be trained to use the system within the pulmonary rehabilitation centre. Training includes different steps such as to turn on the tablet, to connect to the application, to start the session using the app, to synchronise the oximeter with the app, to perform the session and to validate the end of the session.

   Participants will be asked to perform five endurance exercise sessions of forty-five minutes each, over five different days, within the centre. During these sessions a connected pulsed oximeter device will record heart rate and transcutaneous oxygen saturation at a frequency of one hertz. These data will be recorded in the internal memory of the oximeter itself as well as transmitted in real-time through Bluetooth to the app. The app will transmit the data to a secured remote server through the Global System for Mobile communication network. These two datasets (those locally stored and those remotely transmitted) will be analysed and compared (proportion of artefact, data deletion, data transformation, comparability etc - see outcomes for further details).

2. Data from a physical activity tracker.

Concurrently, the same participants will be asked to wear a physical activity tracker over a ten-day period. The data (daily step count) will be automatically and daily transmitted to the app through Bluetooth and then from the app to the remote secured server. Participants will be asked to remove the sensor when going to bed and to note the number of steps displayed on the screen on a standardized data sheet.

Step two: Clinical feasibility. The aim of the second step of the study is to assess the clinical feasibility of using the telerehabilitation system in real life conditions (in the home environment), during an eight week period.

During their initial pulmonary rehabilitation session (held in the centre), participants will be offered to perform their pulmonary rehabilitation program at home, using the telerehabilitation system. Those who agree to participate will be taught to use the system during this first face-to-face session. The telerehabilitation system as well as a cycle ergometer will be subsequently provided in their home environment by a local home healthcare provider.

The telerehabilitation program will take place over an eight-week period and includes:

• Endurance exercise training on a cycle ergometer (performed independently with remote monitoring or through video conference (also with remote monitoring), according to the participant's preference), three times per weeks. The duration of the sessions along with the training intensity will be progressively adjusted using an automated algorithm (aimed to first increase the training duration up to forty-five minutes and then workload intensity). The algorithm is based on previous sessions performed, monitored data and perceived exertion.
• Peripheral muscle strengthening using the app (the patient will be requested to reproduce different exercises after watching a video) or through video conference, three times per weeks (thirty minutes).
• Daily walking (automated coaching based on Demeyer et al. Thorax. 2017).
• Self management education (one to nine sessions according to each individual's needs, scheduled through videoconference).
• A self evaluation of symptoms through daily or weekly questionnaires.

Different types of alerts will be triggered at the center according to remote monitoring : "non-adherence", "clinical issue" during endurance exercise sessions and change in "symptoms".

Participants will be encouraged to contact physiotherapists at the centre for any situation that would require assistance (related to their program or to cope with any technical issue).

Inclusion Criteria:

• Age superior to eighteen years.
• Stable (> four weeks) chronic obstructive pulmonary disease, GOLD stage II to IV
• Referred to pulmonary rehabilitation (no contraindication to exercise training on a cycle ergometer).
• With or without oxygen during exercise.

Specific inclusion criteria for the first step of the study:

• Able to perform forty-five minutes of exercise training on a cycle ergometer.

Specific inclusion criteria for the second phase of the study:

• Person of legal age who may be present during home exercise sessions (relatives).

Non-inclusion Criteria:

• Pregnancy or likely to be.
• Guardianship.
• Unable to consent.
• Referred to pulmonary rehabilitation before lung cancer surgery.
• Referred to pulmonary rehabilitation before lung volume reduction surgery scheduled in the next few months.

Exclusion Criteria:

• Consent withdrawal

Chronic obstructive pulmonary disease